THE  LIBRARY 

OF 

THE  UNIVERSITY 

OF  CALIFORNIA 

LOS  ANGELES 


THE 

PRINCIPLES  AND  PRACTICE 

OF 

DENTISTRY 


IN'CLUDING 


ANATOMY,   PHYSIOLOGY,   PATHOLOGY,  THERA- 
PEUTICS,  DENTAL  SURGERY 
AND   MECHANISM. 


BY 


CHAPIN  A.   HARRIS,  M.D.,  D.D.S., 

LATE   PRESIDENT   OF   THE   BALTIMORE  MEDICAL   COLLEGE,   AUTHOR   OF    "  DICTIONARY 
OF   MEDICAL  TERMINOLOGY  AND  DENTAL  SURGERY." 


Ubirteentb  BMtion. 

REVISED     AND     EDITED     BY 
FERDINAND  J.  S.  GORGAS,  A.M.,  M.D.,  D.D.S., 

AUTHOR    OF    "  DENTAL   MEDICINE,"    EDITOR    OF   HARRIS'S    "  DICTIONARY    OF    MEDICAL  TERMIl*- 

OLOGY  AND    DENTAL    SURGERY,"   PROFESSOR    OF   THE    PRINCIPLES  OF   DENTAL    SCIENCE, 

DENTAL  SURGERY,  AND  PROSTHETIC  DENTISTRY  IN  THE  UNn-ERSITY  OF  MARYLAND. 


WITH  TWELVE  HUNDRED  AND  FIFTY  ILLUSTRATIONS. 


PHILADELPHIA 

P.   BLAKISTON'S    SON    &   CO. 

I0I2    WALNUT   STREET 
IOI3 


Entered  according  to  Act  of  Congress,  in  the  year  1895,  by 

P.  BLAKISTON,  SON  &  CO., 

In  the  Office  of  the  Librarian  of  Congress,  at  Washington,  D,  C. 


WM.  F.   FELL  &   CO., 

KLECTnOTVPERS    AMD    PRINTERS, 

1320-34   SANSON    STRICT, 

PHILADELPHIA. 


3\cmeA 

iUO   ■ 
\00 

EDITOR'S  PREFACE       "^.^ 


THIRTEENTH     EDITION. 


The  continued  demand  for,  as  well  as  the  exhaustion  of,  the  twelfth 
edition  of  this  well-known  and  universally  used  text-book,  has  stimu- 
lated the  author  to  prepare  a  new  edition  with  the  care  demanded  by 
a  due  consideration  of  the  needs  of  the  dental  practitioner  and  student. 

In  the  preparation  of  this  new  edition,  every  chapter  of  the  entire 
work  has  been  carefully  revised,  and,  with  few  exceptions,  important 
additions  made  to  all  of  them. 

By  omitting  considerable  matter  that  was  either  obsolete,  or  more 
properly  belonged  to  works  treating  of  special  as  well  as  kindred  sciences, 
this  new  edition  has  been  somewhat  abridged  as  to  the  number  of  pages, 
and  thereby  prevented  from  becoming  unwieldy.  In  the  anatomical 
portion  it  was  deemed  necessary  to  add  to  the  description  of  the  bones 
of  the  jaws  that  of  the  entire  skull.  Many  new  processes  appear  in 
the  new  edition,  and  the  already  large  number  of  illustrations  has  been 
greatly  increased.  Special  care  has  been  taken  to  mention  the  latest 
methods  for  constructing  crown-  and  bridge-work  and  artificial  den- 
tures, and  the  most  approved  systems  for  correcting  irregularity  of  the 
teeth,  fractures  of  the  jaws,  etc.,  etc.  Many  chapters  have  been  re- 
written, and  the  entire  work  brought  up  to  the  present  advanced 
standard  of  dentistry  in  all  its  branches.  The  author,  therefore,  pre- 
sents this  new  edition  in  the  belief  that  it  will  prove  to  be  more  useful 
even  than  its  predecessors,  and  meet  the  requirements  expected  of  a 
text-book  on  such  subjects  as  it  comprises. 

Ferdinand  J.  S.  Gorgas. 
Hamilton  Terrace,  Baltimore,  Md. 


EDITOR'S  PREFACE 


TWELFTH     EDITION 


The  reputation  and  success  of  this  text-book  as  an  elementary 
treatise  on  the  principles  and  practice  of  dentistry  have  been  so  appar- 
ent, and  so  universally  recognized  for  many  years  by  the  practitioner 
and  student,  that  no  words  of  commendation  on  our  part  need  be 
said.  It  has  reached  every  civilized  country  and  been  translated  into 
several  languages. 

The  rapid  advance  of  dental  science,  without  a  parallel  when  com- 
pared with  that  of  other  professions,  has  necessitated  repeated  addi- 
tions, until  the  present  volume  has  attained  a  size  greatly  above  any 
that  has  preceded  it. 

In  presenting  the  twelfth  edition,  it  is  with  the  hope  that  the  efforts 
made  to  render  the  work  such  that  it  may  receive  the  kind  approval 
so  generally  bestowed  upon  the  editions  that  have  preceded  it  may  be 
appreciated  by  those  for  whose  benefit  it  has  been  prepared.  It  is  an 
encouraging  fact  that  the  eleventh  edition  was  exhausted  some  months 
before  the  present  one  was  ready  to  be  issued. 

Additions  have  been  made  to  almost  every  chapter,  and  new  matter 
added  to  such  an  extent  that  this  new  edition  contains,  notwithstand- 
ing omissions  deemed  necessary,  some  two  hundred  and  twenty-six  pages 
more  than  its  immediate  predecessor.  Three  hundred  and  eighty-two 
new  illustrations  have  also  been  added  and  considerable  changes  made 
in  the  general  arrangement  of  subjects,  all  of  which  it  is  hoped  will 
increase  its  value  as  a  text-book. 

vii 


Vlil  EDITOR  S    PREFACE    TO    THE    TWELFTH    EDITION. 

A  number  of  systems  not  before  published  in  works  of  this  charac- 
ter appear  in  the  present  volume,  and  every  effort  has  been  made 
to  sustain  the  reputation  heretofore  accorded  to  it  by  the  dental  pro- 
fession. 

The  editor  and  publishers  are  under  many  obligations  to  dental 
practitioners  of  recognized  ability  and  reputation  for  systems  of  prac- 
tice of  which  they  are  the  authors ;  and  also  to  the  S.  S.  White 
Dental  Manufacturing  Company,  the  Welch  Dental  Company,  Samuel 
A.  Crocker  &  Company,  through  whose  courtesy  many  of  the  valuable 
wood-cuts  which  appear  in  the  present  volume  were  furnished,  and 
which  greatly  add  to  its  value  as  a  text-book. 

Ferdinand  J.  S.  Gorgas. 

Hamilton  Terrace,  Baltimore,  Md., 
February  /,  i88g. 


EDITOR'S  PREFACE 


ELEVENTH     EDITION 


The  first  edition  of  Chapin  A.  Harris's  "  Principles  and  Practice 
of  Dentistry"  was  published  in  1841,  and  from  that  date  it  has  been 
the  principal  text-book  in  all  dental  schools. 

The  last  or  tenth  revision  was  issued  under  the  careful  supervision 
of  the  late  Professor  Philip  H.  Austen,  M.D.,  D.D.S.,  assisted,  in 
the  parts  relating  to  anatomy  and  physiology,  by  Dr.  Thomas  S. 
Latimer,  and  in  parts  relating  to  pathology  and  surgery,  by  the 
editor  of  the  present  edition.  As  the  ten  years  prior  to  this  revi- 
sion had  nearly  revolutionized  dental  mechanism.  Professor  Austen 
found  it  necessary  to  almost  re-write  the  portion  of  the  work 
relating  to  "  Mechanics,"  and  its  superior  excellence  was  universally 
acknowledged. 

Nearly  fourteen  years  having  elapsed  since  this  was  done,  the  rapid 
advances  made  during  this  period  in  Dental  Histology,  Pathology, 
Surgery,  and  also  to  a  considerable  degree  in  Mechanism,  have  neces- 
sitated another  revision,  and  at  the  request  of  the  author's  family  and 
of  the  publishers,  the  editor  has  alone  undertaken  the  task  of  revi- 
sion, and  the  present  edition  is  the  result  of  more  than  a  year's  labor. 
This  duty  has  been  assumed  with  the  hope  that  an  experience  of  over 
a  quarter  of  a  century  as  a  teacher  in  dental  schools,  and  also  as  a 
dental  practitioner,  may  have  furnished  the  qualifications  for  such  an 
undertaking. 

The  time  which  has  elapsed  since  the  first  appearance  of  the  tenth 

ix 


X  EDITOR  S    PREFACE   TO   THE    ELEVENTH    EDITION. 

edition  has  necessitated  a  greater  revision  of  this  work  than  has  been 
the  case  with  any  former  edition,  and  the  task  of  preparing  an  entirely 
new  work  would  have  been  no  greater. 

Considerable  changes  have  been  made  in  the  general  arrangement  of 
subjects ;  a  number  of  entirely  new  chapters  have  been  added  in  the 
consideration  of  subjects  not  even  alluded  to  in  former  editions ;  addi- 
tions have  also  been  made  to  the  text  of  nearly  every  chapter,  some 
of  the  latter  being  far  in  excess  of  the  original  text. 

The  number  of  illustrations  has  been  greatly  increased,  and  the  new 
matter  now  inserted  has  brought  the  work  fully  up  to  the  time  of  its 
publication. 

Obsolete  theories  and  processes,  together  with  unimportant  details, 
have  been  omitted  and  more  useful  matter  substituted.  The  aim  of 
the  editor  has  been  to  meet  the  demands  of  the  present  advanced  state 
of  dental  science. 

The  new  matter  added  includes :  The  Development  of  the  Bones  of 
the  Head  and  Face ;  Temporo-Maxillary  Articulation ;  Description 
of  Mucous  Membrane ;  The  Origin  and  Development  Of  the  Teeth  ; 
Analysis  of  Tooth  Structures  ;  Secondary  Dentine  ;  Dentition  ;  Calci- 
fication and  Decalcification  of  the  Teeth ;  Alveolar  Pyorrhea  ] 
Aphthous  Stomatitis;  Thrush;  Sanguinary  Calculus;  Malformed 
Teeth ;  Effects  of  Syphilis  upon  the  Dental  Structures ;  Caries  of 
the  Maxillary  Bones;  Sensitive  Dentine;  Theories  as  to  the  Cause 
of  Dental  Caries ;  Treatment  of  Dental  Caries ;  New  Methods, 
Materials,  and  Instruments  Employed  in  Filling  Teeth  and  other 
Operations;  Electric  Mouth  Lamp;  Electric  Mallet;  Dental 
Engines  and  Attachments ;  Rubber  Dam  Appliances ;  Treatment 
and  Appliances  for  Correcting  Irregularity  of  the  Teeth  ;  Contour 
Fillings;  Replantation  and  Transplantation  of  Teeth;  Different 
Methods  of  Inserting  Artificial  Crowns  on  Natural  Roots ;  Bridge- 
Work  ;  General  and  Eocal  Anesthetic  Agents ;  Improved  Forceps ; 
New  Materials  and  Trays  for  Impressions ;  Articulators  ;  Blowpipes ; 
Furnaces ;  Celluloid ;  New  Apparatus  for  Vulcanizing  Rubber  and 
Molding  Celluloid;  Repairing  Vulcanite;  Duplicating  Dentures; 
Theory  of  Vulcanizing ;  Regulators ;  Gold  Alloy  and  other  Cast 
Bases;    Temperament  in  Relation  to  Natural  and  Artificial  Teeth; 


EDITOR  S    PREFACE    TO    THE    ELEVENTH    EDITION.  XI 

Improvements  in  Porcelain  Teeth ;  New  Splints  for  Fracture  of  the 
Jaws,  etc.,  etc.,  etc. 

The  editor  desires  to  acknowledge  his  indebtedness  to  Drs.  George 

B.  Snow,  James  H.  Harris,  Charles  L.  Steel,  W.  Storer  How,  and 
D.  Genese,  for  valuable  suggestions ;  and  also  to  the  writings  of 
Drs.  James  W.  White,  Frank  Abbott,  J.  Foster  Flagg,  John  Tomes, 
Charles  Tomes,  Henry  Sewell,  Henry  W.  Williams,  C.  N.  Peirce,  W. 
D.  Miller,  G.  V.  Black,  George  Watt,  J.  L.  Williams,  James  B. 
Dexter,   Norman  W.  Kingsley,   Theo.  F.  Chupein,   J.  N.  Farrar,   W. 

C.  Barrett,  J.  D.  Hutchinson,  W.  G.  A.  Bonwill,  A.  W.  Harlan,  C. 
T.  Stockwell,  the  late  M.  A.  Dean,  M.  H.  Webb,  and  others.  The 
courtesy  of  The  S.  S.  White  Dental  Manufacturing  Company,  Johnson 
&  Lund,  Snowden  &  Cowman,  Codman  &Shurtleff,  The  Buffalo 
Dental  Manufacturing  Company,  Spencer  &  Crocker,  Ransom  & 
Randolph,  Gideon  Sibley,  and  Dr.  Norman  W.  Kingsley,  is  acknowl- 
edged, for  the  use  of  many  valuable  wood-cuts. 

The  Eleventh  Edition  of  Harris's  ''  Principles  and  Practice  of 
Dentistry"  is  submitted  to  the  profession,  with  a  hope  that  it  will  be 
found  a  useful  elementary  treatise,  a  text-book  for  the  student,  and  a 
reliable  guide  for  the  dental  practitioner. 

Ferdinand  J.  S.  Gorgas. 


PREFACE  TO  THE  SECOND   EDITION. 


In  submitting  to  the  profession  a  Second  Edition  of  his  Dental 
Practice,  the  author  is  happy  to  avail  himself  of  the  opportunity  to 
express  his  grateful  appreciation  of  the  approbation  which  the  First 
has  received.  He  trusts  that  the  additions  which  he  has  made  to  the 
primary  work  will  make  the  one  now  presented  still  more  acceptable. 
The  alteration  in  the  plan,  which  has  resulted  from  the  effort  at  im- 
provement, has,  however,  rendered  a  slight  change  of  title  necessary, 
in  order  to  express  the  character  of  the  present  book. 

In  the  First  Edition  the  Anatomy  of  the  Mouth  was  omitted, 
because  a  thorough  knowledge  of  it  can  be  obtained  from  works  on 
General  Anatomy.  But  it  has  been  suggested  that  such  works  may 
not  be  at  hand  when  wanted  by  the  dental  student,  and  the  author 
has  thought  it  better  to  furnish  a  description  of  the  several  structures 
which  enter  into  the  formation  of  this  cavity.  He  has,  however, 
confined  himself  to  brief  expositions  of  the  parts  ;  not  wishing  to 
encumber  the  work,  or  distract  the  student  with  the  consideration  of 
matters  foreign  to  the  purpose  for  which  it  was  written,  and  for  which, 
he  trusts,  it  will  be  read.  He  is  indebted  to  Bourgery's  Anatomy, 
Quain  and  Wilson's  Anatomical  Plates,  Wilson's  Anatomy,  and  Smith 
and  Horner's  Anatomical  Atlas,  for  a  number  of  the  illustrations  used 
in  this  part  of  the  work. 

The  Second  and  Fifth  Parts  embody  the  substance  of  two  papers 
by  the  author,  which  were  written  subsequently  to  the  publication  of 
the  First  Edition.  The  subjects  of  them  came  properly  within  the 
plan  of  the  present  work. 

The   object  of  the   author  in  the  preparation  of  this  edition  has 

been  to  provide  a  thorough  elementary  treatise  on  Dental  Medicine 

and    Surgery,  which    might   be    a    text-book  for  the  student  and    a 

guide  to  the  more  experienced  practitioner ;  and   he  hopes  that  the 

modifications   he   has   introduced,  and  the    additions  he  has   made, 

will  entitle  it  to  be  so  considered,  at  least,  until  an   abler  hand  shall 

prepare  a  better. 

Chapin  a.  Harris,  M.D.,  D.D.S. 

.  xii 


CONTENTS. 


PART  FIRST. 

ANATOMY  AND  PHYSIOLOGY. 

CHAPTER  I. 

PAGE 

Anatomy  and  Physiology  of  the  Mouth, 25 

CHAPTER  II. 

Osteology,     26 

CHAPTER  III. 

Bones  of  the  Head  and  Face, 28 

Development  of  the  Bones  of  the  Head  and  Face, 29 

Intermaxillary  Bones, 32 

Superior  Maxillary, 33 

Inferior  Maxillary, 37 

Palate, 40 

Frontal, 4I 

Parietal,       43 

Occipital, 44 

Temporal, 45 

Sphenoid, 47 

Ethmoid, 49 

Nasal, 50 

Malar, 50 

Lachrymal, 5 1 

Inferior  Turbinated, 51 

Vomer, 52 

CHAPTER  IV. 
Muscles  of  the  Mouth  and  Face. 

Myology, 53 

Nasal  Group  of  Muscles, 55 

Superior  Maxillary  Group, 56 

Inferior  Maxillary  Group 57 

Temporo-Maxillary  Group, 5^ 

Pterygo-Maxillary  Group, 60 

Lingual  Group,      61 

Pharyngeal  Group, 62 

xiii 


XIV  CONTENTS. 

PAGE 

Palatal  Group, 63 

Soft  Palate,  Fauces,  and  Tonsils, 65 

Articulations — Temporo-Maxillary  Articulation 65 

CHAPTER  V. 
The  Arteries  and  Veins  of  the  Mouth  and  Face. 

Internal  Carotid  Artery, 67 

External  Carotid  Artery  and  Branches, 67 

Veins, 71 

CHAPTER  VI. 
Nerves  of  the  Mouth  and  Face. 

The  Cranial  Nerves, 72 

Fifth  Pair — Trigemini 72 

Gasserian  Ganglion, 72 

Ophthalmic  Branches, 73 

Superior  Maxillary  Branches, 75 

Inferior  Maxillary  Branches, 77 

Facial  Nerve  and  Branches, 78 

CHAPTER   VII. 
Salivary  Glands. 

Parotid  Gland  and  Saliva, 81 

Submaxillary  Glands, 83 

Sublingual  Glands, 84 

Saliva  from  all  Glands, 84 

Mucous  Glands, 85 

Buccal  and  Molar  Glands, ,    , 85 

CHAPTER  VIII. 

Tongue,  Gums,  Peridental  Membrane, 86 

Oral  Mucous  Membrane, 87 

Gum, 90 

Peridental  Membrane, 91 

Relations  of  the  Mouth,  Anatomical, 92 

"          "          "       Physiological 92 

CHAPTER  IX. 

The  Teeth. 

Deciduous  or  Temporary  Teeth,      93-94 

Permanent  Teeth — Incisors, 94-95 

Cuspids  and  Canines, 97 

Bicuspids  or  Pre-Molars, 98 

Molars, 98 

Attachment  of  the  Teeth,      loo 

Articulation, loi 

Comparison  of  Temporary  with  Permanent, loi 

Antagonism  of  Upper  and  Lower, 102 


CONTENTS.  XV 
CHAPTER  X. 

PAGE 

Malformed  Teeth.     Peculiarities  in  Formation  and  Growth. 

Malformed  Temporary  Teeth,      103 

Malformed  Permanent  Teeth, , 104 

United  Teeth, 107 

Geminous  or  Fused  Teeth, 108 

Supernumerary  Teeth, 109 

Supplemental  Teeth, no 

Nodular  Teeth, no 

Odontomes, Ill 

Syphilitic  Teeth, II2 

Organic  Defects  of  Structure, 115 

CHAPTER  XI. 

Origin  and  Development  of  the  Teeth. 

Condition  of  the  Jaws  of  the  Embryo  at  the  Period  of  the  Formation  of  the 

Dental  Follicle,      I19 

Development  of  the  Enamel, 120 

Development  of  the  Dentine, 126 

Development  of  the  Cementum, 132 

Origin  of  the  Permanent  Teeth, I32 

Dental  Pulp, 137 

CHAPTER   XII. 
Osseous  Tooth  Structures. 

Enamel,      140 

Dentine, , I43 

Cementum, 149 

Osteo-  or  Secondary  Dentine, 150 


PART  SECOND. 

DENTAL  PATHOLOGY  AND  THERAPEUTICS. 

CHAPTER  I. 

Temperament  in  Relation  to  the  Teeth, 155 

Characteristics  of  the  Teeth, 159 

CHAPTER  II. 

Dentition — First, 163 

Second, 172 

Third, 177 


XVI  CONTENTS. 

CHAPTER  III. 

PAGE 

Diseases  of  the  Oral  Mucous  Membrane. 

Stomatitis, l8o 

Simple  or  Catarrhal  Stomatitis, 182 

Ulcerous  Stomatitis, 184 

Aphthous  Stomatitis, 186 

Thrush, 187 

Gangrenous  Stomatitis,     .    .    .    ., 189 

Syphilitic  Ulceration  of  the  Mouth, I93 

Mercurial  Stomatitis, 193 

Scorbutus — Scurvy, ,  195 

CHAPTER  IV. 

Diseases  of  the  Gums. 

General  Considerations, 497 

Inflammations,  Acute  and  Chronic, , 198 

Hypertrophy,      203 

Mercurial  Inflammation, 205 

Ulceration,  with  Exfoliation  of  Bone, 207 

Adhesion  of  Gum  to  Cheek, 209 

CHAPTER  V. 
Diseases  of  the  Peridental  Membrane. 

Periodontitis,  Pericementitis, 210 

Alveolar  Abscess, 217 

Alveolar  Pyorrhea, 226 

CHAPTER  VI. 
Diseases  of  the  Dental  Pulp. 

General  Remarks 231 

Hyperemia, ,  232 

Irritation, 232 

Inflammation — Pulpitis, 235 

Abscess  of  Pulp, 244 

Degeneration  of  Pulp, 245 

Disorganization,  or  Gangrene, 246 

Fatty  Degeneration, 246 

Fungous  Growth, 247 

Calcareous  Concretions, 248 

Ossification, 249 

Causes  and  Treatment  of  Odontalgia, 250 

Devitalization  and  Removal  of  Pulp, 257 

CHAPTER  VII. 

Hypersensitiveness  of  Dentine, 263 

CHAPTER  VIII. 

Tumors  of  the  Mouth  and  Jaws, 268 

Cystic  Tumors — Dentigerous  Cysts, 278 


CONTENTS.  XVU 
CHAPTER  IX. 

PAGE 

Calcic  Deposits  on  the  Teeth. 

Salivary  Calculus — Classification  of  Varieties, 285 

Chemical  Composition, 289 

Origin  and  Deposition, 290 

Effects  upon  Teeth,  Gums,  and  Alveoli, 292 

Manner  of  Removing, 293 

Sanguinary  or  Serumal  Calculus, 297 

Mucous  Deposits  upon  Teeth,      298 

CHAPTER  X. 
Diseases  of  the  Alveolar  Processes. 

Necrosis  and  Exfoliation, 300 

Phosphor-Necrosis, 301 

Absorption, 303 

Hypertrophy  of  Walls  of  Cavities, 306 

CHAPTER  XI. 
Diseases  of  the  Teeth. 

Necrosis, 307 

Hypercementosis,      -  311 

Erosion,      313 

Mechanical  Abrasion, 317 

Fractures  and  other  Injuries, 319 

Dental  Caries,        321 

Classification, 323 

Liability  of  Teeth  to  Caries, 323 

Causes  of  Caries, 32^333 

Prevention  of  Caries, t^^ 


PART  THIRD. 

DENTAL  SURGERY. 

CHAPTER  I. 

Irregularity  of  the  Teeth, 339 

Treatment  of, i 350 

CHAPTER  II. 

Treatment  of  Dental  Caries, 427 

Treatment  of  Superficial  Caries  by  the  Use  of  Files,  Enamel    Chisels, 

Discs,  etc., 427 

Separation  of  the  Teeth , 438 

Treatment  of  Deep- Seated  Caries, 448 


XVI  a  CONTENTS. 

PAGE 

Materials  Employed  for  Filling  Teeth, 449 

Gold  :   Non-Cohesive  Foil, 449 

Cohesive  Foil, 450 

Crystal  or  Sponge, 451 

Platinum, 451 

Tin  Foil  and  Fusible  Alloys, 452 

Amalgam, 452 

Gutta  Percha  :   Hill's  Stopping, 457 

Zinc  Preparations — Oxychlorid  and  Oxyphosphate, 459 

Formation  of  the  Cavity, 473 

Instruments  Used — Dental  Engine,  etc., 466 

Rules  for  Shaping  Cavity,     .    .            473 

Protection  against  Saliva — Rubber  Dam,  etc. 477 

Drying  the  Cavity, 480 

Filling  the  Cavity  :   Instruments  Used, 484 

Preparation  and  Use  of  Materials, 489 

Non-Cohesive  Foil:   Rope  and  Fold,  Ribbon,  Cylinder,  etc.,  .    .  489 

Cylinder  Filling, 49I 

Herbst  Method, 492 

Pellets,  Mats,  and  Blocks 494 

Cohesive  Foil, 494 

Heavy  Foil, 497 

Crystal  or  Sponge  Gold, 498 

Condensation  of  Filling  with  Mallet — Automatic,  Electric,  and  Hand 

Mallets,  etc., 500 

Finishing  .Surface  of  Filling, 502 

Non-Conductors  over  Sensitive  Structures, 508 

Filling  Particular  Cavities  in, 509 

Superior  Incisors  and  Cuspids, 509 

Superior  Bicuspids  and  Molars, ^iS 

Inferior  Incisors  and  Cuspids, 5^9 

Inferior  Bicuspids  and  Molars, 531 

Contour  Fillings, 534 

CHAPTER  III. 

Filling  Teeth  over  Exposed  Pulps, 545 

Non-Conductors  and  Protectors, 54^ 

Different  Methods  and  Materials  for  Capping, 546 

CHAPTER  IV. 
Filling  Pulp  Chamber  and  Canals  of  Teeth. 

General  Considerations, 55^ 

Preparatory  Treatment, 552 

Preparation  of  Cavity  and  Root,  and  Filling, 559 

Immediate  Root  Filling, 561 

CHAPTER  V. 
Extraction  of  Teeth. 

General  Remarks, 5^4 

Indications  for  Extraction, 5^5 


CONTENTS.  XIX 

PAGE 

Instruments, 567 

Key  of  Garengeot, 568 

Manner  of  Using, 568 

Forceps :   Various  Forms, 568 

Manner  of  Using, 580 

Manner  of  Using  Gum  Lancets, 5^^ 

Extraction  of  Roots, ...  584 

Extraction  of  the  Temporary  Teeth, 591 

Sterilizing  Instruments, 592 

Hemorrhage  after  Extraction,  and  Treatment, 59^ 

CHAPTER  VI. 
Use  of  Anesthetics  in  Extraction  of  Teeth. 

General  Anesthesia  by  Ether, 595 

Chloroform, 595 

Nitrous  Oxid, 596 

Bromid  of  Ethyl, 600 

Bichlorid  of  Methylene,    .    , 601 

Hydrate  of  Chloral, 60I 

Local  Anesthesia  by  Cold, 602 

Electro-Magnetism, 603 

Spray  Apparatus, 604 

Obtunding  Mixtures, 605 

Hydrochlorate  of  Cocain, 606 

Rapid  Breathing  as  a  Pain  Obtunder, 607 

CHAPTER   VII. 

Replantation,  Transplantation,  and  Implantation  of  Teeth,     .   .  608 

CHAPTER  VIII. 
Dislocation  and  Fracture  of  the  Jaw, 612-635 

CHAPTER  IX. 

Diseases  of  the  Antrum, 635 

CHAPTER  X. 

Caries  of  the  Maxillary  Bones, 650 


PART  FOURTH. 

PROSTHETIC  DENTISTRY. 

Classification  of  Operations, 655 

CHAPTER  I. 

Prosthesis  of  Dental  Organs, 657 

Teeth  as  Indicated  by  Temperament, 660 


XX  CONTENTS. 

CHAPTER  II. 

PAGE 

Substances  Used  as  Dental  Substitutes. 

Human  Teeth 662 

Teeth  of  Cattle 663 

Elephant  and  Hippopotamus  Ivory, 664 

Porcelain,  or  Incorruptible  Teeth 665 

CHAPTER  III. 
Different  Methods  of  Inserting  Teeth. 

Retention  of  Artificial  Teeth, 667 

Placed  upon  Natural  Roots, 667 

Secured  by  Clasps, 669 

Retained  by  Spiral  Springs, 671 

Held  by  Atmospheric  Pressure  and  Contact  of  Adhesion, 672 

CHAPTER  IV. 
Preparatory  Treatment  of  the  Mouth, 675 

CHAPTER  V. 
Preparation  of  Natural  Roots  and  Attachment  of  Artificial 
Crowns. 

Crown  and  Bridge-Work — Different  Methods  of, 679-739 

Porcelain  Inlaying,    .        803 

Metallic  Enamel  Sections, 805 

CHAPTER  VI. 
Refining  and  Alloying  Gold  and  Calculating  Fineness  of  Gold 
Plate. 

Quality  of  Gold  for  Plate, 809 

Refining  Gold, 812 

Alloying  Gold, 818 

Calculating  Fineness  of  Gold  Plate, 820 

Gold  Plate,  Gold  Solders,  Fineness  and  Composition  of, 822 

CHAPTER   VII. 
Manufacture  of  Gold  Plate  and  Solders. 

Ingot  Molds,      .' 822 

Rolling  Mills,    . 824 

Gauge  and  Draw  Plates, 826 

Gold  and  Silver  Solders, 828,  976 

CHAPTER  VIII. 
Cups  and  Materials  for  Impressions  of  the  Mouth — Plaster  Models. 

Impression  Cups  or  Trays, 830 

Impression  Materials, 837 

Comparative  Value  of, 844 

Plaster  Models, 847 


CONTENTS.  XXI 
CHAPTER  IX. 

PAGE 

Metallic  Dies  and  Counter  Dies — Process  of  Swaging  Plates. 

Method  of  Making  Dies  and  Counter-Dies, 854 

Metals  used  for  Dies  and  Counter-Dies, 863 

Processes  of  Swaging, 866 

CHAPTER  X. 

Articulation,  or  Antagonism  of  Teeth, ,  .  873 

CHAPTER  XI. 

Adjustment  of  Porcelain  Teeth  to  the  Plate. 

Selection  of  Porcelain  Teeth, 908 

Varieties, 909 

Dental  Lathes, 912 

Grinding  and  Arranging  Teeth, >    .    .  916 

Backing  and  Investing  Teeth, 922-925 

Soldering  Backings  to  Teeth  and  Plate, 926 

CHAPTER   XII. 

Principles  and  Appliances  of  Soldering — Finishing  Procesk. 

Principles  of  Soldering, 928 

Soldering-Lamps,      929 

Blowpipes :   Mouth,      930 

Self-acting, 932 

Mechanical, 933 

Oxyhydrogen, 936 

Other  Appliances  of  Soldering, 938 

Finishing  Process 940 

CHAPTER  XIII. 

Retention  of  Base  Plates  in  the  Mouth — Their  Size  and  Form  of 
Outline — Materials  of  Swaged  Plates  —  Continuous-Gum 
Work. 

Different  Methods  of  Retention, 944 

Spiral  Springs, 944 

Clasps  :   Utility  and  Application, 946 

Atmospheric  Pressure  Principle, 962 

Adhesion  of  Contact, 965 

Vacuum  Cavity, 969 

Continuous-Gum  Work, 977 

CHAPTER   XIV. 

Molded  Plates  or  Plastic  Work — Ceramo-Plastic  Work. 

Classification  of  Plastic  Work, 986 

Comparison  of  Varieties, 9^7 

Ceramo-Plastic  Work, 988 


XXn  CONTENTS. 

CHAPTER    XV. 

PAGE 

Metallo- Plastic  Work — Vulcano-Plastic  Work. 

Tin  and  its  Alloys, 989 

Cheoplastic  Metal, 990 

Stanno- Plastic  Process,Wood's, Weston's,  and  Watt's,  Metals,    .    .    .  990 

Aluminium,  Properties  of, looi 

Swaged  Aluminium  Plates, 1002 

Aluminium  Cast  Base — Carroll's, 1003 

Gold  Alloy  Cast  Base — Reese's, loo8 

Electro-Metallic  Process — Ward's, i  )I3 

Vulcano-Plastic  Work,      1013 

Corallite, 1014 

Vulcanite:  History, 1014 

Composition  and  Varieties, 1015 

Vulcano-Plastic  Process, 1018 

Vulcanite  Attachment  of  Teeth  to  Swaged  Plates,    . ioS9 

Lining  Vulcanite  Plates  with  Gold, 1065 

General  Remarks  on  Value  of  Vulcanite, 1065 

Celluloid:   History,  Composition,  and  Preparation, 1066 

Different  Processes  and  Apparatus  by  which  Celluloid  is  Molded,  .    .  1067 

New  Mode  Continuous- Gum, 1082 

Zylonite, 1088 

CHAPTER  XVI. 
Composition,  Manufacture,  and  Esthetics  of  Porcelain  Teeth, 

General  Considerations, 1088 

Porcelain  Materials  :   Silica,  Feldspar,  Kaolin :  Coloring  Materials,  .    .    .  1089 

Formulas  for  Body  and  Enamel, 1092 

Process  of  Manufacture  of  Dental  Porcelain,     . 1093 

^Esthetics  of  Dental  Porcelain,  with, 1096 

Illustrations  of  Form  and  Arrangement, 1097 

Carving  Blocks  for  Special  Cases, ^^^5 

Porcelain  Plates — Ceramo- Plastic  Work, 1121 

Esophagotomy, 1123 

CHAPTER  XVII. 
Defects  of  the  Palatine  Organs. 

Classification  and  Description, 1 1 24 

Fissure  of  the  Hard  and  Soft  Palate, 1 126 

Staphylorraphy :    History, H28 

Forms  of  Operations, 1 130 

Obturators  and  Artificial  Palates, .  ^136 

Artificial  Palates, 1139 

Obturators  and  Palates  Combined, 1148 

Construction  of  Artificial  Palates, II51 


THE 


PRINCIPLES    AND    PRACTICE 


OF 


DENTISTRY. 


CHAPTER  I. 

ANATOMY  AND  PHYSIOLOGY  OF  THE  MOUTH. 

The  mouth  {oral  or  buccal  cavity)  is  the  entrance  to  the  alimentary 
canal,  and  in  the  human  subject  signifies  the  space  included  between 
the  palatine  arch  above,  the  mylo-hyoid  muscles  beneath,  the  lips  in 
front,  the  soft  palate  and  fauces  behind,  and  the  cheeks  on  either  side. 
The  teeth  and  closed  jaws  separate  the  inner  portion,  or  lingual  cavity, 
from  the  outer,  or  vestibular  space. 

The  form  of  the  mouth  is  nearly  oval,  and  it  is  lined  with  mucous 
membrane,  which  is  continuous  with  the  integument  at  the  free  mar- 
gin of  the  lips,  and  with  the  same  membrane  lining  the  fauces  be- 
hind. The  mucous  membrane  of  the  mouth  is  naturally  of  a  rose-pink 
tinge,  covered  by  stratified  epithelium,  and  variable  in  thickness,  being 
very  thick  where  it  covers  the  hard  parts  bounding  this  cavity. 

In  the  mouth  are  the  tongue,  teeth,  and  the  alveolar  ridges  invested 
by  the  gums ;  into  it  are  poured  the  secretion  of  the  parotid,  sub-maxil- 
lary, and  sublingual  glands,  as  well  as  that  of  the  ordinary  mucous  and 
of  the  special  lingual  follicles;  and  in  it  the  food  is  subjected  to  the 
processes  of  mastication  and  insalivation  previous  to  deglutition. 

It  is  further  concerned  in  the  prehension  of  aliment ;  and  besides 
containing  the  organs  of  taste,  is  employed  in  articulation,  expecto- 
ration, suction,  etc. 

25 


26  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

The  parts  concurring  to  constitute  the  mouth  form  a  very  compli- 
Gated  piece  of  mechanism;  through  them  it  has  a  wide  range  of 
sympathies,  and  by  them  it  performs  a  great  variety  of  functions. 

The  anatomical  elements  composing  these  parts  consist  of  Bone, 
Ligament,  Muscle,  Gland,  Blood-vessel,  Nerve,  Areolar  and  Adipose 
tissues,  and  Mucous  membrane. 

These  different  elements  combine  together  and  form  the  various 
organs  which  constitute  the  mouth. 

These  organs  will  be  considered  in  their  physiological  order,  thus 
combining  their  anatomy  and  physiology,  studying  at  the  same  time 
both  their  healthy  structure  and  function. 


CHAPTER  II. 

OSTEOLOGY. 


Bone  is  one  of  the  hardest  substances  in  the  body,  and  is  endowed 
with  a  certain  degree  of  toughness  and  elasticity.  Its  natural  color  is 
pinkish-white  externally  and  red  internally.  It  is  composed  of  animal, 
or  organic,  matter,  in  intimate  association  with  earthy,  or  inorganic, 
matter.  From  the  organic  matter  the  bone  derives  the  properties  of 
toughness  and  elasticity  ;  and  from  the  earthy  material,  hardness  and 
solidity.  The  mineral  matter  may  be  dissolved  out  by  a  dilute  solu- 
tion of  nitric  or  muriatic  acids,  while  the  animal  matter  remains 
unaffected,  retaining  its  form,  though  losing  its  hardness,  so  that  the 
long  bones,  so  great  is  their  flexibility,  may  be  tied  into  a  knot ;  on 
the  other  hand,  by  subjecting  them  to  a  high  heat  in  an  open  fire, 
while  exposed  to  the  air,  the  animal  matter  may  be  consumed,  leaving 
the  mineral  to  preserve  the  form  of  the  bone,  but  so  insecurely  that  it 
will  crumble  to  ashes  in  the  grasp  of  the  hand. 

The  composition  of  bone,  according  to  Berzelius,  is  about  one-third 
animal  and  two-thirds  mineral  matter: — 


Organic,  or 
Animal,  Matter, 

Inorganic, 

or 
Earthy,  Matter. 


Gelatin  and  Blood-vessels, .3330 

Phosphate  of  Lime, 5^°4 

Carbonate  of  Lime, 1 1- 3°. 

Fluorid  of  Calcium, 2.00 

Phosphate  of  Magnesia, I.16 

Soda  and  Chlorid  of  Sodium, 1.20 


The  proportion  of  earthy  and  animal  matter  is  generally  thought 


OSTEOLOGY.  2^ 

to  vary  with  varying  age.     According  to  Shreger,  this  difference  is  as 
follows :  — 

Child.  Adult.  Old  Age. 

Animal  Matter, 47-20  20.18  12.2 

Earthy  Matter, 48.48  74-84  84.1 

In  childhood,  when  the  animal  matter  is  in  excess,  the  bones,  on 
account  of  injury,  may  become  bent  or  partially  fractured ;  whereas  in 
old  age,  the  earthy  matter  being  in  excess,  the  bones  are  more  brittle 
and  fracture  more  easily. 

The  local  position  of  bone  is  first  occupied  by  a  mucoid  (mucous- 
like)  substance  which  is  transformed  into  temporary  cartilage  (blas- 
tema) during  the  second  month  of  fetal  life.  The  young  bone-cells 
{osteoblasts')  are  then  deposited  in  the  cartilage  at  certain  points,  and 
their  deposition  and  subsequent  pressure  cause  the  absorption  of  the 
cartilage.  This  is  the  form  of  ossification  described  as  intra  cartilagi- 
nous. 

In  the  second  form  of  ossification,  described  as  intramembranous,  no 
temporary  cartilage  (or  cartilage  mold)  precedes  the  appearance  of 
the  bone-tissue.  The  bones  of  the  vertex  of  the  skull  are  entirely 
formed  by  intramembranous  ossification.  In  the  local  position  of  the 
bone  about  to  be  formed,  a  little  network  of  osseous  spiculae  first  ap- 
pears radiating  from  the  point  of  ossification,  which  under  the  micro- 
scope consists  of  fine,  clear  fibres  and  granular  corpuscles,  with  an 
intermediate  ground-substance.  These  fine  fibres  are  termed  osteo- 
genic fibres,  which  soon  become  dark  and  granular  from  calcification, 
and  as  they  calcify  they  enclose  the  bone-cells  {osteoblasts).  The  cal- 
cification includes  both  the  fibres  and  intermediate  or  ground-substance 
in  which  the  former  are  contained.  The  number  of  ossific  centers 
differs  :  In  the  long  bones  there  is  a  central  point  of  ossification  for 
the  shaft  and  one  for  each  extremity. 

Bone  is  composed  of  an  outer  compact  layer,  and  an  inner  cellular 
or  spongy  structure,  and  is  surrounded,  except  at  the  articular  cartil- 
ages, by  a  vascular  fibrous  membrane  termed  the  Periosteum,  which 
envelops  the  bone  and  receives  the  insertions  of  all  tendons,  ligaments, 
etc.  The  central  cavity  of  the  long  bones  is  lined  by  a  structure  simi- 
lar to  the  periosteum,  known  as  the  Endosteum. 

The  Haversian  Canals  are  tunnels  in  the  compact  substance  of  the 
bone  which  contain  the  blood-vessels.  Whenever  the  bone  is  so  thin 
as  to  be  able  to  derive  its  nutrition  from  the  vascular  membrane  cover- 
ing its  surface,  there  are  no  Haversian  canals  in  it,  as  none  are  re- 
quired. Such  bones,  however,  have  numerous  lacunae,  which  send  out 
canaliculi  to  open  on  the  surface  and  imbibe  the  requisite  nutrition. 

The  Haversian  canals  vary  in  diameter  from  yw^^  ^°  tott  °^  ^^  inch, 


28  PRINCIPLES    AND    PRACTICE   OF   DENTISTRY, 

the  average  being  j^.  The  smallest  are  found  near  the  outer  surface, 
where  the  bone  is  the  most  compact,  but  they  gradually  become  larger 
toward  the  interior,  where  they  open  out  into  the  spongy  or  cancellous 
tissue  or  into  the  medullary  cavity.  The  smaller  canals  contain  only  a 
single  capillary  blood-vessel ;  the  larger  contain  a  network  of  vessels, 
while  the  largest,  which  gradually  merge  into  the  cancellous  tissue, 
contain  marrow  as  well  as  blood-vessels. 

Tke  Lacuna  are  the  irregular  hollow  cavities  or  spaces  between  the 
lamellae,  arranged  in  concentric  circles  around  the  Haversian  canals. 
They  are  characteristic  of  true  bone,  and  each  lacuna  contains  a  soft 
nucleated  substance  termed  bone  corpuscle,  which  sends  its  soft  pro- 
cesses along  the  canaliculi.  The  bodies  in  the  lacunae  and  canalicuH  cir- 
culate nutritious  matter  through  the  bone.  The  lacunae  are  commonly 
oval. and  flattened,  so  that  one  of  their  broad  sides  is  turned  toward  the 
Haversian  canal.  The  lacunae  measure  about  -^-^  of  an  inch  in  their 
long  diameter,  and  about  ^^jVir  ^^^  their  short.  The  Canaliculi  are  ex- 
ceedingly minute  canals  which  in  their  course  cross  the  lamellae  and 
connect  the  lacunae  with  each  other  and  also  with  the  Haversian 
Canal.  They  run  off  from  all  parts  of  the  circumference  of  the 
lacunae  and  communicate  most  freely  with  the  canaliculi  of  the  adjoin- 
ing lacunae.  Their  diameter  ranges  from  y^^^  of  an  inch  to  -giy-jTnr 
of  an  inch,  but  some  are  even  smaller. 

The  Lamell(X  are  the  concentric  thin  plates  of  bone  tissue  encir- 
cling the  Haversian  Canal,  and  result  from  successive  layers  of  bone 
being  deposited  around  the  Haversian  vessel,  the  one  within  the  other  ; 
a  process  which  renders  the  bone  more  dense  in  structure. 


CHAPTER  HI. 

BONES  OF  THE  HEAD  AND  FACE. 

Although  most  of  the  bones  of  the  human  body  pre-exist  in  the 
shape  of  cartilage,  there  are  some  which  are  directly  formed  in  mem- 
brane, namely,  such  bones  of  the  skull  as  the  frontal,  parietal,  the 
upper  half  of  the  occipital,  the  squamous  and  tympanic  parts  of  the 
temporal ;  also  the  bones  of  the  face,  and  the  inner  plate  of  the  ptery- 
goid process  of  the  sphenoid  bone.  In  fact,  none  of  the  bones  of  the 
skull  pre-exist  as  cartilage,  except  those  which  form  the  base  of  the 
skull.  The  bones  of  the  head  are  twenty-two  in  number,  of  which 
eight  compose  the  cranium  and  fourteen  the  face.  Those  of  the 
cranium  are  one  frontal,   two  parietal,  two  temporal,  one  occipital, 


BONES   OF   THE   HEAD   AND   FACE. 


29 


one  sphenoid,  and  one  ethmoid.  Those  of  the  face  are  six  pairs  and 
two  single  bones  ;  the  pairs  are  the  two  malar,  two  superior  maxillary, 
two  lachrymal,  two  nasal,  two  palatine,  and  two  inferior  turbinated. 
The  vomer  and  inferior  maxillary  are  the  two  single  bones. 

Development  of  the  Bones  of  the  Head  and  Face. — The  first  definite 
form  which  is  developed  in  the  embryo  is  that  of  the  rudimentary 
spinal  column,  its  earliest  trace  being  a  faint  streak,  which  is  known 
as  the  primitive  trace  or  groove.  This  groove  deepens  into  a  furrow, 
which  is  bounded  by  two  plates,  beneath  which  a  delicate  fibril  ap- 
pears, called  the  chorda  dorsalis,  or  notochord,  in  which  cartilage  is 
very  early  developed. 


Fig.  I.— Face  of  an  Embryo  of  25  to  28  Days.    (Magnified  15  Times.) 
I.  Frontal  prominence.     2,  3.  Right  and  left  olfactory  fossae.    4.  Inferior  maxillary  tubercles, 
united   in   the   middle  line.     5.   Superior   maxillary   tubercles.     6.  Mouth  or  fauces.     7. 
Second  pharyngeal  arch.     8.  Third.     9.  Fourth.     10.  Primitive  ocular  vesicle.     11.  Primi- 
tive auditory  vesicle. 


The  upper  end  of  the  chorda  dorsalis  terminates  in  a  pointed  ex- 
tremity extending  as  far  forward  as  the  sphenoid  bone. 

The  embryonal  cranium  is  developed  from  the  primitive  vertebral 
discs,  which  surround  the  upper  extremity  of  the  chorda  dorsalis. 
These  discs  advance  in  the  form  of  a  membranous  capsule,  which 
molds  itself  on  the  cerebral  vesicles,  so  as  to  constitute  the  mem- 
brane in  which  the  vault  of  the  skull  is  developed,  and  which  is 
replaced  by  cartilage  in  the  part  corresponding  to  the  base  of  the 
skull.  A  portion  of  this  primitive  cartilaginous  cranium  atrophies 
and  disappears,   while  another  portion  remains   and    forms   the  car- 


30  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

tilages  of  the  nose  and  the  articulations,  the  basilar  part  of  the 
occipital,  the  greater  part  of  the  sphenoid,  the  petrous  and  mastoid 
portions  of  the  temporal,  the  ethmoid,  and  the  septum  nasi. 

From  the  anterior  end  of  the  chorda  dorsalis  the  four  pharyngeal 
arches  proceed  on  either  side  and  meet  in  the  middle  line. 

In  these  pharyngeal  arches  the  secondary  bones  are  developed,  so 
called  to  distinguish  them  from  those  already  referred  to,  which  are 
formed  from  the  primitive  cranium  itself.  The  buccal  depression, 
which  afterward  becomes  the  cavity  of  the  mouth,  or  rather  the 
fauces,  is  situated  between  the  first  pharyngeal  arch  and  the  frontal 
protuberance. 

The  first  pharyngeal  arch  divides  at  its  anterior  extremity  into  two 
parts — a  superior  and  inferior  maxillary  protuberance,  the  inferior 
maxillary  uniting  very  early  to  the  corresponding  one  of  the  opposite 
side,  to  form  the  lower  jaw. 

The  superior  maxillary  protuberances  are  united  to  the  external 
nasal  process,  and  the  palate  bone,  the  superior  maxillary,  the  malar, 
and  also  the  internal  plate  of  the  pterygoid  process  are  developed 
from  this  process.  From  the  internal  nasal  process,  the  nasal  bones, 
the  lateral  portions  of  the  ethmoid,  and  the  os  unguis  are  developed. 
From  the  incisive  tubercle  or  process,  which  unites  the  rest  of  these 
processes  on  either  side,  and  which  grows  downward  from  the  frontal 
prominence,  filling  in  the  space  between  the  extremities  of  the  two 
processes  which  proceed  from  the  first  pharyngeal  arch,  the  intermaxil- 
lary bone,  the  middle  of  the  upper  lip,  and  the  vomer  are  formed- 
When  the  middle  and  two  lateral  processes  fail  to  unite,  the  deformity 
known  as  hare-lip  is  caused.  From  the  lateral  processes  of  the  supe- 
rior maxilla  the  plates  which  form  the  hard  palate  grow  toward  each 
other,  union  occurring  in  the  median  line.  This  union  of  the  plates 
separates  the  nose  from  the  buccal  cavity,  and  is  generally  completed 
at  the  end  of  the  second  month.  Prior  to  this  union  of  the  plates  by 
their  complete  development,  the  nose  and  buccal  cavity  form  but  one 
cavity  ;  and  when  this  union  does  not  take  place  the  deformity  known 
as  cleft-palate  results.  Cleft-palate  often  accompanies  hare-lip,  as  the 
causes  which  produce  the  latter  deformity,  during  the  development  of 
the  intermaxillary  bones,  may  prevent  the  natural  development  of 
the  palate  bones. 

At  an  early  period  of  embryonal  life  the  inferior  maxillary  arch; 
which  also  arises  from  the  first  pharyngeal  arch,  is  altogether  destitute 
of  any  trace  of  osseous  tissue,  but  it  encloses  within  the  elements  com- 
posing it  a  symmetrical  cartilaginous  band,  which  performs  a  transitory 
part  only  in  the  development  of  the  jaw. 

This   band    is   called    "Meckel's   Cartilage,"    and  it  occupies  the 


BONES    OF    THE    HEAD    AND    FACE. 


31 


interior  of  the  maxillary  arch,  having  the  form  of  a  whitish  cord 
situated  in  a  bed  of  soft  transparent  tissue,  and  is  composed  of  two 
symmetrical  parts  corresponding  to  the  right  and  left  sides  of  the  lower 
jaw,  which  parts  soon  become  united  at  the  mental  symphysis.  From 
this  point  or  juncture  the  two  halves  extend  on  either  side  to  the 
bones  of  the  ear,  terminating  in  the  malleus,  which,  with  the  incus, 
is  formed  from  it. 

Meckel's  cartilage  gives  form  and  stability  to  the  lower  jaw  of  the 
embryo,  and  is  the  first  solid  structure  discovered  in  the  maxillary 
arch.  It  first  appears  about  the  twenty-fifth  day,  and  during  its  exist- 
ence, which  extends  to  the  fifth  month  of  fetal  life,  it  is  subject  to 
constant  modifications  or  transitory  states. 


Fig.  2. — Meckel's  Cartilage,  from  Embryo  of  40  to  42  Days,  before  Appearance  of 

Maxillary  Bone. 

a.  Enlargement  of  cartilage  near  neck  of  malleus,  b.  A  slightly  enlarged  portion  of  cartilage, 
but  contracted  at  median  line,  where  it  unites  with  that  of  opposite  side.  n.  Handle  of 
malleus,  o.  Cartilage  of  the  os  lenticulare.  /.  Cartilage  of  the  stapes,  j.  Outline  of  the 
jaw  to  be  formed. 


As  soon  as  the  cartilage  has  attained  its  full  development,  a  period 
which  corresponds  to  the  ossification  of  the  malleus,  it  begins  to  disap- 
pear, except  the  end,  which  extends  up  to  the  tympanum  and  becomes 
ossified  into  the  malleus,  owing  to  the  action  of  the  osteoblasts  by 
which  this  cartilage  is  ossified,  and  becomes  a  part  of  the  maxilla. 

In  the  upper  jaw  the  period  of  evolution  corresponds  with  that  of 
the  lower  jaw  ;  Meckel's  cartilage  belongs  exclusively  to  the  lower 
jaw. 

At  a  period  between  the  thirty-fifth  and  fortieth  days  of  embryonal 
life,  slight  traces  of  ossification  are  observed  at  points  midway  between 
the  angle  and  symphysis  of  the  future  jaw,  and  the  ossification  extends 
rapidly  in  both  directions,  anterior  and  posterior,  along  the  external 
face  of  Meckel's  cartilage,  and  in  contact  but  not  united  with  it. 


32 


PRINCIPLES    AND    PRACTICE   OF    DENTISTRY. 


At  about  the  second  month  of  gestation,  the  rudimentary  jaw-bone 
is  formed,  but  not  completed  ;  it  is  composed  of  two  arches,  an  internal 
cartilaginous  one,  composed  of  Meckel's  cartilage;  and  an  external 
one,  composed  of  osseous  matter ;  the  former  being  only  needed  for 
a  time  to  support  the  jaw,  and  the  latter  the  rudiment  of  the  bone 
of  the  jaw. 

While  later  in  life  there  are  two  superior  maxillary  bones,  in  early 
fetal  life  there  exists  what  are  called  inter-maxillary  bones,  the  upper 
jaw  during  its  development  being  composed  of  four  bones — two  maxil- 
lary and  two  inter-maxillary.  In  each  of  the  two  inter-maxillary 
bones  are  developed  two  incisors — a  central  and  a  lateral,  and  in 
each  of  the  two  maxillary 
bones — a  canine  and  two 
molars — later  a  canine, 
two   bicuspids,  and    three 


Fig.  3. — From  Human 
Embryo  of  60  Days, 
Natural  Size. 

A.  Extra-tympanic  por- 
tion of  Meckel's  carti- 
lage. B.  Symphysis. 
N.  Handle  of  malleus. 


Fig.  4.— Internal  Face  of  Right  In- 
ferior Maxilla  of  Embryo  of  Three 
Months. 

a.  Extra-tympanic  portion,  b.  Symphysis 
of  the  cartilage,  n.  Handle  of  malleus. 
e.  Cartilage  of  incus. 


molars.  Before  birth  the  intermaxillary  and  the  maxillary  bones  unite, 
reducing  the  number  to  two  instead  of  four,  and  the  inter-maxillary 
suture,  where  the  union  takes  place,  can  be  seen  at  birth  on  the  palatal 
surface,  but  not  on  the  outer  surface. 

These  inter-maxillary  bones  are  desig- 
nated by   Huxley  as  premaxillce,  and   in 
some  animals  they   remain    permanently 
as  separate  bones. 
/£>   /  //-H-..,    •  >-^^^  The  buccal  cavity  comprises  the  mouth 

f       /  r~^''''^%\  ^"^  ^°^^  until  a  lamina  is  formed  from 

the  superior  maxillary  tuberosity  on  either 
side,  which  has  a  horizontal  inward  direc- 
tion. The  two  palatine  lamellae  meet  in 
the  median  line,  in  front,  about  the 
eighth  week,  and  the  septum  is  completed 
about  the  ninth  week.  The  superior  maxillary  bones  and  the  soft 
parts  covering  them  unite  at  an  early  period  with  the  inter-maxillary 
or  incisive  bone,  and  the  median  portion  of  the  lower  lip.  The  nos- 
trils are  formed  by  the  olfactory  fossae  opening  into  the  upper  or  respi- 
ratory portion  of  the  cavity. 


Fig.  5. — From  Fetus  of  Four 
Months,  Showing  Inter-max- 
illary Suture  on  Palatal 
Surface,  Where  the  Inter- 
maxillary Bones  Have  United 
with  the  Maxillary  Bones. 


THE    SUPERIOR    MAXILLARY    BONES. 


33 


THE    SUPERIOR    MAXILLARY    BONES. 

The  Superior  Maxillary  Bones,  two  in  number,  are  in  pairs,  and 
united  on  the  median  line  of  the  face.  They  occupy  the  anterior 
upper  part  of  the  face,  are  of  very  irregular  form,  and  consist  of  a 
body  and  processes.  They  are  the  largest  bones  of  the  face  except 
the  inferior  maxilla,  and  enter  into  the  formation  of  three  cavities, 
the  orbit,  the  mouth,  and  the  nares;  they  also  enter  into  the  forma- 
tion of  the  zygomatic  and  spheno-maxillary  fossae,  and  the  spheno 
maxillary  and  pterygo-maxillary  fissures. 


OUTEP 


SURFACE 


mClSlVE  FOSSA 


posren/o/i  eei/rM 

CAMALS 


MAXILLAHV   TUBC/iOSirr 


"^NIHE.     BICUSPIDS. 


Fig.  6, 


The  body  is  the  central  part  of  the  bone,  and  has  four  surfaces ; 
namely,  the  external  or  facial,  the  posterior  or  zygomatic,  the  superior 
or  orbital,  and  the  internal  or  palatine. 

The  External  Surface  is  irregularly  convex,  and  has  a  depression 
about  its  center,  just  above  the  canine  and  first  bicuspid  teeth,  called 
the  canine  fossa ;  immediately  above  which  is  the  infra-orbital  foramen 
for  transmitting  an  artery  and  nerve  of  the  same  name;  its  upper  and 
inner  edge  forms  part  of  the  lower  margin  of  the  orbit,  to  which  is 
attached  the  levator  labii  superioris  proprius  muscle. 
3 


34 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


The  Posterior  Surface  has  a  bulging,  called  tuberosity,  which  is 
connected  with  the  palate  bones,  and  bounds  the  antrum  behind;  it 
is  perforated  by  three  or  four  small  holes — the  posterior  dental  canals, 
which  transmit  nerves  and  blood-vessels  to  the  molar  teeth.  This 
surface  presents  also  on  its  nasal  face  a  groove,  which  becomes,  by 
articulation  with  the  palate  bone,  the  posterior  palatine  canal. 

The  Internal  Surface  extends  from  the  alveolar  processes  in  front  to 
the  horizontal  plate  of  the  palate  bones  behind,  called  the  palatine 
processes,  which  are  rough  below,  forming  the  roof  of  the  mouth,  and 


WlTHJ?^>, 


BOWrS  PflRT/ALLV  CiOSINC  ORIFICE  OF 
/»NTRUM    MMKCD   IN    OUTLINE 


ANTER.  NASAL 
SPINE 


BRISTLE  PASSED 
JHROUCH  ANTE. 
P/iLAT,  CAfiAL 


Fig.  7. 


smooth  above,  making  the  floor  of  the  nostrils.  They  are  united 
along  the  median  line,  at  the  anterior  part  of  which  is  the  foramen 
incisivum,  having  two  openings  in  the  nares  above,  while  there  is  but 
one  in  the  mouth  below.  The  body  of  the  superior  maxilla  is  occupied 
by  a  large  and  very  important  cavity  called  the  Antrum  Highmoriafium, 
or  Maxillary  Sinus.  This  cavity  is  somewhat  triangular  in  shape,  with 
its  base  generally  looking  to  the  nose,  and  its  apex  to  the  malar  pro- 
cess. Its  upper  wall  is  formed  by  the  floor  of  the  orbit,  its  lower  by 
the  alveoli  of  the  molar  teeth,  which  sometimes  perforate  this  cavity. 
The  canine   fossa  bounds  it  in  front,  while  the  tuberosity  closes  it 


THE    SUPERIOR    MAXILT.ARY    BONES.  35 

behind.  But  the  shape  of  this  cavity  is  exceedingly  variable.  In 
examining  a  collection  of  nearly  one  hundred  maxillae  in  the  Dental 
Department  of  the  University  of  Maryland,  no  two  sinuses  were  found 
to  be  shaped  alike  ;  and  this  difference  is  as  marked  between  the  right 
and  the  left  in  the  same,  as  in  different  subjects.  The  floor  of  some 
is  nearly  flat,  but  in  the  majority  of  cases  it  is  very  uneven  ;  some- 
times crossed  by  a  single  septum,  varying  from  one-eighth  to  half  an 
inch  in  height ;  at  other  times  there  are  found  three  or  four  septa, 
dividing  the  lower  part  of  the  cavity  into  as  many  separate  compart- 
ments, with  the  bottom  or  floor  of  no  two  on  a  level  with  each  other. 
Some  are  perforated  by  the  roots  of  one  or  more  teeth  ;  at  other  times 
the  roots  of  several  teeth  extend  considerably  above  the  level  of  the 
floor  of  the  antrum,  covered  by  a  lamina  of  bone  scarcely  thicker 
than  bank-note  paper.  In  other  cases,  the  floor  of  the  antrum  is  half 
an  inch  above  the  extremities  of  the  roots  of  the  teeth.  This  cavity 
also  varies  as  much  in  size  as  it  does  in  shape. 

The  opening  of  the  antrum  is,  on  its  nasal  portion  or  base,  into  the 
middle  meatus  of  the  nose ;  in  the  skeleton  it  is  large,  while  in  the 
natural  state  it  is  much  contracted  by  the  ethmoid  bone  above,  the 
inferior  turbinated  bone  below,  the  palate  bone  behind,  and  by  the 
mucous  membrane  which  passes  through  the  opening  and  lines  the 
interior  of  the  antrum.  A  deep  groove  lies  in  front  of  the  opening 
in  the  antrum,  which  is  converted  into  a  canal  for  the  nasal  duct  by 
the  lachrymal  and  inferior  turbinated  bones. 

The  Malar  Process  is  a  rough,  triangular  process,  marking  the 
boundary  between  the  external  and  internal  surfaces.  It  presents  on 
its  upper  margin  a  roughened  surface  for  articulation  with  the  malar 
bone. 

The  Nasal  Process  forms  the  lateral  boundary  of  the  nose.  It  is  a 
thick,  triangular  prominence  articulating  at  its  upper  extremity,  by  a 
serrated  edge,  with  the  frontal  bone,  and,  by  an  uneven  surface,  with 
the  ethmoid  bone  ;  a  little  lower  on  its  internal  surface  it  offers  a  trans- 
verse ridge,  the  superior  turbinated  crest,  for  articulation  with  the 
middle  turbinated  bone ;  below  this  is  the  inferior  turbinated  crest,  to 
which  is  attached  the  inferior  turbinated  bone ;  and  lying  between 
these  crests  is  a  smooth,  concave  space,  forming  part  of  the  middle 
meatus,  while  beneath  the  inferior  crest  is  a  like  space  which  forms 
part  of  the  inferior  meatus.  By  its  anterior  border  it  is  articulated 
with  the  nasal  bone,  and  by  its  posterior  with  the  lachrymal  bone, 
forming  with  it  the  canal  for  the  nasal  duct,  while  at  the  junction  of 
the  anterior  lip  of  the  nasal  groove  with  the  orbital  surface  is  placed 
the  lachrymal  tubercle,  serving  as  a  guide  to  the  duct  in  all  operations 
for  fistula  lachrymalis. 


36 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


Fig.  8. 


The  Alveolar  Process  is  formed  on  the  lower  edge  of  the  external 
surface;  it  is  broader  behind  than  in  front,  and  is  perforated  with 
excavations  corresponding  in  number  with  the  teeth ;  those  depres- 
sions which  receive  the  teeth  of  more  than  one  root  are  subdivided  by- 
bony  septa  into  compartments  of  a  sufficient  number  to  receive  these 
roots. 

The  bottom  of  each  Of  these  cavities  is  perforated  by  a  small  fora- 
men, for  the  passage  of  nerves 
and  blood-vessels  which  supply 
the  teeth.  The  alveolar  bor- 
der externally  presents  a  fluted 
appearance;  the  projections 
correspond  with  the  alveolar 
cavities,  and  the  depressions 
with  the  septa  which  divide 
them  from  one  another. 

The  Palate  Process  forms  the 
roof  of  the  mouth  and  part  of 
the  floor  of  the  nose ;  it  is  thick  and  strong,  and  presents  in  front  the 
orifice  of  the  anterior  palatine  canal  through  which  passes  the  anterior 
palatine  vessels,  whilst  the  inferior  naso-palatine  nerves  pass  along  the 
inter-maxillary  suture.  The  inferior  surface  at  the  back  part  has  a 
deep  groove,  sometimes  a  canal,  for  the  passage  of  the  posterior  pala- 
tine vessels,  and  a  nerve  of  large  size ;  it  is  also  perforated  with  nu- 
merous foramina  for  the  passage  of  nutrient  vessels.  The  outer  border 
is  closely  attached  to  the  rest  of  the  bone.  The  inner  border,  thicker 
in  front  than  behind,  presents  a  ridge,  which,  together  with  a  similar 
ridge  on  the  opposite  bone,  forms  a  groove  in  which  the  vomer  is 
received.  The  anterior  margin  is  prolonged  into  a  sharp  process,  the 
nasal  spine.  By  its  posterior  border  it  articulates  with  the  horizontal 
plate  of  the  palate  bone. 

The  structure  of  the  upper  jaw,  with  its  alveolar  and  numerous 
other  processes,  is  thick  and  cellular ;  the  cancellated  structure  being 
invested  with  a  thin  layer  of  compact  bone. 

It  is  articulated  with  two  bones  of  the  cranium,  the  frontal  and 
ethmoid,  and  seven  of  the  face,  namely :  the  nasal,  malar,  lachrymal, 
palate,  inferior  turbinated,  vomer,  and  to  its  fellow,  by  sutures ;  also 
to  the  teeth  by  the  articulation  termed  ^^w/Zz^j/V. 

Its  development  commences  at  so  early  a  period  of  intra-uterine 
life,  and  ossification  proceeds  so  rapidly,  that  the  number  of  ossific 
centers  is  uncertain  ;  some  give  a  center  for  the  body  and  each  pro- 
cess, others  think  that  most  probably  there  are  but  four  centers  in  all. 
It  may  be  seen  as  early  as  the  thirty-fifth  or  fortieth  day  after  concep- 


THE    INFERIOR    MAXILLARY    BONE. 


37 


tion  ;  and  although  at  birth  it  has  acquired  but  little  height,  it  has 
increased  considerably  in  breadth.  But  at  this  period  the  alveolar 
border,  which  constitutes  the  largest  portion  of  the  bone,  is  almost  in 
contact  with  the  orbit.  The  antrum  is  still  scarcely  perceptible,  but 
as  the  vertical  dimensions  of  the  bone  are  increased,  it  is  gradually 
developed.  With  the  loss  of  the  teeth,  the  alveolar  border  nearly 
disappears,  so  that  the  vault  of  the  palate  loses  its  arched  form,  and 
sometimes  becomes  almost  flat. 

The  Upper  or  Orbital  Surface  is  triangular  in  shape,  with  its  base  in 
front  forming  the  anterior,  lower,  and  internal  edges  of  the  orbit,  while 
its  apex  extends  back  to  the  bottom,  forming  the  floor  of  the  orbit 
and  roof  of  the  antrum  ;  its  internal  edge  is  united  to  the  lachrymal, 
ethmoid,  and  palate  bones  ;  its  external  edge  assists  in  forming  the 
spheno-maxillary  fissure,  and  along  its  central  surface  is  seen  a  canal 
running  from  behind,  forward  and  inward — the  infra-orbital  canal. 
This  canal  divides  into  two  ;  the  smaller  is  the  anterior  defital,  which 
descends  to  the  anterior  alveoli  along  the  front  wall  of  the  antrum ; 
the  other  is  the  proper  continuation  of  the  canal,  and  ends  at  the 
infra-orbital  foramen. 

THE    INFERIOR    MAXILLARY    BONE. 

The  Inferior  Maxillary  Bone  (Fig.  9)  is  the  largest  bone  of  the  face, 


,^0'^/ 


CO/V^. 


^Ys  m"  a"  ■  ■  M  V  oVbE,^^^ 

aROOUET  rOR  facial  ART'V' 

Fig.  9. 


— /\/VGLE 


and  though  single  in  the  adult,  it  consists  of  two  symmetrical  pieces 
in  the  fetus,  which  become  joined  at  the  symphysis  in  the  first  year. 


3S 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY 


It   occupies  the  lower   part   of  the   face,  has  a  parabolic  form,  and 
extends  backward  to  the  base  of  the  skull. 

It  is  divided  into  a  body  and  extremities. 
*  The  body  is  the  middle  and  horizontal  portion  ;  this  is  divided 
along  its  center  by  a  ridge  called  the  symphysis,  which  is  the  place  of 
separation  in  the  infant  state  ;  the  middle  portion  projects  at  its  inferior 
part  into  an  eminence  called  the  mentalprocess,  or  chin  ;  on  each  side 
of  which  is  a  depression  for  the  muscles  of  the  lower  lip  ;  and  exter- 
nally to  these  depressions  are  two  foramina,  called  anterior  mental,  for 
transmitting  an  artery  and  nerve  of  the  same  name. 

The  horizontal  portions  extend  backward   and    outward,   and  on 


MYLO-HYO/O  RiaCE 

BOO  y 

Fig.  io. 


the   outward   surface   have   an    oblique    line    for    the  attachment   of 
muscles. 

On  the  inner  surface  of  the  middle  part,  behind  the  chin,  along  the 
line  of  the  symphysis,  there  is  a  chain  of  eminences  called  genial 
tubercles,  to  the  superior  of  which  the  frenum  linguae  is  attached,  to 
the  middle  the  genio-hyo-glossi,  and  to  the  inferior  the  genio-hyoid 
muscles;  on  each  side  of  these  eminences  are  depressions  for  the  sub 
lingual  glands ;  and  beyond  these  depressions  there  runs  an  oblique 
ridge  upward  and  outward,  to  the  anterior  part  of  which  is  attached 
the  mylo-hyoid  muscle,  and  to  the  posterior  part,  the  superior  con- 
strictor of  the  i)harynx;  this  latter  muscle  is  consequently  involved 
more  or  less  in  the  extraction  of  the  last  molar  tooth.      Below  this  line 


THE    INFERIOR    MAXILLARY    BONE.  39 

there  is  a  groove  for  the  mylo-hyoid  nerve,  and  a  depression,  the  sub- 
maxillary fossa,  for  the  reception  of  the  submaxillary  gland. 

The  alveolar  border,  in  the  fetus,  constitutes  nearly  the  whole  body 
of  the  bone.  After  the  loss  of  the  teeth,  this  part  of  the  inferio'" 
maxillary  is  gradually  wasted.  The  alveolar  border  in  the  lower  ja"/ 
describes  a  rather  smaller  arch  than  it  does  in  the  upper,  and  both  'ts 
anterior  walls  are  thinner  than  the  posterior.  Passing  over  the  inferior 
border,  near  the  junction  of  the  body  with  the  ramus,  is  z  groove  for 
the  facial  artery. 

The  extremities  of  the  body  have  two  large  processes  rising  up  to 
an  obtuse  angle,  named  the  rami  of  the  lower  jaw.  These  processes 
are  flat  and  broad  on  their  surfaces  ;  the  outer  one  is  covered  by  the 
masseter  muscle ;  the  inner  one  has  a  deep  groove  which  leads  to  a 
large  hole,  the  posterior  dental  or  maxillary  foramen,  for  transmitting 
the  inferior  dental  nerves  and  vessels  to  the  dental  canal  running  along 
the  roots  of  the  teeth.  This  foramen  is  protected  by  a  spine  to  which 
the  spheno-maxillary  ligament  is  attached. 

The  ramus  has  a  projection  at  its  lower  part,  which  is  the  angle  of 
the  lower  jaw;  its  upper  ridge  is  curved,  having  a  process  at  each  end 
— the  anterior  one  is  the  coronoid  process ;  this  is  triangular,  and  ha«« 
the  temporal  muscle  inserted  into  it  ;  the  posterior  is  the  condyloid. 
and  articulates  with  the  temporal  bone.  This  process  has  a  neck  which 
receives  the  insertion  of  the  external  pterygoid  muscle. 

The  Coronoid  Process  is  thin,  flat,  and  triangular.  To  its  externaJ 
surface  is  attached  the  temporal  and  masseter  muscles.  On  its  interna' 
surface  is  a  long  latitudinal  ridge  extending  to  the  posterior  part  of 
the  alveolar  process,  and  to  which  is  attached  the  temporal  m"scle 
above  and  the  buccinator  muscle  below.  In  front  of  this  ridg':*  is  r 
deep  groove,  to  which  the  temporal  and  buccinator  muscles  are  in  part 
attached. 

The  Condyloid  Process  consists  of  two  portions — a  condyle  and  a 
neck.  The  condyle  is  of  an  oval  form,  convex  both  laterally  and 
from  before  backward.  The  neck  of  the  condyle,  flattened  from 
before  backward,  convex  on  its  posterior  surface,  presents  anteriorly 
a  depression,  the  pterygoid  fossa,  for  the  attachment  of  the  external 
pterygoid  muscle.  Between  these  two  processes  is  the  sigmoid  notch. 
a  semilunar  depression  over  which  passes  the  masseteric  artery  and 
nerve. 

The  structure  of  the  inferior  maxilla  is  compact  externally,  cellular 
within,  and  is  traversed  the  greater  part  of  its  extent  by  the  inferior 
dental  canal. 

The  lower  jaw  is  developed  from  two  centers  of  ossification,  which 
meet  at  the  symphysis.     It  articulates  on  each  side,  by  one  of  its  con 


40 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


dyles,  with  the  glenoid  cavity  of  the  temporal  bone,  situated  at  the 
base  of  the  zygomatic  process.  This  cavity  is  divided  into  two 
portions — an  anterior  and  a  posterior.  The  former  constitutes  the 
articular  portion,  the  latter  lodges  a  process  of  the  parotid  gland.  The 
two  are  separated  by  the  fissure  of  Glaserius,  which  transmits  the 
chorda  tympani  nerve,  the  laxator  tympani  muscle,  and  the  anterior 
tympanic  artery.  It  also  gives  lodgment  to  the  long  ^ixocQi'S,,  processus 
gracilis,  of  the  malleus. 

Between  this  cavity  and  the  condyle  there  is  interposed  an  inter- 
articular  cartilage,  so  molded  as  to  fit  the  two  articular  surfaces.  The 
circumference  of  this  being  free,  except  where  it  adheres  to  the  external 
lateral  ligament,  affords  attachment  to  a  few  fibres  of  the  external 
pterygoid  muscle,  and  facilitates  the  movements  of  the  joint. 

The  union  of  this  articulation  is  maintained  by  the  external  lateral, 
the  spheno-maxillary,  and  the  stylo-maxillary  ligaments. 

THE    PALATE    BONES. 

The  Palate  Bones,  two  in  number,  are  situated  at  the  back  part  of 
the  superior  maxillary  bone,  between  its  tuberosities  and  the  pterygoid 
process  of  the  sphenoid  bone. 


,f/lt   "ffo. 


SUPEKIDR  MEATUS 
SfHlHQ    PALATIMC  FOUAMEN- 


HORIZONTAL      PLATE 

Fig.  II. 


The  palate  bone  is  divided  into  two  plates  :   the  inferior,  or  horizon- 
tal, and  the  superior,  or  vertical. 

The  horizontal  plate  is  broad  and  on  the  same  line  with  the  palate 


THE    PALATE    BONES. 


41 


processes  of  the  superior  maxillary  bone ;  its  upper  surface  is  smooth 
and  forms  the  posterior  floor  of  the  nostrils ;  the  lower  surface  is  rough 
and  forms  the  posterior  part  of  the  roof  of  the  mouth ;  its  anterior 
edge  is  connected  with  the  palate  processes  of  the  upper  jaw,  and  its 
posterior  is  thin  and  crescentic,  to  which  is  attached  the  velum- 
pendulum  palati,  or  soft  palate ;  at  the  posterior  point  of  the  suture, 
uniting  the  two  palate  bones,  there  projects  backward  a  process  called 
^Q.  posterior  7iasal  spine,  which  gives  origin  to  the  azygos-uvulse  muscle. 
The  vertical  plate  ascends,  helps  to  bound  the  nasal  cavity,  diminishes 
the  opening  into  the  antrum  by  projecting  forward,  and  by  its  external 
posterior  part,  in  conjunction  with  the  pterygoid  processes  of  the 
sphenoid  bone,  forms  the  posterior  palatine  canal ;  the  lower  orifice 
of  which  is  seen  on  the  margin  of  the  palate  plate,  and  is  called  the 
posterior  palatine  foramen,  transmitting  the  palatine  nerve  and  artery 
to  the  soft  palate ;  behind  this  foramen  is  often  seen  a  smaller  one, 
passing  through  the  base  of  the  pterygoid  process  of  this  bone,  and 
sending  a  filament  of  the  same  nerve  to  the  palate. 

The  upper  end  of  the  vertical  or  nasal  plate  has  two  processes — the 
one  is  seen  at  the  back  of  the 
orbit,  called  the  orbital  pro- 
cess; the  other  is  posterior, 
and  fits  against  the  under 
surface  of  the  body  of  the 
sphenoid  bone.  Between 
these  two  processes  is  a  fora- 
men, the  spheno  -  palatine, 
which  transmits  to  the  nose 
a  nerve  and  artery  of  the 
same  name. 

The  palate  bone  articulates 
with  six  others,  namely :  the 
superior  maxillary,  inferior 
turbinated,  vomer,  sphenoid, 
ethmoid,  and  opposite  palate. 

The  structure  of  this  bone 
is  very  thin,  and  consists 
almost   entirely   of    compact 

tissue.  Its  development,  it  is  said,  takes  place  by  a  single  point  of 
ossification  at  the  union  of  the  vertical,  horizontal,  and  pyramidal 
portions. 

.    THE    FRONTAL    BONE. 

The  Frontal  Bone  consists  of  two  portions — a  vertical,  or  frontal,  at 
the  front  part  of  the  cranium,  forming  the  forehead,  and  a  horizontal, 


^-C^•-      "fin 

0?" 


SPHENO.PALA  TIME  rORA. 


SPHENOIDAL    PROCESS 

AnnCULAft  PORT. 


'"^/T-i 


YCOS    UVI 

RIZONTAL 
PLATE 

Fig.  12. 


42 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY, 


Dr  orbito-nasal,  which  enters  into  the  formation  of  the  roofs  of  the 
orbits  of  the  eyes  and  nasal  fossae.  The  following  points  are  found 
on  the  vertical  portion  :  — 

The  frontal  eminences,  one  on  each  side  of  the  median  line  ;  the 
superciliary  ridges,  behind  which  are  the  frontal  sinuses ;  the  supra- 
orbital notches,  or  fora?nina,  situated  in  the  supraorbital  arches  about 
their  inner  third,  for  the  supraorbital  vessels  and  nerves  ;  the  nasal 
eminence  at  the  lower  end  of  the  frontal  depression ;  the  external 
angular  processes,  which  articulate  with  the  malar  bones  and  form  the 
interior  part  of  the  temporal   ridges;   \}ciQ.  internal  angular  processes  ^ 


—    Nasal  spine. 
Fig.  13. — The  Frontal.     {Anterior  view.) 

which  articulate  with  the  lachrymal  bones;  the  nasal  spine  and  notch, 
between  the  internal  angular  processes;  and,  internally,  a  groove  for 
the  superior  longitudinal  sinus  and  the  falx  cerebri ;  and  the  frontal 
crest,  for  the  attachment  of  the  falx  cerebri ;  and  the  foramen  c cecum, 
for  a  small  vein  to  the  longitudinal  sinus  ;  and  depressions  and  eleva- 
tions, for  the  convolutions  of  the  brain.  Between  the  two  tables  of 
the  vertical  |)ortion  are  the  frontal  sinuses,  which  are  lined  with 
mucous  membrane  and  open  into  the  middle  meatus  of  the  nose  by 
means  of  an  infundibulum  for  each  one. 

The  following  points  are  found  on  its  horizontal  portion  :  a  fossa 


THE    PARIETAL    BONES. 


43 


for  the  lachrymal  gland,  near  the  external  angular  process;  a  depres- 
sion at  the  nasal  margin,  for  the  pulley  of  the  superior  oblique  muscle; 
the  ethmoidal  notch,  having  on  its  margin  the  anterior  ethmoidal 
foramen;  t\iG  posterior  ethmoidal  foramen,  the  former  for  the  anterior 
ethmoidal  vessels  and  the  nasal  branch  of  the  ophthalmic  nerve,  and 
the  latter  for  the  posterior  ethmoidal  vessels ;  also  grooves  on  the 
cranial  surface,  for  branches  of  the  anterior  and  middle  meningeal 
arteries. 

The  frontal  bone  articulates  with  twelve  bones :  the  sphenoid,  eth= 
moid,  two  parietal,  two  nasal,  two  superior  maxillary,  two  lachrymal, 
and  two  malar.  The  following  muscles  are  attached  to  it :  temporal, 
corrugator  supercillii,  and  orbicularis  palpebrarum. 


Fig.  14. 
3,  3.  Parietal  bones.     7,  7.  Spheno-parietal  sutures.    9,  9.  Temporo-parietal  sutures. 


THE    PARIETAL    BONES. 

The  two  Parietal  Bones  are  quadrilaterally  shaped,  so  named  from 
their  forming  the  lateral  walls  of  the  skull,  and  situated  at  the  superior 
and  lateral  regions  of  the  cranium.  They  are  joined  at  the  superior 
borders  by  the  sagittal  suture,  and  the  anterior  border  joins  the  frontal 
bone  by  a  part  of  the  coronal  suture ;  the  posterior  border  articulates 
with  the  occipital  bone,  forming  the  lamhdoidal  suture ;  the  inferior 
border  articulates  with  the  sphenoid  and  temporal  bones.  Externally 
this  bone  is  convex,  and  on  this  surface  are  found  the  following  points  : 
the  temporal  ridge,  which  is  continuous  with  the  same  ridge  on  the 
frontal  bone  ;  \h^  parietal  eminence,  the  point  where  ossification  com- 
mences ;  the  parietal  foramen,  which  is  close  to  the  upper  border  and 
transmits  a  vein  to  the  superior  longitudinal  sinus.  Internally  this 
bone  is  concave,  and  on  this  surface  the  following  points  are  found  ; 
depressions,  for  the  Pacchionian  bodies  and  for  the   cerebral  convo- 


44 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


lutions  of  the  brain  ;  furrows,  for  branches  of  the  middle  meningeal 
artery  ;  a  groove,  for  the  lateral  sinus,  at  the  posterior  inferior  angle  ; 
a  half-groove  along  the  upper  border,  for  the  superior  longitudinal 
sinus  of  the  dura  mater.  Each  parietal  bone  articulates  with  five 
bones,  namely,  the  frontal,  occipital,  sphenoid,  temporal,  and  the 
opposite  parietal  bone.  The  temporal  muscle  is  the  only  one 
attached  to  the  parietal  bone. 


THE    OCCIPITAL    BONE. 

The  Occipital  Bone  is  trapezoidal  in  form,  curved  upon  itself,  and 
situated  at  the  posterior  and  inferior  region  of  the  cranium.     Itsexter-. 

nal  surface  is  convex,  and  upon  it 
are  found  the  following  points : 
The  external  oblique  protuberajice 
and  crest,  which  affords  attachment 
for  the  ligamentum  nuchse ;  the 
superior  and  ififeHor  curved  lines, 
which  extend  outward  on  each  side 
of  the  external  occipital  crest ;  the 
foramen  magtium,  which  transmits 
the  medulla  oblongata,  the  verte- 
bral arteries,  and  the  spinal  acces- 
sory nerves ;  the  two  condyles,  for 
articulation  with  the  atlas  vertebra  j 
two  tubercles,  one  on  each  condyle, 
for  the  check  ligaments ;  the  two 
anterior  condyloid  foramina,  for  the 
hypoglossal  nerves ;  the  two  posterior 
condyloid  foramina,  when  present, 
for  veins ;  two  jugular  processes, 
which  assist  in  forming  the  foramen  lacerum  posterius  basis  cranii. 
Its  internal  surface  is  concave,  and  presents  the  following  points :  four 
fossce,  for  the  cerebellar  and  posterior  cerebral  lobes ;  the  internal  occip- 
ital protuberance,  where  the  six  cranial  sinuses  meet  to  form  the  tor- 
cular  Herophili ;  the  crucial  ridge,  which  is  the  vertical  portion  for  the 
falx  cerebri  and  falx  cerebelli ;  a  groove,  for  the  lateral  sinus  and  the 
inferior  petrosal  sinus;  the  basilar  process,  which  lies  in  front  of  the 
foramen  magnum  and  articulates  with  the  body  of  the  sphenoid  bone, 
and  grooved  internally  for  the  medulla  oblongata  and  pons  varolii, 
which  lie  upon  it;  inferiorly  it  is  rough,  for  the  attachment  of  the  mus- 
cles, and  presents  the  pharyngeal  spine  for  the  attachment  of  the 
superior  constrictor  muscle  of  the  pharynx.  The  occipital  bone  articu- 
lates with  six  bones, — the  two  parietal,  the  two  temporal,  sphenoid,  and 


Fig.  15. 


(Postero-infe- 


-OcciPiTAL    Bone. 
rior  view.) 

.  Basilar  process.  2.  Foramen  magnum. 
3,3.  Posterior  condyloid  foramina.  4.  Crest. 
5.  External  occipital  protuberance.  6,  6. 
Condyles.  7,  7.  Jugular  processes.  8,  8. 
Jugular  fossEe. 


THE    TEMPORAL    BONES. 


45 


atlas.  The  muscles  attached  to  the  occipital  bone  are  twelve  \n  num- 
ber,— theoccipito-frontalis,  trapezius,  sterno-cleido-mastoid,  complexus, 
splenius,  obliquus  capitis  superior,  rectus  capitis  posticus  major  and 
minor,  superior  constrictor  of  pharynx,  rectus  capitis  anticus  major 
and  minor,  and  the  rectus  capitis  lateralis. 

THE    TEMPORAL    BONES. 

The  two  Temporal  Bones  are  situated  at  the  inferior  lateral  portion 
of  the  skull,  and  contain  the  organs  of  hearing.  Each  bone  is  divided 
into  three  parts, — the  squamous  (scale-like),  wai'/^/'^  (nipple-like),  and 
petrous  (hard\  and  the  bone  is  named  from  tetnpus — time. 

''The  squamous  portion  is  semicircular,  smooth  externally,  and 
grooved  internally,  for  the  middle  meningeal  artery,  with  depressions 


Zygomatic  tubercle. 

Glenoid  fossa. 

Glaserian  fissure. 

Tympanic  plate. 

Styloid  process. 


Temporal  fossa. 
Post-glenoid 

tubercle. 
Auditory  meatus. 

Auricular  fissure. 


Fig.  i6.— The  Left  Temporal  Bone.    {Outer  view.) 


for  the  cerebral  convolutions.  Externally  the  following  points  are 
found :  the  zygomatic  process,  or  zygoma,  extending  forward  to 
articulate  with  the  malar  bone ;  the  zygo??iatic  tubercle  at  the  base 
of  the  process  for  the  external  lateral  ligament  of  the  lower  jaw; 
the  eminentia  articularis,  which  is  formed  by  the  anterior  root 
of  the  zygomatic  process;  the  glenoid  fossa,  vf\nc]\  is  between  the 
anterior  and  middle  roots  of  the  zygomatic  process,  its  anterior  part 
receiving  the  condyle  of  the  lower  jaw,  and  its  posterior  part  lodging 
the  parotid  gland ;  the  Glaserian  fissure,  which  divides  the  glenoid 
fossa  and  transmits  the  laxator  tympani  muscle,  the  tympanic  artery, 
and  the  processus  gracilis  of  the  malleus  ;  the  opening  of  the  canal  of 
Hugier,  which  lies  in  the  angle  between  the  squamous  and  petrous 
portions,  and  transmits  the  chorda  tympani  nerve  ;  and  a  part  of  the 
temporal  ridge.     The  mastoid  portion  presents  the  following  points  : 


46  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

it  projects  like  a  nipple  from  the  inferior  part  of  the  bone  posteriorly, 
and  internally  it  is  grooved  for  the  lateral  sinus.  Externally  are  found 
the  mastoid  forafnen  for  a  vein  ;  the  mastoid  process  at  the  tip,  for 
sterno-cleido-mastoid,  splenius,  and  trachelo-mastoid  muscles ;  the 
digastric  fossa,  for  the  posterior  belly  of  the  digastric  muscle ;  the 
occipital  groove,  for  the  occipital  artery  ;  and  the  mastoid  cells,  which 
open  on  the  posterior  wall  of  the  middle  ear  and  are  lined  with 
mucous  membrane. 

The  petrous  portion  is  hard,  pyramidal  in  form,  and  contains  the 
internal  and  middle  ear,  projecting  inward  and  forward,  and  having  a 
base,  an  apex,  three  surfaces,  and  three  borders.  On  the  base  are 
found  the  meatus  auditorius  externus — the  external  opening  of  the  ear ; 
and  the  auditory  process,  which  is  an  osseous  ring  for  the  external 
cartilage  of  the  ear.  The  Apex  is  situated  internally  at  the  base  of  the 
skull,  and  forms  the  outer  boundary  of  the  foramen  lacerum  medium, 
and  contains  the  internal  carotid  canal.  The  Anterior  Surface,  from 
within  outwards,  presents  the  opening  of  the  carotid  canal,  for  the 
internal  carotid  artery  and  plexus.  The  depression  contains  the  Gas- 
serion  ganglion  of  the  fifth  pair  of  nerves.  The  hiatus  fallopii  is  for 
the  great  petrosal  nerve  and  an  artery  ;  and  the  foramen  is  for  the 
small  petrosal  nerve. 

The  Posterior  Surface  presents  the  meatus  auditorius  internus,  for 
the  transmission  of  the  seventh  and  eighth  pairs  of  cranial  nerves  and 
the  auditory  artery,  and  also  lodges  a  process  of  the  dura  mater.  The 
Inferior  Surface  presents  the  opening  of  the  carotid  canal  for  transmit- 
ting the  internal  carotid  artery,  and  the  carotid  plexus  of  the  sym- 
pathetic nerve  ;  the  rough  quadrilateral  surface,  for  the  origin  of  the 
tensor  tympani  and  levator  palati  muscles  ;  the  aqueductus  cochlea, 
for  transmitting  a  vein  from  the  cochlea  ;  the  jugular  fossa,  a  depres- 
sion for  the  sinus  of  the  internal  jugular  vein,  forming  with  the  oc- 
cipital bone  the  foramen  lacerum  posterius,  which  transmits  that  vein 
and  the  eighth  pair  of  nerves  ;  a  foramen  for  Jacobson's  nerve  and 
another  foramen  for  Arnold's  nerve  ;  the  jugular  surface,  for  articula- 
tion with  the  jugular  process  of  the  occipital  bone ;  the  vaginal  pro- 
cess ensheathing  the  root  of  the  styloid  process ;  the  styloid  process,  for 
the  stylo-pharyngeus,  stylo-hyoid,  and  the  stylo-glossus  muscles ;  the 
stylo-tnastoid  foramen,  for  the  exit  of  the  facial  nerve,  and  the  entrance 
of  the  stylo-mastoid  artery  ;  the  septum  tubcz  lamina,  which  separates 
the  tympanum  and  is  called  processus  cochleariformis  ;  opening  of  the 
canal  for  the  tensor  tympani  muscle  ;  the  osseous  opening  of  the  Eusta- 
chian tube.  The  temporal  bone  articulates  with  five  bones, — the 
occipital,  parietal,  sphenoid,  malar,  and  inferior  maxillary.  Fourteen 
muscles  are   attached  to  the  different  parts  of  this  bone  :   the  tem- 


THE    SPHENOID    BONE, 


47 


poral,  masseter,  occipito-frontalis,  sterno-cleido-niastoid,  splenius 
capitis,  trachelo-mastoid,  digastric,  retrahens  aurem,  tensor  tympani, 
levator  palati,  stapedius,  stylo-glossus,  stylo-hyoid,  and  stylo-pharyn- 
geus. 

THE    SPHENOID    BONE. 

The  sphenoid  bone  resembles  a  bat  with  outstretched  wings,  and  is 
named  from  the  Greek  word  afev,  a  wedge.  Wedged  in  between  the 
bones  of  the  skull  anteriorly,  this  bone  enters  into  the  formation  of 
five  cavities,  four  fossae,  three  fissures,  and  consists  of  a  body,  two 
greater  wings,  tiuo  lesser  wijigs,  two  pterygoid  processes,  two  styloid  pro- 
cesses, six  clinoid processes,  three  lesser  processes,  twelve  foramina,  has 
twelve  articulations  with  other  bones  of  the  head  and  face,  and  to  it 


Fig.  17. — The  Sphenoid.    {Anterior  view.) 
I.  Orbital  surface.    (The  pointer  crosses  the  malar  crest.)     2.  Ext.  pterygoid  plate.     3.  Ptery- 
goid notch.     4.  Hamular  process.     5.  Optic  foramen.     6.  Sphenoidal  fissure.     7.  Foramen 
rotundum.     8.  Vidian  canal.     9.  Pterygo-palatine  canal. 


are  connected  twelve  pairs  of  muscles  ;■  it  has  also  ten  points  of  ossifi- 
cation. The  body  of  the  sphenoid  bone  is  cuboid  in  shape,  and  lo- 
cated in  the  median  line.  Its  Upper  Surface  from  before  backward, 
presents  the  following  points  :  A  smooth  surface,  grooved  for  the  olfac- 
tory nerves  ;  eth?noidal  spine  ;  optic  groove,  for  the  support  of  the  com- 
missure of  the  optic  nerve  ;  olivary  process,  in  the  form  of  an  olive- 
shaped  eminence  behind  the  optic  groove;  middle  clinoid  processes, 
bounding  the  sella  turcica  in  front ;  sella  turcica,  which  lodges  the 
pituitary  body  and  circular  sinus  of  the  brain  (so  called  from  its  resem- 
blance to  a  Turkish  saddle)  ;  dorsum  sellce  (or  back  of  saddle),  which 
is  grooved  for  the  sixth  pair  of  nerves;  posterior  clinoid  processes,  for 
attachment  of  the  tentorium  cerebelli  ;  lateral  grooves,  for  the  cavern- 
ous sinus  and  internal  carotid  artery. 


48  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

The  Anterior  Surface  is  almost  vertical,  and  presents  the  following 
points  :  lamella  in  the  median  line,  articulating  with  the  perpendicular 
plate  of  the  ethmoid  bone,  and  forming  part  of  the  nasal  septum  ; 
opening  of  the  sphenoidal  sinuses  or  cavities  in  the  body  of  the  bone — 
common  to  adults  only ;  sphenoidal  turbinated  bones  (the  pyramids  of 
Wistar),  which  partially  close  the  sinuses,  and  articulate  with  the  eth- 
moid and  palate  bones. 

The  Inferior  Surface  assists  in  forming  the  nasal  fossae,  and  presents 
the  following  points  :  rostrum,  which  articulates  with  a  groove  on  the 
vomer  ;  vaginal  processes,  one  on  each  side  of  the  rostrum  ;  pterygo- 
palatine grooves,  which  in  connection  with  the  sphenoidal  processes  of 
the  palate  bones  form  the  pterygo-palatine  canals  for  the  transmission 
of  the  pterygo-palatine  arteries  and  nerves.  Each  of  the  greater  wmgs 
of  the  sphenoid  bone  on  its  superior  surface  presents  the  following 
points :  foramen  rotundum,  for  the  superior  maxillary  division  of  the 
fifth  pair  of  nerves  ;  foramen  ovale,  for  the  inferior  maxillary  division 
of  the  fifth  pair  of  nerves,  the  small  petrosal  nerve,  and  the  sm'all  men- 
ingeal artery;  Xhe  foratnen  vesalii,  for  transmitting  a  small  vein ;  fora- 
men spinosum,  for  transmitting  the  middle  meningeal  artery. 

The  Anterior  Surface  assists  in  forming  the  external  wall  of  the  orbit 
of  the  eye,  the  spheno-maxillary  and  sphenoidal  fissures.  It  articulates 
with  the  frontal  and  malar  bones,  and  contains  a  fiotch,  for  a  branch  of 
the  ophthalmic  artery  ;  z.spine,  for  part  of  the  lower  head  of  the  external 
rectus  muscle  ;  the  external  orbital  for aynina,  for  arterial  branches. 

The  external  surface  presents  the  following  points  :  pterygoid  ridge, 
which  divides  the  temporal  fossa  from  the  zygomatic  ;  the  spine  of  the 
sphenoid,  to  which  the  internal  lateral  ligament  of  the  lower  jaw  and 
the  laxator  tympani  muscles  are  attached.  The  circumference  is 
partly  serrated  for  articulation  with  the  temporal  bone,  and  partly 
smooth  for  the  anterior  margin  of  the  foramen  lacerum  medium  and 
the  inferior  margin  of  the  sphenoidal  fissure,  which  margin  it  assists  in 
forming. 

The  lesser  wings  of  the  sphenoid  bone  (Processes  of  Ingrassias)  termi- 
nate internally  in  the  anterior  clinoid  processes.  Their  anterior  bor- 
ders articulate  with  the  orbital  plate  of  the  frontal  bone,  while  the  pos- 
terior are  free,  dividing  the  anterior  cerebral  fossa  from  the  middle. 
Intimately  connected  with  each  of  these  wings  are  the  optic  foramen, 
for  the  transmission  of  the  optic  nerve  and  the  ophthalmic  artery ; 
also  the  sphenoidal  fissure,  or  foramen  lacerum  anterius,  which  transmit 
the  third,  fourth,  the  ophthalmic  division  of  the  fifth  and  sixth  pairs 
of  nerves,  the  ophthalmic  vein,  branches  of  the  lachrymal  and  middle 
meningeal  arteries,  some  filaments  of  the  sympathetic  nerve,  and  a 
process  of  the  dura  mater.     The  wing-like  processes  (^pterygoid  pro- 


THE    ETHMOID    BONE. 


49 


cesses)  descend,  one  on  each  side  of  the  body  of  the  bone,  and  each 
divide  into  two  thin  bony  plates  connected  together  in  front,  and  pre- 
senting the  pterygoid  fossa,  the  origin  of  the  external  pterygoid  mus- 
cle ;  the  scaphoid  fossa,  which  serves  as  the  origin  of  the  tensor  palati 
muscle;  the  vidian  canal  aX  the  root  of  the  process  for  the  vidian  nerve 
and  vessel ;  the  triangular  notch  at  the  end  of  the  process,  which 
articulates  with  the  pterygoid  process  of  the  palate  bone. 

The  sphenoid  bone  articulates  twelve  other  bones  of  the  cranium  and 
face,  such  as  the  remaining  seven  of  the  cranium  and  the  five  of  the 
face,  viz.:  the  vomer,  two  malar,  and  two  palate  bones.  The  muscles 
attached  to  the  sphenoid  bone  are  twelve  pairs,  viz.:  the  six  orbital 
muscles,  the  temporal,  external  and  internal  pterygoids,  superior  con- 
strictor, tensor  palati,  and  laxator  tympani. 


Crista  galli. 


Anterior  ethmoi- 
dal groove. 


Uncilorm  pro- 
cess. 


Inferior  turbinal. 


Posterior  ethmoi- 
dal groove. 


Sphenoidal  tur- 
binal. 


Middle  turbinal. 


Fig.  i8. — The  Ethmoid.    [Side  view.) 


THE    ETHMOID    BONE. 

The  Ethmoid  Bone  is  light  and  spongy,  depending  from  the  eth- 
moidal notch  of  the  frontal  bone,  and  from  between  its  orbital  plates. 
It  consists  of  a  body  and  two  lateral  masses,  and  is  named  from  the 
Greek  word  tj^/jo?,  a  sieve.  The  body  of  this  bone  consists  of  a  horizontal 
cribriform  plate,  and  a  perpendicular  plate,  and  presents  the  following 
points  :  the  crista  galli,  or  cock's  comb,  projecting  upwards  for  the  at- 
tachment of  the  anterior  end  of  the  falx  cerebri ;  the  cribriform  plate 
on  each  side  of  the  crista  galli,  which  is  concave  for  the  olfactory- 
bulbs,  and  perforated  for  the  transmission  of  the  olfactory  nerves,  the 
nasal  branch  of  the  ophthalmic  nerve,  and  numerous  small  vessels ; 
the  perpendicular  plate,  which  assists  to  form  the  septum  of  the  nose, 
usually  inclined  to  one  side,  and  grooved  for  filaments  of  the  olfactory 


5° 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


nerves,  and  having  attached  to  it  the  cartilage  of  the  nose.  The 
lateral  masses  consist  of  a  number  of  cellular  cavities  and  each  mass 
presents  the  following  points  :  ethmoid  cells,  the  anterior  opening  by 
the  infundibulum  into  the  middle  meatus  of  the  nose,  the  posterior 
opening  into  the  superior  meatus  of  the  nose;  the  os planum,  or  orbital 
plate,  which  helps  to  form  the  inner  wall  of  the  orbit  of  the  eye,  and 
which  is  notched  superiorly  to  form  with  the  frontal  bone  the  two 
ethmoidal  foramina;  Xho.  unciform  process,  which  descends  to  articu- 
late with  the  inferior  turbinated  bone,  and  forms  part  of  the  inner 
wall  of  the  antrum ;  the  superior  turbinated  process,  which  curves 
downward  and  outward  ;  the  middle  turbinated  process,  which  is  larger 
and  more  curved  than  the  superior.  These  processes  bound  the  superior 
meatus  of  the  nose  and  are  frequently  called  the  superior  and  middle 
turbinated  bones .    The  ethmoid  bone  articulates  with  fifteen  bones — all 

those  of  the  face,  except  the  malar,  and  the  frontal 
e     <      •  and   sphenoid    of    the    cranium.      There   are    no 

muscles  attached  to  it. 


THE    NASAL    BONES. 

The  Nasal  Bones  are  two  in  number,  and  together 
they  form  the  bridge  of  the  nose  by  articulation 
with  each  other  in  the  median  line.  They  are 
convex  externally,  and  concave  internally,  and 
are  grooved  for  the  external  branch  of  the  nasal 
nerve  and  for  small  arteries.  Each  of  the  nasal 
bones  articulates  with  four  bones — the  frontal, 
ethmoid,  superior  maxillary,  and  the  opposite  nasal 
bone.     They  have  no  muscles  attached  to  them. 


Fig.  19. — Nasal  Bones. 
(Exterval  asf>ect.) 

I,  I.  The  Uvo  nasal 
bones.  2,  2.  Superior 
extremity.  3,  3.  In- 
ferior border.  4,  4. 
Internal  border.  5,5, 
5,  5.  External  border. 


THE    MALAR    BONES. 

The  Malar  or  Cheek  Bones  are  situated  at  the  outer  and  upper  part 
of  the  face,  and  assist  in  forming  the  cavities  of  the  orbits  of  the 
eyes,  and  the  temporal  and  zygomatic  fossae.  Each  malar  bone 
presents  the  following  points:  An  external  surface,  which  is 
convex,  for  the  attachment  of  the  zygomatic  muscles ;  a  foramen, 
■xternally,  for  the  malar  branch  of  the  temporo-malar  nerve;  z.  foramen, 
.nternally,  for  the  temporal  branch  of  the  temporo-malar  nerve;  a 
frontal  process  \\\v\c\\z.xX\cv\dXQ?,  with  the  external  angular  process  of 
the  frontal  bone  ;  an  orbital  process  projecting  backwards,  and  form- 
ing part  of  the  floor  and  outer  wall  of  the  orbit  of  the  eye,  and  also  a 
part  of  the  temporal  fossa ;  a  zygofnatic  process,  which  projects  back- 
wards to  articulate  with  the  zygomatic  process  of  the  temporal  bone  by 
a  serrated  edge ;  an  upper  border,  which  forms  the  outer  and  inferior 


LACHRYMAL    BONES INFERIOR    TURBINATED    BONES. 


51 


margin  of  the  orbit  of  the  eye ;  a  lower  border,  which  is  thick  and 
rough  for  the  origin  of  the  masseter  muscle ;  an  anterior  border,  which 
articulates  with  the  superior  max- 
illary bone ;  a  posterior  border, 
which  terminates  the  temporal 
fossa  below. 

Each  Malar  Bone  articulates 
with  four  bones :  the  frontal, 
sphenoid,  temporal,  and  superior 
maxillary.  Five  muscles  are  at- 
tached to  it :  the  levator  labii 
superioris,  zygomaticus  major  and 
minor,  masseter  and  temporal. 


THE    LACHRYMAL    BONES. 

The  Lachrymal  Bones  consist 
of  two  small  quadrilateral  bones, 
situated  in  the  anterior  part  of  the 
inner   wall    of  the   orbit   of  the 


Fig.  20. — Malar  Bone.  {External  aspect.") 
:.  Orifice  for  malar  nerve.  2,  2.  Superior  or 
orbital  border.  3,  3.  Inferior  or  zygomatic 
border.  4,  4.  Posterior  or  temporal  border. 
5,  5.  Anterior  or  maxillary  border.  6.  Supe- 
rior angle.  7.  Inferior  angle.  8.  Anterior 
angle.     9.  Posterior  angle. 


eye.  Each  lachrymal  bone  presents 
the  following  points :  a  groove  on  the 
external  surface,  which  forms  a  part  of 
the  nasal  duct ;  a  ridge,  externally,  for 
attachment  of  the  tensor  tarsi  muscle ; 
a. /arrow,  internally,  corresponding  to 
the  ridge  on  the  external  surface ;  the 
hamiclar  process,  which  projects  down- 
wards to  articulate  with  the  lachrymal 
process  of  the  inferior  turbinated  bone  ; 
an  internal  surface,  which  closes  the 
anterior  ethmoidal  cells.  Each  lach- 
rymal bone  articulates  with  four  bones: 
the    frontal,    ethmoid,    superior    max- 

There 
is  but  one  muscle  attached  to  it — the 
tensor  tarsi. 


Fig.  21. — Lachrymal  Bone.  {Ex- 
ternal aspect^ 

I,  I.  Vertical  crest,  dividing  external 
surface  into  two  parts.  2.  Spine,  in 
whicli  crest  terminates.  3.  Sulcus 
contributing  to  formation  of  lachry- 
mal canal.  4.  Continuation  of  pre- 
ceding, contributing  to  formation  of 
nasal  canal.  5.  Posterior  division  of 
external  surface,  contributing  to  for- 
mation of  orbit.  6,  6.  Anterior  bor- 
der. 7,  7.  Posterior  border.  8.  Su- 
perior extremitw  g.  Portion  of  inferior     .,,  J     •     r     •         .L      ■!_  •       .      1 

border  that  articulates  with  lachrymal    iHary,  and  inferior  turbinated. 

process  of  inferior  turbinated  bone. 
10.  Portion  that  articulates  with  or- 
bital plate  of  superior  maxillary  bone. 


THE    INFERIOR   TURBINATED    BONES. 

The  Inferior  Turbinated  Bones  are  two  in  number,  situated  in  tne 
nasal  fossae,  their  convex  surfaces  presenting  inwardly.  They  are  in 
the  form  of  two  thin,  curved  osseous  plates,  and  each  is  attached  above 
to  the  inferior  turbinated  crests  of  the  superior  maxillary  and  palate 
bones,  and  presents   the   following  :     The  lachrymal  process,    which 


52 


PRINCIPLES    AND    PRACTICE    OF    DENlSlRY. 


assists  in   forming  the  nasal  duct,  by  articulation  with  the  lachrymal 
and  superior  maxillary  bones  ;  the  ethmoidal  process,  which  articulates 

with  the  unciform  process  of  the 
ethmoid  bone,  thus  assisting  to  par- 
tially close  the  aperture  of  the 
antrum  ;  the  maxillary  process, 
which  also  assists  in  partially  closing 
the  aperture  of  the  antrum  by  bend- 
ing over  the  lower  edge  of  that 
orifice  ;  "C^tfree  border,  below,  which 
reaches  to  about  one-half  an  inch 
above  the  floor  of  the  nose.  Each 
inferior  turbinated  bone  articulates 
with  four  bones,  the  ethmoid,  lach- 
rymal, palate,  and  superior  maxillary, 
and  has  no  muscles  attached  to  it. 


Fig.  22. — Inferior  Turbinated  Bone. 
(Internal  or  Convex  aspect.) 
I,  I.  Antero-posterior  ridge,  dividing  the 
internal  surface  into  two  almost  equal 
parts.  2,  2.  Inferior  border.  3,  3.  Ante- 
rior portion  of  superior  border,  articu- 
lating with  nasal  process  of  superior 
maxillary  bone.  4.  Lachrj'mal  process. 
5.  Ethmoidal  process.  6.  Portion  of  su- 
perior border  that  articulates  with  palate 
bone.  7.  Anterior  extremity.  8.  Pos- 
terior extremity. 


THE    VOMER. 

The  Vomer,  so  called  from  its  shape  resembling  that  of  a  plow- 
share, forms  the  posterior  part  of  the  nasal  septum,  but  is  usually  bent 
to  one  side.     It  presents :  A  superior  border,  with  a  groove  and  two 


Anterior  border. 

Groove  for  naso- 
palatine nerve. 

Groove  for  septal 
cartilage. 

Inferior  border. 


Ala. 


Posterior  border. 


Fig.  23.— The  Vomer.    (Side  view.) 


wings  (alae),  for  articulation  with  the  rostrum  and  vaginal  processes 
of  the  sphenoid  bone ;  an  anterior  border,  which  is  grooved  for 
the  ethmoidal  plate  and  the  nasal  cartilage ;  an  inferior  border, 
which  is  the  longest,  and  articulates  with  the  nasal  crest  of  the  superior 
maxillary  and  palate  bones  ;  2l posterior  border,  which  is  free  and  pre- 
sents toward  the  pharynx  ;  naso-palatine grooves,  laterally,  for  the  naso- 
jialatine  nerves ;  furrows,  on  the  lateral  surface,  for  nerve  filaments 
and  blood-vessels.  The  vomer  articulates  with  six  bones, — sphenoid, 
ethmoid,  two  superior  maxillary,  and  two  palate  bones.  It  has  no 
muscles  attached  to  it. 


MUSCLES,  55 

CHAPTER  IV. 

MUSCLES. 

Muscles  are  the  fleshy  parts  of  the  body.  They  are  the  active 
organs  of  locomotion,  and  are  composed  of  fibres  bound  together  in 
bundles,  or  fasciculi,  by  delicate  areolar  tissue. 

The  muscular  fibres  of  which  each  muscle  is  compounded  are  called 
ultimate  fibres.  Of  these  anatomists  recognize  two  kinds — voluntary 
or  animal  fibres  (striped),  and  involuntary  or  organic  fibres  (unstriped). 
The  former  are  generally  under  the  influence  of  the  will,  are  of  uniform 
size,  and  present  transverse  markings.  They  compose  the  muscles  of 
the  trunk  and  limbs,  as  well  as  those  of  the  heart,  urethra,  internal  ear, 
and,  in  part,  those  of  the  oesophagus  ;  though  the  muscles  of  the  heart 
are  striped,  they  are  not  voluntary;  the  muscular  coat  of  the  urethra 
consists  of  two  layers  of  plain,  muscular  fibre ;  the  muscles  of  the  internal 
ear  are  striped,  but  are  not  voluntary  ;  in  the  upper  part  of  the  oesoph- 
agus the  muscular  fibres  consist  chiefly  of  the  striped  variety,  but  below 
they  consist  entirely  of  the  involuntary  or  unstriped  muscular  fibre. 

The  involuntary  fibres  are  not  under  volitional  control,  are  not 
striped,  are  of  smaller  size  and  homogeneous  structure.  They  are 
found  in  the  digestive  canal,  uterus,  and  bladder.  The  voluntary 
muscles  terminate  in  fibrous  tissue,  which  is  sometimes  gathered 
together  in  bundles  to  form  tendon,  or  is  spread  out  in  a  membranous 
form,  and  is  then  called  aponeurosis.  By  one  or  the  other  of  these 
terminal  forms  almost  all  muscles  are  attached  to  those  parts  which  it 
is  their  office  to  move. 

The  involuntary  muscles  are  generally  found  interlacing  freely 
around  a  cavity,  which,  by  their  contraction,  they  constrict,  expelling 
its  contents.  Each  muscle  is  closely  though  loosely  invested  by  a  sheath 
of  cellular  tissue,  which  also  sends  prolongations  into  the  body  of  the 
muscle,  investing  each  fibre  and  binding  them  together.  The  muscles 
of  expression,  which  are  especially  interesting  in  their  relation  to  pros- 
thetic dentistry,  are  quite  numerous,  and  are  very  closely  connected 
with  the  subcutaneous  tissue  and  the  skin.  Muscles  are  variously 
named,  according  to  their  form,  long,  broad,  short,  etc.  These  names 
sufficiently  explain  themselves.  Other  names  are  given  them,  depend- 
ing on  the  arrangement  of  their  fibres,  their  situation,  number  of 
divisions,  office,  etc.  The  muscles  of  the  mouth,  for  example,  are 
named  elevators,  depressors,  sphincters,  etc.,  according  to  their  respect- 
ive functions.  For  fuller  explanation,  students  are  referred  to  more 
exclusively  anatomical  works. 


54  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

The  Fascia,  which  everywhere  invests  the  more  delicate  organs,  is 
of  two  kinds — superficial,  or  fibro-areolar,  and  deep,  or  aponeurotic. 
The  superficial  fascia  lies  just  beneath  the  skin,  and  covers  nearly  the 
entire  surface  of  the  body.  It  serves  to  connect  the  skin  with  the  deep 
fascia,  and  furnishes  a  nidus  for  nerves  and  blood-vessels  passing  to  the 
skin. 

The  deep  fascia  is  composed  of  fibres  arranged  in  a  reticulated 
manner,  forming  a  dense,  inelastic  membrane,  which  invests  each 
muscle  in  a  separate  sheath.  Sheaths  are  also  fonned  from  it  for  the 
vessels  and  nerves ;  and  it  serves  also  as  points  of  attachment  for  the 
muscles. 

Each  striped  muscular  fibre  is  composed  of  two  parts — a  proper  sub- 
stance called  the  sarcous  element,  in  which  the  contractile  property 
resides,  and  a  sheath  or  sarcolemma,  a  transparent,  structureless  mem- 
brane, in  which  is  contained  the  contractile  substance.  These  ele- 
mentary fibres  are  connected  by  areolar  tissue,  with  which  a  little  fat  is 
often  associated.  Lying  between  these  fibres  are  blood-vessels,  nerves, 
and  lymphatics. 

The  sarcous  element  is  a  soft,  granular  material,  on  the  varying 
relations  of  which  granules  to  each  other  depend  the  alterations  in 
appearance  of  the  striae.  If  they  approach  each  other  more  closely  in 
the  direction  of  the  length  of  the  fibre  than  in  its  width,  it  will  appear 
fibrillated ;  if  the  reverse,  it  will  present  the  appearance  of  discs. 

Muscles,  like  all  other  tissues,  are  developed  from  germinal  matter 
which  has  undergone  special  metamorphosis,  under  the  impulse  of  the 
parent  cell,  to  construct  this  tissue.  "  Germinal  matter"  and  "  formed 
material  "  constitute  the  "elementary  part,"  according  to  Mr.  Beale, 
or  the  muscular  cell,  of  the  other  writers,  from  which  the  muscular  fibre 
is  formed.  In  the  formed  material,  which  is  the  constructed  muscle, 
resides  the  power  of  contraction.  The  germinal  matter,  or  construc- 
tive part,  does  not  possess  this  property. 

Following  the  arrangement  of  Mr.  Gray,  we  shall  divide  the  muscles 
which  it  is  our  purpose  to  describe  into  certain  groups,  as  follows: — 

I.  Nasal  Group.  2.  Superior  Maxillary  Group. 

Pyramidalis  Nasi.  Levator  Labii  Superioris  Proprius. 

Levator  Labii  Superioris  Alasque  Nasi.        Levator  Anguli  Oris. 
Levator  Proprius  Alas  Nasi  Posterior.  Zygomaticus  Major. 

Levator  Proprius  Alse  Nasi  Anterior.  Zygomaticus  Minor. 

Compressor  Naris. 

Compressor  Narium  Minor.  3.  Inferior  Maxillary  Group. 

Depressor  Alae  Nasi.  Levator  Labii  Inferioris. 

Depressor  Labii  Inferioris. 

Depressor  Anguli  Oris. 

Platysma  Myoides. 


MUSCLES.  55 

Adjunct  Group. 
Musculus  Risorius. 
Orbicularis  Oris. 
Buccinator. 

4.  Temporo-Maxillary  Group.  7.  Pharyngeal  Group. 

Masseter.  Constrictor  Inferior. 

Temporal.  Constrictor  Medius. 

Constrictor  Superior. 

5.  Pterygo-Maxillary  Group.  Stylo-pharyngeus. 

Pterygoideus  Externus.  Palato-pharyngeus. 
Pterygoideus  Internus. 

8.  Palatal  Group. 

6.  Lingual  Group.  Levator  Palati. 

Genio-hyo-glossus.  Tensor  Palati. 

Hyo-glossus.  Azygos  Uvulae. 

Lingualis.  Palato-glossus. 

Stylo-glossus.  Palato-pharyngeus. 
Palato-glossus. 

I.  Nasal  Group. 

Pyramidalis  Nasi. 

Levator  Labii  Superioris  Alnsque  Nasi. 

Levator  Proprius  Alee  Nasi  Posterior. 

Levator  Proprius  Alas  Nasi  Anterior. 

Compressor  Naris. 

Compressor  Narium  Minor. 

Depressor  Alse  Nasi. 

The  Pyramidalis  Nasi  is  a  triangular,  muscular  slip  extended  from 
the  occipito-frontalis.  It  lies  along  the  side  of  the  nose,  and  blends 
by  a  tendinous  expansion  with  the  compressor  naris. 

The  Levator  Labii  Superioris  Alceqiie  Nasi  is  also  a  triangular 
muscle,  arising  from  the  nasal  process  of  the  superior  maxilla,  its  upper 
part.  Passing  down  behind  the  muscle  just  described,  it  divides  into 
two  muscular  slips,  one  of  which  is  inserted  into  the  cartilage  of  the 
ala  of  the  nose,  the  other  is  continued  to  the  angle  of  the  mouth, 
where  it  blends  with  the  orbicularis  oris  and  levator  labii  proprius. 

Beneath  this  muscle  is  a  small  muscular  slip  extending  from  the 
origin  of  the  compressor  naris  to  the  nasal  process,  about  an  inch 
above  it.  It  is  called  the  "Musculus  Anomalus,"  or  the  "  Rhom- 
boideus. ' ' 

The  Levator  Proprius  AlcB  Nasi  Posterior,  or  Dilator  Naris  Posterior, 
extends  from  the  nasal  notch  to  the  margin  of  the  nostril. 

The  Levator  Proprius  Alee  Nasi  Anterior,  or  the  Dilator  Naris  An- 
terior, is  situated  a  little  in  front  of  the  last  described  muscle,  and 


56  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

arises  from  the  cartilage  of  the  wing  of  the  nose,  and  is  inserted  into 
the  integument  near  its  margin. 

The  Compressor  Naris,  triangular  in  form,  arises  from  the  superior 
maxilla,  a  little  above  and  external  to  the  incisive  fossa,  and  is  attached 
to  the  fibro-cartilage  of  the  nose,  joining  at  the  median  line  with  its 
fellow  of  the  opposite  side. 

The  Compressor  Narium  Minor  extends  from  the  alar  cartilage  to 
the  integument  of  the  end  of  the  nose. 

The  Depressor  Al(z  Nasi  arises  from  the  incisive  fossa  of  the  su- 
perior maxilla,  and,  dividing  into  two  sets  of  fibres,  ascending  and 
descending,  is  inserted  into  the  septum  and  posterior  portion  of  nasal 
cartilage,  and  by  some  fibres  of  the  latter  into  the  back  part  of  the 
orbicularis  oris. 

The  facial  nerve  supplies  all  the  muscles  of  this  group. 

Their  respective  actions  are  sufficiently  explained  by  their  names, 
except  the  pyramidalis,  which  draws  down  the  inner  angle  of  the  eye- 
brow, and  perhaps  aids  in  dilating  the  nostril,  and  the  compressores 
nasi,  whose  action  is  directly  opposite  to  that  implied  by  their  names. 

The  contraction  of  the  levator  labii  superioris  alaeque  nasi  gives  to 
the  face  the  expression  of  contempt. 

2.  Superior  Maxillary  Group. 
Levator  Labii  Superioris  Proprius. 
Levator  Anguli  Oris. 
Zygomaticus  Major. 
Zygomaticus  Minor. 

The  Levator  Labii  Superioris  Proprius ,  arises  from  the  lower  margin 
of  the  orbit,  some  of  its  fibres  from  the  superior  maxillary,  others  from 
the  malar  bone ;  they  pass  down  to  be  inserted  in  the  fleshy  part  of 
the  upper  lip. 

The  Levator  Anguli  Oris  arises  from  the  canine  fossa,  just  below  the 
infra-orbital  foramen,  and  descends  to  the  angle  of  the  mouth,  where 
it  blends  with  the  orbicularis  oris,  the  zygomatici,  and  the  depressor 
anguli  oris  muscles. 

The  Zygomaticus  Major  ii,  a  delicate  fasciculus,  arising  from  the  malar 
bone,  and  finding  attachment  to  the  orbicularis  and  depressor  anguli 
oris  at  the  angle  of  the  mouth. 

The  Zygomaticus  Minor  arises  from  the  malar  bone,  just  behind  the 
maxillary  suture,  and  passes  downward  and  inward,  to  be  inserted 
in  the  outer  margin  of  the  levator  labii  superioris,  with  which  it  is 
continuous. 

These  muscles  are  also  supplied  by  the  facial  nerve. 

The  action  of  the  levator  muscles  is  described  in  their  names.  The 
zygomatici  draw  the  lip  upward  and  outward,  as  in  laughing. 


MUSCLES.  57 

3.  Inferior  Maxillary  Group. 

Levator  Labii  Inferioris.  (Levator  Menti.) 

Depressor  Labii  Inferioris.  (Quadratus  Menti.) 

Depressor  Anguli  Oris.  (Triangularis  Menti.) 

Platysma  Myoides. 

The  Levator  Labii  Inferioris  arises  from  the  incisive  fossa  just  exter- 
nal to  the  symphysis  of  the  chin  ;  it  is  a  small,  conoidal  fasciculus, 
and  is  inserted  into  the  integument  of  the  chin. 

The  Depressor  Labii  Inferioris  is  a  quadrilateral  muscle,  arising 
from  the  oblique  line  of  the  inferior  maxilla,  between  the  incisive 
fossa  and  mental  foramen,  and  is  attached  to  the  integument  of  the 
lower  lip,  blending  with  the  orbicularis  and  with  its  fellow  of  the 
opposite  side. 

The  Depressor  Anguli  Oris,  situated  externally  to  the  last-men- 
tioned muscle,  also  arises  from  the  external  oblique  line  of  the  lower 
jaw,  and  is  attached  at  the  angle  of  the  mouth  to  the  orbicularis, 
levator  anguli,  and  zygomaticus  major  muscles. 

The  facial  nerve  supplies  this  group. 

Their  action  is  indicated  by  their  names. 

The  Platysma  Myoides  arises  from  the  subcutaneous  tissue  over  the 
pectoralis  major,  trapezius,  and  deltoid  muscles,  and  passes  obliquely 
over  the  clavicle  and  the  side  of  the  neck,  its  fibres  terminating  in 
the  skin  of  the  chin,  the  subcutaneous  tissue  of  the  cheek,  the  muscles 
at  the  corner  of  the  mouth,  the  middle  fibres  being  attached  along 
the  base  of  the  jaw.  It  forms  a  defense  for  the  neck,  and  is  a  muscle 
of  expression  from  its  functions  of  moving  the  skin,  belonging  to  the 
class  known  as  cutaneous  muscles. 

The  Musculus  Risorius,  Orbicularis  Oris,  and  Buccinator  form  a 
group  closely  connected  with  the  superior  and  inferior  maxillary 
groups. 

The  Musculus  Risorius  is  considered  by  many  as  a  part  of  the 
platysma  myoides,  the  large  subcutaneous  muscle  of  the  neck.  It 
arises  from  the  fascia  over  the  masseter  muscle,  and,  after  passing 
horizontally  forward,  is  inserted  into  the  angle  of  the  mouth,  where 
it  joins  the  orbicularis  oris  and  depressor  anguli  oris.  It  gives  the 
smile  of  derision. 

The  Orbicularis  Oris  surrounds  the  mouth,  and  forms  a  center  from 
which  muscles  diverge  and  are  fixed  into  the  surrounding  bones.  It 
is  the  antagonist  of  all  the  muscles  which  move  the  lips,  and  has  no 
bony  origin  or  insertion.  It  is  nearly  an  inch  in  breadth,  and  the 
prominence  of  the  lips  depends  upon  its  size  and  thickness. 

The  Buccinator  arises  from  the  outer  surface  of  the  alveolar  borders 


58 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


of  the  superior  and  inferior  maxillae,  corresponding  to  the  molar 
teeth,  and  its  fibres  pass  forward  and  are  inserted  into  the  angle  of  the 
mouth  and  the  muscular  structure  of  the  lips.  The  buccinator  is  the 
principal  muscle  of  the  cheek,  and,  with  the  superior  constrictor  of 
the  pharynx,  forms  a  muscular  wall  for  the  sides  of  the  mouth  and 
pharynx.  It  is  pierced  by  the  duct  of  the  parotid  gland,  which  opens 
into  the  mouth  opposite  the  superior  second  molar  tooth.  The  func- 
tions of  the  buccinator  are  to  expel  air  from  the  mouth  by  inflating 
the  cheek,  to  widen  the  mouth,  and  to  keep  the  food  between  the  teeth 
during  mastication.  The  facial  nerve  supplies  this  muscle,  which  is 
affected  in  facial  paralysis.  The  buccinator  muscle  is  covered  by  a 
thin  layer  of  fascia  known  as  the  buccal  fascia,  which  adheres  closely 
to  its  surface  and  is  attached  to  the  alveolar  border  of  the  superior  and 
inferior  maxillae.  The  density  of  this  fascia  prevents  abscesses  from 
readily  discharging  into  the  mouth  or  the  pharynx. 


Fig.  24. 


4.  Temporo-Maxillary  Group. 

Temporal. 
Masseter. 

The  Temporal  Muscle  (Fig.  24)  is  seen  on  the  side  of  the  head.  It 
has  its  origin  from  the  semicircular  ridge,  commencing  at  the  external 
angular  process  of  the  os-frontis,  and  extending  along  this  and  the 
parietal  bone ;  also  from   the  surface  below  this  ridge  formed  by  the 


MUSCLES. 


59 


frontal  and  squamous  portion  of  the  temporal  and  sphenoid  bones  ; 
likewise  from  the  under  surface  of  the  temporal  aponeurosis,  and  from 
a  fascia  covering  this  muscle ;  and  its  fibres  are  inserted,  after  they 
have  converged  and  passed  under  the  zygoma,  into  the  coronoid  process 
of  the  lower  jaw,  surrounding  it  on  every  side  by  a  dense,  strong  tendon. 


LKVATOR  MINI 


Fig.  25. 

The  Masseter  Muscle  (Fig.  25)  is  seen  at  the  side  and  back  part  of 
the  face,  in  front  of  the  meatus  externus,  and  lies  directly  under  the 
skin.  It  arises  by  two  portions  :  the  one,  anterior  and  tendinous, 
from  the  superior  maxilla  where  it  joins  the  malar  bone ;  the  other 
portion,  mostly  fleshy,  from  the  inferior  edge  of  the  malar  bone  and 
the  zygomatic  arch  as  far  back  as  the  glenoid  cavity,  and  is  inserted, 


6o 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


tendinous  and  fleshy,  into  the  external  side  of  the  ramus  of  the  jaw 
and  its  angle  as  far  up  as  the  coronoid  process. 

The  inferior  maxillary  nerve  supplies  both  these  muscles. 

The  office  of  the  temporal  muscle  is  to  bring  the  two  jaws  together, 
as  in  the  cutting  and  rending  of  the  food. 

The  use  of  the  masseter  muscle,  when  both  portions  act  together, 
is  to  close  the  jaw;  if  the  anterior  acts  alone,  the  jaw  is  brought  for- 
ward ;  if  the  posterior,  it  is  drawn  backward. 

The  use  of  the  pterygoid  muscle  is  to  aid  the  temporal  and  masseter 
muscles  in  the  trituration  of  the  food.  The  external  pterygoids  carry 
the  lower  jaw  directly  forward  when  acting  together ;  to  one  or  the 
other  side  when  acting  separately.  The  internal  pterygoid  aids  the 
masseter  and  temporal  in  bringing  the  lower  jaw  firmly  up  against  the 
superior  maxilla,  and  also  assists  in  carrying  the  lower  jaw  forward. 

The  inferior  maxillary  nerve  supplies  these  muscles,  which  form  the 
pterygo-maxillary  group,  and  which  come  next  in  order  of  description. 


Fig.  26. 


5.    PtERYGO-M AXILLARY    GROUP. 
Pterygoideus  Externus. 
Pterygoideus  Internus. 

Pterygoideus  Externus  (Fig.  26)  arises  from  the  outer  surface  of  the 
external  plate  of  the  pterygoid  process  of  the  sphenoid  bone,  from  the 
tuberosity  of  the  superior  maxilla,  and  from  the  ridge  on  the  sphenoid 
bone  separating  the  zygomatic  from  the  pterygoid  fossa,  and  is  in- 


MUSCLES. 


6l 


serted  into  the  inner  side  of  the  neck  of  the  lower  jaw,  and  capsular 
ligament  of  the  articulation. 

Pterygoideus  Internus  arises,  tendinous  and  fleshy,  from  the  inner 
surface  of  the  pterygoid  plate,  fills  the  greater  part  of  the  pterygoid 
fossa,  and  is  inserted,  tendinous  and  fleshy,  into  the  inner  face  of  the 
angle  of  the  inferior  maxilla  and  the  rough  surface  above  the  angle. 

The  external  one  is  triangular,  having  its  base  at  the  pterygoid  pro- 
cess and  running  outward  and  backward  to  the  neck  of  the  condyle. 
The  internal  is  strong  and  thick,  placed  on  the  inside  of  the  ramus  of 
the  jaw,  and  running  downward  and  backward  to  the  angle. 


Fig.  27. 


6.  Lingual  Group. 

Genio-hyo-glossus.  Lingualis. 

Hyo-glossus.  Stylo-glossus. 

Palato-glossus. 

The  Genio-hyo-glossics  (Fig.  27)  is  attached,  as  its  name  implies,  to 
the  chin,  hyoid  bone,  and  tongue.  It  is  a  triangular,  fan-like  muscle, 
arising  by  its  apex  from  the  superior  genial  tubercle,   and   has   its 


62 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


inferior  fibres  running  parallel  with  the  genio-hyoid  to  be  inserted 
into  the  hyoid  bone,  while  its  middle  and  anterior  fibres  are  inserted 
into  the  under  surface  of  the  tongue  its  whole  length. 

The  Hyo-glossus,  a  thin,  broad,  quadrilateral  muscle,  has  its  origin 
from  the  body,  cornu,  and  appendix  of  the  os-hyoides,  and  is  inserted 
into  the  side  of  the  tongue,  forming  the  greater  part  of  its  bulk. 

The  Litigualis  has  its  origin  on  the  under  surface  of  the  tongue, 
extending  from  its  base  and  hyoid  bone  to  the  apex,  and  so  inter- 
mingling with  the  other  muscles  as  to  be  considered  rather  a  part  of 
them  than  a  distinct  muscle. 

The  Stylo-glossus  arises  from  the  point  of  the  styloid  process  and 
stylo-maxillary  ligament.  It  is  inserted  into  the  side  of  the  tongue 
near  its  root,  its  fibres  running  to  the  tip. 

The  Palato-glossus  is  more  directly  associated  with  the  soft  palate, 
and  will  consequently  be  described  with  the  palatal  group. 


lar 


appearance 


7.  Pharyngeal  Group. 

Constrictor  Inferior. 
Constrictor  Medius. 
Constrictor  Superior. 
Stylo-pharyngeus. 
Palato-pharyngeus. 

The  Inferior  Constrictor  of 
the  pharynx  (Fig.  28)  arises 
from  the  side  of  the  thyroid 
cartilage  and  its  inferior  cornu, 
and  from  the  side  of  the  cri- 
coid cartilage,  and  is  inserted 
with  its  fellow  into  the  middle 
line  on  the  back  of  the  pha- 
rynx. This  is  the  largest  of 
the  constrictor  muscles,  and 
overlaps  the  middle  con- 
strictor. 

The  Middle  Constrictor  of  the 
pharynx  (Fig.  28)  arises  from 
the  appendix  and  both  cornua 
of  the  os-hyoides,  and  from 
the  thyro-hyoid  ligament ;  its 
fibres  ascend,  run  transversely, 
and  descend,  giving  a  triangu- 
the   upper   ones   overlap   the   superior   constrictor, 


Fig.  28. 


MUSCLES.  63 

while  the  lower  are  beneath  the  inferior ;  the  whole  pass  back  to  be 
inserted  into  the  middle  tendinous  line  of  the  pharynx. 

The  Superior  Constrictor  (Fig.  28)  arises  from  the  cuneiform 
process  of  the  occipital  bone,  from  the  lower  part  of  the  internal 
pterygoid  plate  of  the  sphenoid  bone,  from  the  pterygo-maxillary 
ligament,  and  from  the  posterior  third  of  the  mylo-hyoid  ridge  of  the 
lower  jaw,  near  the  root  of  the  last  molar  tooth.  It  is  inserted  with 
its  fellow  into  the  middle  tendinous  line  at  the  back  of  the  pharynx. 

The  Stylo-pharyngeus  arises  from  the  root  of  the  styloid  process,  and 
is  inserted  into  the  side  of  the  pharynx  and  corner  of  the  os  hyoides 
and  thyroid  cartilage.  It  is  a  long  and  narrow  muscle,  and  passes  to 
the  pharynx  between  the  upper  and  middle  constrictors. 

The  Palato-pharyngeus ,  which  forms  the  posterior  pillar  of  the  soft 
palate,  is  a  long,  fleshy  muscle,  wider  at  either  extremity  than  in  the 
middle,  and  arises  from  the  soft  palate  by  a  divided  fasciculus,  between 
which  points  of  attachment  lies  the  levator- palati.  It  passes  behind 
the  tonsil,  downward  and  outward,  to  be  inserted  into  the  posterior 
part  ot  the  thyroid  cartilage,  together  with  the  stylo-pharyngeus. 

The  muscles  of  this  group  are  supplied  with  nerves  from  the  pharyn- 
geal plexus  and  glosso-pharyngeal  nerve  ;  an  additional  branch  from 
the  external  pharyngeal  nerve  being  sent  to  the  inferior  constrictor ; 
the  palato-pharyngeus  receives  a  branch  from  Meckel's  ganglion. 

These  muscles  are  exercised  in  the  act  of  deglutition,  and  also  exert 
an  influence  in  modulating  the  voice. 


8.  Palatal  Group. 

The  Levator  Palati. 

The  Tensor,  or  Circumflex  Palati. 

Constrictor  Isthmi-faucium,  or  Palati-glossus. 

Palato-pharyngeus. 

Azygos-uvulas. 

The  Levator  Palati  (Fig.  29)  arises  from  the  point  of  the  petrous 
portion  of  the  temporal  bone  and  adjoining  portion  of  the  Eustachian 
tube,  descends,  and  is  inserted  into  the  soft  palate. 

The  Tensor,  or  Circumflexus  Palati,  arises  from  the  base  of  the 
pterygoid  process  of  the  sphenoid  bone  and  from  the  Eustachian  tube ; 
it  descends  in  contact  with  the  internal  pterygoid  muscle  to  the  hamu- 
lus, round  which  it  winds,  and  is  inserted  into  the  soft  palate,  where 
it  expands  and  joins  its  fellow. 

The  Constrictor  Isthmi-faucium,  or  Paiato-glossus,  occupies  the  an- 
terior lateral  half  arches  of  the  palate  ;  it  arises  from  the  side  of  the 
tongue  near  its  root,  and  is  inserted  into  the  velum  near  the  uvula. 


64 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


The  Palato-pharyngeiis  has  already  been  described  with  the  muscles 
of  the  pharyngeal  group. 

The  Azygos  Uvulce  arises  from  the  posterior  spine  of  the  palate  bones 
at  the  termination  of  the  palate  suture,  runs  along  the  central  line  of 
the  soft  palate,  and  ends  in  the  point  of  the^uvula.  It  raises  and  shortens 
the  uvula. 


Fig.  29. 


It  is  thus  seen  that  the  various  muscles  of  the  soft  palate  are  all  con- 
cerned, more  or  less,  in  conducting  the  food  into  the  pharyngeal  cav- 
ity. The  elevators  raise  the  palate,  and  at  the  same  time  protect  the 
posterior  nares  from  regurgitation  of  the  food  ;  while  the  tensor  puts 
it  on  the  stretch,  and  after  it  has  passed  the  velum,  the  constrictor 
isthmi-faucium  and  palato-pharyngeus  draw  the  palate  down,  and  thus 
close  the  opening  into  the  mouth ;  after  which  the  food,  as  already 
mentioned,  is  grasped  by  the  constrictor  muscles  of  the  pharynx  and 
conveyed  into  the  oesophagus. 


ARTICULATIONS.  65 

The  Soft  Palate  is  a  movable  curtain,  composed  of  mucous  mem- 
brane, inclosing  five  muscles  on  each  side,  known  as  the  muscles  of  the 
soft  palate,  namely  :  the  levator  palati,  tensor  palati,  azygos  uvulae, 
palato-glossus,  and  palato-pharyngeus.  It  is  situated  at  the  back  part 
of  the  mouth  between  this  cavity  and  the  pharynx,  is  connected  above 
to  the  posterior  edge  of  the  hard  palate,  and  laterally  to  the  side  of  the 
tongue  and  pharynx. 

By  this  arrangement,  the  soft  palate  has  the  appearance  of  a  lunated 
or  arched  veil  between  the  cavity  of  the  mouth  and  the  pharynx. 

In  the  center  of  this  arch  an  oblong  body  is  suspended,  called  the 
uvula,  which  divides  the  soft  palate  into  lateral  half  arches,  that  pass 
on  either  side  from  the  uvula  to  the  root  of  the  tongue. 

There  is  also  seen  passing  from  the  uvula  on  each  side  to  the  pharynx 
two  other  arches,  which,  from  being  behind  the  first,  are  called  the 
posterior  arches  or  pillars. 

Between  the  anterior  and  posterior  pillars,  on  either  side,  is  a  tri- 
angular interval  containing  the  tonsil  glands. 

The  Fauces  are  the  straits  or  passage  leading  from  the  mouth  to  the 
pharynx ;  and  the  space  included  between  the  soft  palate  above,  the 
half  arches  or  tonsils  on  either  side,  and  the  root  of  the  tongue  below, 
is  called  the  isthmus  of  the  fauces. 

The  Tonsils  are  two  bodies,  each  about  the  size  of  an  almond,  seen 
at  the  root  of  the  tongue  on  its  sides,  occupying  the  cavity  between 
the  anterior  and  posterior  arches.  They  consist  of  a  group  of  com- 
pound follicular  glands,  forming  somewhat  oval  bodies,  whose  enlarge- 
ment constitutes  an  obstacle  to  deglutition,  and  by  their  locality  near 
the  mouths  of  the  Eustachian  tubes  frequently  cause  obstruction  and 
deafness. 

ARTICULATIONS. 

Articulation  is  a  term  used  in  Anatomy  to  denote  the  various  modes 
of  union  between  the  bones  of  the  skeleton.  Articulations  are  classed 
under  three  general  heads,  namely — movable  joints,  immovable  joints, 
and  joints  of  a  mixed  order,  the  latter  being  somewhat  movable  with- 
out much  relative  displacement  of  the  contiguous  surfaces.  The  lower 
jaw  is  an  example  of  a  movable  articulation  which  is  known  as  the — 

Temporo-maxillary  Articulation  (Figs.  30  and  31). — The  inferior 
maxillary  bone  articulates  with  the  anterior  portion  of  the  glenoid 
cavity  of  the  temporal  bone,  forming  the  temporo-maxillary  articu- 
lation. This  joint  consists  of  the  convex  condyloid  head  or  process 
of  the  inferior  maxillary  bone,  the  concave  surface  of  the  glenoid 
fossa,  the  interarticular  fibro-cartilage,  a  double  synovial  membrane, 
and  a  loose  capsular  ligament. 
5 


66 


PRINCIPLES   AND    PRACTICE   OF   DENTISTRY. 


The  Capsular  Ligament  is  a  very  loose  sac,  attached  above  to  the 
circumference  of  the  glenoid  cavity,  and  in  front  to  the  articular  root 


^  ,tvi<N^  ^i"  '■"""" 


Fig.  30. 


of  the  zygoma;  below  it  embraces  the  neck  of  the  inferior  maxillary 
bone,  immediately  below  the  head  or  condyloid  process. 

The  Interarticidar  Fibro- cartilage  is  an  ovoid  plate  placed  between 


Fig.  31. 


the  bones,  and  is  supported  in  position  by  a  circumferential  attach- 
ment to  the  common  capsule,  the  external  lateral  ligament,  and  to  the 
tendon  of  the  external  pterygoid  muscle.  Below  its  face  is  concave, 
corresponding  with  the  convexity  of  the  condyle :  above  it  is  concave 


THE    ARTERIES    AND    VEINS    OF    THE    MOUTH.  67 

in  front  and  convex  behind,  corresponding  with  the  glenoid  cavity 
j)roper  and  the  articular  eminence.  The  composition  of  the  circumfer- 
ence is  fibrous  with  a  cartilaginous  center,  being  frequently  quite  soft 
and  sometimes  perforated. 

The  Synovial  Membranes,  one  above  and  the  other  below  the  inter- 
articular  fibro-cartilage,  are  the  lubricating  membranes,  and  in  form  are 
similar  to  two  small  sacs.  They  secrete  the  synovia,  a  fluid  which 
resembles  the  white  of  an  ^gg,  but  which  is  more  oily  and  resistive  in 
its  nature. 

The  Internal  Lateral  Ligament  descends  from  the  spinous  process 
of  the  great  wing  of  the  sphenoid  bone,  and  is  attached  to  the  inner 
surface  of  the  ramus. 

The  Stylo- maxillary  Ligament  ])as&t%  behind  from  the  styloid  process 
of  the  temporal  bone  to  be  inserted  just  above  the  angle. 

The  External  Lateral  Ligament  has  its  origin  from  the.  zygoma, 
and  passes  obliquely  downward  and  backward  to  be  inserted  about  the 
neck  of  the  condyle  ;  it  is  a  short,  somewhat  triangular-shaped  band 
of  fibrous  tissue,  and  assists  in  forming  the  common  capsule.  Exter- 
nally it  is  very  superficial,  being  covered  only  by  the  integuments,  ex- 
cept in  cases  where  the  parotid  gland  overlaps  it. 


CHAPTER  V. 

THE  ARTERIES  AND  VEINS  OF  THE  MOUTH. 

The  arteries  that  supply  the  mouth  come  from  the  external  carotid. 
This  is  a  division  of  the  common  carotid  which  arises  on  the  right 
side  from  the  arteria  innominata,  and  on  the  left  from  the  arch  of  the 
aorta  ;  after  passing  up  the  neck  on  either  side,  along  the  course  of  the 
sterno-cleido-mastoid  muscles,  it  divides,  on  a  level  with  the  top  of 
the  thyroid  cartilage,  into  its  two  great  branches — the  external  and 
internal  carotid  arteries. 

The  Internal  Carotid  Artery  has  a  tortuous  course  ;  is  first  to  the 
outside  and  behind  the  external  carotid ;  then  ascends  in  front  of  the 
vertebral  column  by  the  side  of  the  pharynx  and  behind  the  digastric 
and  styloid  muscles  to  the  carotid  foramen  in  the  petrous  portion  of 
the  temporal  bone  ;  thence  it  traverses  the  canal  in  this  bone  and 
enters  the  brain,  supplying  it  with  most  of  its  vessels,  not  giving  any 
to  the  mouth,  v. 

The  External  Carotid  extends  from  the  top  of  the  larynx  to  the  neck 
of  the  condyle  of  the  lower  jaw ;  at  first  anterior  and  on  the  inside  of 


68 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


the  internal  carotid,  it  soon  gets  to  the  outside,  then  passes  under  the 
digastric  and  stylo-hyoid  muscles  and  lingual  nerve,  becomes  imbedded 
in  the  parotid  gland,  and  terminates  between  the  neck  of  the  inferior 
maxilla  and  the  auditory  meatus  in  the  temporal  and  internal  maxillary 
arteries. 

The  branches  of  the  external  carotid  with  which  w^e  have  to  do 
are  the — 

Lingual. 

Facial. 


INCISTUS 


Fig.  32. 


Ascending  Pharyngeal. 

Temporal. 

Internal  Maxillary. 

The  Lingual  Artery  arises  from  the  external  carotid,  between  the 
superior  thyroid  and  facial ;  passing  obliquely  up  to  the  great  corner 
of  the  hyoid  bone,  it  runs  parallel  with,  and  ascending  perpendicularly 
to,  the  base  of  the  tongue,  continues  its  course  to  the  tip  of  that  organ, 
under  the  name  of  the  ranine  artery.  This  part  of  the  artery  lies  just 
beneath  the  mucous  membrane,  and  is  in  danger  of  being  wounded  in 
division  of  the  fr?enum  in  children.  This  accident  may  be  avoided  by 
using  blunt-pointed  scissors,  and  directing  the  points  downward  and 
backward- 


THE    ARTERIES    AND    VEINS    OF    THE    MOUTH.  69 

The  hypo-glossal  nerve  accompanies  this  artery. 

The  branches  of  the  lingual  artery  with  which  we  are  concerned 
are  the — 

Dorsalis  Linguae. 

Sublingual. 

Ranine. 

The  Dorsalis  Linguce  arises  from  the  lingual  artery,  beneath  the 
hypo-glossus  muscle,  and  is  distributed  to  the  tonsil,  epiglottis,  soft 
palate  and  mucous  membrane  of  the  tongue. 

The  Sublingual  arises  from  the  lingual  at  the  point  of  bifurcation, 
near  the  anterior  margin  of  the  hyo-glossus  muscle,  and  passes  forward 
to  be  distributed  to  the  sublingual  gland,  to  the  mucous  membrane  of 
the  mouth  and  gums,  and  to  the  neighboring  muscles. 

The  Ranine  may  be  considered  the  continuation  of  the  lingual. 
It  passes  along  the  inferior  surface  of  the  tongue,  just  beneath 
its  mucous  membrane.  At  the  tip  of  the  tongue  it  anastomoses 
with  its  fellow  of  the  opposite  side.  It  is  accompanied  by  the 
gustatory  nerve. 

The  Facial  Artery  is  the  third  branch  of  the  external  carotid.  It 
ascends  to  the  submaxillary  gland,  behind  which  it  passes  on  the  body 
of  the  lower  jaw ;  thence  it  goes  in  front  of  the  masseter  muscle  to  the 
angles  of  the  mouth,  and  finally  terminates  at  the  side  of  the  nose  by 
anastomosing  with  the  ophthalmic  arteries. 

In  its  course  it  gives  off  the  submental,  inferior  labial,  superior  and 
inferior  coronary  arteries,  which  mainly  supply  the  elevators,  depres- 
sors, and  circular  muscles  of  the  mouth.  The  branches  of  the  facial 
artery  are  divided  into  two  sets  : — 

Cervical  Branches.  Facial  Bra7iches. 

•  Inferior  or  Ascending  Palatine.  Muscular. 

Tonsillitic.  Inferior  Labial. 

Submaxillary.  Inferior  Coronary. 

Submental.  Superior  Coronary. 

Lateralis  Nasi. 
Angular. 

The  Inferior  Palatine  passes  up  between  the  stylo-glossus  and  stylo- 
pharyngeus  muscle,  which  it  supplies,  to  give  branches  to  the  tonsil, 
Eustachian  tube,  soft  palate  and  palatine  glands,  anastomosing  with 
the  tonsillitic  artery  and  with  a  branch  of  the  internal  maxillary. 

The  Tonsillitic  Artery  is  distributed  to  the  tonsil  and  root  of  the 
tongue. 

The  Submaxillary  supplies  the  submaxillary  gland,  together  with 
the  neighboring  lymphatic  glands,  muscles  and  integuments. 

The  Submental  is  the  largest  of  the  cervical  branches  of  the  facial 


'JO  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

artery;  it  is  given  off  from  it  just  as  it  emerges  from  the  submaxillary 
gland,  and,  passing  along  the  lower  border  of  the  inferior  maxilla, 
is  distributed  to  the  muscles  attached  to  the  jaw,  and  terminates  in 
a  superficial  and  deep  branch  ;  the  former  of  which  is  distributed 
to  the  depressor  labii  inferioris  and  integument,  anastomosing  with 
the  inferior  labial ;  the  latter  is  also  distributed  to  the  lip,  and  anas- 
tomoses with  the  inferior  labial  and  mental  arteries. 

The  Facial  branches  are  distributed  to  the  muscles  of  the  face. 
The  muscular  to  the  pterygoid,  masseter  and  buccinator  muscles. 
The  superior  coronary  to  the  upper  lip,  giving  branches  to  the  sep- 
tum and  ala  nasi.  The  inferior  coronary  passes  to  the  lower  lip,  and 
anastomoses  with  its  fellow  of  the  opposite  side.  The  lateralis  nasi 
supplies  the  wing  and  back  of  the  nose.  The  angular  is  the  terminal 
branch  of  the  facial.  It  supplies  the  cheek,  lachrymal  sac  and  orbi- 
cularis palpebrarum  muscle,  and  terminates  by  anastomosing  with  the 
ophthalmic  by  its  nasal  branch. 

The  AsceJiding  Pharyngeal,  the  smallest  of  the  external  carotid 
branches,  is  given  off  from  the  posterior  part  of  the  external  carotid, 
passes  up  beneath  its  other  branches  and  the  stylo-pharyngeus  muscle 
to  the  base  of  the  skull ;  it  has  three  sets  of  branches — the  external, 
meningeal  and  pharyngeal.  To  the  latter  only  will  attention  be 
directed. 

The  Pharyngeal  branches  are  three  or  four  in  number,  two  of 
which  are  distributed  to  the  middle  and  inferior  constrictors  and 
to  the  stylo-pharyngeus,  and  their  mucous  membrane.  The  largest 
branch  supplies  the  tonsil,  Eustachian  tube  and  soft  palate,  substi- 
tuting the  palatine  branch  of  the  facial  when  it  is  absent  or  of  small 
size. 

The  Temporal  Artery  gives  off  a  transverse  facial  branch  just  before 
it  emerges  from  the  parotid  gland,  which  is  distributed  to  that  gland, 
the  masseter  muscle  and  the  integument,  terminating  by  anastomosis 
with  the  facial  and  infra-orbital  arteries. 

'\!\\&  Internal  Maxillary  Artc7y  covi\u\Q.nz&'i  in  the  substance  of  the 
parotid  gland  ;  then  goes  horizontally  behind  the  neck  of  the  condyle 
of  the  lower  jaw  to  the  pterygoid  muscles,  between  which  it  passes, 
and  then  proceeds  forward  to  the  tuberosity  of  the  superior  maxillary 
bone ;  from  thence  it  takes  a  vertical  direction  upward  between  the 
temporal  and  external  pterygoid  muscles  to  the  zygomatic  fossa,  where 
it  again  becomes  horizontal,  and  finally  ends  in  the  spheno-maxillary 
fossa  by  dividing  into  several  branches. 

The  branches  of  this  artery  which  we  shall  describe  are  the — 

Inferior  Dental.  Alveolar. 

Infra-orbital.  Descending  Palatine. 


THE    ARTERIES    AND    VEINS    OF    THE    MOUTH.  7 1 

The  Inferior  Denial  Artery  er\\.&Vh  the  inferior  dental  foramen  of  the 
lower  jaw,  passes  along  the  dental  canal  beneath  the  roots  of  the 
teeth ;  sending  up,  in  its  course,  a  twig  through  the  aperture  of  each 
to  the  pulp  of  the  teeth,  and  finally  escapes  at  the  mental  foramen  on 
the  chin  ;  a  branch  of  it,  however,  continues  forward  to  supply  the 
incisors.  After  emerging  from  the  mental  foramen,  it  supplies  the 
muscles  and  integument  of  the  chin  and  anastomoses  with  the  inferior 
labial,  submental,  and  inferior  coronary  arteries.  Before  entering  the 
dental  foramen  a  large  branch,  the  mylo-hyoid,  which  lies  in  a  groove 
of  the  same  name  on  the  inner  surface  of  the  maxillary  bone  and  is 
lost  on  the  under  surface  of  the  mylo-hyoid  muscle,  is  given  off. 

The  Alveolar  is  given  off  from  the  internal  maxillary  by  a  trunk 
common  to  it  and  the  infra-orbital,  just  before  it  enters  the  spheno- 
maxillary fossa.  At  the  tuberosity  of  the  superior  maxillary  bone 
it  divides  into  numerous  branches,  some  of  which,  passing  into  the 
alveolar  foramina,  supply  the  bicuspid  and  molar  teeth ;  others 
pierce  the  bone  to  supply  the  antrum,  while  some  are  distributed 
to  the  gums. 

The  Infra-orbital  Artery  Qwi&xs  the  infra-orbital  canal,  traverses  its 
whole  extent,  and  comes  out  at  the  foramen  of  the  same  name,  upon 
the  face  ;  just  before  it  emerges  it  sends  through  the  anterior  dental 
canal  a  twig  for  the  incisors  and  cuspids,  having  previously  given 
branches  to  the  inferior  rectus  and  inferior  oblique  muscles  and  to 
the  lachrymal  gland ;  also  other  branches  to  the  lining  membrane 
of  the  antrum.  After  escaping  from  the  orbit,  it  supplies  the  lach- 
rymal sac  and  neighboring  tissues  and  anastomoses  with  the  facial, 
nasal  branch  of  the  ophthalmic,  and  with  the  transverse  facial  and 
buccal  branch. 

The  Descending  Palatine  passes  along  the  posterior  palatine  canal, 
accompanied  by  palatine  branches  of  Meckel's  ganglion;  emerging 
thence  it  runs  along  a  groove  on  the  inner  border  of  the  alveoli,  and 
is  distributed  to  the  mucous  membrane  of  the  hard  palate,  to  the  gums 
and  the  palatine  glands.  In  the  posterior  palatine  canal  it  gives  ofif 
branches,  which  pass  along  the  accessory  palatine  canal  to  be  dis- 
tributed to  the  soft  palate.  In  front  it  terminates  in  a  small  branch 
which  enters  the  anterior  palatine  canal,  through  which  it  passes  to 
reach  the  septum  naris,  where  it  unites  with  a  branch  of  the  spheno- 
palatine. 

The  Veins  correspond  so  nearly,  both  in  name  and  course,  with  the 
arteries,  that  a  description  of  them  would  only  be  a  repetition  of 
what  has  been  said ;  suffice  it,  therefore,  to  observe  that  there  are  two 
companion  veins  with  every  considerable  artery,  and  that  the  venous 
branches  are  mostly  collected  at  the  angle  of  the  jaw  into  a  common 


72  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

trunk  called  the  external  jugular  vein,  which  passes  down  the  neck  in 
the  course  of  the  fibres  of  the  platysma  muscle,  and  terminates  in  the 
subclavian  vein  at  the  posterior  edge  of  the  sterno-mastoid  muscle. 
The  office  of  the  veins  is  to  return  the  blood  to  the  heart. 


CHAPTER  VI. 
THE  NERVES  OF  THE  MOUTH. 

The  Cranial  Nerves  pass  in  pairs  through  the  foramina  in  the  base 
of  the  skull.  According  to  the  order  of  succession  from  before  back- 
ward, they  are  known  as  the  first,  second,  third,  fourth,  fifth,  sixth, 
seventh,  eighth,  ninth,  tenth,  eleventh,  and  twelfth  pairs. 

The  nerves  supplying  the  mouth  belong  to  the  fifth  pair,  and  the 
portio  dura  of  the  seventh  pair  or  facial  nerve. 

The  Fifth  (Trigemini)  is  the  largest  of  the  cranial  nerves,  and 
gives  sensibility  to  all  the  organs  concerned  in  the  primary  stages  of 
digestion. 

This  nerve  will  also  be  found  to  be  a  compound  nerve,  having 
motor  filaments  as  well  as  sensitive,  and  thereby  giving  motion  as 
well  as  sensation.     It  is  also  a  nerve  of  special  sense. 

It  is  first  seen  at  the  side  of  the  pons  Varolii  near  its  junction  with 
the  crura-cerebelli,  but  its  origin  is  much  deeper  and  further  back. 
It  arises  by  two  unequal  roots,  one  of  which  may  be  traced  through 
the  pons  Varolii  into  the  lateral  tract  behind  the  olivary  body ;  the 
smaller,  or  motor  root,  is  lost  in  the  medulla  oblongata.  From  its 
origins  this  nerve  has  been  called  a  cranial-spinal  nerve. 

These  two  fasciculi,  the  one  anterior  and  the  other  posterior,  con- 
stitute the  fifth  nerve,  which  consists  of  eighty  or  one  hundred 
filaments  that  pass  forward  and  outward,  in  a  canal  formed  of  dura 
mater,  to  a  depression  on  the  anterior  surface  of  the  petrous  bone. 

At  this  })oint  it  spreads  into  a  ganglion,  called  the  Gasserian  gang- 
lion, on  the  under  surface  of  which  is  seen  the  anterior  root  \  but  it 
has  no  intimate  connection  with  the  ganglion,  and  can  be  traced  on, 
as  will  be  presently  shown,  to  the  inferior  maxillary  nerve. 

The  Gasserian  ganglion  receives  filaments  from  the  carotid  plexus 
of  the  sympathetic,  and  gives  off  several  minute  branches  to  the  dura 
mater  and  tentorium  cerebelli.  Three  large  branches  are  given  off 
from  its  anterior  border,  the  ophthalmic  and  superior  and  inferior 
maxillary.  The  ophthalmic  and  superior  maxillary  are  exclusively 
nerves  of  sensation,  their  fibres  being  derived  entirely  from  the  pos- 


THE  NERVES  OF  THE  MOUTH. 


73 


terior  or  sensory  root,  whilst  the  inferior  maxillary  receives  fibres  from 
both  roots,  and  is  consequently  more  variously  endowed. 

The  Ophthalmic  Nen>e  is  a  short  trunk  that  enters  the  orbit  through 
the  foramen  lacerum  superius.  It  supplies  the  eyeball,  the  mucous  mem- 
brane of  the  eye  and  nose,  and  the  lachrymal  gland,  also  the  muscles 
and  integument  of  the  eyebrow  and  forehead.     It  is  a  sensitive  nerve ; 


Olfactory  bulb, 


Optic  nerve 

Third  nerve, 

Fourth  nerve,  .... 
Fifth  nerve, 

Sixth  nerve 

Seventh  nerve,  .  .  .  ) 
Eighth  nerve,     ...  J 

Twelfth  nerve,   .... 

Ninth  nerve,  .  .  .  .  I 
Tenth  nerve,  ....-< 
Eleventh  nerve,     .  .   (. 


Fig.  33.— Diagram  of  the  Exit  of  the  Cranial  Nerves. 


is  the  first  given  off  from  the  Gasserian  ganglion,  and  is  the  smallest 
of  the  three  branches.  It  receives  a  few  filaments  from  the  cavernous 
plexus  of  the  sympathetic,  and  divides  into  three  principal  branches — 

1.  The  Frontal, 

2.  The  Lachrymal,  and 

3.  The  Nasal. 


74 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


The  Frontal,  which  is  the  largest  branch  of  the  ophthalmic,  passes 
along  the  roof  of  the  orbit  to  the  supra-orbital  foramen,  through 
which  it  passes,  and  is  then  called  the  supra-orbital  nerve,  and  is  spent 
on  the  muscles  and  integuments  of  the  forehead.  It  gives  off  several 
branches  in  its  course. 

The  Lachrymal,  the  smallest  branch  of  the  ophthalmic,  generally 
arises  by  two  branches,  one  from  the  fourth  nerve  and  the  other 
from   the   ophthalmic.     It   enters  the    orbit  through   the  sphenoidal 


SENSOflY  ROOT 
MOTOR    ROOT 


AUmCULO  TtMPORM  N. 


Fig.  34. 

fissure,  receives  a  communicating  branch  from  the  superior  maxil- 
lary, and  is  finally  distributed  to  the  lachrymal  gland,  taking  the 
outward  direction,  and  sending  branches  in  its  course  to  the  upper 
eyelid,  conjunctiva,  and  other  parts,  receiving  on  the  eyelid  branches 
from  the  facial. 

The  Nasal  takes  its  direction  along  the  inner  side  of  the  orbit  to 
the  anterior  ethmoidal  foramen,  through  which  it  passes  into  the 
cranium,  on  the  upper  surface  of  the  cribriform  plate  of  the  ethmoidal 


THE    NERVES    OF    THE    MOUTH.  75 

bone ;  descends  by  the  side  of  the  crista-galli  through  a  slit-like 
opening  into  the  nose,  and  there  terminates  by  filaments  which  are 
spent  upon  the  septum,  mucous  membrane,  anterior  nares,  etc.  It 
sends  off  several  branches  in  its  course ;  one  in  particular  to  the 
lenticular  ganglion  at  the  bottom  of  the  eye,  others  to  the  caruncula 
lachrymalis,  lachrymal  sac,  conjunctiva,  etc.;  but  as  these  do  not 
belong  to  the  mouth  and  dental  apparatus,  we  will  pass  to  the  second 
great  division  of  the  fifth. 

TAe  Superior  Maxillary  Nerve. — This  nerve  proceeds  from  the 
middle  of  the  Gasserian  ganglion,  passes  through  the  foramen  rotun- 
dum  of  the  sphenoid  bone  into  the  pterygo-maxillary  fossa ;  here 
it  enters  the  canal  of  the  floor  of  the  orbit— the  infra-orbital  canal — 
traverses  its  whole  extent,  and  emerges  on  the  face  at  the  infra- 
orbital foramen,  where  it  terminates  in  numerous  filaments  in  the 
muscles  and  integuments  of  the  upper  lip,  cheek,  lower  eyelid  and 
side  of  the  nose. 

The  superior  maxillary  nerve  supplies  the  upper  jaw,  and  gives  off 
many  important  branches,  which  are  as  follows  :  — 

In  the  pterygo-maxillary  fossa  two  branches  descend  to  a  small 
reddish  body  called  the  ganglion  of  Meckel,  or  the  spheno-palatine 
ganglion,  situated  on  the  outer  side  of  the  nasal  or  vertical  plate  of 
the  palate  bone. 

From  this  ganglion  proceed  three  sets  of  branches  :  — 

1.  Inferior,  Descending  or  Palatine  Nerves. 

2.  Nasal  or  Spheno-palatine. 

3.  Posterior,  Pterygoid  or  Vidian. 

The  Palatine  Nerves  descend  through  the  posterior  palatine  canal, 
come  out  at  the  posterior  palatine  foramen,  along  with  an  artery  of 
the  same  name,  and  supply  with  filaments  the  soft  palate,  uvula, 
tonsils,  the  roof  of  the  mouth,  and  the  inner  alveoli  and  gums. 

The  Nasal  Nerves  enter  the  nose  through  the  spheno-palatine 
foramen,  and  divide  into  several  filaments,  which  enter  the  mucous 
membrane  covering  the  upper  and  lower  turbinated  bones  and 
vomer;  one  long  branch  can  be  traced  along  the  septum  nasi,  as  far 
as  the  foramen  incisivum,  where  it  meets  the  anterior  palatine  branches 
in  a  ganglion  called  the  naso-palatine. 

The  Vidian,  or  Pterygoid,  passes  backward  from  the  ganglion  of 
Meckel  through  the  pterygoid  canal  at  the  root  of  the  pterygoid  pro- 
cess ;  then  enters  the  cranium  through  the  foramen  lacerum  anterius, 
and  divides  into  two  branches,  one  of  which  enters  the  carotid  canal 
and  unites  with  the  sympathetic  branches  of  the  superior  cer- 
vical ganglion,  thus  connecting  this  ganglion  with  the  ganglion  of 
Meckel. 


76  PRINCIPLES    AND    PRACTICE    OF   DENTISTRY. 

The  other,  the  proper  vidian  nerve,  enters  the  vidian  foramen  or 
hiatus  Fallopii  in  the  petrous  bone,  joins  the  portio  dura  nerve, 
accompanies  this  as  far  as  the  back  part  of  the  tympanum ;  then 
leaves  it,  enters  the  cavity  of  the  tympanum,  and  receives  there  the 
name  of  Chorda  Tympani.  It  leaves  this  cavity  by  the  glenoid 
fissure,  then  joins  the  gustatory  nerve,  continues  with  it  to  the 
submaxillary  gland,  where  it  leaves  it,  and  is  lost  in  the  submax- 
illary ganglion,  situated  at  the  posterior  part  of  the  submaxillary 
gland. 

The  exceedingly  intricate  course  of  the  vidian  nerve  is  interesting 
from  the  number  of  communications  which  it  establishes  between 
different  and  distant  parts  ;  for  it  unites  the  ganglion  of  Meckel  with 
the  superior  cervical  ganglion  of  the  sympathetic,  and  both  with  the 
submaxillary  ganglion  ;  it  also  connects  the  superior  and  inferior 
maxillary  nerves  to  one  another  and  to  the  portio  dura. 

The  Superior  Maxillary  Nerve  gives  off  next  in  the  spheno-maxillary 
fossa — 

1.  The  Orbital. 

2.  The  Posterior  Dental. 

3.  The  Anterior  Dental. 

The  Orbital  enters  the  orbit  through  the  spheno-maxillary  fissure, 
and  then  sends  off  a  malar  and  temporal  branch,  which  pass  out 
through  the  malar  bone  ;  the  first  supplying  the  cheek,  the  latter 
accompanying  the  temporal  artery  to  the  integuments  of  the  side  of 
the  head,  receiving  filaments  from  the  facial  and  auriculo-temporal 
branch  of  the  inferior  maxillary. 

The  Posterior  Dental  Nerves,  two  in  number,  descend  on  the  tuber- 
osity of  the  superior  maxillary  bone,  and  enter  the  posterior  dental 
canals  to  supply  the  bicuspid  and  molar  teeth  ;  one  branch  penetrates 
the  antrum  and  courses  along  the  outer  wall,  anastomosing  with  the 
anterior  dental  nerves,  while  another  runs  along  the  alveolar  border, 
supplying  the  gums. 

The  Anterior  Dental  \%  given  off  from  the  superior  maxillary,  just 
before  it  escapes  from  the  infra-orbital  foramen.  It  anastomoses  with 
the  posterior  dental,  and  sends  filaments  to  the  incisor,  canine,  and 
first  bicuspid  teeth  ;  others  are  sent  to  the  mucous  membrane  of  the 
inferior  meatus. 

This  nerve  now  emerges,  as  before  mentioned,  at  the  infra-orbital 
foramen,  between  the  levator  labii  superioris  alaeque  nasi  and  levator 
anguli  muscles,  dividing  here  into  many  branches,  some  of  which 
ascend  to  the  nose  and  eyelids,  others  pass  downward  and  outward  to 
the  lip  and  cheek,  anastomosing  with  the  nasal  branch  of  the  ophthal- 
mic and  the  facial  branches  of  the  portio  dura. 


THE  NERVES  OF  THE  MOUTH.  77 

Inferior  Maxillary  Nerve. — This  nerve  forms  the  third  great  division 
of  the  fifth.  It  is  the  largest  branch,  and  passes  from  the  ganglion  of 
Gasser,  through  the  foramen  ovale  of  the  sphenoid  bone,  to  the  zygo- 
matic fossa. 

This  nerve,  as  stated,  is  attached  to  the  anterior  or  motor  root, 
and  they  come  together  on  the  outside  of  the  foramen  ovale  ;  then  in 
the  zygomatic  fossa,  the  inferior  maxillary  nerve  divides  into  two 
branches :  — 

1.  Anterior. 

2.  Posterior. 

The  Anterior  is  the  motor  branch,  and  gives  off  the  following  fila- 
ments to  the  several  muscles : — 

1.  Masseteric,    crossing    the    sigmoid    notch    to    the    masseter 

muscle. 

2.  Temporal,  anterior  and  posterior  deep,  to  the  temporal  muscle 

and  fascia. 

3.  Buccal,   to  the  buccinator,  external  pterygoid,  and  temporal 

muscles. 

4.  Pterygoid,  to  the  pterygoid  muscles. 

The  Internal d\v\%\ovi  of  the  inferior  maxillary  nerve  consists  of  three 
branches,  all  of  which  are  sensitive  ;  they  are  : — 

1.  The  Anterior  Auricular. 

2.  The  Gustatory. 

3.  The  Inferior  Dental. 

The  Anterior  Auricular  passes  behind  the  neck  of  the  lower  jaw  and 
in  front  of  the  meatus  of  the  ear,  and  ascends  through  the  parotid 
gland,  over  the  zygoma,  along  with  the  temporal  artery,  and  divides 
into  anterior  and  posterior  branches. 

In  its  course  it  unites  with  the  facial  nerve,  and  supplies  the  parotid 
gland,  the  articulation  of  the  lower  jaw,  the  meatus,  and  cartilages  of 
the  ear  and  side  of  the  head. 

The  Gustatory  JVen>e,  the  nerve  of  the  special  sense  of  taste,  imme- 
diately after  its  origin  sends  a  branch  to  the  inferior  dental ;  it  then 
descends  between  the  pterygoid  muscles,  where  the  chorda  tympani 
joins  it ;  it  now  passes  along  the  ramus  of  the  lower  jaw,  covered  by 
the  internal  pterygoid  muscle,  then  above  the  submaxillary  glands, 
and  forward  above  the  mylo-hyoid  and  between  it  and  the  hyo-glossus 
muscles,  accompanied  by  the  duct  of  Wharton  ;  and  finally  ascends 
above  the  sublingual  gland  to  the  lateral,  inferior,  and  anterior  parts 
of  the  tongue. 

In  its  course,  the  following  branches  are  given  off  by  this  nerve  ; — 

"  First,  one  or  two  small  filaments  to  the  internal  pterygoid  muscle. 
Second,  several  to  the  tonsils,  to  the  muscles  of  the   palate,  to  the 


^8  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

upper  part  of  the  pharynx,  and  to  the  mucous  membrane  of  the  gums. 
Third,  the  chorda  tympani,  and  some  accompanying  filaments  to  form 
a  plexus,  which  supplies  the  submaxillary  gland.  Fourth,  a  few 
branches  which  descend  along  the  hyo-glossus  muscle  to  communicate 
with  the  ninth  or  lingual  nerve.  Fifth,  a  fasciculus  of  nerves  to  the 
sublingual  gland  and  to  the  surrounding  mucous  membrane.  Lastly, 
at  the  tongue  it  divides  into  several  branches  ;  some  pass  deep  into  the 
tissue  of  this  organ ;  others,  firm  and  soft,  rise  toward  its  surface,  and 
are  lost  in  the  mucous  membrane  and  in  a  small  conical  papilla  near 
its  tip." 

The  Inferior  Dental  Nerve  passes  between  the  pterygoid  muscles, 
then  along  the  ramus  of  the  lower  jaw  under  the  pterygoideus  internus 
to  the  inferior  dental  foramen,  which  it  enters  along  with  an  artery  and 
vein  ;  it  now  traverses  the  inferior  dental  canal,  sending  twigs  into  all 
the  roots  of  the  molars  and  bicuspids.  Opposite  the  mental  foramen 
it  divides  into  two  branches ;  the  smaller  is  continued  forward  in  the 
substance  of  the  jaw  to  supply  the  roots  of  the  cuspids  and  incisors; 
while  the  larger  comes  out  at  the  mental  foramen,  is  distributed  to  the 
muscles  and  integuments  of  the  lower  lip,  and  finally  communicates 
with  the  facial  nerve. 

The  inferior  dental,  just  as  it  enters  the  posterior  dental  foramen, 
gives  off  the  jfiylo  hyoid  nerve ;  this  passes  forward  in  a  groove  of  the 
lower  jaw,  and  supplies  the  mylo-hyoid  and  digastric  muscles,  and 
occasionally  the  submaxillary  gland. 

The  Facial  Nerve. — The  seventh  or  facial  nerve  {portio  dura)  is 
the  last  nerve  to  be  noticed  as  particularly  belonging  to  the  mouth. 

This  nerve  arises  from  the  medulla  oblongata  between  the  olivary 
and  restiform  bodies,  close  behind  the  lower  margin  of  the  pons 
Varolii ;  it  then  passes  forward  and  outward  with  the  portio  mollis  to 
the  foramen  auditorium  internum,  which  it  enters  and  passes  on  to 
the  base  of  this  opening ;  here  these  two  nerves  separate,  the  portio 
mollis  going  to  the  labyrinth  of  the  ear,  while  the  facial  enters  the 
aqueduct  of  Fallopius,  in  which  it  is  joined  by  the  vidian.  Within 
the  aqueductus  Fallopii  it  gives  off  two  branches — the  tympanic  and 
chorda  tympani.  The  former  supplies  the  stapedius  muscle.  The 
latter  passes  along  a  distinct  canal  and  enters  the  cavity  of  the  tym- 
panum near  the  attachment  of  the  membrana  tympani,  where  it  is 
covered  by  mucous  membrane.  It  escapes  from  this  cavity  by  the 
inner  side  of  the  Glaserian  fissure;  after  receiving  a  communicating 
branch  from  the  gustatory  nerve  it  passes  to  the  submaxillary  gland, 
then  joining  the  submaxillary  ganglion  it  is  lost  in  the  lingual  muscle. 
The  facial  then  goes  in  a  curved  direction  outward  and  backward 
behind  the  tympanum,  where  it  parts  with  the  vidian,  and  proceeds  on 


THE  NERVES  OF  THE  MOUTH. 


79 


to  the  stylo-mastoid  foramen,  from  which  it  emerges.     At  this  point 
it  sends  off  three  small  branches:  — 

1.  The  Posterior  Auricular, 

2.  The  Stylo-hyoid,  and 

3.  The  Digastric. 


Fig.  35- 


The  Posterior  Auricular  ascends  behind  the  ear,  crosses  the  mastoid 
process,  where  it  receives  branches  from  the  pneumogastric,  and  the 
auricularis  magnus ;  it  then  divides  into  two  branches,  one  of  which 
passes  to  the  retrahens  aurem,  the  other  to  the  occipito-frontalis 
muscle. 


8o  PRINCIPLES    AND    PRACTICE    OF   DENTISTRY. 

The  Stylo-hyoid  is  distributed  to  the  stylo-hyoid  muscle.  It  com- 
municates with  filaments  of  the  sympathetic  sent  to  the  carotid 
artery. 

The  Digastric  is  distributed  to  the  posterior  belly  of  the  digastric 
muscle,  receiving  a  communicating  branch  from  the  glosso-pharyn- 
geal. 

The  facial  nerve,  while  deeply  imbedded  in  the  substance  of  the 
parotid  gland,  divides  into  two  sets  of  branches,  of  which  one  is 
superior  and  the  other  inferior ;  these  two,  by  frequent  unions,  form 
the/(?j-  anserinus  ox  parotidean  plexus,  and  send  branches  to  the  whole 
of  the  side  of  the  face. 

The  upper  division,  called  the  temporo-facial,  ascends  in  front  of 
the  ear  upon  the  zygoma,  accompanies  the  temporal  artery,  and  its 
branches,  supplying  the  side  of  the  head,  ear,  and  forehead,  and 
anastomosing  with  the  occipital  and  supra-orbital  nerves ;  a  set  of 
branches  pass  transversely  to  the  cheek,  furnishing  the  lower  eye- 
lid, lips,  and  side  of  the  nose,  and  uniting  with  the  infra-orbital 
nerve. 

The  inferior  or  cervico-facial  division  descends,  supplying  the 
lower  jaw  and  upper  part  of  the  neck,  giving  off  the  following 
branches  :  — 

1.  Buccal. 

2.  Inferior  Maxillary,  and 

3.  Cervical. 

The  Buccal,  or  superior  branches,  supply  the  muscles  of  the  cheek, 
nose,  and  upper  lip. 

The  Inferior  Maxillary  nerves  are  distributed  in  the  muscles  of  the 
chin  and  lower  lip,  and  •  by  means  of  anastomotic  branches  commu- 
nicate with  the  inferior  dental  nerve. 

The  Cervical  branches  form  a  close  connection  with  the  superior 
cervical  nerves,  and  supply  the  platysma  myoid  and  the  levator  labii 
superioris  muscles. 

The  facial  is  the  motor  nerve  of  the  face,  and  by  its  means  the 
passions  or  emotions  find  their  expression  in  the  peculiar  action  of 
the  muscles  to  which  it  is  distributed. 

In  consequence  of  the  numerous  communications  which  this  nerve 
has  Avith  other  nerves,  the  name  of  Sympatheticus  Minor  has  been  given 
to  it  by  some  anatomists 


SALIVARY    GLANDS    AND    SALIVA. 


8i 


Mr.  Gray  furnishes  the  following  concise  statement  of  these  com- 
munications :  — 


In  the  internal  auditory  meatus,  .    . 


In  the  aqueductus  Fallopii, 


At  its  exit  from  the  stylo-mastoid 
foramen, 


On  the  face, 


With  the  auditory  nerve. 
With   Meckel's   ganglion   by  the  large 
petrosal  nerve. 

With  the  optic  ganglion  by  the  smaller 
petrosal  nerve. 

With  the  sympathetic  on  the  middle 
meningeal  by  the  external  superficial 
petrosal  nerve. 

With  the  pneumogastric. 
"      "    glosso-pharyngeal. 
"      "    carotid  plexus. 
"      "    auricularis  magnus. 
"      "    auriculo-temporal. 
With  the  three  divisions  of  the  fifth. 


CHAPTER  VII. 
SALIVARY  GLANDS  AND  SALIVA. 

The  Salivary  Glands  are  six  in  number,  three  on  each  side  of  the 
face,  named  the  Parotid,  Submaxillary  and  Sublingual. 

These  glands  are  the  prime  organs  in  furnishing  the  salivary  fluids 
to  the  mouth  during  the  process  of  mastication. 

The  Parotid  Gland  (Fig.  36),  so  called  from  its  situation  near  the 
ear,  is  the  largest  of  the  salivary  glands.  Its  form  is  very  irregular ; 
it  fills  the  space  lying  between  the  ramus  of  the  inferior  maxilla  and 
mastoid  process  of  the  temporal  bone,  as  far  back  as,  and  even  behind, 
the  styloid  process  of  the  same  bone.  Its  extent  of  surface  is  from  the 
zygoma  above  to  the  angle  of  the  lower  jaw  below,  and  from  the  mas- 
toid process  and  meatus  behind  to  the  masseter  muscle  in  front,  over- 
lapping its  posterior  portion.  It  weighs  between  five  and  eight 
drams,  and  is  separated  from  the  submaxillary  gland  by  the  stylo- 
maxillary  ligament ;  but  sometimes  the  two  glands  are  continuous. 

This  gland  is  one  of  the  conglomerate  order,  and  consists  of  num- 
erous small  lobes  connected  together  by  cellular  tissue,  each  of  which 
may  be  considered  a  small  gland  in  miniature,  as  each  is  supplied  with 
an  artery,  vein  and  excretory  duct. 

This  gland  thus  formed  presents  on  its  external  surface  a  pale,  flat 
and  somewhat  convex  appearance. 

It  is  covered  by  a  dense,  strong  fascia,  extending  from  the  neck,  and 
6 


82 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


attached  to  the  meatus  externus  of  the  ear,  which  sends  countless  pro- 
cesses into  every  part  of  the  gland,  separating  its  lobules  and  conduct- 
ing the  vessels  through  its  substance. 

The  use  of  this  gland  is  to  secrete  ot  separate  from  the  blood  the 
greater  part  of  the  saliva  furnished  to  the  mouth.  As  the  parotid  is, 
however,  on  the  outside,  and  at  some  little  distance  from  the  mouth, 
it  is  furnished  with  a  duct  to  convey  its  fluid  into  this  cavity;  this 
duct  is  called  the  duct  of  Steno,  or  the  parotid  duct.     It  is  formed  of 


Fig.  36. 


the  excretory  ducts  of  all  the  granules  composing  this  gland,  which, 
successively  uniting  together,  at  last  form  one  common  duct. 

The  duct  of  Steno  commences  at  the  anterior  part  of  the  gland  and 
passes  over  the  masseter  muscle,  on  a  line  drawn  from  the  lobe  of  the 
ear  to  the  middle  part  of  the  upper  lip  ;  then  passes  through  a  quantity 
of  soft  adipose  matter,  and  finally  enters  the  mouth  by  passing  through 
the  buccinator  muscle  and  mucous  membrane,  opposite  the  second 
molar  of  the  upper  jaw. 

The  diameter  of  this  duct  is  about  that  of  a  crow-quill,  but  its  orifice 
is  small  and  contracted,  and  is  concealed  by  a  fold  of  mucous  mem- 


COMPOSITION    OF    HUMAN    PAROTID    SALIVA.  83 

brane.  It  is  thick  and  strong,  and  is  more  exposed  to  injury  than  the 
duct  of  the  submaxillary  gland. 

The  arteries  supplying  the  parotid  gland  are  from  the  external 
carotid  or  some  of  its  branches. 

The  nerves  are  derived  from  the  carotid  plexus  of  the  sympathetic, 
and  from  the  facial,  temporal,  and  great  auricular. 

The  parotid  secretion  is  a  clear,  watery,  alkaline  liquid,  which  is 
poured  out  abundantly  during  mastication,  but  in  very  small  quantity 
when  the  mouth  is  at  rest.  Its  secretion  may  also  be  excited  by  men- 
tal emotion,  as  when  observing  a  savory  article  of  food,  or  by  artificial 
stimuli,  as  of  glass  beads  or  other  irritants  in  the  mouth. 

The  following  analysis  is  taken  from  Dalton's  Physiology  : — 

COMPOSITION    OF    HUMAN    PAROTID   SALIVA. 

Water, 983.308 

Organic  Matter  precipitable  by  alcohol, 7-352 

Substance  destructible  by  heat,  but  not  precipitated  by  alcohol  or  acids,  .    .  4.810. 

Sulpho-cyanide  of  Sodium, ^0.330 

Phosphate  of  Lime, 0.240 

Chloride  of  Potassium, 0.900 

Chloride  of  Sodium  and  Carbonate  of  Soda, 3.060 

Total, looo.ooo 

It  will  be  seen  that  the  quantity  of  organic  matter  is  comparatively 
large. 

Observation  has  shown  that  this  secretion  is  unilateral,  the  saliva 
flowing  only  from  that  side  on  which  mastication  is  then  being  con- 
ducted, and  that  the  quantity  is  directly  related  to  the  physical  char- 
acter of  the  food,  and  not  to  its  chemical  constitution,  being  more  or 
less  abundant,  according  to  the  dryness  of  the  food. 

The  Submaxillary  is  the  next  in  size  of  the  salivary  glands.  It  is 
situated  under  and  along  the  inferior  edge  of  the  body  of  the  lower 
jaw,  and  is  separated  from  the  parotid  by  the  stylo-maxillary  ligament. 

The  submaxillary  gland  is  partially  concealed  by  the  jaw  when  the 
head  is  in  the  natural  position,  and  weighs  about  two  drams.  It  is 
divided  into  several  lobes,  and  the  facial  artery  occupies  a  groove  on 
its  deeper  surface,  and  also  upon  its  upper  border. 

It  is  of  oval  form,  pale  color,  and,  like  the  parotid,  consists  in  its 
structure  of  small  lobules,  held  together  by  cellular  tissue  ;  each  having 
a  small  excretory  duct,  which,  successively  uniting  with  one  another, 
finally  form  one  common  duct.  This,  the  duct  of  Wharton,  passes 
above  the  mylo-hyoid  muscle,  and  running  forward  and  inward,  enters 
the  mouth  below  the  tip  of  the  tongue  at  a  papilla  seen  on  either  side 
of  the  frenum  linguae. 


84  PRINCIPLES    AND    PRACTICE    OF    DENTISTKY. 

The  use  of  this  gland  is  the  same  as  the  parotid,  to  secrete  a  fluid 
constituent  of  the  saliva,  and  its  duct  is  the  route  by  which  it  is 
conducted  into  the  mouth.  Its  arteries  are  derived  from  the  facial 
and  lingual.  The  veins  correspond.  Its  nerves  are  received  from  the 
submaxillary  ganglion,  the  inferior  dental  and  sympathetic  nerves. 

The  Sublingual  Glands  are  the  last  in  order  of  the  salivary  glands, 
and  the  smallest  in  size. 

They  are  situated  beneath  the  anterior  and  lateral  parts  of  the 
tongue,  are  covered  by  the  mucous  membrane,  and  rest  upon  the 
mylo-hyoid  muscle.  Each  sublingual  gland  is  oblong  in  shape  and 
weighs  about  one  dram. 

The  Sublingual  Glands,  like  the  two  glands  just  described,  consist 
of  a  lobular  structure  with  excretory  ducts ;  which,  however,  do  not 
unite  into  one  common  duct,  but  enter  the  cavity  of  the  mouth  by 
many  ducts  (ducts  of  Rivinius),  from  eight  to  twenty  in  number,  whose 
openings  are  through  the  mucous  membrane  between  the  tongue  and 
the  inferior  cuspid  and  bicuspid  teeth. 

These  ducts  terminate  by  minute  openings  behind  the  orifice  of  the 
submaxillary  duct  along  the  ridge  upon  the  floor  of  the  mouth.  One 
or  more  of  these  ducts  enter  the  submaxillary  duct,  and  one  is  known 
by  the  name  of  the  duct  of  Bartholin. 

Their  office  is  the  same  as  the  parotid  and  submaxillary.  Their 
arteries  are  derived  from  the  sublingual  and  submental.  Their  nerves 
from  the  gustatory;  salivary  glands  are  found  in  all  vertebrate  animals 
except  fishes. 

The  Saliva,  or  oral  fluid,  consists  of  the  commingled  secretion  of  all 
these  glands.  It  is  a  glairy,  slightly  opalescent,  alkaline  fluid,  con- 
sisting of  organic  and  mineral  substances  held  in  solution  with  water. 
Its  composition,  according  to  Bidder  and  Schmidt,  is  as  follows:  — 

COMPOSITION    OF    THE    ORAL    FLUID. 

Water, 995-i6 

Organic  Matter, •  1. 34 

Sulplio-cyanide  of  Potassium, 0.06 

Phosphate  of  Soda,  Lime,  and  Magnesia, .98 

Chlorides  of  Sodium  and  Potassium, .84 

Mixture  of  Epithelium, 1.62 

1000.00 

Two  kinds  of  organic  matter  exist  in  the  saliva;  the  first,  which  is 
found  in  the  submaxillary  and  sublingual  secretions,  is  csW^d  pty  a  line  ; 
to  it  the  saliva  owes  its  viscidity.  Alcohol  coagulates  it,  but  heat  does 
not,  differing,  in  this  respect,  from  the  organic  matter  derived  from 
the  parotid  gland,  which  is  coagulated  by  heat  and  is  not  viscid. 


COMPOSITION    OF    THE    ORAL    FLUID.  85 

Sulpho-cyanogen,  the  only  mineral  ingredient  that  is  peculiar  to 
saliva,  is  detected  by  a  solution  of  the  chloride  of  iron,  with  which  it 
strikes  a  red  color  characteristic  of  it. 

When  saliva  has  stood  for  some  time  it  deposits  a  whitish  flocculent 
sediment,  which  is  found  under  the  microscope  to  consist  of  epithe- 
lium scales,  and  other  nucleated  cells,  granular  matter,  and  oil  globules. 
Although  saliva  possesses  the  power  to  change  the  starchy  matter  of 
the  food  into  sugar,  yet  in  view  of  the  facts  that  this  change  is  inter- 
rupted by  the  gastric  juice  with  which  it  is  so  soon  to  come  in  contact, 
and  that  the  quantity  secreted  is  directly  related  to  the  physical 
characteristics  of  the  food,  and  not  to  its  chemical  constitution,  not 
being  more  abundant  during  the  mastication  of  starchy  food,  except 
it  be  ^dry,  than  of  any  other  aliment,  and,  furthermore,  since  the 
conversion  of  starch  into  sugar  is  otherwise  provided  for,  it  may  be 
considered  an  established  fact  that  its  only  purpose  is  to  aid  mechan- 
ically in  mastication  and  deglutition  by  moistening  and  lubricating 
the  food.  The  quantity  of  saliva  secreted  daily  has  been  variously 
estimated  by  different  observers.  Mitscherlich  thought  it  about  four- 
teen ounces  daily,  and  Todd  and  Bowman  consider  his  estimate  reli- 
able. Bidder  and  Schmidt  estimated  it  at  about  three  and  a  half 
pounds  avoirdupois,  and  Mr.  Dalton  at  "  rather  less  than  three  pounds 
avoirdupois,"  which  is  probably  very  nearly  correct. 

The  Mucous  Glands. — Besides  the  glands  furnishing  the  saliva, 
there  is  another  series  of  much  smaller  size,  called  the  mucous  glands. 
They  are  simply  the  little  crypts,  follicles,  or  depressions  every- 
where found  in  the  mucous  membrane  of  the  mouth,  and  named, 
according  to  their  situation,  the  glandulae  labiales,  glandulae  buc- 
cales,  etc.  The  lips,  cheeks,  and  palate  are  also  furnished  with 
glands  about  the  size  of  a  small  pea,  which  present  the  true  salivary 
structure. 

The  use  of  these  glands  is  to  furnish  the  mucus  of  the  mouth, 
which  they  pour  into  this  cavity  by  single  orifices,  opening  everywhere 
on  its  surface. 

The  Buccal  Glands  in  structure  resemble  the  salivary,  and  also  the 
labial  found  beneath  the  mucous  membrane  of  the  lips,  though  some- 
what smaller  than  the  latter.  The  buccal  glands  are  situated  between 
the  buccinator  muscle  and  the  mucous  membrane. 

The  Molar  Glands,  three  or  four  in  number,  are  situated  between 
the  masseter  and  buccinator  muscles,  and  their  secretion,  which  is 
mucous,  is  conveyed  to  the  mouth  by  ducts  which  open  near  the  third 
molar  teeth. 


86  PRINCIPLES    AND    PRACTICE    OF   DENTISTRY. 

CHAPTER  VIII. 

THE  TONGUE. 

The  Tongue  is  a  very  complicated  organ  ;  it  consists  of  a  great 
variety  of  parts,  and  performs  a  great  variety  of  functions;  it  is  one 
of  the  organs  of  deglutition  ;  a  glandular  organ,  to  secrete  ;  a  sentient 
organ,  to  feel  and  taste ;  and  likewise  an  intellectual  organ,  to  assist 
in  producing  speech. 


Fig.  37. — "Upper  Surface  of  the  Tonguk"  with  the  Fauces  and  Tonsils. 
I.  Papillae  circumvallatse.     2.  Papillae  fungiformes. 

The  tongue  is  divided  into  apex,  body,  and  root;  the  apex  is  the 
anterior  free  and  sharp  portion  ;  the  root,  which  is  thin,  is  attached  to 
the  OS  hyoides  and  is  posterior;  while  the  body,  which  occupies  the 
center,  is  thick  and  broad  ;  it  is  confined  in  its  situation  by  the  origin 
of  its  component  muscles  and  by  reflections  of  the  mucous  membrane. 

The  mucous  membrane  of  the  tongue  covers  its  free  surface  every- 
where ;  it  is  thinnest  on  its  under  surface,  where  it  maybe  traced 
along  the  ducts  of  the  submaxillary  and  sublingual  glands.  Passing 
over  the  dorsum,  it  assumes  a  ])apillary  character,  and  becomes  much 
thickened. 

The  papillae  of  the  tongue  are  the  papillae  circumvallatae,  papillae 
fungiformes,  and  papillae  filiformes. 

The  papillae  circumvallatae  (maximae)  are  situated  on  each  side  of 
the  back  part  of  the  tongue,  meeting  at  the  foramen  caecum  so  as  to 
form  a  triangular  figure.     They  number  from  eight  to  fifteen. 


THE    MUCOUS    MEMBRANE    LINING    THE    MOUTH.  Sy 

Each  papilla  is  arranged  in  the  form  of  an  inverted  cone,  with  its 
apex  received  into  a  depression  of  mucous  membrane,  and  its  base  ex- 
posed on  the  free  surface,  and  upon  it  may  be  seen  numerous  smaller 
papillae. 

The  papilla  fungiformes  are  scattered  irregularly  over  the  surface  of 
the  tongue,  but  are  most  numerous  at  its  sides  and  apex.  They  also 
are  studded  on  their  free  surface  with  smaller  papillae. 

The  papillae  filiformes  are  found  on  the  anterior  two-thirds  of  the 
tongue,  and  are  very  minute.  They  are  somewhat  conical  or  filiform 
in  shape,  are  covered  with  an  unusually  dense  epithelium,  which  gives 
them  a  whitish  appearance,  and  are  filled  with  secondary  papillae. 
Small  hairs  are  often  found  in  them. 

Structure  of  the  Papillce. — They  consist  of  papillary  loops,  through 
which  nerves  are  abundantly  distributed,  covered  by  a  homogeneous 
tissue,  upon  which  is  superposed  a  thick  layer  of  squamous  epithelium. 

The  nerves  are  large  and  numerous  in  the  papillae  circumvallatae ;  in 
the  papillae  fungiformes  and  papillae  filiformes  they  are  smaller. 

In  the  mucous  membrane  are  also  found  follicles  or  glands.  The 
former  are  very  numerous,  especially  so  between  the  circumvallate 
papillae  and  the  epiglottis,  but  are  found  scattered  over  the  entire  sur- 
face of  the  tongue.  The  latter,  called  mucous  or  lingual  glands,  are 
most  abundant  on  the  posterior  third  of  the  tongue,  but  are  found  also 
on  its  tip,  sides,  and  in  the  neighborhood  of  the  circumvallate  papillae. 
The  ducts  open  on  the  free  surface  of  the  mucous  membrane. 

THE   MUCOUS   MEMBRANE    LINING   THE    MOUTH. 

The  whole  interior  cavity  of  the  mouth,  palate,  pharynx,  and  lips 
is  covered  by  mucous  membrane,  forming  folds  or  duplicatures  at  dif- 
ferent points,  called  frenae,  or  bridles.  Beginning  at  the  margin  of 
the  lower  lip,  this  membrane  can  be  traced  lining  its  posterior  surface, 
and  from  thence  reflected  on  the  anterior  face  of  the  lower  jaw,  where 
it  forms  a  fold  opposite  the  symphysis  of  the  chin — the  frenum  of  the 
lower  lip;  it  is  now  traced  to  the  alveolar  ridge,  covering  it  in  front, 
and  passing  over  its  posterior  surface,  where  it  enters  the  mouth.  Here 
it  is  reflected  from  the  posterior  symphysis  of  the  lower  jaw  to  the 
under  surface  of  the  tongue,  where  it  forms  a  fold  or  bridle,  called  the 
frenum  linguce.  It  now  spreads  over  the  tongue,  covering  its  dorsum, 
and  sides  to  the  root,  from  whence  it  is  reflected  to  the  epiglottis, 
forming  another  fold ;  from  this  point  it  can  be  followed,  entering  the 
glottis  and  lining  the  larynx,  trachea,  etc. 

In  the  same  way,  commencing  at  the  upper  lip,  it  is  reflected  to  the 
upper  jaw,  and  at  the  upper  central  incisors,  forming  a  fold,  the 
frenum  of  the  upper  lip ;  from  this  it  passes  over  the  alveolar  ridge 


88  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

to  the  roof  of  the  mouth,  which  it  completely  covers,  and  extends  as 
far  back  as  the  posterior  edge  of  the  palate  bones;  from  this  it  is 
reflected  downward  over  the  soft  palate,  or,  more  strictly  speaking,  the 
soft  palate  is  formed  by  the  duplicature  of  this  membrane  at  this 
point,  between  the  folds  of  which  are  placed  the  muscles  of  the  palate 
already  described. 

From  the  palate  it  is  traced  upward  and  continuous  with  the  mem- 
brane lining  the  nares,  and  downward  with  the  same,  lining  the 
pharynx,  esophagus,  stomach,  and  intestinal  canal. 

The  mucous  membrane,  after  entering  the  nostrils  and  lining  the 
roof,  floor,  septum  nasi,  and  turbinated  bones,  enters  the  maxillary 
sinus,  between  the  middle  and  lower  spongy  bones,  and  lines  the  whole 
of  this  great  and  important  cavity  of  the  superior  maxilla. 

Many  mucous  glands  or  follicles,  already  enumerated,  are  scattered 
over  the  whole  of  this  membrane,  and  furnish  the  mouth  with  its 
mucus. 

The  mucous  membrane  of  the  mouth,  which  is  directly  concerned  in 

the  development  of  the  teeth,  and  afterward  is  in  close  relation  with 

these  organs,  is  composed  of  different  layers,  as  follows  : — 

^   .  ,    ,.         (  Corneous. 
Epithelmm.  i  , ,  ,   .  ,  . 
^  C  Malpighian. 

Basement  Membrane. 

^  , ,  , ,      ,  ( Papillary. 

Corium,  or  Proper  Mucous  Membrane,  i  ^    .     , 

'  ^  (  Reticulary. 

Submucous  Areolar  Tissue. 

The  epithelium,  which  corresponds  to  the  epidermis  of  the  skin, 
and  is  derived  from  the  same  source,  is  com- 
posed of  two  layers,  an  external  and  an  inter- 
nal. The  external  layer,  of  horny  consistence, 
3  m  and  known  as  the  corneous  layer — stratum  cor- 
neum — is  formed  of  old  epithelial  cells,  which, 
owing  to  changes  from  prismatic  or  columnar 
cells  during  their  migration  from  the  internal 
to  the  external  surface  of  the  membrane,  have 
D  become  thin,  devitalized  scales,  devoid  of 
function.  These  old  epithelial  cells  are  being 
continually  cast  off  as  effete  matter,  others 
taking  their  places,  which  in  turn  undergo  a 


Fig.  38.— Different  Layers  similar  process  of  devitalization  and  exfolia- 

OF  Mucous  Membrane.         tion. 

^m^e^mb'^anrc  Co?ruT!S'       The  epithelium  of  the  mouth  is  analogous  in 

Submucous  areolar  tissue.       ^^^.^  ^^  ^j^^  ^^^^^  ^^^  ^j^g  gjjgj^j  modification  is 

due  to  its  immersion  in  the  oral  fluids,  which  prevents  its  external 


THE    MUCOUS    MEMBRANE    LINING    THE    MoUlH.  89 

layer  from  assuming  the  horn-like  or  corneous  nature  of  the  same  layer 
of  the  skin.  The  epithelial  cells  are  united  in  layers  by  an  intercellu- 
lar cement-substance,  and  the  superficial  layer,  which  is  composed  of 
thin  scales  or  discs,  contains  nuclei,  differing,  in  this  respect,  from 
the  corneous  layer  of  the  skin,  which  does  not  usually  contain  nuclei. 

The  internal  or  Malpighian  layer  is  formed  of  living  epithelial 
scales  or  cells,  which  are  of  various  forms  and  sizes,  and  are  placed 
vertically  upon  the  "basement  membrane,"  which  separates  the 
epithelium  from  the  corium  (proper  mucous  membrane).  The  cells 
of  this  internal  layer  are  variously  designated  as  the  prismatic, 
columnar,  cylindrical,  or  Malpighian  layer,  and  have  large  nuclei, 
but  are  destitute  of  a  cell-wall.     This  layer  constitutes  the  perpetual 


Fig.  39. — Cklls  Com- 
posing THE  Stratum 
CoRNEUM  OR  Exter- 
nal Layer  of  Epi- 
thelium {from  Frey). 


Fig.  40.— Internal  or  Malpighi- 
an Layer  of  the  Epithelium. 

a.  Infant  cells,  known  as  prismatic, 
columnar,  or  cylinder  cells,  b. 
Intermediate  matter,  d.  Fibrous 
tissue  of  the  corium. 


Fig.  41.— a.  Flat  layer  of  epithelial  cells  thrown 
upward  into  the  "  burrelet  "  of  Legros  and 
Magitot.  h.  Enlargement  and  proliferation 
of  cells  in  cuboidal  layers,  forcing  flat  layer 
upward  and  columnar  layer  downward,  c. 
Columnar  layer  of  cells  directly  over  position 
which  will  be  occupied  by  future  jaw. 


Fig.  42. — a.  Stratum  cor- 
neum.  b.  Stratum  Mal- 
pighii.  bm.  Basement 
membrane,  c.  Corium. 


portion  of  the  enamel  organ,  which  during 
the  development  of  a  tooth  is  known  as  the 
"enamel  membrane." 

The  basement  membrane,  known  as  the  mem- 
brana  prcpformativa  of  Raschow,   is  situated  below  the  internal  or 
Malpighian    layer,   and  is  a  homogeneous  structure,   which  in  some 
parts  partakes  of  the  character  of  a  membrane,  especially  where  it  is 
of  considerable  thickness. 

Although  not  usually  recognized  as  a  layer  of  mucous  membrane, 
yet  it  is  interesting  from  the  fact  that  the  dentine  bulb  or  germ  and 
the  enamel  organ  are  found  on  the  opposite  sides  of  it,  the  former 
below  and  the  latter  above  it. 

The  Corium  or  mucosa,  which  is  the  proper  mucous  membrane,  is 


go  PRINCIPLES    AND    PRACJICE    OF    DENTISTRY. 

situated  beneath  the  basement  membrane,  and  is  analogous  to  the 
derma  of  the  skin.  It  consists  of  a  fibro-vascular  layer  of  variable 
thickness,  merging  into  the  submucous  areolar  tissue,  and  contains, 
besides  the  white  and  yellow  fibrous  tissue  and  the  vessels,  muscular 
fibre  cells  (forming  what  is  known  in  some  localities  as  the  musfu/arts 
mucosa).,  nerves  and  lymphatics. 

Mucous  glands  project  from  its  surface,  and  with  the  processes 
known  as  villi  and  papillae,  common  to  mucous  membrane  covering 
the  tongue,  are  analogous  to  the  papillse  of  the  skin. 

THE    GUM. 

The  gum  is  composed  of  dense,  elastic,  fibrous  tissue,  adhering  to 
the  periosteum  of  the  alveolar  tissue.  It  is  remarkable  for  its  in- 
sensibility and  hardness  in  the  healthy  state,  but  exhibits  great 
tenderness  upon  the  slightest  injury  when  diseased.  The  gum 
differs  in  texture  from  that  of  the  mucous  membrane  lining  the 
inside  of  the  lips,  covering  the  floor  of  the  mouth  and  the  palate,  of 
which  it  is  a  continuation,  by  being  thicker  and  denser,  and  of  less 
sensibility.  Its  hardness  is  due,  in  a  great  measure,  to  the  numer- 
ous tendinous  fasciculi  in  its  substance,  and  also  to  its  being  closely 
blended  with  the  dense  fibrous  fasciculi  of  the  periosteum,  which 
causes  it  to  closely  adhere  to  the  bone.  These  fasciculi  of  the  gum, 
arising  from  the  periosteum,  expand  in  fan-like  form  as  they 
approach  the  epithelial  surface.  The  substance  of  the  gum  contains 
broad-based  papillae,  either  single  or  compound,  and  the  epithelium 
is  formed  of  laminae  of  tessellated  cells,  very  much  flattened  near 
the  surface,  but  with  cylindrical  cells  composing  the  Malpighian  or 
deepest  layer.  The  gums  are  very  vascular,  being  freely  supplied 
with  vessels,  but  with  few  nerves.  A  free  margin  of  gum,  about 
half  a  line  in  width,  surrounds  the  base  of  each  tooth,  and  they 
present  a  festooned  appearance,  caused  by  elongations  in  the  inter- 
dental space.  The  portion  of  the  gum  which  adheres  to  the  neck 
of  the  tooth  is  of  a  very  fibrous  structure.  At  the  necks  of  the 
teeth  the  gum  is  continuous  with  the  periosteum  of  the  inner  sur- 
face of  the  alveoli,  being  reflected  back  upon  itself,  and  uniting 
with  the  true  peridental  membrane.  The  gum  of  the  upper  jaw  is 
supplied  with  vessels  from  the  superior  coronary  artery,  and  that  of 
the  lower  jaw  from  the  submental  and  sublingual  arteries.  They 
derive  their  nerves  from  the  superior  dental  branches  of  the  fifth 
pair. 

In  the  infant  state  of  the  gum,  the  central  line  of  each  dental  arch 
presents  a  white,  firm,  cartilaginous  ridge,  which  gradually  becomes 
thinner  as  the  teeth  advance  ;   and  in  old  age,  after  the  teeth  drop 


THE    PERIDENTAL    MEMBRANE.  9I 

out,  the  gum  again  resumes  somewhat  its  former  infantile  condition, 
showing  "second  childhood." 

The  gum,  being  endowed  with  a  high  degree  of  vascularity,  indi- 
cates very  correctly,  the  state  of  the  constitutional  health. 

THE    PERIDENTAL    MEMBRANE. 

The  Peridental  Membrane  lines  the  alveolar  cavities  or  sockets,  of  the 
teeth,  covers  the  roots  of  each,  is  attached  to  the  gums  at  the  necks, 
and  to  the  blood-vessels  and  nerves  where  they  enter  the  roots  of 
the  teeth  at  their  apices ;  and,  further,  Mr.  Thomas  Bell  believed  it 
passes  into  the  cavities  of  the  teeth,  forming  their  lining  membrane, 
and  is  continuous  with  or  the  same  as  that  of  the  pulp. 

Mr.  Charles  Tomes,  in  describing  this  membrane,  says:  "It  is 
thicker  near  to  the  neck  of  the  tooth,  where  it  passes  by  impercep- 
tible gradations  into  the  gum  and  periosteum  of  the  alveolar  process, 
and  near  to  the  apex  of  the  root.  The  general  direction  of  the  fibres 
is  transverse — that  is  to  say,  they  run  across  from  the  alveolus  to 
the  cementum,  without  break  of  continuity,  as  do  also  many  capil- 
lary vessels ;  a  mere  inspection  of  the  connective-tissue  bundles,  as 
seen  in  a  transverse  section  of  a  decalcified  tooth  in  its  socket,  will 
suffice  to  demonstrate  that  there  is  but  a  single  'membrane,'  and 
that  no  such  thing  as  a  membrane  proper  to  the  root  and  another 
proper  to  the  alveolus  can  be  distinguished  ;  and  the  study  of  its 
development  alike  proves  that  the  soft  tissue  investing  the  root  and  that 
lining  the  socket  are  one  and  the  same  thing ;  that  there  is  but  one 
'membrane,'  namely,  the  alveolo-dental  periosteum.  At  that  part 
which  is  nearest  to  the  bone  the  fibres  are  grouped  together  into  con- 
spicuous bundles;  it  is,  in  fact,  much  like  any  ordinary  fibrous  mem- 
brane. On  its  inner  aspect,  where  it  becomes  continuous  with  the 
cementum,  it  consists  of  a  fine  network  of  interlacing  bands,  many  of 
which  lose  themselves  in  the  surface  of  the  cementum.  But  although 
there  is  a  marked  difference  in  histological  character  between  the 
extreme  parts  of  the  membrane,  yet  the  markedly  fibrous  elements  of 
the  outer  blend  and  pass  insensibly  into  the  bands  of  the  fine  network 
of  the  inner  part,  and  there  is  no  break  of  continuity  whatever.  At 
the  surface  of  the  cementum  it  is  more  richly  cellular,  and  here  occur 
abundantly  large,  soft,  nucleated  plasm  masses,  which  are  the  osteo- 
blasts concerned  in  making  cementum,  and  which,  by  their  offshoots, 
communicate  with  plasm  masses  imprisoned  within  the  cementum." 
According  to  Wedl,  the  vascular  supply  of  the  peridental  membrane  is 
derived  from  the  gums,  the  vessels  of  the  bone,  and  the  vessels  destined 
for  the  pulp  of  the  tooth,  the  last  being  the  most  important.  The 
nerves  supplying  this  membrane  are  derived  from  the  dental  pulp  and 


92  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

from  the  nerves  of  the  bone;  hence  it  is  apparent  that  the  relationship 
between  the  pulp  and  peridental  membrane  of  the  teeth  is  very 
intimate. 

ANATOMICAL    RELATIONS    OF    THE     MOUTH. 

The  mouth  has  many  interesting  anatomical  relations  with  the  rest 
of  the  body,  a  few  of  which  it  may  be  well  to  mention. 

By  means  of  its  lining  mucous  membrane  it  is  connected,  through 
continuity  of  structure,  with  the  pharynx,  oesophagus,  stomach,  and  the 
whole  of  the  intestinal  canal,  etc. 

Disease  still  further  establishes  this  structural  relation.  Inflam- 
mation, ulceration,  or  any  other  pathological  change  in  the  stomach 
or  intestines,  is  felt  and  reported  on  the  tongue,  gums,  and  other  parts 
of  the  mouth,  showing  the  sympathy  and  close  relationship  of  these 
several  parts. 

The  mouth  is  also  connected  by  the  same  mucous  membrane  with 
the  organs  of  respiration,  by  being  continued  down  into  the  larynx, 
trachea,  and  bronchi. 

Widespread  sympathies  are  established  between  the  mouth  and  other 
parts  by  means  of  the  numerous  nerves  which  animate  the  parts  consti- 
tuting its  boundaries  and  lying  in  its  cavity,  as  the  sympathetic,  the 
seventh,  the  glosso-pharyngeal,  the  par  vagum,  the  hypoglossal,  and 
upper  cervical. 

Simple  irritation  from  teething  has  thrown  children  into  convulsions, 
and  in  adults  toothache  often  creates  extreme  irritability  of  the  whole 
nervous  system.  But  it  is  not  necessary  to  dwell  here  on  the  sympa- 
thies of  the  mouth  in  disease  with  other  parts  of  the  body,  as  the  author 
will  have  occasion  to  do  this  in  other  parts  of  this  work. 

It  will  be  well,  however,  to  mention  in  this  place  that  there  is  a 
general  anatomical  relation  of  the  mouth  with  the  rest  of  the  body, 
by  means  of  the  blood-vessels  and  areolar  tissue. 

PHYSIOLOGICAL    RELATIONS    OF    THE    MOUTH. 

It  has  been  shown  that  the  mouth  consists  of  a  great  variety  of  parts, 
and,  also,  that  it  has  an  equally  great  diversity  of  functions. 

The  functions  of  the  mouth  have  been  stated  to  be  those  of  pre- 
hension, mastication,  insalivation,  and  deglutition. 

These  functions,  it  has  been  seen,  are  all  closely  related  to  one 
another  and  mutually  dependent ;  and  how  beautiful  is  the  harmony 
of  action  as  well  as  its  regular  and  orderly  succession  !  We  see,  in  the 
first  place,  the  prehensile  instruments  laying  hold  of  and  introducing 
the  food  into  the  mouth ;  then  the  organs  of  mastication,  the  teeth 
and  upper  and  lower  jaw  bones,  put  into  operation  by  the  temporal, 
masseter,  and  pterygoid  muscles,  grind  it  down  into  minute  portions; 


THE    TEETH.  9J 

these,  at  the  same  time,  are  formed  into  a  bolus  by  being  mixed  with 
the  salivary  fluids  furnished  by  the  parotid,  submaxillary,  and  sub- 
lingual glands ;  then  the  mass  is  taken  by  the  organs  of  deglutition, 
namely,  the  tongue,  palate,  and  pharynx,  and  passed  into  the  oesoph- 
agus, to  be  thence  conducted  into  the  stomach,  thus  demonstrating 
the  harmony  existing  among  the  several  functions  belonging  to  the 
mouth. 

But  the  functional  relation  of  the  mouth  is  no  less  extensive  than  its 
structural  relation  ;  the  one  is  commensurate  with  the  other ;  and  as 
the  structure  of  the  mouth  has  been  shown  to  be  continuous  with  that 
of  other  parts  of  the  body,  so  we  find  that  the  functions  of  the  mouth 
exert  an  influence  upon,  and  are  themselves  influenced  by,  many  great 
and  leading  functions  of  the  body.  The  connection  between  mastica- 
tion and  insalivation,  for  example,  with  stomachal  digestion,  or 
chymification,  is  especially  obvious. 

Again,  the  mouth  is  intimately  related  with  the  intellectual  func- 
tions, as,  for  instance,  that  of  speech.  Who  does  not  know  that 
when  any  of  the  teeth  are  wanting,  the  palate  cleft,  or  there  is  a  hare- 
lip, how  much  the  speech  is  impaired  ?  And  so  with  all  the  other 
functions  of  the  body  ;  the  relations  between  them  and  the  mouth, 
and  the  mutual  dependence  of  each  on  the  other,  is  equally  demon- 
strable. 


CHAPTER  IX. 
THE  TEETH. 


The  teeth  in  the  human  mouth  are  the  prime  organs  of  mastication, 
are  the  hardest  portion  of  the  body,  and  are  implanted  in  the  alveolar 
cavities  of  both  the  upper  and  lower  jaw. 

A  tooth  is  composed  of  four  distinct  structures :  i.  The  pulp,  occu- 
pying the  chamber  in  the  crown  and  the  canal  extending  through  the 
root;  2.  The  dentine,  which  constitutes  the  principal  part  of  the 
organ  ;  3.  The  enamel,  which  forms  the  covering  and  protection  of 
the  crown  ;  4.  The  cementum,  or  crusta  petrosa,  which  covers  the  root. 
(See  Fig.  43.) 

Two  sets  of  teeth  are  developed  in  the  mouth,  one  of  first  dentition 
and  one  of  second  dentition. 

The  teeth  of  first  dentition,  termed  the  milk,  temporary,  or  deciduous 
teeth,  are  designed  merely  to  supply  the  wants  of  childhood,  and  are 
replaced  with  a  larger,  stronger,  and  more  numerous  set.     The  teeth 


04 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


of  second  dentition  are  termed  the  permanent  or  adult  teeth,  and  are 
intended  to  continue  through  life. 

The  anatomical  divisions  of  a  tooth  are  :  i.  The  crown,  or  exposed 
part,  situated  above  the  gum  ;  2.  The  root,  occupying  the  alveolar 
cavity,  or  socket ;  3.  The  neck,  which  is  the  constricted  portion  be- 
tween the  crown  and  root. 


THE    TEMPORARY    TEETH. 

The  temporary  teeth  (Figs.  44  and  45)  are  divided  into  three 
classes:  first,  the  incisors  ;  second,  the  cuspids,  or  canine  teeth  ;  third, 
the  molars,  which  are  succeeded  by  the  bicus- 
pids, or  premolars,  which  are  not  represented 
in  the  temporary  set. 

The  temporary  teeth  are  twenty  in  number, 
ten  in  each  jaw,  namely:  four  incisors,  two 
cuspids,  and  four  molars. 

The  incisors  of  the  upper  jaw  are  implanted 
in  the  pre-maxillary  bones,  which  early  in  life 
unite  with  the  maxillaries. 

The  pulp-cavity  in  a  temporary  tooth  is  also 
larger  in  proportion  to  the  size  of  the  organ 


Canine. 


Milk  Molars. 


Fig.  43.— a.  The  coronal 
surface  divested  of  enam- 
el, b.  The  dentine,  c. 
The  pulp  cavity,  d.  The 
cementum,  or  crust  a 
petrosa.     e.  The  enamel. 


Upper  Set. 


Lower  Set. 


Fig.  45- 


than  in  a  permanent  tooth.  The  pulp-cavities  of  the  central  and 
lateral  incisors  are  of  the  same  general  shape,  like  that  of  an  elongated 
tube,  while  those  of  the  canines  and  molars  correspond  with  the  form 
of  these  teeth. 

THE    PERMANENT    TEETH. 

There  are  thirty- two  teeth  in  the  permanent  set,  sixteen  to  each 
jaw — being  an  increase  of  twelve  over  the  temporary,  designated  as 
follows:   incisors,  four  ;  cuspids,  two;   bicuspids,  or  premolars,   four; 


DESCRIPTION    OF    TEETH    BELONGING    TO    EACH    CLASS. 


95 


molars,  six — in  each  jaw.  The  surfaces  of  the  teeth  covered  by  the 
lips  are  called  "labial;"  by  the  cheeks,  "buccal;"  toward  the  roof 
of  the  mouth  on  the  upper  jaw,  "  palatal;"  toward  the  tongue  on  the 
lower  jaw,  "lingual."  The  name  "proximate"  is  given  to  the  sur- 
faces next  to  each  other ;  the  surfaces  looking  toward  the  center  are 
called  "  mesial ;"  and  those  looking  from  the  center,  "  distal." 

DESCRIPTION    OF    TEETH    BELONGING    TO    EACH    CLASS. 

Each  tooth,  as  has  already  been  remarked,  has  a  bodyor  crown,  a 
neck,  and  a  root  or  fang.  In  describing  these  several  parts,  we  shall 
begin  with 

The  Incisors  (four  to  each  jaw,  and  so-called  from  the  Latin  word 
incidere,  to  cut,  on  account  of  their  sharp,  cutting  edges  (Figs.  46 


Canine. 


Bicuspids. 


Pig.  45  — Upper  Incisors,  Canines,  and  Bicuspids. 


Fig.  47.— Lower  Incisors,  Canines,  and  Bicuspids. 


and  47).  They  occupy  the  anterior  central  part  of  each  maxillary 
arch.  The  body  of  each  is  wedge-shaped — the  anterior  or  labial  sur- 
face is  convex  and  smooth ;  the  posterior  or  palatal  is  concave,  and 
presents  a  tubercle  near  the  neck  ;  the  palatal  or  labial  surfaces  come 
together  and  form  a  cutting  edge.  In  a  front  view,  the  edge  is  gen- 
erally the  widest  part ;  it  diminishes  toward  the  neck,  and  continues 
narrowing  to  the  extremity  of  the  root. 

The  crown  of  an  incisor  has  four  surfaces  :  X\so proximate,  or  mesial 
and  distal,  the  mesial  toward  the  median  line  and  the  distal  away 
from  the  median  line,  one  labial,  and  ont palatal,  or  lingual — the  term 
palatal  being  applied  to  the  inner  surface  of  an  upper,  and  lingual  to 


96  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

the  inner  surface  of  a  lower,  incisor.  It  also  has  four  angles:  namely, 
a  right  and  a  left  labio-proxbnate  and  a  right  and  left palato -proximate, 
or  linguaproximate . 

The  two  large  incisors  which  are  situated  one  on  each  side  of  the 
median  line  are  termed  the  central  incisors;  the  other  two,  the  lateral 
incisors,  or  laterals,  because  they  occupy  a  position  on  either  side  of 
the  centrals.  The  crowns  of  the  upper  central  incisors  are  about  four 
lines  in  breadth,  and  the  laterals  three.  In  the  lower  jaw,  the  crowns 
of  the  central  incisors  are  only  about  two  lines  and  a  half  in  width, 
while  the  laterals  are  usually  a  little  wider.  But  the  width  of  the 
crowns  of  all  the  incisors  varies  in  different  individuals. 

The  length  of  a  superior  central  incisor  is  usually  about  one  inch, 
and  that  of  a  lateral  is  half  of  a  line  less.  In  the  lower  jaw  the  central 
incisors  are  only  about  ten  lines  in  length ;  the  laterals  are  about  one 
line  and  a  half  longer. 

The  length  of  the  crown  of  an  incisor  is  exceedingly  variable. 
That  of  an  upper  central  varies  from  four  and  a  half  to  six  lines;  and 
there  is  the  same  want  of  uniformity  in  this  respect  with  the  crowns 
of  all  the  incisors. 

The  superior  central  incisors  are  somewhat  more  prominent  than 
the  lateral  incisors,  owing  to  the  curve  of  the  alveolar  process.  The 
newly-erupted  incisors  have  three  points  or  cusps  on  their  cutting 
edges,  which  soon  disappear  through  wear,  leaving  such  edges  smooth 
and  uniform.  The  labial  aspect  of  the  crown  of  a  superior  central 
incisor  is  convex,  and  the  vertical  diameter  is  greater  than  the  trans- 
verse. Of  the  lateral  surfaces,  the  mesial  is  generally  flat,  while  the 
distal  is  more  rounded.  The  lateral  incisors  are  more  slender  in  shape 
and  smaller  than  the  central  incisors,  but  have  the  same  general  form, 
with  somewhat  more  convexity  of  the  labial  surface. 

The  roots  are  all  single,  of  a  conical  form,  flattened  laterally,  and 
slightly  furrowed  longitudinally.  Those  of  the  lateral  incisors  (Figs. 
46  and  47)  are  more  flattened  laterally  than  the  roots  of  the  centrals, 
slightly  longer,  and  more  gradually  tapering  toward  the  apex.  The 
pulp-cavities  of  all  the  incisors  have  the  same  shape — like  that  of  an 
elongated  tube.  The  enamel  is  thicker  before  than  behind,  and 
thinnest  at  the  sides. 

The  function  of  this  class  of  teeth,  as  their  name  imports,  is  to  cut 
the  food,  and  for  the  performance  of  this  office  they  are  admirably 
fitted  by  their  shape.  As  age  advances,  their  edges  often  become 
blunted  ;  but  the  rapidity  with  which  they  are  worn  away  depends 
altogether  upon  the  manner  in  which  those  of  the  upper  and  lower  jaw 
come  together. 


THE   CUSPIDATI,    OR   CUSPIDS.  97 

THE    CUSPIDATI,    OR   CUSPIDS. 

The  Cuspidati,  Canini,  or  Cuspids,  so  called  from  the  Latin  word 
cuspis,  ''  a  point,"  because  they  terminate  in  a  point,  are  commonly 
known  by  the  name  of  canines  (Figs.  46  and  47).  They  are  situated 
next  to  the  incisors,  and  occupy  the  space  between  the  lateral  incisor 
and  first  bicuspid,  two  to  each  jaw,  one  on  either  side.  They  some- 
what resemble  the  upper  central  incisors  with  their  angles  rounded. 
Their  crowns  are  conical,  very  convex  externally,  and  their  palatal 
surface  more  uneven,  and  they  have  a  larger  tubercle  than  the  incisors. 
The  crown  ends  in  a  blunt  point,  and  the  cutting  edge  slopes  away  on 
each  side.  The  slope  toward  the  bicuspid  is  the  longer,  and  causes 
the  crown  to  be  asymmetrical.  The  lingual  surface  presents  a  median 
and  two  lateral  ridges ;  they  converge  toward  the  well-marked  cingu- 
lum,  which  is  often  produced  into  a  distinct  cusp  (Fig.  48). 

The  lower  canines  have  not  such  pronounced  features  as  the  upper; 
the  point  is  blunter,   and   the   median  ridge  is 
absent  from  the  lingual  surface.    They  are  stronger 
and  generally  more  durable   teeth  than  the  in- 
cisors, and  their  roots  form  a  vertical  ridge  on 
the  external  surface  of  the  alveolar  process.    Their 
roots  are   also  larger,  and  of  all   the   teeth  the      Hfll — ^^'^''' 
longest ;   like  the  incisors,  they  are  also  single,      MJiH —  Cinguium. 
but  have  a  groove  extending  from  the  neck  to  the 
extremity,  showing  a  step  toward  the  formation 
of  two  roots.     A  cuspid,  like  an  incisor,  has  four 
surfaces  and  four  angles,  designated  by  the  names  already  given — 
labial,  palatal  or  lingual,  mesial,  distal. 

The  breadth  of  the  crown  of  an  upper  cuspid  is  about  four  lines, 
that  of  a  lower  is  about  three  and  a  half;  but,  as  in  the  case  of  the 
incisors,  the  width  of  the  crowns  of  these  teeth  is  variable.  The  length 
of  a  cuspid  is  greater  than  that  of  any  other  tooth  in  the  dental  series 
— it  being  about  thirteen  lines.  The  breadth  of  the  neck  of  one  of 
these  teeth  is  about  one-third  greater  in  front  than  behind,  and  from 
before  backward  it  measures  about  four  lines. 

The  upper  cuspids,  with  no  good  reason,  are  sometimes  called  eye 
teeth  ;  the  lower  are  termed  stomach  teeth. 

The  inferior  cuspids  have  a  shorter  root  than  the  superior  cuspids, 
and  the  median  cusp  is  not  so  pointed. 

These  teeth  are  for  tearing  the  food,  and  in  some  of  the  carnivorous 
animals,  where  they  are  very  large,  they  not  only  rend  but  also  hold 
their  prey. 

The  incisors  and  cuspids  together  are  termed  the  ora/  teeth. 
7 


98  PRINCIPLES    AND    PRACTICE    OF   DENTISTRY. 

THE   BICUSPIDS. 

Tht  Bicuspids,  SO  called  from  the  Latin  words  bis,  "twice,"  and 
cuspis,  "a  point"  (Figs.  46  and  47),  four  to  each  jaw  and  two  on 
either  side,  are  next  in  order  to  the  cuspids.  They  have  two  distinct 
prominences  or  cusps  on  their  grinding  surfaces,  one  external  and  the 
other  internal,  and  separated  by  a  deep  depression  or  notch.  In  the 
superior  bicuspids  the  external  cusp  is  somewhat  larger  than  the  inter- 
nal cusp,  while  in  the  inferior  bicuspids  the  internal  cusp  is  larger  than 
the  external,  and  the  root  is  more  cylindrical  in  form.  They  are  also 
named  premolars  or  the  small  molars,  but  are  more  commonly  desig- 
nated as  the  first  and  second  bicuspids.  They  are  thicker  from  their 
buccal  to  their  palatine  surface  than  either  of  the  incisors,  and  are 
flatter  on  their  sides.  The  buccal  surfaces  are  very  convex,  and  the 
crowns  of  the  second  bicuspids  are  generally  somewhat  larger  than 
those  of  the  first  bicuspids,  and  more  of  a  square  form. 

A  bicuspid  has  five  surfaces:  namely,  two  proxitnate — mesial 
and  distal ;  one  buccal ;  one  palatal  or  lingual  surface,  as  the  tooth 
may  be  in  the  upper  and  lower  jaw,  and  one  grinding  surface.  It 
has  four  angles  ;  one  anterior  or  inesio-  and  one  posterior  or  disto- 
palato-proximate  and  one  anterior  or  ?nesio-  and  one  posterior,  or 
disto-bucco-proximate  angle. 

The  size  of  these  teeth,  like  that  of  the  incisors  and  cuspids,  is 
variable.  The  buccal  surface  of  the  crown  of  a  superior  bicuspid  of 
ordinary  size  at  its  broadest  part  is  about  three  lines  in  breadth,  while 
the  anterior  and  posterior  proximal  surfaces  are  about  four  lines. 
The  palatal  is  quite  as  wide  as  the  buccal  surface.  All  the  diameters 
of  the  crown  of  a  lower  bicuspid  are  usually  a  little  less  than  those 
of  an  upper.  The  entire  length  of  a  bicuspid  is  ordinarily  about 
eleven  lines. 

The  superior  bicuspids  have  generally  two  roots,  but  sometimes  a 
single  root,  which  is  often  deeply  grooved,  while  the  inferior  bicus- 
pids have  but  one  root.  The  deeply-grooved  root  is  indicative  of  two 
pulp-cavities,  which  may  unite  at  the  central  portion  of  the  root  and 
form  a  narrow  transverse  fissure  at  the  neck  of  the  tooth.  Of  the  two 
roots  of  the  superior  bicuspids,  the  inner  or  palatal  is  smaller  than 
the  outer  or  buccal,  each  root  having  an  opening  for  the  vessels  and 
nerves  to  enter. 

THE    MOLARS. 

The  J/<7/ar.f,  so  called  from  the  Latin  -word  tnolaris,  "grinding," 
and  designated  as  first,  second,  and  third  molars  (Figs.  49  and  50), 
occupy  the  posterior  part  of  the  alveolar  arch,  and  are  six  in  each  jaw, 
three  on  either  side.     The  first,  owing  to  the  period  of  their  eruption. 


THE    MOLARS. 


99 


are  called  the  sixth-year  molars,  and  the  second,  for  the  same  reason, 
are  called  the  twelfth-year  molars,  while  the  third  are  called  the  dentes 
sapientise,  or  wisdom  teeth,  from  the  Latin  word  dens,  "  a  tooth,"  and 
sapientia,  "wisdom,"  being  erupted  at  a  period  when  maturity  is 
reached.  The  molars  are  distinguished  by  their  greater  size — the  first 
and  second  being  the  largest ;  the  grinding  surfaces  have  the  enamel 
thicker,  and  are  surmounted  by  four  or  five  tubercles  or  cusps,  with  as 
many  corresponding  depressions  arranged  in  such  a  manner  that  the 
tubercles  of  the  upper  jaw  are  adapted  to  the  depressions  of  the  lower, 
and  vice  versa. 

A  molar,  like  a  bicuspid,  has  also  five  surfaces  and  five  angles, 
designated  by  the  names  already  given  to  similar  surfaces  on  the 
bicuspids. 

The  upper  molars  have  three  roots,  sometimes  four,  and  as  many  as 


Molars. 


Wisdom  Tooth. 


Upper  Molars. 


Fig.  49. 


Lower  Molars. 


Fig.  50. 


five  are  occasionally  seen  ;  of  these  roots  two  are  situated  externally, 
almost  parallel  with  each  other,  and  perpendicular ;  the  third  root 
forms  an  acute  angle,  and  looks  toward  the  roof  of  the  mouth.  The 
former  are  called  the  buccal  roots,  and  the  latter  the  palatal.  The 
roots  of  the  first  two  superior  molars  correspond  with  the  floor  of  the 
maxillary  sinus,  and  sometimes  protrude  into  this  cavity,  their  diverg- 
ence securing  them  more  firmly  in  their  sockets.  '  The  lower  molars 
have  but  two  roots — the  one  anterior,  the  other  posterior  ;  they  are 
nearly  vertical,  parallel  with  each  other,  and  much  flattened  laterally. 
The  last  molar,  or  wisdom  tooth,  is  both  shorter  and  smaller  than 
the  others  ;   the  roots  of  the  upper  wisdom  tooth  are,  occasionally, 


lOO  PRINCIPLES    AND    PRACTICE   OF    DENTISTRY. 

united  so  as  to  form  but  one  ;  while  the  last  molar  of  the  lower  jaw  is 
generally  single  and  of  a  conical  form. 

The  roots  of  the  molar  teeth,  both  of  the  upper  and  lower  jaw,  after 
diverging,  sometimes  approach  each  other  (converge),  embracing  the 
intervening  bony  partition  in  such  a  manner  as  to  constitute  an  obstacle 
to  their  extraction. 

The  bucco-palatal  diameter  of  the  crown  of  an  upper  molar  is 
usually  a  little  less  than  the  antero-posterior.  In  the  lower  jaw,  the 
bucco-lingual  and  antero-posterior  diameters  are  generally  about  the 
same. 

The  crown  of  the  first  molar  is  generally  larger  than  the  second, 
and  the  second  larger  than  the  third  or  wisdom  tooth  ;  and  the  crown 
of  the  last-named  tooth  is  always  smaller  in  the  upper  than  in  the 
lower  jaw. 

The  pulp-cavities  correspond  to  the  external  form  of  the  roots,  and 
at  the  necks  of  these  teeth  they  unite  into  a  common  cavity  called 

the  pulp-chamber,  which  often  ends  in 
cornua  corresponding  to  the  cusps  (Fig. 

50- 

.  The  length   of  a   molar   tooth  varies 

Cavity,     from  eight  to  twelve  and  a  half  or  thir- 

,_.-,_,  teen  lines. 

Root. \  §  1  \  !•■ 

The   molars    and    bicuspids    together 

constitute  what   are   termed   the   buccal 

teeth. 
Fig.  51. 

The  use  of  the  molars,  as  their  name 
signifies,  is  to  triturate  or  grind  the  food  during  mastication,  and  for 
this  purpose  they  are  admirably  adapted  by  their  mechanical  arrange- 
ment. 

ATTACHMENT    OF    THE    TEETH. 

The  manner  in  which  the  teeth  are  confined  in  their  sockets  is  by  a 
union  called  go7nphosis,  from  the  resemblance  of  this  kind  of  articula- 
tion to  the  way  in  which  a  nail  is  received  into  a  board.  The  teeth 
having  but  one  root,  and  those  with  two  perpendicular  roots,  depend 
greatly,  for  the  strength  of  their  articulation,  on  their  nice  adaptation 
to  their  sockets. 

Those  having  three  or  four  roots  have  their  firmness  much  increased 
by  their  divergence ;  also  teeth  with  two  roots  which  converge. 

But  there  are  other  bonds  of  union  ;  by  the  periosteum  lining  the 
alveolar  cavities,  and  investing  the  roots  of  the  teeth  ;  also  by  the 
blood-vessels  entering  the  apices  of  the  roots;  and  finally,  by  the 
gums,  which  will  be  noticed  in  another  place. 


TEMPORARY  AND  PERMANENT  TEETH.  lOI 

DIFFERENCES  BETWEEN  THE  TEMPORARY  AND  PERMANENT  TEETH. 

The  temporary  and  permanent  teeth  differ  in  several  respects,  and 
on  this  point  I  will  give  Mr.  Bell's  observations  : — 

"The  temporary  teeth  are,  generally  speaking,  much  smaller  than 
the  permanent ;  of  a  less  firm  and  solid  texture,  and  their  characteris- 
tic forms  and  prominences  much  less  strongly  marked.  The  incisors 
and  cuspids  of  the  lower  jaw  are  of  the  same  general  form  as  in  the 
adult,  though  much  smaller;  the  edges  are  more  rounded,  and  they 
are  not  much  more  than  half  the  length  of  the  latter.  The  molars  of 
the  child,  on  the  contrary,  are  considerably  larger  than  the  bicuspids 
which  succeed  them,  and  resemble  very  nearly  the  permanent  molars. 

''The  roots  of  the  tooth  in  the  molars  of  the  child  are  similar  in 
number  to  those  of  the  adult  molars,  but  they  are  flatter  and  thinner 
in  proportion,  more  hollowed  on  their  inner  surfaces,  and  diverge  from 
the  neck  at  a  more  abrupt  angle,  forming  a  sort  of  arch." 

In  the  temporary  teeth  the  union  of  the  enamel  and  cementum  is 
distinctly  marked  by  a  well-defined  ridge  of  enamel  at  the  base  of  the 
crown,  which  forms  a  constricted  neck ;  whereas  in  the  permanent 
teeth  the  union  of  the  enamel  and  cementum  at  the  base  of  the  crown 
is  very  indistinct. 

RELATIONS    OF    THE   TEETH    OF     THE    UPPER     TO    THOSE    OF     THE    LOWER 
JAW,    WHEN    THE    MOUTH    IS    CLOSED    (ARTICULATION). 

The  crowns  of  the  teeth  of  the  upper  jaw  are  generally  arranged  in 
the  form  of  a  semi-ellipse,  and  describe  a  rather  larger  arch  than  those 
of  the  lower.  The  upper  incisors  and  cuspids  naturally  shut  over  and 
in  front  of  the  lower ;  but  sometimes  they  fall  plumb  upon  them,  and 
at  other  times,  though  unnaturally,  they  come  on  the  inside.  In  the 
curve  of  the  arch,  the  cuspids  stand  a  little  prominent,  giving  a  full- 
ness to  the  angles  of  the  mouth.  The  external  tubercles  or  cusps  of 
the  superior  bicuspids  and  molars  generally  strike  on  the  outside  of 
those  of  the  corresponding  inferior  teeth.  By  this  beautiful  adaptation 
of  the  tubercles  of  the  teeth  of  one  jaw  to  the  depressions  of  those  of 
the  other,  every  part  of  the  grinding  surface  of  these  organs  is  brought 
into  immediate  contact  in  the  act  of  mastication ;  which  operation  of 
the  teeth,  in  consequence,  is  rendered  more  perfect  than  it  would  be 
if  the  organs  came  together  in  any  other  manner. 

The  incisors  and  cuspids  of  the  upper  jaw  are  broader  than  the  cor- 
responding teeth  in  the  lower ;  in  consequence  of  this  difference  in 
the  lateral  diameter  of  the  teeth  of  the  two  jaws,  the  central  incisors 
of  the  upper  cover  the  centrals  and  about  half  of  the  laterals  in  the 
lower,  while  the  superior  laterals  cover  the  remaining  half  of  the  infe- 


I02  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

rior  and  the  anterior  half  of  the  adjoining  cuspids.  Continuing  this 
peculiar  relationship,  the  upper  cuspids  close  over  the  remaining  half 
of  the  lower  and  the  anterior  half  of  the  first  inferior  bicuspids,  while 
the  first  superior  bicuspids  cover  the  remaining  half  of  the  first  inferior 
and  the  anterior  half  of  the  second.  In  like  manner,  the  second  bi- 
cuspids of  the  upper  jaw  close  over  the  posterior  half  of  the  second  and 
the  anterior  third  of  the  first  molars  in  the  lower.  The  first  superior 
molars  cover  the  remaining  two-thirds  of  the  first  inferior  and  the  an- 
terior third  of  the  second,  while  the  two-thirds  of  this  last  and  anterior 


Fig.  52. 


third  of  the  lower  dentes  sapientiae  are  covered  by  the  second  upper 
molars.  The  dentes  sapientise  of  the  superior  maxilla,  being  usually 
about  one-third  less  in  their  antero-posterior  diameter,  cover  the  re- 
maining two-thirds  of  the  corresponding  teeth  in  the  lower  jaw.     (See 

Fig.  52-) 

Thus,  from  this  arrangement  of  the  teeth,  it  will  be  seen  that  when 
the  mouth  is  closed  each  tooth  is  opposed  to  two ;  and  hence,  in  biting 
hard  substances  and  in  mastication,  by  extending  this  mutual  aid,  a 
power  of  resistance  is  given  to  these  organs  which   they  would  not 


MALFORMED    TEETH.  I03 

Otherwise  possess.  Moreover,  as  Mr.  Tomes  very  justly  observes,  if 
one,  or  even  two  adjoining  teeth  should  be  lost,  the  corresponding 
teeth  in  the  other  jaw  would,  to  some  extent,  still  act  against  the  con- 
tiguous organs,  and  thus,  in  some  degree,  counteract  a  process,  which 
nature  sometimes  sets  up  for  the  expulsion  of  such  teeth  as  have  lost 
their  antagonists. 


CHAPTER  X. 

MALFORMED  TEETH. 


Peculiarities  in  the  Formation  and  Growth  of  the  Teeth. — In  the 
development  and  growth  of  the  various  parts  of  the  body,  curious  and 
interesting  anomalies  are  sometimes  observed  ;  but  in  no  portion  of  it 
are  they  more  frequent  in  their  occurrence  or  diversified  in  their  char- 


FiG.  53.  Fig.  54. 

Fig.  53  shows  the  front  view  of  the  lateral  incisor  and  canine  from  the  left  side  of  the  under 
jaw,  united  throughout  their  entire  length,  but  with  the  line  of  junction  well  marked.  The 
age  at  which  they  were  removed  was  seven  years.  The  corresponding  teeth  on  the  oppo- 
site side  of  the  jaw  were  similarly  united. 

Fig.  54  shows  the  representation  of  the  lateral  incisor  and  canine  from  the  lefl  side  of  the 
lower  jaw  of  a  patient  aged  nine  years.  In  this  example  the  line  of  junction  is  less  dis- 
tinctly marked  than  in  the  preceding  illustration,  and  is  altogether  wanting  near  the  base 
of  the  enamel. 

acter  than  in  the  teeth.  But  aberrations  in  the  formation  and  growth 
of  these  organs  are,  for  the  most  part,  confined  to  the  teeth  of  second 
dentition. 

Although  the  deciduous  teeth  are  much  more  exempt  from  deviation 
in  form,  size,  and  number  than  the  permanent  teeth,  yet  they  are  not 
altogether  free  from  such  irregularities.  One  form  of  irregularity  of 
these  teeth  may  consist  in  a  greater  number  than  twenty;  while  in 
other  cases  there  may  be  a  numerical  deficiency.  Deciduous  teeth, 
especially  the  molars,  are  occasionally  met  with  having  more  than  the 
normal  number  of  roots.  A  more  common  form  of  irregularity  is  the 
union  of  two,  or  sometimes  even  three,  deciduous  teeth,  generally 
incisors,  or  an  incisor  and  a  canine,  either  by  a  union  in  the  cemen- 
tum,  or  in  the  dentine  and  enamel  (Figs.  53  and  54}.  When  the 
union  is  in  the  cementum,  the  roots  only  are  united,  but  where  it 


I04 


PRINCIPLES    AND    PRACTICE   OF    DENTISTRY. 


is  in  the  dentine  and  enamel  there  is  a  fusion  of  both  the  crowns  and 
the  roots,  and  one  pulp  common  to  the  two  teeth  (geminous). 

Fig.  55'  represents  two  specimens  of  triple  fusion  of  the  deciduous 
right  superior  lateral  incisor  and  cuspid,  with  a  supernumerary  tooth 
between  the  two,  taken  from  the  mouth  of  a  boy  three  years  of  age. 
Fig.  55^*  represents  another  specimen  of  triple  fusion  of  deciduous 
teeth  from  the  mouth  of  a  little  girl,  which  occupied  the  same  position 
as  that  represented  by  Fig.  55^  and  was  composed  of  the  same  teeth. 
Both  of  these  specimens  were  extracted  by  Dr.  Isaac  Douglass. 

Malformed  Permanent  Teeth. — Irregularity  in  the  forms  of 
permanent  teeth  is  much  more  common  than  is  the  case  with  decid- 
uous teeth ;  some  of  the  former  differing  so  much  in  size,  either  above 
or  below  what  is  normal,  as  to  occasion  disfigurement ;  in  the  same 
mouth  very  large  teeth  may  be  associated  with  others  extremely  small, 
or  the  malformation  may  be  confined  to  a  single  tooth  of  the  set.  But 
examples  of  this  kind  are  not  very  frequent ;  for  where  there  is  an 


Fig.  55. 


Fig.  56. 


Fig.  57. 


increase  or  diminution  in  the  size  of  the  teeth  of  one  class,  there  is 
generally  a  corresponding  change  in  that  of  the  other. 

Aberrations  of  this  character  are  probably  dependent  upon  some 
diathesis  of  the  general  system,  whereby  the  teeth,  during  the  earlier 
stages  of  their  formation,  are  supplied  with  an  excessive  or  diminished 
quantity  of  nutriment.  Again,  the  malformation  may  be  confined  to 
the  root,  while  the  crown  of  the  tooth  is  of  the  normal  size. 

A  superior  central  incisor  may  have  a  root  which  is  abnormally 
small,  while  the  crown  is  of  the  usual  size. 

Another  malformation  consists  in  an  excess  of  the  normal  number 
of  roots,  the  superior  molars  sometimes  having  four  or  six  slender  roots, 
and  the  inferior  molars  three  and  four,  the  inferior  canines  two,  and 
the  superior  bicuspids  three  roots.  (Figs.  56,  57.)  The  variations  in 
form  of  the  permanent  teeth  are  beyond  enumeration  ;  in  some  cases 
teeth  with  single  roots  are  bent  at  different  angles.  The  crowns  of  the 
teeth,  also,  frequently  present  deviations  from  the  natural  shape 
equally  striking  and  remarkable. 


MALFORMED    TEETH. 


105 


Figs.  58,  59,  and  60  represent  molar  and  incisor  teeth  with  mal- 
formed roots. 

Teeth  with  flexed  roots  are  also  met  with.  Figs.  61  and  62  repre- 
sent superior  central  incisors  with  single  and  double  flexions  of  the 
roots. 

Mr.  Fox  gives  a  drawing  of  a  tooth  very  much  resembling  the  letter 
S.  The  author  has  also  met  with  several  examples  of  teeth  similarly 
deformed,  and  from  like  causes. 

Some  very  remarkable  deviations  have  been  known  to  take  place  in 
the  growth  of  the  teeth.  The  most  singular  case  on  record  is  that 
related  by  Albinus,  "  Two  teeth,"  says  he,  "  between  the  nose  and  the 
orbits  of  the  eye,  one  on  the  right  side  and  the  other  on  the  left,  were 
inclosed  in  the  roots  of  those  processes  that  extend  from  the  maxillary 


Fig.  58. 


Fig.  59. 


Fig.  60. 


Fig.  61. 


Fig.  62. 


bones  to  the  eminence  of  the  nose.  They  were  large,  remarkably 
thick,  and  so  very  like  the  canines  that  they  seemed  to  be  these  teeth, 
which  had  not  before  appeared  ;  but  the  canines  themselves  were  also 
present,  more  than  usually  small  and  short,  and  placed  in  their  proper 
sockets.  The  former,  therefore,  appear  to  have  been  new  canines, 
which  had  not  penetrated  their  sockets,  because  they  were  situated 
where  these  same  teeth  are  usually  observed  to  be  in  children.  But 
what  is  still  more  remarkable,  their  points  were  directed  toward  the 
eyes,  as  if  they  were  the  new  eye  teeth  inverted.  And  they  were  also 
so  formed  that  they  were,  contrary  to  what  usually  happens,  convex 
on  the  posterior  and  concave  on  the  anterior."  A  case  of  a  somewhat 
similar  character  is  mentioned  by  Mr.  John  Hunter. 

The  following  case  is  in  the  words  of  Mr.  G.  Wait :   "While  I  was 


Io6  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

prosecuting  my  anatomical  studies,  I  was  struck  with  the  appearance 
of  a  cuspid  of  the  upper  jaw  ;  it  was  short,  and  appeared  as  if  the  body 
of  the  tooth  was  in  the  jaw,  and  that  it  was  the  tip  of  the  root  that 
presented  itself.  Upon  further  examination  I  found  this  verified,  and 
after  the  cranium  and  lower  jaw  were  properly  macerated  and  cleansed, 
I  found  one  of  the  lower  bicuspids  in  the  same  position." 

The  following  is  one  of  the  several  cases  of  deviation  in  the  growth 
of  the  teeth  that  have  come  under  the  author's  observation  :  In  1840, 
he  was  requested  to  extract  a  tooth  for  a  lady  of  Baltimore  under  the 
following  circumstances.  She  had,  for  a  time,  experienced  a  great 
deal  of  pain  in  her  upper  jaw,  and  supposed  it  to  originate  from  the 
second  molar  of  the  right  side,  but  which  was  perfectly  sound.  Mean- 
while her  general  health  became  impaired,  and  her  attending  physi- 
cian, thinking  that  the  local  irritation  might  have  contributed  to  her 
debility,  advised  the  extraction  of  the  tooth.  On  removing  it,  the 
cause  of  the  pain  at  once  became  apparent.  The  dens  sapientiae, 
which  had  not  hitherto  appeared,  was  discovered  with  its  roots  extend- 
ing back  to  the  utmost  verge  of  the  angle  of  the  jaw,  while  its  grinding 
surface  had  been  in  contact  with  the  posterior  surface  of  the  crown 
and  neck  of  the  tooth  just  extracted.  On  the  removal  of  the  wisdom 
tooth  the  pain  ceased. 

About  the  middle  of  December,  1849,  a  youth  aged  sixteen  applied 
to  the  author  to  extract  aright  superior  bicuspid,  which,  he  said,  was 
ulcerated  at  the  root.  On  examining  his  mouth,  he  discovered  only 
one  bicuspid,  but  above  and  between  the  root  of  this  and  that  of  the 
first  molar,  he  observed  a  small  fistulous  opening.  On  introducing  a 
small  probe,  it  immediately  came  in  contact  with  the  crown  of  a  tooth 
looking  toward  the  malar  process  of  the  superior  maxillary,  which,  on 
extraction,  proved  to  be  the  second  bicuspid. 

The  author  has  in  his  possession  several  molar  and  bicuspid  teeth 
which  have  small  nodes  upon  their  necks,  covered  with  enamel ;  and 
there  are  jaws  in  the  Museums  of  the  Baltimore  Dental  Colleges 
which  have  a  number  of  teeth  presenting  this  anomaly. 

The  author  has  two  teeth  in  his  possession  of  most  singular  shape, 
presented  to  him  by  his  brother,  the  late  Dr.  John  Harris.  They 
were  extracted  in  July,  1822,  from  the  right  side  of  the  upper  jaw 
of  a  young  gentleman,  nineteen  years  of  age,  by  the  name  of  Craw- 
ford. They  occupied  the  place  of  the  first  and  second  bicuspids  and 
their  crowns  are  almost  wholly  imbedded  in  lamellated  dentine,  that 
should  have  constituted  their  roots,  but  which  are  entirely  wanting. 
Judging  from  their  appearance,  one  would  be  inclined  to  suppose  that, 
their  sacs  failing  to  contract,  they  remained  stationary  in  their  sockets, 
and  as  the  base  of  the  pulps  elongated,  they  came  in  contact  with  the 


MALFORMED    TEETH.  I07 

bottom  of  the  alveoli,  and  were  caused  to  bulge  out  and  to  be  reflected 
upon  their  crowns,  to  the  enamel  of  which,  nearly  to  their  grinding 
surfaces,  they  are  perfectly  united.  For  some  time  previously  to  the 
extraction  of  these  teeth,  they  had  been  productive  of  considerable 
irritation  and  pain  in  the  gums  and  jaw,  and  it  was  for  the  relief  of 
the  suffering  which  their  presence  induced  that  they  were  removed. 

Since  the  above  was  written,  the  author  has  seen  a  still  more  remark- 
able deviation  in  the  growth  of  a  tooth.  It  is  in  the  upper  jaw  of  an 
adult  skull  in  which  the  natural  teeth  are  all  well  formed  and 
regularly  arranged  in  the  alveolar  border,  but  between  the  ex- 
tremities of  the  roots  of  the  superior  central  incisors,  in  the 
substance  of  the  jaw,  there  is  a  supernumerary  tooth  the  crown 
of  which  looks  upward  toward  the  crest  of  the  nasal  plates  of 
the  two  bones.     The  whole  tooth  is  about  one  inch  in  length, 

°  Fig.  63. 

and  the  apex  of  the  crown  is  nearly  on  a  level  with  the  floor 
of  the  nasal  cavities.     There  is  also  in  the  Dental  Museum  of  the 
University  of  Maryland  a  central  incisor  of  the  upper  jaw,  with  the 
root  bent  upon,  and  in  contact  with,  the  labial  surface  of  the  crown 
(Fig.  6^). 

United  Teeth. — Inclosed  as  each  tooth  is  in  a  distinct  sac,  and  sep- 
arated on  either  side  by  a  bony  partition  from  the  adjoining  teeth, 
until  after  the  completion  of  the  formation  of  the  enamel,  it  may  be 
difficult  to  conceive  how  osseous  union  could  take  place  between  two 
of  these  organs,  but  so  many  examples  of  such  union  are  met  with, 
that  there  is  no  longer  any  question  concerning  its  possibility. 

Two  or  more  teeth,  generally  the  molars,  may  be  permanently  joined 
together  by  a  union  in  the  cementum  of  their  roots,  occasioned  by 
diseased  action,  such  as  exostosis,  taking  place  after  the  complete  de- 
velopment of  the  teeth.  The  term  "  osseous  union  "  has  been  applied 
to  such  cases. 

Fig.  64  represents  united  second  and  third  molars,  the  one  figure 
presenting  the  buccal  aspect,  and  the  other  the  palatal. 

Fig.  65  also  represents  the  osseous  union  of  superior  second  and 
third  molars. 

Many  years  ago  we  had  an  opportunity  of  seeing  two  interesting  cases. 
One  consisted  in  the  union  of  the  crowns  of  the  central  incisors  of 
the  upper  jaw,  the  palatine  surface  of  which  presented  the  appearance 
of  one  broad  tooth,  while  anteriorly  they  had  the  semblance  of  two 
teeth:  the  other  case  consisted  in  the  union  of  the  right  central  and 
lateral  incisors  of  the  lower  jaw. 

A  professional  friend  informed  the  author,  in  a  conversation  some 
years  since,  that  he  had  met  with  a  case  of  osseous  union  between  a 


io8 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


second  bicuspid  and  the  first  molar  of  the  lower  jaw,  which  was  so 
palpable  that  there  could  have  been  no  doubt  of  its  existence. 

Cases  of  this  nature  are  not  very  common,  and  a  connection  of  the 
roots  of  two  teeth,  by  an  intervening  portion  of  the  alveolus,  is  very 
easily  mistaken  for  osseous  union  of  the  roots  themselves.  A  few  years 
since,  in  extracting  a  second  molar  of  the  upper  jaw,  the  author 
brought  the  dens  sapientise  along  with  it.  At  first  he  thought  there 
was  osseous  union  of  the  roots,  but  upon  close  examination  found  a 
very  thin  portion  of  the  alveolar  wall  between,  to  which  their  roots 
were  firmly  attached.  Such  a  case  as  this  would,  in  many  instances, 
be  set  down  as  an  example  of  osseous  union. 

An  osseous  union  of  the  teeth  is,  fortunately,  of  rare  occurrence  ; 
if  it  were  otherwise,  it  would  be  productive  of  many  accidents  in  the 
extraction  of  teeth.  Apart  from  this  consideration,  it  can  be  of  but 
little  importance  either  to  the  practitioner  or  to  the  physiologist. 


Fig.  64. 


Fig.  65. 


Since  the  publication  of  the  first  edition  of  this  work,  a  number  of 
cases  of  osseous  union  of  the  teeth  have  fallen  under  the  observation 
of  the  author.  Among  them  are  a  number  of  examples  of  osseous 
union  of  the  temporary  teeth. 

Geminous  or  Fused  Teeth. — When  two  teeth  are  united  by  a  union 
in  the  enamel  and  dentine  throughout  the  entire  length  of  their  crowns 
and  roots,  they  are  termed  "geminous"  or  "fused"  teeth,  as  the 
malformation  is  occasioned  by  a  fusion  of  their  pulp,  from  close  prox- 
imity and  pressure,  one  pulp  being  common  to  the  two  teeth.  The 
two  central  incisors  and  the  lateral  incisors  and  canines  are  more  com- 
monly joined  together  in  this  manner  than  any  of  the  other  teeth. 
Fig.  66  represents  geminous  central  and  lateral  incisors,  showing  the 
labial  and  palatal  aspects,  these  specimens  being  in  the  Dental  Museum 
of  the  University  of  Maryland. 

Other  cases  occur  where  the  union  or  fusion  is  confined  to  the  crowns 
of  the  teeth,  the  roots  being  separate. 


MALFORMED    TEETH. 


109 


Fig.  67  represents  two  geminous  central  incisors,  the  crowns  of 
which  are  united  while  the  roots  are  separate. 

Supernumerary  Teeth. — The  development  of  supernumerary  teeth  is 
usually  confined  to  the  anterior  part  of  the  mouth,  and  more  fre- 
quently to  the  upper  than  to  the  lower  jaw.  They  sometimes,  how- 
ever, appear  as  far  back  as  the  dentes  sapientiae,  and  Hudson  says  he 
has  seen  them  behind  these  teeth.  We  have  now  in  our  anatomical 
collection  two  supernumerary  teeth  that  were  extracted,  one  from  be- 
hind and  the  other  at  the  side  of  one  of  the  upper  wisdom  teeth.* 

The  crowns  of  supernumerary  teeth  which  appear  in  the  anterior 
part  of  the  mouth  are  usually  of  a  conical  shape,  and  for  the  most 
part  situated  between  the  central  incisors ;  they  usually  have  short, 
knotty  roots  ;  sometimes,  however,  they  bear  so  strong  a  resemblance 
to  the  other  teeth  that  it  is  difficult  to  distinguish  the  one  from  the 
other.     We  once  saw  two  lateral  incisors  in  the  lower  jaw,  both  of 


Fig.  66. 


Fig.  67. 


which  were  so  well  arranged  and  perfectly  formed  that  it  was  impossi- 
ble to  determine  which  of  the  two  ought  to  be  considered  as  the  super- 
numerary. Mr.  Bell  mentions  a  case  in  which  there  were  five  lower 
incisors,  all  of  which  were  well  formed  and  regularly  arranged.  Such 
teeth,  however,  are  more  properly  known  as  "  supplemental." 

Supernumerary  cuspids  rarely  if  ever  occur,  but  supernumerary  bi- 
cuspids are  occasionally  met  with.  Delabarre  says  he  has  seen  them ; 
and  we  have  met  with  three  examples  of  the  sort ;  in  each  of  these 
instances  the  teeth  were  very  small,  not  being  more  than  one-fourth  as 
large  as  the  natural  bicuspids,  with  oval  crowns,  and  placed  partly  on 
the  outside  of  the  circle  and  partly  between  the  bicuspids.  We  ex- 
tracted one  of  them,  and  have  it  still  in  our  possession.  Its  root  is 
short,  round,  and  nearly  as  thick  at  its  extremity  as  it  is  at  the  neck 
of  the  tooth. 

The  supernumerary  teeth  that  appear  further  back  than  the  bicuspids, 
though  much  smaller,  bear  a  strong  resemblance  to  the  dentes  sapientiae. 


*  These  teeth  were  removed  by  Dr.  Chewning,  dentist,  of  Fredericksburg,  Va. 


no  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

Supernumerary  teeth,  although  generally  imperfect  in  their  forma- 
tion, are  less  liable  than  other  teeth  to  decay.  This  may  be  attribut- 
able to  the  fact  that  they  are  harder,  and,  consequently,  not  so  sus- 
ceptible to  the  action  of  the  causes  that  produce  the  disease. 

Although  the  occurrence  of  supernumerary  teeth  rarely  disturbs  the 
arrangement  of  the  others,  their  presence  is  sometimes  productive  of 
the  worst  form  of  irregularity  (Fig.  68  represents  a  case  of  this  kind) ; 
and  even  when  they  do  not  have  this  effect,  they  impair  the  beauty  of 
the  mouth,  and,  for  this  reason,  should  be  extracted  as  soon  as  their 
crowns  have  completely  emerged  from  the  gums. 

To  the  practitioner  of  dental  surgery,  the  occurrence  of  supernu- 
merary teeth  is  interesting  only  in  so  far  as  it  affects  the  beauty  of  the 
mouth  and  the  relationship  which  the  teeth  of  the  upper  jaw  sustain  to 
those  of  the  lower  ;  but  to  the  physiologist  it  involves  the  question, 
what  determines  their  development?     In  propounding  this  interroga- 


FlG.  68. 

tory,  however,  it  is  not  our  intention  to  enter  upon  its  discussion  in 
this  place.     (See  "  Origin  of  Permanent  Teeth.") 

Supplemental  Teetli. — The  term  supplemental  is  employed  to  desig- 
nate teeth  which  resemble  in  shape  and  size  those  of  the  regular  series, 
as  a  third  lateral  incisor  or  canine,  or  a  fifth  bicuspid,  in  either  the 
upper  or  lower  jaw,  the  additional  teeth  being  perfectly  normal  in 
form.  Such  teeth  are  extremely  rare,  but  we  have  met  with  several 
examples  in  which  supplemental  teeth  so  closely  resembled  the  natural 
incisors  that  no  difference  could  be  discerned  between  them.  We 
have  also  met  with  three  superior  lateral  incisors  where  it  was  im.possi- 
ble  to  determine  which  was  the  supplemental  tooth. 

Nodular  Teeth. — Occasionally  teeth  are  found  having  small,  white, 
pearly  nodules  on  their  necks,  or  upon  the  roots  near  the  termination 
of  the  enamel.  These  enamel  nodules  consist  of  a  thick  layer  of 
enamel  covering  a  cone  of  dentine,  which  projects  from  the  neck  or 
root  of  the  tooth,  and  contains  dentinal  tubuli.  They  are  similar  to 
the  excrescences  in  the  form  of  extra  cusps,  which  are  sometimes  found 
on  the  crowns  of  the  teeth,  especially  the  molars,  and  the  enamel  cov- 


MALFORMED    TEETH.  Ill 

enng  them  is  formed  by  a  true  enamel  organ.  These  nodules  are  of 
physiological  interest  only,  as  they  do  not  give  rise  to  any  pathologi- 
cal symptoms.  They  are  a  variety  of  dental  exostosis  which  is  ex- 
tremely rare  and  difificult  to  account  for.  Sometimes  they  may  be 
mistaken  for  supernumerary  teeth,  and  an  attempt  to  remove  them  may 
result  in  the  extraction  of  the  tooth  t6  which  they  are  attached. 

Figs.  69  and  70  represent  permanent  teeth  with  nodules  of  enamel 
attached  to  the  necks  and  sides  of  the  roots. 

Odontoines. — This  term  has  been  generally  applied  to  tooth  tumors 
developed  from  the  hard  tissues  of  the  teeth,  but  it  is  now  restricted 
to  those  irregular  masses  of  dentinal  tissues  which  result  from  some 
hypertrophied  condition  of  the  tooth  papilla  or  formative  pulp.  In 
such  cases  the  irregular  mass  consists  of  dentine  and  enamel,  bearing 
little  or  no  resemblance  to  a  tooth;  and  it  originates  after  the  com- 
mencement of  calcification. 

Fig.  71  represents  an  odontome  consisting  of  an  irregular  mass  of 
tooth  tissues. 


Fig.  70. 


Fig.  71. 
.  Smooth  enamel-coated 
surface,    b.  Nodules  of 
enamel. 


The  teeth  described  by  Salter,  Wedl,  and  others,  under  the  name  of 
"  Warty  Teeth,'''  and  which  are  composed  of  tissues  hypertrophied 
and  folded  together  into  an  irregular  and  complicated  mass,  afford  a 
fair  example  of  odontomes. 

It  is  not  unusual  for  odontomes  to  remain  in  the  mouth  for  a  con- 
siderable time  without  causing  trouble,  but  sooner  or  later  they  may 
give  rise  to  inflammation  followed  by  suppuration  in  the  adjoining 
parts,  when  their  immediate  removal  is  necessary.  Mr.  John  Tomes 
refers  to  a  case  where  the  body  of  the  sphenoid  bone  was  found  to  be 
the  seat  of  a  tumor  containing  dentine. 

Figs.  72,  73  represent  dental  anomalies  extracted  from  the  mouth 
of  an  old  woman  seventy  years  of  age,  one  of  the  hairy  Burmese 
family,  by  Dr.  J.  A.  Daly,  and  are  described  as  follows  by  Dr.  C.  T. 
Caldwell : — 

"  I  find  two  very  remarkable  instances  of  gemination  or  organic 


112  PRINCIPLES   AND    PRACTICE   OF   DENTISTRY. 

union  of  two  neighboring  teeth.  The  measurements  and  outlines  of 
the  drawing  are  as  near  as  possible  correct.     Figs.  72  and  73. 

''The  lines  A  B  and  C  D  are  intended  to  show  the  position  of  the 
teeth  in  the  jaw,  the  portions  above  A  B  and  below  C  D  indicating 
the  parts  exposed  above  the  gum.  They  were  covered  by  a  thick 
layer  of  dark-brown  concretion,  the  exact  nature  of  which  I  have  not 
determined. 

"Fig.  72  shows  the  right  second  molar  and  wisdom-tooth  of  the 
lower  jaw  so  completely  joined  together  that  both  crowns  and  roots 
are  united  throughout  their  entire  length.  The  two  roots  of  the  second 
molar  may  be  easily  made  out  in  the  specimen,  and  just  behind  them, 
and  completely  fused  with  them,  is  the  connate  root  of  the  wisdom- 
tooth. 

"  Still  more  remarkable  than  this  is  the  specimen  represented  by  Fig. 
73,  wherein  the  union  of  two  upper  molars  is  confined  to  the  roots,  which 
are  so  welded  or  blended  together  as  to  leave  but  little  trace  of  the  several 
roots.     This  specimen  was  at  first  supposed  to  be  a  large-sized  molar 


Fig.  72.  Fig.  73. 

with  an  enormous  exostosis,  but  a  section  through  the  parts  shown  in 
the  drawing  disclosed  a  pulp-cavity,  and  close  examination  revealed 
the  fact  that  this  portion  of  the  mass  is  in  reality  the  crown  of  a  tooth, 
made  up  of  enamel,  dentine,  and  pulp-cavity,  filled  with  nerve  and 
nutrient  vessels,  as  in  ordinary  teeth.  The  tubercles  or  cusps,  having 
never  been  subjected  to  wear,  are  in  a  perfect  condition  on  what  should 
have  been  the  top  or  free  surface  of  the  crown,  while  the  roots  had 
become  coalescent  with  those  of  its  neighbor  in  such  a  manner  that 
only  one  of  the  united  teeth  could  assume  an  upright  or  natural  posi- 
tion in  the  jaw,  the  other  being  forced  into  a  horizontal  position,  with 
only  a  side  protruding  above  the  surface  of  the  bone. 

"This  gemination  or  coalescence  of  contiguous  teeth  occurs  during 
an  early  stage  of  their  development,  and  is  due  to  absorption  of  the 
intervening  bony  tissue  caused  by  pressure,  where,  as  in  this  case, 
several  very  large  teeth  crowd  themselves  into  a  very  small  mouth." 

Syphilitic  Teeth. — Mr.  J.  Hutchinson  was  the  first  to  call  attention 
to  a  class  of  malformed  permanent  teeth,  the  result  of  inherited  syph- 


MALFORMED   TEETH. 


113 


ilis.  and  he  asserts  that  certain  deviations  in  the  forms  of  teeth  are 
valuable  as  diagnostic  marks  of  the  existence  of  syphilis  of  a  congenital 
constitutional  type,  and  he  classes  them  with  syphilitic  interstitial 
keratitis.  This  author  describes  syphilitic  teeth  as  follows:  "  In  those 
who  had  cut  their  permanent  teeth  the  condition  of  the  incisor  teeth 
was  very  peculiar,  both  in  form,  color,  and  size.  As  a  diagnostic  of 
hereditary  syphilis,  various  peculiarities  are  often  presented  by  the 
others,  especially  the  canines  ;  but  the  upper  central  incisors  are  the 
test  teeth.  When  first  cut,  these  teeth  are  short,  narrow  from  side  to 
side  at  their  edges,  and  very  thin.  After  awhile  a  crescentic  portion 
from  their  edge  breaks  away,  leaving  a  broad,  shallow,  vertical  notch, 
which  is  permanent  for  some  years,  but  between  twenty  and  thirty 
usually  becomes  obliterated  by  the  premature  wearing  down  of  the 
teeth.  The  two  teeth  often  converge,  and  sometimes  they  stand 
widely  apart.     In  certain  instances  in  which  the  notching  is  either 


Fig.  74. 


R 


Fig.  75. 


wholly  absent  or  but  slightly  marked,  there  is  still  a  peculiar  color  and 
a  narrow  squareness  of  form,  which  are  easily  recognized  by  the  prac- 
ticed eye Indeed,  there  can  be  no  doubt  whatever  as 

to  the  truth  of  the  assertion  that  malformed  upper  incisors  (permanent 
set)  are  all  but  invariably  coincident  with  this  disease." 

Henry  W.  Williams,  M.  D.,  Professor  of  Ophthalmology  in  Harvard 
University,  confirms  Mr.  Hutchinson's  observations,  and  says:  "The 
central  incisors  of  the  second  dentition  have  a  peculiar  crescentic 
notch  at  their  lower  margins,  and  the  lateral  incisors  and  canines,  as 
well  as  the  molars,  are  often  small,  peg-shaped,  and  with  tuberculated 
prominences  upon  their  surface.  They  are,  perhaps,  also  irregularly 
set  in  the  jaw,  and  of  bad  color,  or  prematurely  decayed." 

Figs.  74  and  75  represent  syphilitic  teeth  in  a  boy  and  two  girls, 
aged  respectively  twelve,  fourteen,  and  seventeen  years. 


114  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

Mr.  John  Tomes  describes  these  teeth  as  being  of  "  a  dusky,  opaque 
appearance,  and  are  small  relatively  to  the  size  of  the  jaws,  so  that 
distinct  intervals  are  left  between  them ;  moreover,  they  are  of  a  very 
soft  character,  so  that  they  speedily  become  worn  down,,  and  the 
characteristic  transverse  notch  obliterated."  Mr.  Hutchinson  re- 
marks :  "  Inasmuch  as  specific  inflammations  do  not  occur  during  the 
period  of  intra-uterine  life,  the  teeth  belonging  to  the  deciduous  series 
are  not  liable  to  be  affected,  though  they  may  be  lost  by  exfoliation  con- 
sequent on  stomatitis  and  periostitis.  On  the  other  hand,  the  occur- 
rence of  specific  affections  of  the  mouth  soon  after  birth  may  be  readily 
supposed  to  affect  the  permanent  teeth  which  are  at  this  time  develop- 
ing, and  certain  characters  are  enumerated  as  indicative  of  such  inter- 
ference with  the  growing  teeth." 

Deviations  of  the  teeth  from  the  normal  condition  are  so  numerous 
and  varied  in  their  character,  that  it  would  be  impossible  to  describe 
all  of  them. 

Under  the  title  of  "  dilaceration,^'  Mr.  John  Tomes  describes  a  con^ 
dition  of  tooth  resulting  from  displacement  of  the  calcified  portion  of 
a  tooth  from  the  tissues  which  were  instrumental  in  its  production,  the 
development  being  continued  after  the  normal  position  of  the  calcified 
portion  was  lost ;  for  example,  the  crown  of  an  incisor  when  partly 
formed  may  move  from  its  position  upon  the  pulp,  and  be  turned  out- 
ward or  inward,  or  to  either  side,  and  there  remain  in  a  state  of  rest, 
the  development  of  the  tooth  continuing  with  the  displacement  of 
one-half  of  the  crown  permanently  preserved. 

Fig.  76  represents  three  cases 

Jof  dilaceration,  two  incisors  and 
a  bicuspid. 
Teeth  have  also  been  found 
with  the  root  at  the  apex  ex- 
panded  into  a  cup-shaped  disc, 
on  the  margins  of  which  are 
several  openings  or  foramina  for  the  entrance  of  the  nerves  and  vessels. 
Also  teeth  with  dentine  excrescences  in  the  form  of  nodules  growing  from 
the  wall  of  the  pulp-chamber.  Sometimes  these  nodules  of  secondary 
dentine  almost  fill  the  pulp-chamber,  while  the  parenchyma  of  the  pulp 
is  extensively  occupied  by  small  granules.  Such  excrescences  frequently 
cause  pain  of  neuralgic  character.  The  devitalization  of  the  pulp  is 
the  only  treatment. 

Dilated  roots  of  teeth  are  caused  by  the  dentinal  pulp  becoming 
hypertrophied  into  a  globular  structure  of  considerable  size,  and 
when  calcified  forming  an  osseous  mass,  often  larger  than  the  tooth 
itself.     Such  tumors  are  composed  of   an  outer  layer  of  cementum, 


MALFORMED   TEETH.  H5 

and  a  thin  shell  of  dentine  enclosing  a  voluminous  pulp,  which  may 
or  may  not  be  calcified.  Dilated  roots  of  teeth  may  occasion  pain 
when  the  jaws  are  opened,  with  expansion  of  the  jaw  at  the  alveolar 
portion. 

Malformed  teeth  also  result  from  interrupted  development  of  the 
dental  tissues,  which  is  manifested  by  the  crowns  being  irregularly 
grooved  or  pitted  and  smaller  than  the  natural  size.  The  incisors  are 
generally  thin  and  atrophied,  and  the  cusps  of  the  canines  and  molars 
sharp-pointed,  such  teeth  being  deficient  in  quantity  and  quality  of 
their  tissues,  and  of  a  yellow,  opaque  color.  Malformed  teeth  are  some- 
times, though  rarely,  met  with  where  the  roots  are  perfectly  developed, 
while  the  crowns  present  a  peculiar  deficiency,  and  consist  of  rudi- 
mentary formations  which  appear  like  small  irregular  masses  of  dentine 
without  any  enamel  covering.  These  crownless  teeth,  as  they  may  be 
styled,  are  sometimes  found  worn  level  with  the  gum  line. 

Another  anomaly  of  tooth-structure,  and  one  that  is  also  very  rare, 
consists  of  teeth  with  crowns  flattened  in  an  antero-posterior  direction, 
the  jaws  presenting  an  edentulous  appearance.  The  sulci  of  such 
teeth  are  misshapen,  and  the  cusps  are  like  narrow  ridges. 

Exostosed  teeth  are  also  included  in  those  that  deviate  from  the 
normal  form,  one  of  the  most  re- 
markable instances  of  which  was 
a  case  exhibited  by  Mr.  Tomes — 
a  molar  of  the  upper  jaw,  removed 
from  a  patient  aged  forty-one,  who 
had  long  suffered  pain  in  the  jaw, 
from  which  a  fistulous  passage  led  p^^ 

through  the  cheek.     Fig.  77  repre- 
sents this  case.     (See  "  Exostosis  of  the  Teeth.") 

Unerupted  or  Impacted  Teeth  are  often  malformed,  and  may  cause 
dentigerous  cysts.     (See  "  Dentigerous  Cysts.") 

Organic  Defects  of  Structure. — Malformation  of  teeth  caused  by 
organic  disease,  or  disease  of  tooth-structure,  is  less  frequent  in  its 
occurrence  than  any  other  disease  to  which  these  organs  are  liable; 
but  as  the  progress  of  the  affection  usually  terminates  with  the  action 
of  the  causes  concerned  in  its  production,  it  has  scarcely  been  deemed 
of  sufficient  importance  to  merit  serious  consideration.  Hence  its 
etiology  and  pathology  have  not  been  very  carefully  investigated. 

Fig.  78  represents  superior  and  inferior  front  teeth  with  crowns 
disfigured  by  irregular  grooves  and  pits. 

This  affection  consists  in  a  congenital  defect  of  structure  in  teeth 
rather  than  in  the  wasting,  for  want  of  nourishment,  of  any  of  the 
dental  tissues.     The  congenital  form  of  the  disease  is  evidently  the 


Ji6 


PRINCIPLES    AND    PRACTICE    OF    DENTISIRY. 


result  of  altered  function  in  a  portion  of  one  or  more  of  the  formative 
organs — if  not  of  absolute  degeneration,  from  vicious  nutrition. 

Teeth  presenting  these  organic  structural  defects  may  very  properly 
be  divided  into  three  varieties.  Each  has  characteristic  peculiarities 
which  distinguish  it  from  either  of  the  others.  Two  are  always  con- 
genital, and  the  other,  although  most  frequently  congenital,  sometimes 
occurs  subsequently  to  the  eruption  of  the  tooth. 

First  Variety. — The  peculiarities  that  distinguish  this  variety  from 
either  of  the  others  are,  that  it  never  impairs  the  uniformity  and 
smoothness  of  the  surface  of  the  enamel,  and  is  characterized  by  one 
or  more  white,  or  dark,  or  light  brown,  irregularly  shaped  spots,  upon 
the  labial  or  buccal  surface  of  the  tooth.     It  occurs  oftener  than  the 


Fig.  78. 


third  variety,  and  less  frequently  than  the  second.  It  rarely  appears 
on  more  than  one  or  two  teeth  in  the  same  mouth,  though  several  are 
sometimes  marked  by  it.  It  is  seen  on  the  molars  more  frequently 
than  the  bicuspids,  and  much  oftener  on  the  incisors  of  the  upper  jaw 
than  any  of  the  other  teeth.  We  do  not  recollect  to  have  ever 
observed  it  on  the  cuspids  of  either  jaw,  nor  on  the  palatine  or  lingual 
surfaces  of  the  incisors. 

The  enamel  is  much  softer  on  the  affected  than  on  the  unaffected 
parts  of  the  teeth,  and  may  be  easily  broken  and  reduced  to  powder 
with  a  steel  instrument.  It  seems  to  be  almost  wholly  deprived,  in 
these  places,  of  its  animal  constituents,  and  to  have  lost  its  connec- 
tion with  the  subjacent  dentine.     The  size  of  the  defective  spots  is 


MALFORMED    TEETH.  II7 

almost  as  variable  as  their  shape,  but  the  most  harm  resulting  from 
them  is  the  unsightly  aspect  they  sometimes  give  to  the  tooth. 

Second  Variety. — This  may  be  very  properly  dL^XioxxaxidX^di  perforating 
ox  pitting  defect ;  it  gives  to  the  enamel  an  indented  or  pitted  appear- 
ance, the  irregular  depressions  or  holes  extending  transversely  across 
and  around  the  tooth.  The  pits  are  sometimes  more  or  less  distinctly 
separated  one  from  another  by  prominent  lines  ;  at  other  times  they 
are  confluent,  and  form  an  irregular  horizontal  groove.  Sometimes 
they  penetrate  but  a  short  distance  into  the  enamel ;  at  other  times 
they  extend  entirely  through  it  to  the  dentine.  Their  surface,  though 
generally  irregular,  usually  presents  a  glossy  and  polished  appearance — 
a  peculiarity  which  always  distinguishes  this  variety  of  the  affection 
from  erosion.  The  pits  often  have  a  dark-brownish  appearance,  though 
sometimes  they  have  the  same  color  as  the  enamel  on  other  parts  of  the 
teeth. 

This  variety  is  never  confined  to  a  single  tooth.  Two,  four,  six,  or 
more  corresponding  teeth  are  always  affected  at  the  same  time  in  each 
jaw;  and  the  corresponding  teeth  on  either  side  precisely  in  the  same 
manner  and  in  the  same  place.  When  more  than  two  are  marked,  the 
distance  of  the  pits  from  the  coronal  extremity  of  the  tooth  varies,  ac- 
cording to  the  progress  made  in  the  formation  of  the  enamel  at  the 
time  of  the  operation  of  the  causes  concerned  in  the  production  of  the 
affection.  For  example,  when  the  line  of  pits  in  the  central  incisors 
is  situated  about  two  lines  from  their  cutting  edges,  it  will  scarcely  be 
one  line  from  the  cutting  edges  of  the  laterals,  and  only  the  points  of 
the  cuspids  will  be  marked.  When  the  indentations  are  nearer  the 
edges  of  the  central  incisors,  they  will  be  on  the  edges  of  the  laterals, 
and  the  cuspids  will  have  entirely  escaped. 

Sometimes  the  teeth  are  marked  with  two  or  three  rows  of  pits,  and 
when  this  is  the  case,  the  patient  has  had  either  two  or  three  relapses; 
or  has  been  attacked  two  or  three  times  in  succession  with  some  disease 
capable  of  interrupting  the  progress  of  the  formation  of  the  enamel. 

Although  the  incisors  are  more  frequently  marked  with  these  inden- 
tations than  any  of  the  other  teeth,  the  cuspids,  bicuspids,  and  even  the 
molars,  are  sometimes  affected  with  them.  When  the  disease  attacks  the 
molars,  its  effects  are  generally  located  on  the  grinding  surface.  The 
permanent  teeth  are  more  liable  to  be  attacked  than  the  temporary. 

This  variety  occurs  oftener  than  either  of  the  others,  and  though  it 
sometimes  gives  to  the  teeth  a  disagreeable  and  unsightly  appearance, 
it  rarely  increases  their  liability  to  decay. 

Third  Variety. — In  this  variety  the  whole  or  only  a  part  of  the 
crown  of  a  tooth  may  be  affected  ;  the  dentine  being  often  implicated 
as  well  as  the  enamel.     The  tooth  usually  has  a  pale-yellowish  color,  a 


Il8  PRINCIPLES   AND    PRACTICE    OF    DENTISTRY. 

shriveled  appearance,  and  is  partially  or  wholly  divested  of  enamel. 
Sometimes  the  crown  is  not  more  than  one-half  or  one-third  its  natural 
size.  Its  sensibility  is  usually  much  increased,  and  its  susceptibility 
to  pain  from  external  impressions  is  wonderfully  excited  by  acids.  It 
is  also  more  liable  than  the  other  teeth  to  be  attacked  by  caries.  The 
root  of  the  tooth  is  sometimes,  though  rarely,  affected,  and  presents 
an  irregular  knotted  appearance. 

The  disease  is  often  confined  to  a  single  tooth,  but  it  more  frequently 
shows  itself  on  two  corresponding  teeth  in  the  same  jaw.  According 
to  our  observation,  the  bicuspids  are  more  liable  to  be  attacked  than 
any  of  the  other  teeth.  This  variety  occurs  less  frequently  than  either 
of  the  others;  and,  although  it  increases  the  liability  of  the  affected 
organs  to  caries,  they  sometimes  escape  until  the  twentieth  or  thirtieth 
year  of  age. 

The  nature  of  this  affection  is  such  as  not  to  admit  of  cure.  The 
treatment,  therefore,  must  be  preventive  rather  than  curative.  All 
that  can  be  done  is  to  mitigate  the  severity  of  such  diseases  as  are 
supposed  to  produce  it,  by  the  administration  of  proper  remedies. 
By  this  means  their  injurious  effects  upon  the  teeth  may,  perhaps,  be 
partially  or  wholly  counteracted. 

In  some  forms  of  this  affection  the  teeth  may  not  decay  more 
readily  than  others,  so  that  the  only  evil  resulting  is  a  disfiguration 
of  the  organs ;  but  in  others,  and  especially  in  the  pitted  variety,  it 
may  be  necessary  to  insert  fillings  at  an  early  age.  When  the  cutting 
edges  of  the  incisors  only  are  affected,  the  diseased  part  may  sometimes 
be  removed  without  injury  to  the  teeth. 


CHAPTER   XI. 

ORIGIN    AND    DEVELOPMENT   OF   THE   TEETH.* 

Of  all  the  operations  of  the  animal  economy,  none  are  more  curious 
or  interesting  than  that  which  is  concerned  in  the  production  of  the 
teeth.  In  obedience  to  certain  developmental  laws,  established  by  an 
all-wise  Creator,  it  is  carried  on  from  about  the  sixth  week  of  intra- 
uterine existence,  with  the  nicest  and  most  wonderful  regularity  until 

*The  study  of  the  "  origin  and  development  of  the  teeth  "  should  begin  with  the 
"development  of  the  bones  of  the  head  and  face"  and  the  "description  of  the 
mucous  membrane,"  to  which  subjects  the  reader  is  referred. 


ORIGIN    AND    DEVELOPMENT    OF    THE    TEETH.  II9 

completed,  and  excites  in  the  mind  of  the  physiologist  the  highest 
admiration. 

From  small  papillje,  observable  at  a  very  early  period  of  fetal  life, 
the  teeth  are  gradually  developed,  and  as  they  increase  in  size,  the 
papillae  assume  the  shape  of  the  crowns  of  the  several  classes  of  teeth 
they  are  respectively  designed  to  produce.  Having  arrived  at  this 
stage  of  their  formation,  they  now  begin  to  dentinify,  first  upon  the 
cutting  edges  of  the  incisors,  the  apices  of  the  cuspids,  bicuspids,  and 
eminences  of  the  molars ;  from  thence  the  process  is  continued  over 
the  whole  surface  of  their  crowns,  until  they  become  invested  with  a 
complete  layer  of  dentine  ;  and  so  layer  after  layer  is  formed,  one 
within  the  other,  until  the  process  of  solidification  is  completed. 
Before  the  appearance  of  the  dentinal  germ  or  papilla,  however,  or 
coincident  with  the  development  of  the  latter,  the  organ  for  the  for- 
mation of  the  enamel  of  the  teeth  begins  to  form,  and  when  this 
enamel  organ,  which  arises  in  the  form  of  a  cord,  has  acquired  the 
appearance  of  a  hood  or  cap,  the  dentinal  papilla  is  so  far  developed 
that  its  surface  is  covered  with  cells  (odontoblasts)  engaged  in  the 
formation  of  the  dentine. 

In  the  meantime,  and  in  anticipation  of  the  loss  of  the  temporary 
teeth,  a  second  set  is  forming,  and  as  the  teeth  of  the  one  series  are 
removed,  they  are  promptly  replaced  by  those  of  the  other.  Thus, 
by  a  beautiful  and  most  admirable  provision  of  Nature,  the  first  set 
of  teeth,  intended  to  subserve  the  wants  only  of  childhood,  while 
the  jaws  are  too  small  for  the  reception  of  such  as  are  required  for 
an  adult,  are  removed  and  replaced  by  a  larger,  stronger,  and  more 
numerous  set. 

Commencing  the  description  of  the  development  of  the  teeth  with 
the  condition  of  the  jaws  of  the  embryo  at  the  period  of  the  for- 
mation of  the  organs  which  compose  the  "dental  follicle,"  namely, 
the  enamel  organ,  the  dentinal  germ  or  papilla,  and  the  follicular  wall 
or  sac,  there  is  at  an  early  period  no  trace  of  osseous  tissue  in  the 
lowe?'  jaw,  the  maxillary  arch  having  within  its  component  elements  a 
symmetrical  cartilaginous  band,  which  extends  its  entire  length,  as  far 
as  the  frame  of  the  drum  of  the  ear,  and  which  is  known  as  "  Meckel's 
cartilage."  This  cartilage  acts  a  transitory  part  only,  until  osseous 
tissue  is  developed,  first  by  calcification,  and  afterward  by  ossification, 
when  it  disappears.  (See  Development  of  the  Bones  of  the  Head 
and  Face.     Figs.  2,  3,  and  4.) 

As  regards  the  upper  jaw,  the  same  period  of  evolution  as  that  of 
the  lower  jaw  marks  the  union  of  the  maxillary  germs  with  the  median 
or  inter-maxillary  germs,  which  occurs  in  the  human  embryo  about 
the  fortieth  or  forty-fifth  day.      On  the  surface  or  rounded  portion  of 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


the  two  maxillary  arches  thus  formed,  and  which  later  constitute  the 
alveolar  border  or  process,  a  depression  or  groove, 
called  the  "dental  groove,"  appears,  which, 
however,  is  so  completely  filled  or  "  heaped  up  " 
with  a  bed  of  epithelial  cells  as  to  form  a  protu- 
berance or  smooth  ridge,  destitute  of  any  fold  or 
depression  whatever. 

This  ridge  (Fig.  79)  is  composed  of  a   thick 
bed  of   epithelial  cells,  which,  however,   on  its 
Fig.  79.  sides  form  a  coat  of  a  few  rows  of  cells  only, 

d.  A  mass  of  epithelium—   and  docs  not  include  any  other  well-defined  tis- 

tne  "dental    ridge.       o. 

Younger  layer  ofepithe-   sue  unless  it  be  somc  vcsscls,  ncrvcs,  and  muscle- 

lium.     c.    Deepest  layer 

of  epithelium— the  pris-   fibres  in  proccss  of  development. 

matic  or  columnar  stra-  ... 

turn.  e.  Enamel  germ.  The  principal  Structures  of  the  teeth  are 
derived  from  such  elements  as  compose  the  epi- 
thelial structure  and  the  tissues  beneath  which  represent  the  corium 
and  cellular  tissue  of  the  mucous  membrane,  beneath  which  is  the 
ossifying  substance  of  the  jaw — the  enamel  being  formed  from  the 
epithelium  which  fills  the  dental  groove  and  constitutes  the  rounded 
projection  or  smooth  ridge,  and  the  dentine  and  cementum  (crusta 
petrosa)  from  the  deeper  structures  of  the  mucous  membrane. 

Development  of  the  Enamel. — First,  as  to  the  development  of  the 
enamel,  which  is  very  similar  to  that  of  the  hair  follicle.  About  the 
sixth  or  seventh  week  of  fetal  life,  the  epithelium  fills  the  groove  or 


Fig.  80. 
a.  Flat  layer  of  epithelium,    b.  Proliferation  of  cuboidal  layer,  forcing  columnar  layer  down- 
ward, producing  V-shaped  appearance.     The  removal  of  these  upper  layers  leaves  the 
"primitive  dental  groove."    c.  Lamina  from  which  arise  the  epithelial  cords  of  enamel 
organs. 


depression  on  the  surface  of  the  jaw  so  full  that  a  small,  rounded  pro- 
jection or  ridge  is  formed,  from  the  under  surface  of  which  a  process 
sinks  into  the  tissue  beneath,  the  outlines  of  which  resemble  in  shape 
the  letter  V  with  the  apex  slightly  inclined  toward  the  inner  surface 
(Fig.  80).  This  epithelial  process  or  band  is  simply  a  prolongation 
of  the  natural  covering  of  the  mouth,  which  sinks  into  the  embryonic 


ORIGIN    AND    DEVELOPMENT    OF    THE    TEEIH.  121 

tissue  of  the  jaw,  and  forms  for  itself  a  groove  which  it  completely 
fills,  and  is  composed  of  the  same  histological  elements  as  the  epithe- 
lium of  the  mucous  membrane  of  the  mouth. 

When  this  epithelial  band  is  fully  formed  it  presents  two  surfaces, 
an  external  and  an  internal,  and  from  the  latter  a  process  is  given  off 
which  forms  the  epithelial  lamina.  This  epithelial  lamina  is  a  con- 
tinuous process  extending  over  the  entire  epithelial  band,  being  an 
inflection  of  the  band  itself,  and  its  elements  are  the  same,  namely, 
polygonal  cells  inclosed  by  a  layer  of  prismatic  cells. 

The  "dental  follicle,"  which,  as  was  before  stated,  consists  of  the 
enamel  organ,  the  dentinal  germ  or  papilla,  and  the  follicular  wall,  is 
developed  from  points  on  the  free 

extremity  of  the  epithelial  lamina.  d  ^  =aF=^-^ 

These  follicles  appear  as  small  tuber-  ^^  ^ 

cles    arranged  at  intervals  on   the  ^_  __ 

free  margin  of  the  lamina,  and  cor-  ^^^ji^^-^j,=;^:^3^-^^ 

respond  in  number  and  location  to 
the  future  deciduous  teeth,  being 
the  primitive  germs  of  the  dental 
follicles,  which  retain  their  con- 
nection with  the  lamina  by  means 
of  a  slender  cord,  which  gradually 
increases  in  length  as  the  develop- 
ment of  the  germ  at  its  extremity  f 

progresses.       This   germ   constitutes       Fig.  8i.— prismatic  Dental  Follicle. 

the    enamel    organ,  while    the     neck      "^^  Prismatic  or  columnar  ceils,     d.  Large 
"       '  polygonal  cell  of  the  epithelial  band.    f. 

or  cord  in  its  progressive  lengthen-         Small  cells  of  the  epithelial  laminae. 

ing  merely  serves   as  a  temporary 

connection  with  the  lamina.  This  germ  presents  a  spherical  form  in 
its  early  stage  (Fig.  8i),  and  is  composed  of  an  external  layer  of 
prismatic  cells  (ameloblasts)  including  a  mass  of  polygonal  cells.  The 
younger  layer,  described  as  "infant  cells,"  owing  to  the  active  cell- 
multiplication  which  takes  place  at  the  point  where  the  epithelial  cord 
for  the  tooth  is  to  arise,  sinks  into  the  substance  of  the  tissue  beneath 
the  epithelium  in  the  form  of  a  pouch.  Some  contend  that  the  cells 
of  this  infant  layer  are  not  columnar,  but  are  oval  or  spheroidal. 
The  enamel  organ  at  about  the  fourth  month  of  the  development  of 
the  embryo  has  undergone  very  considerable  changes,  the  primitive 
polygonal  cells  which  compose  the  central  mass  or  middle  region  of 
this  organ  have  been  transformed  into  stellate  bodies  differing  in 
appearance  from  the  primitive  cells,  a  process,  however,  which  is  con- 
fined to  the  cells  of  the  enamel  germ,  and  which  does  not  take  place 


122  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

in  the  cells  of  the  epithelial  cord  or  lamina,  thus  affording  evidence 
that  the  constitution  of  the  one  differs  from  that  of  the  other. 

These  stellate  cells  (Fig.  82)  are  composed  of  a  central  nucleus  sur- 
rounded by  a  transparent  or  finely  granular  mass,  which  mingles  with 
the  neighboring  elements. 

They  occupy  at  first  only  the  center  of  the  enamel  organ,  and  those 
near  the  periphery  preserve  their  primitive  polygonal  form,  but 
become  stellate  as  the  organ  increases  in  size,  and  are  formed  from  the 
original  elements  composing  the  internal  mass  of  the  enamel  organ, 
being  epithelial  in  their  nature. 

After  a  time  the  base  of  these  stellate  cells  presents  the  regular 
prismatic  form  of  a  hexagon  (Fig.  8;^). 

During  this  modification  of  the  enamel  germ,  no  change  appears  to 
take  place  in  the  epithelial  lamina. 

The  primitive  enamel  germ  at  length  loses  its  original  spherical 


Fig.  82.— Stkllate  Cells  of 

THE  Enamel  Organ. 
(Diagrammatic,  from  Frey.) 


Fig.  S3. — Represents 
the  h  kxagonal 
Form  .Assumed  by 
THE  Base  of  the 
Stellate  Cells. 


form,  and  becomes  somewhat  cylindrical,  pursuing  a  horizontal  course 
until  it  undergoes  a  considerable  increase  in  length,  when,  by  an 
abrupt  turn,  it  takes  a  vertical  direction  and  sinks  into  the  tissues  of 
the  jaw. 

During  such  a  progress  the  cord  acquires  a  length  in  accordance 
with  the  requirements  of  the  jaw. 

After  the  epithelial  cord  has  changed  its  course  from  a  horizontal  to 
a  vertical  direction,  its  extremity  expands  and  assumes  a  club-shape, 
on  account  of  the  multiplication  of  the  polyhedral  cells  of  which  its 
greater  portion  is  composed,  and  also  of  the  prismatic  cells  that  sur- 
round it.  This  expanded  extremity  also  becomes  somewhat  spherical, 
and  its  upper  portion  corresponds  to  the  point  of  connection  with  the 
cord,  while  the  lower  portion  points  toward  the  base  of  the  lower  jaw. 

This  condition  represents  a  fully  formed  enamel  organ,  which  is  the 


ORIGIN    AND    DEVELOPMENT    OF    THE    TEETH. 


123 


first  trace  of  the  dental  follicle.  Very  soon  the  lower  portion  of  the 
enamel  organ  becomes  concave,  and  assumes  the  form  of  a  cap  or 
hood,  although  still  retaining  its  connection  with  the  epithelial  cord. 
At  this  stage  in  the  development  of  the  enamel  organ  the  dentinal 
germ  or  papilla  makes  its  appearance. 

During  the  development  of  the  primitive  epithelial   cord,  lateral 
germs  similar  to  small  rounded  nodules,  in  the  form  of  varicosities. 


j.L,yv:  Jiei. 

Fig.  84. 
a.  Epithelial  layers  of  mucous  membrane  lining  mouth,  b.  Embryonal  corpuscles  of  der- 
mal tissue  of  jaw.  c.  Budding  of  cord  of  permanent  tooth  from  cord  of  temporary  tooth. 
d.  Enamel  organ  of  temporary  tooth,  e.  Columnar  or  prismatic  layer  of  cells  from 
which  ameloblasts  or  enamel  cells  are  formed,  f.  Dentine  germ  formed  from  embryonal 
corpuscles  of  dermal  tissue,  g;.  Commencing  ossification  of  inferior  maxilla,  h.  V- 
shaped  band,  resulting  from  proliferation  of  cells  of  cuboidal  layer,  i.  Development  of 
connective-tissue  cells  from  embryonal  corpuscles,  forming  sac  which  incloses  tooth-germ. 


make  their  appearance,  and  which,  according  to  Magitot,  resemble  an 
irregular  chaplet  or  chain.  These  lateral  germs  are  composed  of  small 
polyhedral  cells,  like  those  of  the  cord  itself,  with  walls  formed  of  a 
layer  of  prismatic  cells  in  continuation  of  the  Malpighian  layer  of  the 
epithelium.  From  these  lateral  germs  or  masses,  at  a  later  period, 
after  the  cord  is  ruptured,  epithelial  prolongations  arise. 


124 


PRINCIPLES    AND    PRACTICE   OF   DENTISTRY. 


The  primitive  cells  during  the  early  stage  of  evolution  present  the 
same  characteristics  on  all  parts  of  the  periphery,  but  as  soon  as  the 
dentinal  germ  or  papilla  begins  to  appear  these  primitive  cells  on  the 
concave  surface  lengthen,  while  those  of  the  convex  surface  decrease 
in  size  until  they  disappear  entirely,  before  the  atrophy  of  the  enamel 
pulp;  and  those  of  the  internal  surface  remain  for  the  formation  of 
the  enamel  organ. 

Besides  increasing  in  length,  the  prismatic  cells  of  the  concave  sur- 
face of  the  enamel  organ  undergo  changes,  their  extremities,  directed 
toward  the  center  of  the  enamel  organ,  forming  slender  processes, 
which  either  unite,  or  are  continuous  with  filaments  from  surrounding 


Fig.  85.— Enamel  Organ  and  "  Nasmyth's  Layer  "  of  Cells,  Drawn  Under  a  Magni- 
fying Power  of  1800  Diameters. 

a.  Portions  of  the  reticulum  which  lie  exactly  in  focus;  the  points  of  intersection  are  seen 
to  be  made  up  of  a  finer  and  more  delicate  reticulum,  d.  Parts  which  lie  a  little  beyond 
focus,  c.  Granular  matter  held  in  the  meshes  of  the  reticulum,  d.  "  Nasmyth's  mem- 
brane," or  layer  of  flat  cells,  just  outside  of  enamel  cells. 


cells,  which  constitute  the  portion  of  the  enamel  organ  designated  as 
the  stratum  intermedium.  The  stratum  intermedium  consists  of  cells 
which,  according  to  Mr.  Tomes,  are  intermediate  in  character  be- 
tween those  of  the  bordering  epithelium  and  the  stellate  reticulum, 
being  branched,  but  less  conspicuously  so  than  the  stellate  cells  with 
which  they  are  continuous  on  the  one  hand,  and  on  the  other  with  the 
enamel  cells.  According  to  Waldeyer,  Hertz,  and  Hannover,  since 
the  enamel  cells  may  be  frequently  seen  connected  at  their  lower  ex- 
tremities with  the  cells  of  the  stratum  intermedium,  a  multiplication 
of  enamel  cells  from  the  cells  of  this  stratum,  in  the  direction  of  their 
length,  may  be  admitted  to  occur. 


ORIGIN    AND    DEVELOPMENT    OF    THE    TEETH. 


125 


E.E. 


According  to  Dr.  G.  V.  Black,  and  quoted  by  Dr.  M.  A.  Dean, 
"just  before  the  classification,  and  even  before  the  odontoblasts  make 
their  appearance,  the  ameloblasts  (pris- 
matic cells),  and  the  tissues  of  the  pulp 
are  separated  by  a  well-marked  double 
pellucid  layer,  which  in  sections  appears 
as  a  double  band."  This  double  band 
is  represented  in  Fig.  86  by  the  two 
white  parallel  lines,  A  A,  the  upper  one 
being  the  tissue  which  is  identical  with 
the  membmmi  prceformativa  of  Huxley, 
while  the  lower  one  represents  the  base- 
ment membrane  of  Ladd  and  Bowman, 
and  the  membrana  prceformativa  of 
Raschkow. 

After  the  epithelial  cells  are  changed 
into  hexagonal  prisms,  these  anastomose 
and  form  the  hexagonal  rods  character- 
istic of  fully  matured  enamel. 

The  epithelial  covering  on  the  outer 
surface  of  the  enamel  remains  distinctly 
perceptible,  and  after  the  eruption  of 
the  crown  of  the  tooth  this  layer,  which 
is  known  as  the  "  dental  cuticle  " — cuti- 
cula  dentis — and  also  as  "  Nasmyth's 
membrane,"  may  be  separated  from  the 
enamel  surface  beneath  it  by  strong  acids,  when  the  hexagonal  depres- 
sions of  enamel  prisms  are  apparent,  and  on  the  application  of  nitrate 
of  silver  the  characteristics  of  epithelium  appear. 

Dr.  J.  L.  Williams,  in  an  able  article  on  "embryology,"  dissents 
from  the  opinion  of  Legros  and  Magitot  concerning  the  function  of 
the  membrana  prceformativa  of  RaschkoAV,  and  positively  denies  that 
it  has  any  modifying  influence  in  the  process  of  the  development  of 
the  teeth ;  and,  while  he  is  not  prepared  to  deny  in  toto  the  existence 
of  this  membrane,  says  that  an  examination  of  many  specimens  failed 
to  discover  this  structureless,  transparent  tissue  ;  and  he  asks,  "  How 
is  it  possible  that  the  odontoblasts,  which  are  more  than  -^^-^  of  an 
inch  in  diameter,  can  be  developed  in  a  membrane  which  Beale  says  is 


Fig.  86. — B.  M.  Basement  membrane. 
N.  Neck.  S.  Sac  or  follicular  wall. 
O.  Enamel  organ.  B.  Bulb.  E.  E. 
External  epithelium  of  the  enamel 
organ  and  the  basement  membrane. 
E.  C.  Epithelial  cord.  C.  T.  Con- 
nective tissue  surrounding  the 
enamel  organ.  Ep.  Epidermis  or 
oral  epithelium. 

The  parts  embraced  between  the 
points  where  the  divergent  lines  /l.  A. 
terminate  are:  (i)  The  concave  face  of 
the  enamel  organ,  lined  with  a  layer 
of  ameloblasts,  or  the  "  internal  epi- 
thelium." (2)  The  membrana  prae- 
formativa  of  Huxley,  or  the  tissue 
composed  of  the  basal  coverings  of 
the  ameloblasts.  (3)  The  membrana 
prseformativa  of  Raschkow,  or  the 
basement  membrane.  (4)  The  den- 
tine bulb  itself.     Diagrammatic. 


"  certainly  less  than  the 


20000 


of  an  inch  in  thickness."     Dr.  Wil- 


liams also  remarks  :  "It  has  been  supposed  that  the  so-called  amelo- 
blasts, or  enamel  cells,  are  formed  directly  from  the  layer  of  columnar 
or  prismatic  epithelium  which  covers  the  face  of  the  enamel  organ." 
But  preceding  the  development  of  the  enamel  cells,  the  original  pris- 


126 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


matic  cells  break  up  or  divide  into  round,  nucleated  corpuscles,  which 
change  is  denominated  by  Professor  Heitzmann  and  Dr.  Atkinson  a 
return  to  an  embryonal  condition." 

•'  From  these  embryonal  corpuscles  are  developed  the  enamel- form- 
ing cells,  and  also  an  outer  layer  of  smaller  cells,  from  which  is  formed 
Nasmyth's  membrane." 

The  same  author  also  regards  the  enamel  organ  as  a  ''  true  secreting 


IVWDel 


Fig.  87. —  The  Specimen  from  'i'hich  this  drawing  was  niadf  was  placed  tinder  a  one-tenth 
inch  iniiticrsiun  lens,  magnifying  about  Soa  diameters. 

«.  Connective  tissue  of  tooth-sac.  h.  Capillary  vessels  cut  transversely  and  longitudinally, 
and  filled  with  blood-corpuscles,  c.  Keticuluni  of  enamel  organ,  d.  Round  and  flat 
layer  of  cells,  forming  the  so-called  "  Nasmytli's  ineinhrane."  e.  Ameloblasts  or  enamel 
cells. 


organ,"  and  that  the  material  for  the  formation  of  enamel  has  no  other 
evident  source. 

Development  of  the  Dentine. — As  the  epithelium  is  undergoing  this 
peculiar  development  into  the  enamel  organ,  a  projection  of  the 
corium  of  the  mucous  membrane  of  the  fetal  jaw  rises  up  to  meet 
it  out  of  the  dental  groove.  This  projection  is  the  dentinal  papilla  or 
germ,  which  is  described,  after  Dursy  and  Waldeyer,  as  a  ridge,  "the 


ORIGIN    AND    DEVELOPMENT    OF    THE    TEETH. 


127 


intervening  parts  of  which  are  atrophied  so  as  to  leave  papillae  or 
germs  which  become  coated  all  over  by  the  enamel  organ,  and  thus 
the  saccular  stage  of  the  teeth  is  produced,  the  papillae  which  are  to 


Fig.  i&.— Drawn  under  the  same  magnifying  power  as  Fig.  74. 
a.  Connective-tissue  cells  of  tooth-sac.     b.  Reticulum    of  enamel  organ.     In   this  drawing 
it  is  seen  that  the  reticulum  holds  in  its  meshes  very  large,  soft,  granular  corpuscles,  here- 
tofore known  as  the  gelatinous  fluid  of  the  enamel  organ,     c.  Breaking  down  of  colum- 
nar layer  of  cells  into  embn,onal  corpuscles,  from  which  ameloblasts  are  developed. 

form  the  bulk  of  the  teeth  being  coated  with  a  vascular  connective 
tissue,  isolated  by  the  enamel  organ  and  separated  from  each  other  by 
the  growing  (osseous)  tissue  of  the  fetal  jaw." 


128  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

Dursy,  according  to  Waldeyer,  says:  "The  first  germ  of  the  den- 
tine appears  in  the  dental  sacculus,  as  a  dark  semilunar  area  at  the 
bottom  of  the  dental  groove — that  is  to  say,  of  the  enamel  germ — 
coetaneously  and  continuously  with  which  it  is  developed  along  each 
half  of  the  jaw.  At  certain  points  corresponding  to  the  position  of 
the  subsequent  teeth,  the  young  structure  develops  in  the  form  of 
papillae,  projecting  against  the  enamel  germs,  while  the  remainder 
atrophies.  The  two  horns  of  the  semilunar  mass  (as  seen  in  section) 
extend  from  the  base  of  the  dental  papilla  some  distance  upward,  and 
embrace  the  dentine  germ  and  enamel  organ." 


'M 


KJ 


H-- ^-1-/-- I  i^ 

F — 

F ~ 

I — W^-   -  ■ 


iJ 


■mJa 


Fig.  89. 
m.  Meckel's  cartilage,    b.  Traces  of  ossification,    c.  Lowest  layer  of  Malpighian  stratum,    d. 
Oral  epithelium,    j*^.  Ameloblastic  or  prismatic  layer.    Lower /\  External  layer  of  enamel 
organ    g.  Stellate  reticulum  of  the  enamel  organ.     H.  Dental  germ,  or  papilla.     /.  Folli- 
cular walls. 

According  to  Dr.  Sudduth,  the  epithelial  cord  does  not  penetrate 
tne  underlying  tissue  searching  for  a  dentinal  papilla,  but  it  has  the 
j)Ower  to  superintend  the  differentiation  of  a  papilla  for  itself. 

As  the  dentinal  papilla  or  germ  increases  in  height,  it  assumes  a 
slightly  oblique  direction  in  relation  to  the  axis  of  the  follicle,  and  at 
the  same  time  becomes  constricted  at  its  base,  thus  forming  a  neck  at 
the  line  where  the  enamel  organ  is  reflected  back  upon  itself  (Fig.  89). 

The  follicular  wall,  which  forms  a  part  of  the  dental  follicle,  first 
appears  as  a  process  arising  from  the  base  of  the  papilla,  to  the  neck 
of  which  it  is  attached  like  a  slight  collar.     Its  development  begins  as 


ORIGIN  AND  DEVELOPMENT  OF  THE  TEETH. 


129 


soon  as  the  small  mass  which  constitutes  the  dentinal  germ  assumes  a 
hemispheric  form.  The  follicular  wall,  by  its  gradual  upward  growth, 
at  length  embraces  and  isolates  both  the  enamel  organ  and  the  dentinal 
papilla,  and  during  its  evolution,  from  being  composed  of  embryo- 
plastic  elements,  by  degrees  assumes  the  appearance  of  a  distinct  lami- 
nated membrane,  which  may  be  separated  from  the  adjacent  tissue, 
except  at  the  base  of  the  papilla  to  which  it  remains  adherent.  Accord- 
ing to  both  Kolliker  and  Huxley,  the  transparent  stratum  {ijiembrana 
prceformativa)  which  invests  the  dentinal  papilla  reflects  itself  back  on 
its  internal  surface,  and  thus 
lines  the  whole  inner  surface  of 
the  follicular  wall. 

As  the  evolution  of  the 
follicular  wall  progresses,  it 
closes  over  the  contents  of  the 
dental  follicle,  which,  besides 
the  wall,  consist  of  the  enamel 
organ  and  the  dentinal  papilla ; 
the  enamel  organ  being  sub- 
jacent to  the  follicular  wall,  to 
which  it  conforms  in  such  a 
manner  that,  while  the  ex- 
ternal face  of  the  organ  is  in 
relation  with  the  wall,  the  lower 
concave  face  is  in  immediate 
contact  with  the  papilla.  The 
dentinal  papilla  occupies  the 
lower  and  central  portion  of  the 
follicular  sac. 

The  enamel  organ  fills  the 
entire  space  between  the  sac  wall  and  the  papilla,  terminating  at  the 
base  of  the  latter  in  a  rounded  margin  which  forms  the  dividing  line 
between  the  prismatic  cells  which  cover  its  concave  and  convex  sur- 
faces (Fig.  90).  The  dental  follicle  is  of  an  ovoid  form,  and  varies 
in  size  according  to  the  class  of  tooth  to  be  developed  from  it ;  and 
when  it  is  completely  formed,  it  remains  inclosed  within  the  em- 
bryonal tissues  of  the  jaws,  with  which  it  is  at  first  only  slightly 
connected. 

When  the  rupture  of  the  epithelial  cord  occurs,  it  loses  its  communi- 
cation with  the  mucous  membrane,  and  forms  no  connection  with  the 
maxillary  bone,  as  the  alveolar  processes  are  not  developed  until  a  later 
period. 

The  rupture  of  the  epithelial  cord,  which  brings  about  the  isolation 
9 


Fig.  90. — a.  Wall  of  the  sac,  formed  of  connective 
tissue,  witli  its  outer  stratum  a*  and  its  inner  a*. 
b.  Enamel  organ,  with  its  papillar>'  and  parietal 
layer  of  cells,  c,  d.  The  enamel  niemhrane  and 
enamel  prisms,  e.  Dentine  cells,  f.  Dental 
germ  and  capillaries,  g,  i.  Transitionof  the  wall 
of  the  follicle  into  the  tissue  of  the  dental  germ. 


13°  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

of  the  dental  follicle  from  the  mucous  membrane,  is  due  to  the  upward 
growth  of  the  follicular  wall,  which  closes  over  the  top  of  the  enamel 
organ,  beneath  which  is  the  papilla,  the  union  of  the  edges  of  the  wall 
producing  compression  or  strangulation  of  the  cord  at  that  point.  At 
this  period  of  evolution,  the  saccular  stage,  the  dental  follicle  is  com- 
pleted, and  from  the  cells  of  the  dentinal  papilla  a  soft  matrix  of  ani- 
mal matter  is  formed,  which  becomes  impregnated  with  calcareous 
matter  to  form  the  complete  dentinal  tissue,  while  in  the  interior  of 
the  cavity  of  the  dentine  cells  are  formed,  which  continue  to  form  new 
matrix  for  a  considerable  time. 

After  the  dentinal  papilla  has  become  coated  over  by  the  enamel 
organ,  and  the  saccular  stage  of  the  teeth  is  produced,  and  the  papillae 
have  become  separated  from  each  other  by  the  developing  tissue  of 
the  embryonic  jaw,  odontoblasts  (dentine  cells)  begin  to  form.  These 
odontoblasts  are  large  nucleated  cells  of  elongated  form,  containing 
numerous  processes  developed  from  the  cells  of  the  dentinal  papilla, 
which  at  that  early  period  consist  of  fine  fibrous  tissue  with  numerous 
cells. 

The  odontoblasts  send  out  processes  which,  as  they  develop,  calcify 
externally,  the  calcified  portion  forming  the  dentine,  and  the  uncalci- 
fied  part  the  dentinal  fibrillae,  and  the  lateral  branches  of  anastomosis 
whereby  the  tubuli  or  canals  of  the  dentine  anastomose.  The  remains 
of  the  odontoblasts  form  a  cellular  layer  which  constitutes  the  invest- 
ment of  the  pulp  lying  between  its  nerves  and  vessels  and  the  dentine. 
This  cellular  layer  is  known  as  the  "  ivory  membrane  " — mejnhrana 
eboris  of  Kolliker. 

The  enamel  organ  is  non-vascular,  but  a  network  of  vessels  is  fiir- 
nished  to  the  follicular  wall  and  the  dentinal  papilla  from  the  surround- 
ing tissues. 

At  the  period  when  the  epithelial  cord  is  ruptured,  the  cells  com- 
posing the  epithelial  lamina  become  greatly  increased  in  number, 
and  irregular  proliferations  or  "buddings"  occur,  which  wander  by 
different  courses  into  the  deeper  portions  of  the  embryonal  tissue. 
These  buddings  differ  in  form,  sometimes  in  that  of  cylinders  which 
retain  their  connection  with  the  primitive  lamina;  but  frequently 
this  connection  is  absorbed,  and  an  epithelial  mass  is  set  free. 
Clusters  of  these  masses  occasionally  take  the  globular  form,  resem- 
bling those  in  the  lamina  itself,  but  frequently  they  become  absorbed 
and  disappear  before  the  development  of  the  tooth  is  completed. 
At  the  time  the  absorption  of  the  epithelial  lamina  is  taking  place, 
changes  precisely  analogous  are  transpiring  in  the  severed  epithelial 
cord. 

From  the  remains  of  this  cord  processes  are  given  off,   which  at 


ORIGIN    AND    DEVELOPMENT    OF    THE    TEETH.  I3I 

times  become  quite  numerous,  and  may  remain  almost  to  the  time  of 
the  eruptive  stage  of  the  tooth. 

The  direction  of  these  processes  is  toward  the  epithelium,  and 
they  consist  of  the  same  polyhedral  cells  as  the  cord  and  lamina,  but 
are  never  invested  with  prismatic  cells.  All  these  epithelial  prolifera- 
tions finally  disappear  by  absorption,  unless  some  such  masses  may 
become  detached  and  wander  into  the  deeper  tissues ;  for  it  is  con- 
sidered by  some  eminent  histologists  that  a  dentinal  papilla  or  germ 
may  originate  from  any  point   of  the  dentinal  sheet  of  tissue  with 


0  e 

V              1 

4=m^i 

ai     1    . 

^ff^'j^ 

h    i 

7 

jwi 

w— ^ 

-'■ 

H     '^ 

-       1    ; 

P          E 

j!  e' 

"          .' 

'   \\         '; 

i    /I 

F.     f 

1 

-   - 

'Tim 


Jb 


Fig.  91. 
a.  Meckel's  cartilage.     6.  Traces  of  ossification,     c.  Lowest  layer  of  Malpighian  stratum. 
d.  Oral  epithelium.     F.  Ameloblastic  layer.     Lower  F.   External   layer  of  enamel  organ. 
H.  Dentinal  papilla.     /.  Follicular  wall.     K.  Buddings  of  epithelial  cord. 

which  the  epithelial  mass  comes  in  contact,  and  that  it  is  solely 
through  the  influence  of  the  enamel  organ  upon  this  tissue  that  the 
development  of  the  dentinal  papilla  is  induced. 

Immediately  after  the  rupture  of  the  epithelial  cord,  the  formation 
of  the  secondary  follicle  of  the  permanent  tooth  begins.  There  is  no 
trace  of  the  osseous  tissue  of  the  jaw  at  the  time  of  the  origin  of  the 
primitive  epithelial  cord.  Bone  first  makes  its  appearance  near  the 
base  of  the  follicles,  forming  a  horizontal  layer,  and  separating  the 
groove  of  the  follicles  from  the  canal  reserved  for  the  vessels  and 
nerves.  From  the  layer  or  floor,  lateral  processes  arise  and  form  the 
dental  groove,  in  which  the   follicles  remain  for  some  time  without 


132  PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 

being  separated  by  transverse  partitions,  and  it  is  only  after  the  devel- 
opment of  the  crowns  of  the  teeth  has  commenced  that  bony  processes 
are  thrown  across  the  groove,  forming  receptacles  for  the  lodgment  of 
each  follicle  with  an  opening  in  the  direction  of  the  epithelial  surface 
(Fig.  92). 

Development  of  Cementum  {^Cnista  Petrosa). — There  appears  to  be  a 
difference  of  opinion  among  histologists  concerning  the  origin  of  the 
cementum.  Magitot,  in  1858,  and  again  Robin  and  Magitot,  in 
1 86 1,  described  a  new  tissue,  which,  some  time  before  the  formation 
of  the  first  dentine  cap,  was  supposed  to  exist  between  the  follicular 
wall  and  the  organs  within  it — the  enamel  organ  and  the  papilla — 


Fig.  92.— From  the  Upper  Jaw  of  a  Kitten,  About  the  Time  of  Birth. 

Oral  epithelium,  d.  Bone  of  jaw.  c.  Neck  of  enamel  organ,  d.  Dentinal  papilla,  e.  En- 
amel cells.  /.  Stellate  reticulum,  h.  Germ  or  papilla  of  permanent  tooth,  the  enamel 
organ  of  which  is  derived  from  the  primary  cord. 


differing  from  the  other  tissues  in  color,  consistence,  and  structure, 
and  upon  which  the  formation  of  the  cementum  depended. 

On  the  other  hand,  Kolliker,  Waldeyer,  Hertz,  Kollman,  and 
others,  deny  the  existence  of  such  a  membrane  or  tissue,  and  ascribe 
the  formation  of  the  cementum  (which  resembles  ordinary  bone,  as  it 
contains  canaliculi  and  lacunae)  to  a  periosteal  origin — that  it  is 
developed  from  the  deeper  tissues  of  the  fetal  jaw  by  periosteal  ossifi- 
cation, the  process  being  similar  to  that  of  bone  formation  in  other 
parts  of  the  body. 

Origin  of  the  Permanent  Teeth. — While  Goodsir  held  that  the  folli- 
cles of  the  permanent  teeth  originate  from  a  fold  of  the  sac  of  the 
primitive  or  deciduous  follicle,  the  later  investigations  of  Kolliker 
and  Waldeyer  have  shown  that  the  permanent  follicles  of  teeth  that 


ORIGIN  AND  DEVELOPMENT  OF  THE  TEETH. 


133 


have  deciduous  predecessors  arise  from  certain  prolongations  of  the 
primitive  epithelial  cord. 

The  germ  of  the  permanent  follicle  originates  at  a  point  where  the 
primitive  epithelial  cord  merges  into  the  enamel  organ  of  the  tem- 
porary tooth,  and  is  an  outgrowth  of  this  cord  (see  Fig.  93).  The 
permanent  cord  takes  a  vertical  direction,  and  passes  between  the 
bony  alveolar  wall  and  the 
primitive  follicle,  and  then 
along  the  inner  or  lingual  face 
of  the  follicle,  its  elements  be- 
ing the  same  as  those  of  the 
primitive  cord. 

The  permanent  dentinal  pa- 
pilla or  germ  sinks  to  the  bot- 
tom of  the  osseous  dental  groove, 
where  it  soon  loses  its  connec- 
tion with  the  primitive  follicle, 
though  still  retaining  its  rela- 
tion with  the  epithelial  lamina. 

The  primitive  follicle,  how- 
ever, by  the  severance  of  its 
cord  at  a  point  just  below 
where  the  germ  of  the  perma- 
nent or  secondary  cord  arises, 
loses  all  connection  with  the 
epithelial  lamina,  and  develops  fig.  93.-Section  of  the  Lower  Jaw  of  a 

Human  Fetus. 
g%  inches  in  length  ;  corresponding  to  about  the 

eighteenth  week.  (Magnified  So  diam.) 
K.  Cord  or  bourgeon  of  the  secondary  follicles. 
L.  Points  where  its  separation  from  the  primi- 
tive cord  is  being  effected,  a.  Meckel's  cartil- 
age diminished  by  absorption,  b.  Bone  of  the 
jaw.  c.  (Upper)  dental  artery ;  (lower)  dental 
nerve,  d.  Epitiielium.  E.  Originally  the  cord 
of  the  temporary  follicle,  but  now  the  sole  prop- 
erty of  the  permanent  one. 


as  an  independent  body  or  or- 
gan.      ^ 

The  sinking  of  the  follicle  of 
the  permanent  tooth  is  soon 
followed  by  the  entire  series  of 
phenomena  which  characterize 
the  growth  of  every  dental  fol- 
licle ;  and  while  the  permanent  follicle  is  being  developed,  the  remains 
of  the  ruptured  primitive  cord  which  continues  to  be  attached  to  the 
primitive  follicle  are  subject  to  that  "  budding  "  process  which  invari- 
ably commences  at  the  moment  this  cord  is  severed — about  the  fourth 
month,  or  quickening  period.  The  direction  of  the  permanent  cord 
being  vertical,  its  length  is  governed  by  the  height  of  the  alveolar 
border  and  the  direction  of  the  primitive  follicle.  When  sinking 
into  the  substance  of  the  jaw,  the  permanent  cord  always  assumes  a 
spiral  form,  and  to  such  a  degree  that  it  can  be  readily  distinguished 


134 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


from  the  primitive  cord,  as  this  latter  is  never  so  distinctly  spiral  in 
form  as  the  former. 

This  spirality  of  form  peculiar  to  the  permanent  cord  is  occasioned 
by  the  greater  distance  this  cord  must  traverse  in  the  more  developed 
tissues  of  the  jaw,  to  permit  the  permanent  follicle  to  accomplish  its 
passage  to  a  point  under  the  temporary  tooth,  and  thus  prevent  the 
stretching  of  the  cord  and  the  disturbance  of  the  parts  with  which  the 
cord  an.4  «Tiamel  organ  are  connected.     The  spiral  nature  of  the  cord 


«#^ 

.^i#^. 


A. 


-K' 


€- 


H-^.; 


il) 


Fig.  94.— Vertical  Section  of  the  Lovvkr  Jaw  of  a  Human  Fetus. 

Measuring  iSJ^;  inches  ;  correspond iiig  lo  nearly  the  thirty-ninlli  week  of  gestation.  The 
figure  represents  a  cut  passing  tlirough  the  follicle  of  a  bicuspid. 

b.  Bone  of  the  jaw.  d.  Oral  epithelium,  g.  Enamel  organ.  H.  Dental  bulb.  K.  DSbris 
of  the  cord  of  a  permanent  follicle.  A'',  A".  Epidermal  globules.  Follicle  for  the  per- 
manent tooth  connected  with  the  debris  of  its  cord,  A'. 


continues  from  its  origin  toward  its  termination  in  a  rounded  or  club- 
ihaped  enlargement,  similar  to  that  of  the  extremity  of  the  primitive 
cord,  this  enlargement  representing  the  enamel  oi'gan  of  the  perma- 
nent tooth. 

At  the  period  of  the  evolution  of  the  permanent  follicle,  when  the 
dentinal  papillae  becomes  unicuspid  for  the  incisors  and  canines  and 
multicuspid  for  the  molars,  the  permanent  epithelial  cord,  which  has 


ORIGIN    AND    DEVELOPMENT    OF    THE    TEETH.  I35 

already  been  for  some  time  severed  from  the  primitive  cord  and  folli- 
cle, also  loses  its  connection  with  the  permanent  follicle,  and  has  no 
communication  afterward  with  the  epithelial  lamina.  This  severance 
is  soon  followed  by  the  separation  of  the  permanent  cord  into  frag- 
ments, which,  as  was  before  stated,  bud  and  lengthen  in  different  direc- 
tions, and  become  mingled  and  confounded  with  those  of  the  primi- 
tive cord,  anastomosing  with  them  to  form  a  sort  of  plexus.  Finally, 
all  these  epithelial  masses  atrophy  and  disappear. 

The  above  description  applies  to  the  development  of  the  permanent 
teeth  that  have  temporary  predecessors.  But  the  origin  of  the  perma- 
nent teeth  that  appear  back  of  the  temporary  teeth,  and  have  no 
deciduous  predecessors,  is  entirely  different. 

The  first  permanent  molar,  the  follicle  of  which  makes  its  appear- 
ance during  the  fifteenth  week  of  embryonal  life,  and  only  a  few  days 
after  the  greater  number  of  those  of  the  deciduous  teeth,  and  yet  does 
not  erupt  until  about  the  sixth  year,  originates  directly  from  the 
epithelium  of  the  mucous  membrane,  the  epithelial  cord  from  which 
penetrates  the  fetal  tissue  in  a  region  where  no  follicle  has  preceded  it. 

The  second  permanent  molar  originates  from  an  outgrowth  of  the 
epithelial  cord  of  the  follicle  of  the  first  permanent  molar,  resembling 
in  this  respect  the  twenty  anterior  permanent  teeth,  but  differing  in 
the  direction  of  its  course.  While  the  teeth  derived  from  the  tempo- 
rary follicles  pass  over  the  lingual  face  of  the  latter  to  a  position 
beneath  them,  that  of  the  second  permanent  molar  takes  a  horizontal 
direction  for  some  distance,  and  then  by  an  inflection  takes  its  posi- 
tion at  the  posterior  side  of  the  follicle  of  the  first  molar,  where  it  is 
developed  in  a  line  with  those  anterior  to  it  (Fig.  92). 

The  origin  of  the  third  molar  or  wisdom  tooth  is  effected  in  the 
same  manner  as  that  of  the  second  permanent  molar,  as  the  epithelial 
cord  that  forms  its  enamel  organ  emanates  from  the  cord  of  the  second 
permanent  molar.  Hence  we  find  the  cord  of  the  first  permanent 
molar  originating  from  the  epithelium  ;  that  of  the  second  permanent 
molar  from  the  cord  of  the  first  permanent  molar ;  and  that  of  the 
third  molar  from  the  cord  of  the  second  permanent  molar. 

Dr.  G.  V.  Black,  whose  extensive  researches  in  dental  histology  are 
worthy  of  all  praise,  is  of  the  opinion  that,  "  although  the  epithelial 
cords  of  the  twenty  anterior  permanent  teeth  generally  arise  from 
those  of  the  temporary  follicles,  yet  they  do  sometimes  emanate 
directly  from  the  epithelium  of  the  mucous  membrane." 

If  such  is  the  case,  the  secondary  or  permanent  epithelial  cords  may 
originate  from  either  the  primary  cord,  the  temporary  follicle,  or  the 
epithelial  lamina.  The  follicles  of  the  temporary  teeth  are  developed 
during  the  period  between  the  latter  part  of  the  third  month  of  gesta- 


136 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


tion  and  the  beginning  of  the  fourth  year — within  forty-two  months — 
while  the  follicles  of  the  permanent  teeth  require  a  much  longer  time 
for  their  evolution.  It  would  seem  quite  reasonable  to  suppose  that 
the  dentinal  papilla  acts  as  an  organic  mold  upon  which  the  elements 
of  the  enamel  are  coated,  but  Magitot  asserts  that  as  the  epithelial 
cord  which  represents  the  future  enamel  organ  always  precedes  the 
appearance  of  the  papilla,  which  is  never  formed  until  the  cord  has 
advanced  a  certain  distance,  this  cord  decides  not  only  XkMt  place  of 
genesis,  but  the  form  and  function  of  the  corresponding  tooth.  Ac- 
cording to  Dursy,  a  dentine  germ  or  papilla  may  be  developed  from 


Fig.  95. — Section  on  a  Line  with  the  Follicle  of  the  First  Permanent  Molar. 
Human  subject,  three  months  after  birth.     {Magnified  So  diameters.) 
b.  Maxillary  bone,     c,  c.  Dental  artery  and  nerve.     F.  Cord  of  the  follicle  of  the  first  perma- 
nent molar,    g.  Enamel  organ.     H.  Bulb  of  the  first  permanent  molar.     A'.  Bourgeon  of 
the  enamel  organ  of  the  second  permanent  molar. 


any  point  of  the  semilunar  area  which  is  found  below  the  enamel 
organ  as  soon  as  such  a  point  is  reached  by  this  organ,  and  the  dentine 
germ  depends  upon  the  course  which  the  enamel  organ  takes.  For 
example,  if  the  epithelial  cord  of  a  canine  should  take  an  unnatural 
course,  so  as  to  come  in  contact  with  the  dentinal  tissue  at  a  point 
between  the  bicuspids,  the  canine  would  be  developed  between  those 
teeth  ;  hence  it  seems  reasonable  to  conclude  that  the  enamel  organ 
determines  the  form  and  character  of  the  future  tooth. 

Although  the  proliferations  or  buddings  of  the  remains  of  the  epi- 


THE    DENTAL    PULP. 


137 


thelial  cord,  after  its  severance  from  the  enamel  organ,  usually  disap- 
pear by  absorption,  yet  it  is  possible  that  some  such  masses,  meeting 
with  dentinal  tissue,  may  become  the  enamel  organs  of  supernumerary 
teeth. 

THE    DENTAL   PULP. 

The  pulp,  occupying  the  central  cavity  in  the  crown  of  the  tooth, 
called  the  pulp-charnber,  and  the  root-canal  in  the  root  of  the  tooth,  is 
composed  of  myxomatous  connective  tissue,  in  which  are  distributed 
blood-vessels  and  nerves,  which  enter  the  apical  foramen  of  the  root 
of  the  tooth.  Near  the  middle  of  the  root-canal,  the  small  afferent 
artery,  known  as  the  arteriole,  divides  into  small  vessels, — capillaries, — 
and  forms  throughout  the  pulp-tissue  a  rich  network,  which  terminates 
at  the  periphery  of  the  coronal  portion  of  the  pulp  in  loops.  (See  Fig. 
98.)  The  capillaries  coalesce  with  a  vein,  which  is  a  branch  of  the 
alveolar  vein.     Numerous  bundles  of  nerves  enter  the  substance  of  the 


Fig.  96.— a  Portion  of  the  Body  of  the 
Pulp,  Showing  the  Cellular  Arrange- 
ment. 


Fig.  97.— a  Portion  of  the  Superficial 
Layer  of  the  Pulp,  Showing  the  Ap- 
pearance of  Vesicles. 


pulp  through  the  apical  foramen  of  the  root  of  the  tooth,  in  the  form 
of  medullated  nerve-fibres,  which  on  approaching  the  periphery  of  the 
organ  become  non-medullated  by  the  loss  of  their  medullary  sheaths, 
which  is  characteristic  of  all  nerve-fibres  in  peripheral  organs.  During 
the  development  of  the  tooth,  the  external  surface  of  the  pulp  is  cov- 
ered by  a  layer  of  protoplasmic  cells,  known  as  odontoblasts,  and  of 
which  the  fibrillae  of  the  dentinal  tubuli  are  processes.  The  pulp  of 
the  completed  tooth  represents  the  shrunken  condition  to  which  the 
tooth-germ,  or  dentinal  papilla,  is  permanently  reduced  after  it  has 
normally  accomplished  the  work  of  dentinification,  and  affords  the 
vascular  and  nervous  supply  of  the  dentine.  In  the  development  of 
the  dentine,  the  thickening  of  the  dentinal  wall  is  produced  by  the 
primary  single  layer  of  odontoblasts,  and  this  thickening  is  not  only 
at  the  expense  of  the  pulp-cavity,  but  of  the  pulp  itself,  which  gradu- 
ally diminishes  in  size  as  the  dentine  increases  in  bulk.     The  dental 


138 


PRINCIPLES    AND    PRACTICE    OF   DENTISTRY. 


pulp  is  an  exquisitely  sensitive,  highly  vascular  substance,  of  a  reddish- 
gray  color,  enveloped  in  an  exceedingly  delicate  and  apparently  struc- 
tureless membrane,  continuous  with  the  peridental  membrane,  and 
adherent  to  the  walls  of  the  pulp- cavity.     This  is  designated  by  Pur- 


a.  The  vessels  of  the  pulp  of  an  upper  central  incisor  injected,  as  seen  under  the  microscope, 
very  highly  magnified,    b.  The  natural  size  of  the  pulp. 


kinj6  and  Raschkow,  "the  preformative  membrane,"  because,  in  the 
formation  of  the  dentine,  the  deposition  of  earthy  salts,  according  to 
these  authors,  commences  in  it. 


THE    DENTAL    PULP. 


139 


The  pulp,  according  to  the  two  last-mentioned  authors,  is  composed 
of  minute  globules.  Schwann  describes  it  as  consisting  of  globular, 
nucleated  cells,  with  vessels  and  nerves  passing  between  them,  the 
cells  having  the  same  radical  course  as  the  fibres  of  the  dentine.  Ac- 
cording to  the  microscopic  observations  of  Mr.  Nasmyth,  it  is  princi- 
pally composed  of  minute  vesicular  cells,  varying  in  size  from  the 
ten-thousandth  to  the  one-eighth  of  an  inch  in  diameter,  disposed  in 
concentric  layers ;  these,  when  macerated,  have  an  irregular,  reticu- 
lated appearance,  and  are  found  to  be  interspersed  with  granules,  the 
parenchyma  being  traversed  by  vessels 
having  a  vertical  direction.  See  Figs.  98 
and  99,  copied  from  Mr.  Nasmyth. 

Mr.  Tomes  describes  it  as  consisting, 
from  its  earliest  appearance,  of  a  series  of 
nucleated  cells,  united  and  supported  by 
plasma ;  also,  prior  to  the  commencement 
of  the  formation  of  the  dentine,  of  deli- 
cate areolar  tissue,  occupied  by  a  thick, 
clear,  homogeneous  fluid  or  plasma.  The 
pulp  is  liberally  supplied  with  blood- 
vessels, furnished  by  the  trunk  which  en- 
ters its  base.  The  ramifications  of  these 
vessels  are  distributed  throughout  its  en- 
tire substance,  forming  a  capillary  net- 
work which  terminates  in  loops  upon  its 
surface. 

Three  or  more  arteries  enter  at  the 
apical  foramen,  and  supply  the  pulp, 
dividing  into  branches,  which,  after  pur- 
suing a  parallel  course,  form  a  capillary 
plexus  immediately  beneath  the  cells  of 
the  memh'ana  eboris,  or  ivory  membrane. 
The  nerves  of  the  pulp  enter  the  apical 
foramen  by  one  large  and  three  small 
trunks,  and,  like  the  arteries,  pursue  at 
first  a  parallel  course,  and  about  the  mid- 
dle of  the  root-canal  form  a  rich  plexus  beneath  the  membrana  eboris, 
or  layer  of  odontoblasts. 

The  distribution  of  the  vessels  of  the  pulp  is  represented  in  Fig.  98, 
made  from  an  injected  preparation  of  an  upper  central  incisor.  The 
communication  of  the  arteries  with  the  veins  by  means  of  a  series  of 
looped  capillaries,  presenting  a  densely  matted  appearance  upon  the 
surface,  is  beautifully  represented.     The  nerves  of  the  pulp  have  a  very 


Fig.  99. — The  inerves  of  the 
Pulp  of  an  Upper  Adult  Bi- 
cuspid, Magnified  Twenty 
Diameters. 


I40 


PRINCIPLES    AND    PRACTICE   OF   DENTISTRY. 


similar  arrangement  in  their  distribution,  having  apparently  looped 
terminations  (Fig.  99). 

The  dental  pulp  undergoes  considerable  change  in  advanced  age, 
diminishing  in  size  by  its  progressive  calcification. 

Further  degeneration  shows  an  atrophied  condition  of  the  odonto- 
blastic layer,  and  coincidentally  with  the  diminution  in  the  quantity 
of  the  cellular  elements,  an  increase  of  the  fibrillar  connective  tissue. 
At  last  the  capillary  system  becomes  obliterated,  according  to  Mr. 
Charles  Tomes,  "  by  the  occurrence  of  thrombosis  (effusion  of  blood 
into  the  cellular  substance)  in  the  larger  vessels,  the  nerves  undergo 
fatty  degeneration,  and  the  pulp  becomes  a  shriveled,  unvascular, 
insensitive  mass." 


CHAPTER  XII. 


TOOTH    STRUCTURES. 


Enamel. — With  regard  to  the  formation  of  the  enamel,  the  dental 
follicles  have  their  origin  in  a  cord  which  emanates  from  the  epithelial 
layer  of  the  mucous  membrane  of  the  mouth.  These  cords  arise 
directly  from  a  process  of  the  oral  epithelium,  those  of  the  permanent 
teeth,  which  succeed  the  deciduous  ones,  being  outgrowths  from  the 
primitive  cords.  Concerning  the  cords  of  the  other  permanent  teeth, 
those  for  the  first  molars  originate  directly  from  the  epithelium  of  the 


Fig.  ioi.— a  Side  View  of  the  En- 
amel Fibres;   Magnified 
800  Times. 
I.  The  enamel   fibres.    2,2.  Transverse 
striae  upon  them. 


Fig.  100. — Thk  Hexagon- 
al Termination  of 
THE  Fibres  of  a  Por- 
tion OF  the  Surface 
OFTHE  Enamel;  High- 
ly Magnified. 

At  I,  2,  3,  the  crooked  cre- 
vices between  the  hex- 
agonal fibres  are  more 
strongly  marked. 


mucous  membrane,  and  the  remaining  ones  from 
the  cords  of  the  preceding  molars.  The  enlarged 
extremity  of  the  cord  constitutes  the  enamel 
organ  of  the  future  dental  follicle.  (See  Origin 
and  Formation  of  the  Teeth.) 
When  the  enamel  is  first  deposited  upon  the  surface  of  the  dentinal 
papilla,  it  is  of  a  chalky  appearance,  and  afterward  attains  the  glossy 


TOOTH    STRUCTURES.  141 

hardness  by  which  it  is  characterized,  with  a  white  appearance,  like 
porcelain. 

The  enamel  forms  a  smooth,  dense  layer  enveloping  the  crown  of 
the  tooth  as  far  as  the  neck,  where  it  insinuates  itself  between  the 
cementum  and  dentine.  It  is  thickest  on  the  cutting  edges  and 
grinding  surfaces  of  the  teeth,  tapering  to  a  thin  edge  at  their  necks. 
In  color  it  is  rather  translucent  than  white.  The  analysis  of  enamel 
consists  of 

Calcium  Phosphate, 85.3 

Calcium  Carbonate, 8.0 

Calcium  Fluorid, 3.2 

Magnesium  Phosphate, 1. 5 

Sodium  Salts,    ...        I.o 

Animal  Matter  and  Water, 1.0 

Von  Bibra  gives  the  following : — 

Adult  Man.  Adult  Woman. 

Calcium  Phosphate  and  Fluorid, 89.82  81.63 

Calcium  Carbonate, 4.37  8.88 

Magnesium  Phosphate, 1.34  2.55 

Other  salts, 88  .97 

Cartilage, 3.39  5.97 

Fat,         20  a  trace 

Organic, 3.59  5.97 

Inorganic,      96.41  94-03 


Enamel  consists  of  hexagonal  or  polygonal  fibres  or  rods  arranged 
in  waved  lines  perpendicularly  to  the  dentine.  Those  iibres  or  rods, 
situated  on  the  most  promi- 
nent part  of  the  crown,  are 
arranged  in  a  vertical  di- 
rection ;  those  upon  the 
side  are  placed  horizontally, 
whilst  the  intermediate 
fibres  present  all  degrees 
of  obliquity.  As  these  fibres 
necessarily  diverge  from  the 
dentinal  to  their  free  sur- 
face, the  upper  space   thus 

^ -^^^A  .^.  ^4-  u^  ^11^^  u        Fig-  102.— Human  Enamel  from  the  Masticating 

occasioned  must  be  filled  by  Surf.^ce  of  a  Molar. 

the    gradual    enlargement  of    The  figure  is  merely  intended  to  show  the  general 
°  °  direction  of  the  fibres. 

the  fibres  from  within  out- 
ward or  by  the  addition  of  supplemental  fibres. 

The  enamel  rods  are  marked  by  transverse  striae,  which  indicate, 
according  to  Mr.  Beale,  the  successive  layers  of  calcification,  and  are 


142 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


much  more  strongly  pronounced  in  some  specimens  than  in  others, 
being  most  markedly  so  in  the  enamel  of  unhealthy  subjects. 

Upon  opening  a  dental 
sac  from  a  fetal  jaw,  inter- 
posed between  the  inner 
surface  of  the  sac  and  the 
coronal  surface  of  the  tooth, 
a  semi-fluid,  gelatinous  sub- 
stance will  be  found,  com- 
posed of  nucleated  cylin- 
drical columns  with  more 
or  less  spherical  nucleated 
cells  enveloped  in  fluid. 
Similar  columns  will  be 
found  on  the  inner  surface 
of  the  sac.  This  is  the 
enamel  organ,  or  enamel 
pulp,  and  from  it  the  cells 
found  in  the  gelatinous  fluid 
have  become  separated.  Col- 
umns of  a  like  kind  are  also 
found  on  the  surface  of  the 
enamel.  When  the  tooth 
makes  its  way  through  the 
gum,  and  before  it  has  suf- 
fered from  friction,  by  the 
action  of  hydrochloric  or 
acetic  acid,  a  membrane-like 
surface  (Nasmyth's  mem- 
brane) may  be  raised  from 
the  surface  of  the  enamel ;  it  is  soon  worn  away  from  the  crown  of  the 
erupted  tooth. 

This  membrane,  to  which  Mr.  Nasmyth  first  drew  attention,  has 
been  described  as  the  persistent  dental  capsule,  and  consists  of  a 
delicate  pellicle,  exceedingly  thin,  of  a  reticulated  pattern  and  of  a 
horny  nature,  and  is  indestructible  by  both  acids  and  alkalies.  Ac- 
cording to  Tomes,  Nasmyth's  membrane  is  a  thin  layer  of  cementum  ; 
according  to  Kolliker,  it  is  a  final  product  of  the  enamel  cells  ;  accord- 
ing to  Waldeyer,  it  is  derived  from  the  external  enamel  epithelium  ; 
according  to  the  latest  theory,  that  of  F.  T.  Paul,  it  is  of  an  epithelial 
nature,  consisting  of  a  layer  of  polygonal,  flattened  epithelium, 
measuring  about  i— 2000th  inch  broad,  and  up  to  i-ioooth  inch  long, 
placed  upon  a  thin,  structureless,  elastic  membrane,  the  external  enamel 


Fig.  103. — Cavities  in  Human  Enamel 
Which  communicate  with  the  dentinal  tubes. 


TOOTH    STRUCTURES.  1 43 

epithelium  coming  in  contact  with  and  adherent  to  the  surface  of  the 
enamel. 

The  enamel  differs  from  dentine  in  its  greater  density  ;  the  much 
earlier  period  at  which  entire  calcification  takes  place  ;  the  absence, 
except  in  abnormal  conditions,  of  any  uncalcified  portions ;  the 
direction  in  which  calcification  progresses  ;  and  in  the  fact  that  it  is  the 
least  constant  of  the  dental  tissues.  In  pathological  conditions  irreg- 
ular cavities  are  sometimes  found  in  the  enamel  near  to  the  surface 
of  the  dentine,  and  in  such  cases  the  dentine  tubes  may  communi- 
cate with  them  (Fig.  105).  In  some  cases  the  dentinal  tubes  may 
enter  the  enamel,  but  this  condition  is  more  common  to  some  animals 
than  to  the  human  subject.  "  It  is  more  frequently  absent  than 
present  in  the  teeth  of  the  class  of  fishes;  it  is  wanting  in  the  entire 
order  Ophidia  among  existing  reptiles  ;  and  it  forms  no  part  of  the 
teeth  of  the  Edentata,  and  many  cetacea  among  mammals."  (Owen's 
"Odontography,"  xxiv.)  The  nutrition  of  the  enamel  is  yet  a  mooted 
question,  but  that  this  process  is  extremely  slow  is  beyond  doubt. 
Sensitiveness  of  the  enamel  is  denied  by  R.  Baum  and  others;  but 
Bodecker*  thinks  that  the  simple  experiment  of  eating  a  sour  apple, 
which  in  perfectly  sound  teeth  "sets  them  on  edge,"  is  a  proof  of 
the  sensitiveness  of  the  enamel,  and  he  believes  that  the  pain  is  due  to 
living  matter  in  normal  enamel  and  the  transmission  of  its  contractions 
to  that  of  the  dentine.  It  is  well  known  that  under  morbid  condi- 
tions the  enamel  may  become  very  sensitive.  Dr.  Bodecker,  therefore, 
believes  in  the  existence  of  what  he  designates  as  enamel Jibrillcp.  in  the 
interstices  between  the  enamel  prisms. 

Dentine. — With  regard  to  the  manner  of  the  formation  of  the 
dentine,  the  first  step  in  this  process  is  the  development  of  the  odon- 
toblasts, which  have  the  same  relation  in  the  development  of  the  teeth 
as  osteoblasts  have  in  the  formation  of  bone.  The  odontoblasts  are 
large  nucleated  cells,  of  elongated  form,  provided  with  numerous 
processes  developed  from  the  dentinal  papilla,  which  at  that  early 
stage  consists  of  fine  fibrous  tissue  containing  many  cells.  The 
odontoblasts  send  out  processes,  which,  as  they  develop,  become  cal- 
cified externally,  the  calcified  portion  forming  the  dentine,  and  the 
uncalcified  part  the  dentinal  fibrillte,  and  the  lateral  processes  the 
branches  of  anastomosis  through  which  the  tubuli  or  canals  of  the 
dentine  communicate. 

The  remains  of  the  odontoblasts  themselves  form  the  investment 
of  the  pulp,  situated  between  its  nerves  and  vessels  and  the  dentine,  a 
cellular  laver  known   as   the  membrana  eboris,  or  ivory  membrane  of 

*  "  Anatomy  and  Pathology  of  the  Teeth." 


144  PRINCIPLES   AND   PRACTICE   OF   DENTISTRY. 

Kolliker.  (See  Origin  and  Formation  of  the  Teeth.)  The  dentine 
is  deposited  around  the  fibrils  of  the  odontoblasts,  the  latter  occupy- 
ing a  position  nearly  at  right  angles  to  the  surface  of  the  dentine,  the 
deposition  being  in  the  protoplasm  which  is  found  in  interspaces  be- 
tween the  fibres.  Lime  salts  being  deposited  in  the  protoplasmic 
basis-substance,  the  odontoblast,  as  the  process  of  secretion  proceeds, 
becomes  enclosed  in  a  thin  spherule  of  formed  material,  known  as 
"  calcoglobulin,"  *  and  the  dentine  substance  or  tissue  assumes  the 
form  of  a  homogeneous  mass,  traversed  by  tubes  which  contain  the 
dentinal  fibrils. 

The  greater  portion  or  body  of  every  tooth  is  composed  of  dentine, 
which  is  a  yellowish-white,  semi-transparent,  hard,  elastic  sub- 
stance, and  intermediate  in  consistence  between  the  enamel  and  the 
cementum.  In  a  normal  condition  the  dentine  is  never  exposed,  be- 
ing covered  in  the  crown  of  the  tooth  by  the  enamel,  and  in  the  root 
by  the  cementum. 

In  a  fresh  specimen  the  human  tooth  is  found  to  consist  of  62  per 
cent,  of  its  weight  in  organic  salts,  28  per  cent,  of  tooth  cartilage 
(organic  matter),  and  10  per  cent,  of  water. 

Berzelius  gives  the  following  analysis  of  dentine  : — 

Calcium  Phosphate, 62.00 

Calcium  Carbonate, •   .    .   • 5-5*^ 

Calcium  Fluorid, 2.00 

Magnesium  Phosphate, i.oo 

Sodium  Salts, 1.50 

Gelatin  and  Water, 28.00 

Von  Bibra  gives — 

Calcium  Phosphate  and  Fluorid, 67.54 

Calcium  Carbonate, 7.97 

Magnesium  Phosphate, 2.49 

Salts, I.oo 

Fat, 58 

Cartilage, 20.42 

While  the  organic  basis  of  the  matrix  of  dentine  is  similar  to  that 
of  bone,  yet  it  is  not  identical,  being  of  firmer  consistence,  and  does 
not  yield  gelatin  when  boiled.  A  fresh  section  of  dentine  presents 
a  satiny  aspect,  but  when  submitted  to  the  microscope  it  is  found 
to  consist  of  a  multitude  of  fine  tubes,  known  as  the  dentinal  tubuli. 


■*  Calcoglobulin  is  a  term  applied  to  a  thin  layer  of  partially  calcified  tissue,  found 
between  the  organic  and  inorganic  tissue  in  the  development  of  bone,  dentine,  and 
cementum. 


TOOTH    STRUCTURES. 


145 


with  an  intertubular  substance.  These  minute  tubes  permeate  the 
entire  structure  of  the  dentine,  their  direction  varying  in  the  different 
parts  of  the  tooth.  Each  tube  originates  by  an  open,  circular  mouth 
or  orifice  upon  the  surface  of  the 


pulp-cavity,  where  it  runs  toward 
the  periphery  of  the  dentine  in  a 
direction  usually  perpendicular  to 
the  surface,  just  before  reaching 
which  it  divides  into  branches. 

Proceeding  in  a  wavy  and  ra- 
diated manner  throughout  every 
portion  of  the  dentine  to  its  periphery,  these  tubes,  although  generally 
terminating  at  that  point,  in  some  instances  extend  beyond  and  en- 
croach upon  the  enamel  or  upon  the  cementum.  When  the  latter  is 
the  case,  they  may  communicate  with  the  canaliculi  and  lacunae. 

Toward  the  grinding  surface  of  the  crown  of  a  tooth,  when  occlu- 
sion is  received,  these  tubes  have  a  vertical  direction,  and  a  horizontal 


Fig.  104.— Transverse  Section  of  Dentine, 


Fig.  105. — Dentine  and  Cementum  from  the  Root  of  a  Human  Incisor  ;  Copied  from 

KoLLIKER. 

a.  Dentinal  fibres  or  tubes,  b.  Interglobular  spaces,  having  the  appearance  of  the  lacuntz 
in  bone.  c.  Smaller  interglobular  spaces,  d.  Commencement  of  the  cementum,  with 
numerous  canals  close  together,     e.  Its  laniellcE.   f.  LacuncE.    g.  Canals. 

direction  when  the  pressure  of  adjoining  teeth  has  to  be  resisted  ;  and 
thus  the  shock  of  occlusion  and  pressure  is  more  generally  distributed 
over  the  entire  tooth  structure.  These  dentinal  tubes,  instead  of  pur- 
suing a  straight  course,  describe  curves,  the  longer  ones  less  abruptly 
defined  than  the  others,  and  are  "termed  "primary  curvatures,"  the 
latter  being  more  common  to  the  crown  than  to  the  root.  The  sec- 
ondary curvatures,  although  smaller  than  the  primary,  are  much  more 
numerous.  The  coincidence  of  the  primary  curvatures  of  adjoining 
dentinal  tubes,  or  the  presence  of  rows  of  what  are  known  as  "inter- 
globular spaces"  (Fig.  105),  may  occasion  a  striated  or  laminated  ap- 
10 


146 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


pearance  of  the  dentine,  the  lines  thus  formed  being  at  nearly  right 
angles  with  the  tubes  and  known  as  the  contour  lines  of  Owen.  They 
proceed  in  an  arched  manner,  somewhat  parallel  to  each  other. 

The  dentinal  tubes  are  cemented  together  by  a  sub-granular  matter, 
radiating  from  the  cavity  to  the  surface  of  the  tooth.  From  these 
tubes  branches  are  given  off  in  great  number  in  the  roots  and  as  the 
enamel  approaches  the  dentinal  surface.  In  the  crown  these  branches 
are  few  in  number.  They  anastomose  freely  with  each  other  and  with 
the  superficial  dental  tissues.  They  terminate  in  loops  or  are  lost  in 
the  enamel.  By  their  extension  into  the  superficial  dental  tissues  a 
close  union  is  formed  between  them  and  the  dentine,  notwithstanding 
the  fact  that  each  tissue  is  developed  from  a  distinct  formative  pulp. 
Kdlliker  thought  these  tubes  contained  clear  fluid  in  the  fresh  state. 
In  the  dried  preparation  they  are  empty,  and  are  readily  permeated 
by  colored  fluid.     These  facts  give  rise  to  the  opinion  that  their  sole 

purpose  was  the  conduct  of 
nutrient  fluids.  Mr.  Tomes, 
however,  following  Nasmyth, 
objected  to  this  theory  on 
purely  physiological  grounds. 
The  extreme  sensitiveness  of  an 
exposed  coronal  surface  from 
which  a  portion  of  enamel  lias 
been  broken  ;  the  fact  that  in 
operations  for  the  removal  of 
carious  dentine  the  sensitiveness  was  found  to  be  greatest  just  beneath 
the  enamel ;  and  furthermore,  that  when  the  pulp  was  broken  up  or 
destroyed  by  escharotics,  this  sensibility  was  lost,  led  him  to  conclude 
that  the  sensibility  of  the  dentine  depended  on  its  connection  with 
the  pulp,  and  to  suppose  that  these  tube- 
contents  might  be  in  some  way  associated 
with  the  sensibility  of  the  structure  in  which 
they  were  found,  serving  to  establish  connec- 
tion between  it  and  the  pulps,  to  which 
sujjposition  fluid  contents  opposed  an  insur- 
nountable  difficulty.  Led  by  this  train  of  rea- 
jjning  to  a  careful  examination  of  the  tubes, 
he  found  each  dentinal  tube  tenanted  by  a 
soft  fibril,  which,  after  i)assing  from  the  jnilp 
into  the  tube,  follows  its  ramifications,  and 
that  these  fibrils  may  be  traced  into  the  sub- 
stance of  the  pulp.  Kolliker  and  Lent  were  the  first  to  determine  the 
connection  of  these  fibrils  with  the  odontoblasts  of  the  pulp. 


Fig.  106.— Termination  of  a  Dentinal  Tube  i.n 
THE  Midst  of  the  Dentine — Human. 


OF 


Fig.  107.— a  Fragment 
Dentine. 
a.  Through  wiiich  run  the 
softer  fibrils,  c,  which  seem 
to  be  continuous  with  the 
odontoblast  cells,  h.  {After 
Dr.  Lionel  Beale.) 


TOOTH    STRUCTURES. 


147 


Fig.  108. — Section  of  Dentine. 
From  the  edge  of  which  hang  out  the  dentinal 
sheaths,  and  beyond  these  again  the  fibrils. 
(After  Boll.) 


Mr.  Tomes  says  :  "  It  is  by  no  means  necessary  to  assume  that  the 
dentinal  fibrils  are  actually  nerves  before  allowing  them  the  power  of 
communicating  sensation.  Many  animals  are  endowed  with  sensation 
which  yet  possess  no  demonstrable  nervous  system;  "  whilst,  at  the 
same  time,  it  has  been  impossible  to  demonstrate  nerves  in  the  human 
body  so  numerous  as  to  warrant  the  assumption  that  at  every  prick  of 
a  needle  the  point  must  touch  a  nerve  fibre.  Again,  the  greater  sensi- 
bility of  the  dentine  immediately 
beneath  the  enamel  is  satisfactorily 
accounted  for  by  the  law  which 
refers  to  all  nerves  the  greatest 
sensibility  at  their  terminal  ex- 
tremities. He  also  thinks  "the 
foregoing  facts  will  warrant  the 
conclusion  that  the  dentinal  fib- 
rils are  subservient  to  sensation  in 
the  dentine,  since,  when  their  connection  with  the  pulp  is  cut  off,  all 
sensibility  is  lost  to  the  dentine." 

Dr.  Bodecker,*  on  the  other  hand,  claims  that  he  has  demonstrated 
by  careful  investigations  that  the  dentinal  fibrillae  are  not  nerves,  but 
formations  of  living  matter,  and  gives  the  following  reasons  for  this 
opinion  :  "  First,  that  it  is  impossible  to  admit  of  a  connective  tissue 
holding  nerves  alone  in  its  constituent  soft  parts. 
Second,  neither  have  we,  nor  has  G.  Retzius,  been 
able  to  trace  a  direct  inosculation  of  the  dentinal 
fibrillae  with  the  axis-fibrillss  of  the  nerves  so 
abundantly  distributed  throughout  the  periphery 
of  the  pulp-tissue."  And  he  further  says  that  as 
soon  as  we  admit  that  the  dentinal  fibrillae  are 
formations  of  living  matter,  the  same  as  are  the 
nerves,  all  difficulties  vanish  in  explaining  the 
transmission  of  sensation  from  the  periphery  of 
the  dentine  to  the  nerve  of  the  pulp-tissue.  Liv- 
ing matter  is,  according  to  Heitzmann,  contrac- 
tile matter.  Nerves  are  made  of  living  matter, 
and  owing  to  their  reticulated  or  beaded  structure, 
are  fittest  for  that  transmission  of  contractions 
from  the  periphery  to  the  nervous  centres  which  we  call  sensation. 
Contraction  of  the  dentinal  fibres  transmitted  into  the  reticulum  of 
the  protoplasm  at  the  periphery  of  the  pulp,  and  thence  into  the  ulti- 
mate nerve  fibrillae, — all  of  which  formatives  are  proven  to  be  con- 


FiG.  109  —Transverse 
Section      Through 

THE  DENTINAlTUBU- 

Li  OK  THE  Root  of 
A  Human  Tooth. 
Magnified  350  diame- 
ters, showing  their  nu- 
merous anastomoses. 


*  ♦'  Anatomy  and  Pathology  of  the  Teeth." 


148 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


tinuous, — are  sufficient  to  explain  the  transmission  of  sensation,  or, 
speaking  bluntly,  of  pain." 

The  dentinal  fibrillae  appear  to  be  formed  by  the  peripheral  portions 
of  the  processes  of  the  odontoblasts,  after  the  latter  become  long  and 
narrow,  attaining  considerable  length. 

The  formation  of  dentine  begins  about  the  fourth  month  of  fetal 
life,  at  the  summit  of  the  papilla.  The  superficial  portion  of  the 
crown  is  first  formed,  and  afterward  undergoes  no  alteration  in  size, 
all  subsequent  growth  taking  place  on  the  surface  adjacent  to  the 
dentinal  pulp.  The  growth  of  the  root  takes  place  from  above, 
downward  into  the  alveolus  destined  to  receive  it.  Placed  at  right 
angles  to  the  outer  surface  of  the  pulp,  between  it  and  the  dentine 
already  formed,  or  before  any  dentine  is  formed,  is  situated  a  layer 
of  "elongated  cylindrical  bodies  of  cells,  with  nuclei"  somewhat 
resembling  nucleated,  columnar  epithelium.  With  regard  to  the  exact 
share  taken  by  the  pulp  in  the  formation  of  dentine,  Kolliker  says  a 
layer  of  cells  forming  the  peripheral  portion  of  the  pulp  are  immedi- 
ately concerned  in  its  formation.  He  does  not  consider  that  the 
"same  cell  suffices  for  the  whole  duration  of  the  dentine,"  but  that 
new  cells  may  from  time  to  time  be  formed ;  and  denies  that  the 
whole  pulp  is  progressively  changed  into  dentinal  cells,  and  thinks  its 
only  purpose  is  to  support  the  vessels  essential  to  the  growth  of  the 
dentinal  cells,  from  which  alone  the  dentine  is  formed,  by  the  gradual 

reception  of  calcareous  salts.  (From 
"Tomes's  Dental  Surgery,"  388.) 
Prof.  Christopher  Johnson,  of 
Baltimore,  succeeded  in  tracing 
communication  between  the  fibrillae 
of  the  dentine  and  the  odontoblasts 
of  the  pulp — and  to  it  we  must  refer 
the  sensibility  of  this  tissue. 

On  account  of  the  tubes  dividing 
into  minute  branches,  as  they  ap- 
proach the  surface  of  the  dentine, 
they  appear  to  end  in  very  fine- 
pointed  extremities.  Some  of  these 
tubes  anastomose  with  the  branches 
of  others,  forming  loops  near  the 
periphery,  while  others  terminate 
deei)er  in  the  tissue.  The  inner 
walls  of  the  tubes  surrounding  the  fibrillae  constitute  the  dentinal 
sheaths,  which  are  apparently  of  fibrous  structure. 

The   intertubular  tissue   contains  the   greater   part    of  the   earthy 


Fig.  1 10. 


-INTKRGLOBULAR   SPACES   IN  DEN- 
TINE. 


TOOTH    STRUCTURES. 


149 


constihients  of  the  dentine,   and    under   the   microscope  presents  a 
granular  appearance. 

What  are  known  as  interglobular  spaces  are  indicators  of  arrested 
development  of  the  dentinal  tis- 
sue, and  are  not  considered  to 
be  normal.  These  spaces  are 
dark  and  irregular,  and  are 
most  commonly  observed  a 
little  distance  below  the  sur- 
face in  a  discolored  and  im- 
perfectly developed  tooth  ;  they 
have  a  ragged  outline.  Accord- 
ing to  Bodecker,  soft,  living 
plasm  is  found  in  the  smaller 
interglobular  spaces. 

According  to  Krause,  dentine 
has  a  specific  gravity  of  2.080, 
and  contains  less  earthy  matter 
than  the  enamel,  but  more 
animal  substance,  which  accounts  for  the  rapid  progress  of  caries 
when  the  dentine  is  exposed. 

Cementum. — Cementum  is  developed  from  the  deeper  tissues  of  the 
fetal  jaw,  precisely  like  bone  is  produced  in  other  parts  of  the  body, 
by  periosteal  ossification,  and  is  modified  bone-tissue  peculiar  to  the 
structure  of  the  teeth.  It  contains  canaliculi  and  lacunae,  and,  accord- 
ing to  Salter,  Haversian  canals  in  the  thicker  portion. 

It  is  not  so  dense  as  the  dentine,  and  approaches  more  nearly  in 
character  true  bone,  which  is  necessary  in  order  that  the  tooth 
may  be  tolerated  by  the  more  highly  vitalized  structures  in  relation 
with  it. 

The  analysis  of  cementum  is  as  follows: — 


Fig.  III.— Thick  Laminated  Cementum. 
From  the  root  of  a  human  tooth. 


Calcium  Phosphate  and  Fluorid, 5^.73 

Calcium  Carbonate, 7-22 

Magnesium   Phosphate, 0-99 

Salts, 0.82 

Cartilage Z^-l,^ 

Fat, 0.93 


The  Cementum,  or  Crusta  Pctrosa,  is  the  most  highly  organized  of 
the  dental  structures.  Generally  the  cementum  is  covered  on  its 
external  periphery  by  a  layer  of  calcified  protoplasmic  cells  similar  to 
bone-cells,  osteoblasts,  which  are  in  connection  with  the  fibrous  con- 
nective tissue  of  the  peridental  membrane.     At  the  neck  of  the  tooth 


PRINCIPLES    AND    PRACTICE    OF    DENTISTRY. 


Pig.  112. — Lacuna  of  Cementum, 
Which  communicates  with  the  ter- 
mination of  the  dentinal  tubes. 


it  is  composed  of  calcified  basis-substance,  penetrated  by  spindle- 
shaped  protoplasmic  cells.  In  the  root  portion  there  is  a  distinct 
lamellation,  where  are  presented  the  cement-corpuscles,  which  closely 
resemble  bone-corpuscles.    Cementum  covers  the  roots  of  all  the  teeth, 

encroaching  slightly  upon  the  crown, 
where  it  overlaps  the  enamel.  Its  purpose 
is  to  bind  the  teeth  securely  in  the  alveoli, 
forming  the  vital  bond  between  the  bone 
and  the  commonly  unvascular  constituents 
of  the  teeth.  It  is  thickest  about  the 
terminal  part  of  the  root,  gradually  thin- 
ning as  it  approaches  the  crown.  In  the 
thicker  parts  the  canaliculi  are  seen  anasto- 
mosing freely  with  each  other,  and  estab- 
lishing vascular  relations  between  the 
several  lacunae ;  and  they  occasionally 
become  connected  with  the  terminal  branches  of  the  dental  tubuii. 
Haversian  canals,  as  was  before  remarked,  are  also  found  in  very  thick 
sections  of  cementum.  The  lacunae  and  canaliculi  of  cementum  are 
distributed  lengthwise  around  the  root,  those  in  proximity  to  the 
dentine  joining  with  the  terminal  branches  of  the  dentinal  tubuii, 
while  those  upon  the  external  surface  radiate  toward  the  investing 
membrane. 

By  such  a  provision,  even  after  the  devitalization  and  removal  of  the 
•pulp,  the  vitality  of  the  cementum  of  the  teeth  is  maintained. 

From  irritation  of  the  peridental  membrane  the  cementum  often 
becomes  hypertrophied,  the  affection  being  known  as  "  hyperce- 
mentosis. "  Cementum  contains  more  animal  matter  than  the  dentine, 
and  becomes  very  sensitive  when  exposed  by  the  recession  of  the  gum 
about  the  neck  of  the  tooth. 

Osteo-Dentine. — Osteo-  or  secondary  dentine  is  a  substance  par- 
taking more  of  the  nature  of  cementum  than  of  ordinary  dentine,  as 
it  possesses  no  true  dentinal  tubes,  but  canals  similar  to  the  canaliculi 
of  bone.  It  is  generally  formed  in  the  teeth  of  persons  of  advanced 
age,  where  the  pulp-cavity  is  very  much  diminished  in  size,  and  it  also 
forms  a  protection  against  the  exposure  of  the  pulp  of  the  tooth  which 
has  been  denuded  of  its  natural  tissues  by  mechanical  abrasion,  the 
action  of  caries,  or  by  fracture.  In  other  cases  secondary  dentine  is 
deposited  in  isolated  nodules  scattered  throughout  the  substance  of 
the  dental  pulp,  which  may  unite  and  form  larger  masses  and  become 
adherent  to  the  walls  of  the  pulp-cavity.  Some  of  the.se  masses  are 
occasionally  penetrated  by  blood-vessels  and  surrounded  by  concentric 
lamellae,  like  the  Haversian  canals  of  bone. 


TOOTH    STRUCTURES. 


151 


The  dividing  line  between  the  primitive  and  secondary  formations 
of  dentine  is  characterized  by  numerous  irregular  spaces  and  globular 
contours,  while  deeper  in  the 
mass  of  lately  formed  second- 
ary dentine   tubes  or  canals 
may  exist. 

Not  infrequently,  however, 
the  tubuli  of  secondary  den- 
tine are  arranged  in  a  very 
irregular  manner,  either  "in 
tufts  or  in  bundles,  and  with- 
out any  apparent  reference  to 
points  of  radiation."  Osteo- 
dentine  is  also  usually  very 
transparent,  on  account  of 
this  tissue  being  devoid  of 
light  -  refracting  tubes,  its 
canals  being  so  completely 
filled  up  with  the  secondary 
deposit  that  they  permit  the 
transmission  of  light.  The 
tubuli  of  normal  dentine 
are  frequently  filled  with  a 
secondary  deposit,  especially  in  the  roots  of  teeth,  and  to  which  the 
name  "  horny  dentine  "  has  been  given.  The  formation  of  secondary 
dentine  appears  to  depend  upon  irritation  of  the  pulp,  of  long  con- 
tinuance but  restricted  as  to  degree,  and  during  the  time  "that  the 
slow  conversion  of  the  organ  is  taking  place  the  dentinal  fibrillae  also 
become  impregnated  with  calcareous  matter  and  solidify." 


Fig.  113.— Secondary  Dentine, 

Filling   up   one   of  the   cornua   of  the   pulp-cavity. 

From  a  human  molar  affected  bv  caries. 


PART   SECOND. 


DENTAL  PATHOLOGY,  THERAPEUTICS. 


CHAPTER  I. 

THE  TEMPERAMENTS  IN  RELATION  TO  THE  TEETH. 

The  individual  conditions  or  qualities  known  as  temperaments  exer- 
cise an  influence  upon  the  teeth,  as  well  as  upon  the  other  functional 
operations  of  the  body.  The  word  temperament  is  derived  from  the 
Latin  tempero,  "to  mix  together,"  and  implies  the  constitution  as 
determined  by  the  predominance  of  certain  constituents  of  the  body. 
For  among  the  ancients  it  was  supposed  that  the  manifestations  of  the 
functions  were  tempered  or  so  determined  by  the  predominance  of  any 
one  of  the  three  humors  then  recognized,  namely :  blood,  lymph,  bile, 
and  atrabilis,  or  black  bile.  Dunglison,  in  his  Medical  Dictionary, 
defines  the  temperaments  to  be  those  individual  differences  which  con- 
sist in  "such  disproportion  of  parts,  as  regards  volume  and  activity, 
as  to  sensibly  modify  the  whole  organism,  but  without  interfering  with 
the  health;  "  in  other  words,  a  physiological  condition  in  which  the 
functions  of  the  different  organs  are  so  regulated  as  to  impress  certain 
characteristics  upon  each  individual.  Others  contend  that  these  indi- 
vidual differences,  "though  they  can  scarcely  be  called  morbid,  yet 
certainly  give  a  proclivity  to  disease  in  the  direction  indicated  by  the 
temperaments." 

Dr.  James  W.  White,  on  this  subject,  remarks:  "Temperament 
may  be  defined  as  a  constitutional  organization,  depending  primarily 
upon  heredity — national  or  ancestral — and  consisting  chiefly  in  a  cer- 
tain relative  proportion  of  the  mechanical,  nutritive,  and  nervous  sys- 
tems, and  the  relative  energy  of  the  various  functions  of  the  body — 
the  reciprocal  action  of  the  digestive,  respiratory,  circulatory,  and 
nervous  systems.  The  stomach,  liver,  lungs,  heart,  and  brain — 
digestion,  assimilation,  respiration,  circulation,  and  innervation — are 
all  factors  in  the  differentiation  of  temperament ;  and  according  to 
the  congenital  predominance  of  one  or  the  other,  and  the  relative 
activity  of  these  functions,  is  the  modification  of  the  characteristics  of 
the  individual  which  determines  his  position  as  to  temperament.  Each 
temperament  is  the  result  as  well  as  the  indication  of  the  preponderance 
of  one  or  another  of  these  systems,  and  of  relative  functional  activity. 

"  A  perfect  equilibrium  of  the  different  systems  is  rarely  if  ever  pre- 
sented in  any  individual.  One  having  a  balance  of  all  the  tempera- 
ments would  be  temperamentless,  or  of  no  special  temperament.  It  is 
difficult,  in  some  cases,  to  decide  positively  to  which  variety  a  special 
case  belongs,  the  several  temperaments  being  combined  and  blended 
in  such  ever-varying  proportions.     Not  infrequently  the  indications 

155 


156  DENTAL   PATHOLOGY,    THERAPEUTICS. 

are  even  contradictory,  and  the  blending  of  several  temperaments  re- 
quires a  nice  discrimination  to  define  the  admixture.  The  primary 
elements  of  temperament  are  susceptible  of  such  manifold  combina- 
tions ;  the  determining  forces  are  so  complex,  and  our  knowledge  of 
their  comparative  values  is  so  limited,  that  no  rule  can  be  given  which 
will  not  fail  in  numerous  instances  to  apply  in  all  respects  to  individ- 
ual cases ;  but  that  there  is  a  general  relation  between  constitutional 
qualities  and  external  signs  does  not  admit  of  question. 

"  Temperaments  are  readily  divisible  into  four  basal  classes — bilious, 
sanguineous,  nervous,  and  lymphatic ;  then  again  into  sub-classes  of 
mixed  temperaments — a  combination  of  two  or  more  of  the  primary 
divisions.  In  these  combinations  one  or  other  of  the  so-called  basal 
temperaments  predominates,  and  a  compound  term  is  used  to  express 
the  complexity,  as,  for  instance,  the  nervo-bilious,  signifying  that  the 
bilious  base — the  foundation  temperament — is  qualified  by  an  admix- 
ture of  the  nervous  element,  and  so  throughout  the  series.  Twelve 
varieties  of  temperament,  in  addition  to  the  four  basal,  may  thus  be 
designated  by  the  combination  in  pairs  of  the  original  four.  The 
admixture  of  the  peculiarities  of  three  or  of  all  four  of  the  basal 
temperaments  results  in  what  are  denominated  respectively  ternary 
and  quaternary  combinations,  which  call  for  nice  discrimination  in 
diagnosis ;  but  even  such  complexities  are  registered  in  the  size,  form, 
and  color  of  the  dental  organs." 

The  sanguineous  temperament  is  characterized  by  a  fair,  ruddy  com- 
plexion, yellow,  red  or  light  auburn,  or  light-brown  hair,  a  good  class 
of  teeth,  a  full  muscular  development,  large,  full  veins  and  active 
pulse,  indicating  an  abundant  supply  of  blood,  and  warm  extremities, 
all  showing  perfect  health,  and  in  females  a  tendency  to  voluptuous- 
ness. The  mind  is  hopeful  and  elastic,  yet  at  the  same  time  fickle  and 
volatile,  with  little  determination  and  perseverance.  Although  indi- 
cating perfect  health,  yet  in  this  temperament  diseases  are  prone  to 
assume  the  acute  form,  and  speedily  run  their  course  either  to  recovery 
or  a  fatal  termination. 

The  bilious  temperament  is  characterized  by  a  preponderance  of 
bile,  indicated  by  a  dark  or  sallow  countenance,  black  hair,  generally 
luxuriant,  a  slow  or  moderate  circulation  of  the  blood,  shown  by  a 
hard,  strong  pulse,  dark  eyes,  strong  teeth,  with  a  yellow  tinge  over 
the  entire  crown  ;  and  the  body,  instead  of  the  roundness  of  form 
peculiar  to  the  sanguine  temperament,  is  angular;  wanting  in  ease 
and  grace  of  manner ;  there  is  restlessness,  but  at  the  same  time 
great  force  of  character  and  quickness  of  perception  and  power  of 
will.  The  digestive  organs,  however,  are  more  liable  to  derange- 
ment than  in  other  temperaments,  indicating  some  defective  action 


THE    TEMPERAMENTS.  I57 

in  these  organs ;  the  liver,  of  course,  being  the  principal  one  affected, 
and  necessitating  the  use  of  mercury  as  a  stimulus. 

The  lymphatic  temperament  is  characterized  by  a  predominance  of 
lymph  or  phlegm  in  the  system;  and  persons  possessing  it  have  a 
general  softness  or  laxity  of  the  tissues,  the  proportion  of  the  fluids 
being  too  great  for  that  of  the  solids,  the  lymphatics  and  absorbents 
not  acting  so  thoroughly  as  to  prevent  the  cellular  tissue  from  being 
filled  with  humors  ;  so  that  there  is  a  want  of  sensibility.  The  com- 
plexion is  fair,  but  not  ruddy,  and  the  hair,  either  light  or  dark,  is  not 
luxuriant,  but  thin  and  straight.  The  eyes  are  light,  generally  blue, 
the  circulation  feeble,  and  the  pulse,  as  a  consequence,  weak,  and  a 
want  of  tone  in  the  system.  The  skin  is  pale,  flabby,  and  moist,  and 
the  body  is  heavy  and  rounded,  while  the  teeth,  although  they  may 
often  appear  comparatively  good,  yet  are  sensitive  and  not  highly 
organized.  Although  the  expression  denotes  a  want  of  activity,  yet 
there  is  a  clear  and  active  mind,  characterized  by  prudence  and  sound 
judgment  without  enthusiasm.  Owing  to  the  predominance  of  lymph, 
there  is  a  tendency  to  dropsy  and  chronic  disease. 

The  tiervous  temperament  is  characterized  by  the  predominance  of 
the  nervous  element,  and  by  great  activity  or  susceptibility  of  the 
great  nervous  center — the  brain.  Persons  possessing  this  temperament 
are  distinguished  by  their  impressibility,  susceptibility  to  intense 
feeling  or  intense  excitement.  There  is  great  irritability,  anxiety,  and 
agitation,  which  peculiarities  enable  us  readily  to  recognize  it  by  the 
tone  of  voice  and  manner  of  speaking.  The  body  is  slender,  though 
well  formed,  the  complexion  pale  and  soft,  and  the  muscles  small  and 
yielding.  In  illness,  symptoms  are  often  complicated  with  those  of 
nervous  disorder,  and  the  mind  desponding.  There  is  want  of  power 
and  endurance. 

Upon  the  temperament  the  constitutional  health  depends  to  a 
greater  extent  than  pathologists  generally  admit ;  and  hence  it  is  that 
that  of  the  child  usually  partakes  of  that  of  one  or  other,  or  both,  of 
its  parents.  "This,"  says  M.  Delabarre,  "is  particularly  observable 
in  subjects  that  have  been  suckled  by  a  mother  or  nurse  whose  tem- 
perament was  similar  to  theirs."  To  obviate  the  entailment  of  this 
evil,  he  recommends  mothers  having  teeth  constitutionally  bad  to 
abstain  from  suckling,  and  that  this  highly  important  office  be  intrusteJ 
to  a  nurse  having  good  teeth  ;  asserting  at  the  same  time,  that  by  this 
means  the  transmission  of  so  troublesome  a  heritage  as  bad  teeth  may 
be  avoided. 

Dr.  J.  Foster  Flagg  gives  the  following  tabular  presentations  of  the 
relation  of  the  temperament  to  the  teeth  : — 


158 


DENTAL    PATHOLOGY,    THERAPEUTICS. 


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1 

CHARACTERISTICS    OF    THE    TEETH.  1 59 

CHARACTERISTICS    OF    THE    TEETH. 

Most  dental  physiologists  have  observed  the  marked  differences  that 
exist  in  the  appearances  of  the  teeth,  gums,  lips,  tongue,  and  secre- 
tions of  the  mouth  of  different  individuals;  and  of  that  earthy  sub- 
stance (commonly  called  tartar),  deposited  in  a  greater  or  less  abund- 
ance on  the  teeth  of  every  one  ;  and,  although  all  may  not  have  sought 
their  etiology,  inany  have  had  occasion  to  notice,  at  least,  their  local 
indications,  and  to  profit  by  the  information  which  they  have  thus  ob- 
tained. Nor  have  they  failed  to  observe  that  the  size,  color,  length, 
and  arrangement  of  the  teeth  vary,  and  that  these  are  indications  of 
their  susceptibility  to  disease. 

There  are  five  principal  classes  or  descriptions  of  teeth,  each  of 
which  differs,  in  some  respects,  from  the  others,  a  knowledge  of 
which  is  very  essential  to  the  dental  practitioner,  in  order  that  he  may 
determine  their  liability  to  decay,  strength  of  attachment,  and  the 
form  and  size  of  their  roots. 

Class  First. — The  teeth  belonging  to  this  class  are  white,  with  a 
light  cream-colored  tinge  near  the  gum,  which  becomes  more  and 
more  apparent  as  the  subject  advances  in  age,  of  a  medium  size,  rather 
short  than  long,  with  thick,  square  edges;  those  of  each  class  of  uni- 
form dimensions,  and  very  hard.  This  description  of  the  teeth  is 
most  frequently  met  with  in  persons  of  sanguineous  temperament,  or, 
at  least,  those  in  whom  this  predominates  ;  they  rarely  decay,  and 
generally  occupy  their  proper  position  in  the  dental  arch  ;  the  most 
common  deviation,  and  one  most  peculiar  to  this  class,  is  that  of  the 
superior  incisors  antagonizing  with  the  inferior,  causing  the  form  of 
abrasion  known  as  mechanical.  They  are  not  as  easily  acted  upon  by 
corrosive  agents,  and  caries  attacking  them,  usually  of  the  black 
variety,  makes  but  slow  progress,  and  often  exists  for  a  considerable 
time  without  causing  pain  or  inconvenience.  Operations  performed 
upon  teeth  of  this  class  are  those,  above  all  others,  on  which  we  can 
predict  the  most  perfect  success.  They  indicate,  if  not /^//^r/ health, 
at  least  a  state  which  bordered  very  closely  on  it  at  the  time  of  their 
dentinification. 

This  first  description  of  teeth  is  occasionally  found  among  persons 
of  all  nations.  They  are  very  common  in  cold  and  temperate  climates, 
and  those  who  have  them  usually  enjoy  excellent  health. 

In  confirmation  of  what  has  before  been  said  with  regard  to  the 
influence  which  the  state  of  the  constitutional  health  at  the  time  of 
the  solidification  of  the  teeth  exerts  upon  the  susceptibility  of  these 
organs  to  morbid  impressions,  it  is  only  necessary  to  mention  the  fact, 
well  known  and  frequently  alluded  to,  Of  the  early  decay  of  a  single 


l6o  DENTAL   PATHOLOGY,    THERAPEUTICS. 

class,  or  a  pair  of  a  single  class  of  teeth,  in  each  jaw,  while  the  rest, 
possessing  the  characteristics  just  described,  remain  sound  through 
life.  Thus,  when  it  happens  that  a  child  of  excellent  constitution  is 
affected  with  any  severe  disease,  the  teeth  which  are  at  the  time  receiv- 
ing their  earthy  salts  are  found,  on  their  eruption,  to  differ  from  those 
which  have  received  their  solid  material  at  another  time,  when  the 
operations  of  the  body  were  healthfully  performed.  Instead  of  having  a 
white,  smooth,  and  uniform  surface,  they  have  a  sort  of  chalky  aspect, 
or  are  faintly  tinged  with  blue,  and  are  rougher  and  less  uniform  in 
their  surfaces.  Teeth  of  this  description  are  very  susceptible  to  the 
action  of  corrosive  agents,  and,  as  a  consequence,  rarely  last  long. 

Class  Second. — Having  digressed  thus  far,  we  shall  now  proceed  to 
notice  the  teeth  belonging  to  the  second  class.  They  have  a  faint, 
azure-blue  appearance ;  are  rather  long  than  short ;  the  incisors  are 
generally  thin  and  narrow,  the  centrals  being  frequently  a  little  longer 
than  the  laterals.  In  some  cases  the  lateral  incisors  are  very  small  and 
pointed.  The  cuspids  are  usually  round  and  pointed  ;  the  bicuspids 
and  molars  small  in  circumference,  with  prominent  cusps  and  protuber- 
ances upon  their  grinding  surfaces. 

Teeth  possessing  these  characteristics  are  usually  very  sensitive, 
caused,  doubtless,  by  a  superabundance  of  animal  matter,  and  are 
more  easily  acted  upon  than  teeth  of  the  first  class  by  corrosive  agents, 
and  to  the  ravages  of  which,  unless  great  attention  is  paid  to  their 
cleanliness,  they  often  fall  early  victims.  The  variety  of  caries  almost 
peculiar  to  this  class  is  known  as  the  white,  the  parts  attacked  being 
rendered  soft  and  humid  ;  and  as  they  retain  their  natural  color,  it  but 
too  frequently  happens  that  such  teeth  are  almost  irretrievably  ruined 
before  its  presence  is  suspected.  They  are,  also,  more  frequently 
affected  with  atrophy,  or  have  upon  their  surfaces  white,  brown,  or 
opaque  spots,  varying  in  size  and  number ;  several  are  sometimes  found 
upon  a  single  tooth,  and  in  some  instances  every  tooth  in  the  mouth 
is  more  or  less  marked  with  them. 

But  this  is  not  the  only  description  of  teeth  liable  to  be  affected 
with  this  disease.  These  spots  are  occasionally  met  with  on  teeth  of 
every  degree  of  density,  shape,  shade,  and  size ;  but  they  are,  proba- 
bly, more  frequently  seen  on  teeth  of  the  second  class  than  on  those 
first  described  ;  besides  which,  it  often  happens  that  they  are  affected 
with  erosion  on  emerging  from  the  gums,  and  sometimes  so  badly  as 
to  place  either  their  restoration  or  preservation  beyond  the  reach  of 
art.  This  species  of  erosion,  or  that  which  occurs  previously  to  the 
eruption  of  the  teeth,  is  caused  by  some  diseased  condition  of  the  fluid 
which  surrounds  them  before  they  appear  above  the  gums,  and  is 
denominated  congenital. 


CHARACTERISTICS    OF   THE   TEETH.  l6l 

Teeth  like  those  now  under  consideration  are  indicative  of  a  weakly 
constitution,  of  a  temperament  considerably  removed  from  the  san- 
guineous, resembling  the  lymphatic,  and  of  blood  altogether  too 
serous  to  furnish  materials  such  as  are  necessary  for  building  up  a 
strong  and  healthy  organism.  They  are  more  common  to  females  than 
to  males,  though  many  of  the  latter  have  them.  They  are  met  with 
among  people  of  all  countries,  but  more  frequently  among  those  who 
reside  in  sickly  localities,  and  with  individuals  whose  systems  have 
become  enervated  by  luxurious  living. 

Class  Third. — The  teeth  of  this  class,  though  differing  in  many  of 
their  characteristics  from  those  last  described,  are,  nevertheless,  not 
unlike  them  in  texture  and  sensibility  to  disease.  They  are  peculiar 
to  those  who  have  inherited  a  scrofulous  habit  or  diathesis.  In  this 
state  of  the  system  we  find  a  sufficient  supply  of  blood,  but  it  is 
usually  of  a  pernicious  character;  the  whole  organism  is  affected  by  it 
and  rendered  very  susceptible  to  disease,  more  especially  to  that  class 
superinduced  by  cold.  Teeth  developed  under  constitutional  defects 
of  this  nature  are  larger  than  teeth  of  the  first  or  second  class ;  their 
faces  are  rough  and  irregular,  with  protuberances  arising,  not  only 
from  the  grinding  surfaces  of  the  biscupids  and  molars,  but  also  not 
unfrequently  from  their  sides,  with  correspondingly  deep  indentations. 
They  have  a  muddy  white  color.  The  crowns  of  the  incisors  of  both 
jaws  are  broad,  long,  and  thick.  The  posterior  or  palatine  surfaces 
of  those  of  the  superior  maxilla  are  rough  and  usually  deeply  indented. 
In  the  majority  of  cases  their  arrangement  is  quite  regular,  though 
frequently  found  to  project.  The  alveolar  ridge  usually  describes  a 
broad  arch.  The  excess  in  size,  both  here  and  in  the  teeth,  seems  to 
consist  more  of  gelatin  than  calcareous  phosphate.  Teeth  of  this 
description  decay  rapidly,  and  in  some  instances  appear  to  set  at  defi- 
ante  the  resources  of  the  dentist.  They  are  liable  to  be  attacked  at 
almost  every  point,  but  more  particularly  in  their  indentations  and 
approximal  surfaces.  The  ca»ies  to  which  these  teeth  are  liable  is  in 
color  and  consistence  between  the  two  kinds  mentioned  in  connection 
with  the  first  and  second  classes. 

The  corrosive  properties  of  the  fluids  of  the  mouth,  however,  are 
sometimes  so  changed  by  an  amelioration  of  the  constitution  that,  not- 
withstanding the  great  susceptibility  of  the  teeth  to  disease,  they  are 
sometimes  preserved  to  a  late  period  of  life,  or  until  the  general 
health  relapses  into  its  former  or  some  other  unfavorable  condition. 
This  has  happened  in  several  instances  that  have  come  under  the 
author's  immediate  observation,  and  it  should  be  borne  in  mind  that 
the  solvent  qualities  of  these  secretions  are  influenced  by  the  state  of 
the  constitutional  health. 


1 62  DENTAL    PATHOLOGY,    THERAPEUTICS, 

Class  Fourth. — Teeth  of  this  class  usually  have  a  white,  chalkv 
appearance,  are  unequally  developed,  and  of  a  very  soft  texture.  They 
are  easily  acted  upon  by  corrosive  agents,  and,  like  the  teeth  last 
noticed,  generally  fall  speedy  victims  to  disease,  unless  great  care  is 
taken  to  secure  their  preservation. 

Persons  who  have  teeth  such  as  described  in  this  class,  generally 
have  what  I^aforgue  has  called  lymphatico-serous  temperaments.  Their 
blood  is  usually  pale,  the  fluids  of  the  mouth  abundant,  and  for  the 
most  part  exceedingly  viscid.  They  do  not  have  that  white,  frothy 
appearance  observable  in  healthy,  sanguineous  individuals. 

As  teeth  that  are  neither  too  large  nor  too  small,  and  that  have  a 
close,  compact  texture,  and  tinged  with  yellow,  are  indicative  of  an 
originally  good  constitution,  whatever  it  may  be  at  the  present  time, 
so  those  that  are  long,  narrow,  and  faintly  tinged  with  blue,  as 
well  as  those  that  greatly  exceed  the  ordinary  size,  and  that  are 
irregular  in  shape,  and  have  a  rough,  muddy  appearance,  furnish 
assurance  of  a  constitution  originally  bad.  The  first  of  the  latter 
descriptions  of  teeth  are  more  frequently  met  with  among  females  than 
males,  and  among  those  of  strumous  habit,  than  those  in  whom  this 
diathesis  does  not  exist. 

Class  Fifth. — The  teeth  belonging  to  this  class  are  characterized  by 
whiteness  and  a  pearly  gloss  of  the  enamel.  They  are  long  and  usually 
small  in  circumference,  though  sometimes  well  developed.  They  are 
regarded  by  many  as  denoting  a  tendency  to  phthisis  pulmonalis,  and 
are  supposed  by  some  to  be  very  durable ;  but  the  author  has  observed 
that  individuals  who  have  this  sort  of  teeth,  when  attacked  by  febrile 
or  any  other  form  of  disease  having  a  tendency  to  alter  the  fluids  of 
the  body,  are  very  subject  to  toothache  and  caries  ;  and  that  when 
this  condition  of  the  general  system  is  continued  for  a  considerable 
length  of  time,  the  teeth,  one  after  another,  in  rapid  succession, 
crumble  to  pieces. 

It  would  seem,  from  this  circumstante,  that  the  fluids  of  the  mouth 
in  subjects  of  strumous  habit,  if  free  from  other  morbid  tendencies,  are 
less  prejudicial  to  the  teeth  than  they  are  in  most  other  constitutions, 
and  the  author  is  of  the  opinion  that  it  is  owing  to  this  that  they  are 
so  seldom  attacked  by  caries. 

There  are  other  cases  in  which  the  teeth  are  of  so  inferior  a  quality 
that  they  no  sooner  emerge  from  the  gums  than  they  are  attacked  and 
destroyed  by  caries,  while  the  subjects  who  possess  them  are  enabled, 
by  skillful  treatment,  to  overcome  the  morbid  constitutional  tenden- 
cies against  which,  during  the  earlier  years  of  their  existence,  they 
had  to  contend,  and  eventually  to  acquire  excellent  health.  But  in 
forming  a  prognosis,  it  is  essential  to  ascertain  whether  the  general 


DENTITION.  163 

organic  derangement  which  prevented  the  teeth  from  being  well 
formed,  and  thus  gave  rise  to  their  premature  decay,  is  hereditary,  or 
whether  it  has  been  produced  by  some  accidental  cause  subsequent  to 
birth.  The  procurement  of  health  in  the  former  case  will  be  less  cer- 
tain than  in  the  latter,  for  when  the  original  elements  of  the  organism 
are  bad,  the  attainment  of  a  good  constitution  is  more  difficult. 

Persons  of  sanguineo-mucous  temperaments,  having  suffered  in  early 
childhood  from  febrile  or  inflammatory  diseases, 'often  have  their  teeth 
affected  with  what  Duval  calls  the  decorticating  process  (denudation 
of  their  enamel),  resulting,  no  doubt,  from  the  destruction  of  the  bond 
of  union  between  it  and  the  dentine. 

There  are  other  characteristics  which  the  teeth  present  in  shape, 
size,  density,  and  color,  and  from  which  valuable  inductions  might  be 
made,  both  with  regard  to  the  innate  constitution  and  the  means 
necessary  to  their  own  preservation  ;  but  as  the  limits  assigned  to  this 
part  of  our  subject  will  not  admit  of  their  consideration,  we  shall  con- 
clude by  observing  that  the  appearances  of  these  organs  vary  almost  to 
infinity.  Each  is  indicative  of  the  state  of  the  general  health  at  the 
time  of  their  formation,  and  of  their  own  physical  condition  and  sus- 
ceptibility to  disease. 


CHAPTER  II. 

DENTITION. 


The  term  "dentition"  implies  the  eruption  of  the  teeth,  and  is;, 
process  which  consists  of  two  stages,  namely,  first  dentition  and  sec- 
ond dentition.  At  about  the  seventh  week  of  intrauterine  existence 
the  process  of  development  of  the  teeth  of  first  dentition  begins,  and 
shortly  after  birth  the  outlines  of  the  forms  of  the  deciduous  teeth  may 
be  observed  on  the  external  aspect  of  the  jaws ;  but  as  age  advances, 
owing  to  the  increased  development  of  the  mucous  membrane  and 
alveolar  processes,  these  outlines  become  less  apparent.  As  the  period 
of  dentition  approaches,  a  slight  ridge  on  the  summit  of  each  jaw  is 
seen,  which  is  attributed  to  the  dipping  down  of  the  process  of  epi- 
thelium which  forms  the  enamel  organ.  Prior  to  the  sixth  month  of 
age  (first  dentition  commencing  generally  between  the  fifth  and  sev- 
enth months  after  birth),  small  prominences  are  observed  on  the  sum- 
mits of  the  alveolar  processes,  which  gradually  become  more  distinct 
and  almost  as  light  in  color  as  the  teeth  themselves.  As  soon  as  the 
tooth  has  penetrated  the  mucous  membrane,  the  latter  contracts  so  as 
to  permit  the  crown  of  the  tooth  to  project  above  its  level. 


164  DENTAL  PATHOLOGY,  THERAPEUTICS. 

The  deciduous  teeth  begin  to  erupt  between  the  fifth  and  seventh 
months,  and  at  the  age  of  two  years  and  a  half  all  of  the  first  set  have 
appeared,  the  corresponding  teeth  of  the  two  sides  of  the  jaw  erupting 
at  the  same  time.  The  two  inferior  central  incisors  appear  at  the  age 
of  six  or  seven  months,  in  the  order  in  which  they  are  named,  followed 
by  the  superior  central  incisors,  the  superior  lateral  incisors,  the  infe- 
rior lateral  incisors,  the  four  first  molars,  the  four  canines,  and  last,  the 
four  second  molars.  The  usual  order  of  the  eruption  of  the  deciduous 
teeth  is  as  follows  :  — 

Central  incisors  between  the    5th  and    8th  months. 

Lateral  incisors        *'         "      7th  and  loth         " 

First  molars  "         "    12th  and  i6th        " 

Cuspids  "         "    14th  and  20th         " 

Second  molars  "         "    20th  and  30th         " 

The  lower  teeth  generally  precede  the  upper  teeth  by  a  few  weeks, 
appearing  in  the  same  order. 

This  order,  however,  is  not  invariably  followed,  for  teeth  may  be 
prematurely  erupted  so  as  to  be  seen  at  birth.  But  the  cases  of  retarded 
eruption  are  much  more  common  than  those  of  premature  eruption, 
owing  to  constitutional  debility  or  the  existence  of  some  constitutional 
disease. 

During  the  eruptive  period  there  is  a  gradual  elongation  and  pro- 
trusion of  the  teeth,  and  a  coincident  dissolving  away  of  both  the  hard 
and  soft  tissues  which  overlie  them.  The  approximal  edges  of  the 
alveolar  borders  of  the  maxillary  bones  disappear  by  an  absorptive 
process,  the  teeth  rise  in  their  cavities,  and  their  roots  lengthen  to 
such  a  degree  that  the  crowns  press  upon  the  opposing  gums,  which, 
under  such  pressure,  become  thinner  and  thinner,  until  finally  the 
crowns  escape. 

Henry  Sewell,  m.r.c.s.,  gives  the  following  concise  description  of 
the  process  of  eruption  :  "The  eruption  of  the  teeth  is  a  process  of 
gradual  elongation  of  the  teeth  on  the  one  hand,  and  the  simultaneous 
absorption  of  the  super-imposed  tissue  on  the  other.  The  absorption 
commences,  first,  in  the  overhanging  margins  and  front  walls  of  the 
alveoli,  which  gradually  disappear  until  room  is  afforded  for  the  pas- 
sage of  the  advancing  tooth.  The  growth  of  the  tooth  keeps  pace 
with  this  absorption,  and  the  crown  of  the  tooth  at  length  pressing 
against  the  membranous  coverings,  these  undergo  atrophy,  and  becom- 
ing by  degrees  thinner,  and  at  last  transparent,  give  way  and  disclose 
the  advancing  crown." 

The  exact  relation  of  dentition  to  infantile  diseases  is  not  generally 
recognized,  and  many  affections  have  been  erroneously  ascribed  to  this 
process. 


DENTITION.  165 

There  is  no  doubt,  however,  that  the  condition  of  the  system  at  the 
period  of  first  dentition  is  such  that  the  infant  is  very  susceptible  to 
nervous  impressions,  and  hence  the  symptoms  of  any  constitutional 
disease  that  may  be  present  are  greatly  aggravated. 

Owing  to  the  predominance  of  the  nervous  system  in  infancy,  there 
is  a  greater  sympathy  between  distant  organs  than  in  adult  life,  and 
considerable  disturbances  may  be  excited  early  in  life  by  even  slight 
functional  disorders.  The  brain  is  proportionally  larger  and  less  per- 
fect in  structure  than  in  the  adult ;  the  tissues  of  the  body  are  also 
softer  and  more  vascular,  the  skin  is  more  sensitive,  the  abdomen, 
glands,  kidneys,  liver,  pancreas,  and  lacteal  vessels  are  disproportion- 
ately large,  and  functional  activity  depends  chiefly  upon  the  nutritive 
processes.  Such  peculiarities,  therefore,  account  for  the  susceptibility 
to  disease  in  infants  and  the  tendency  of  their  disease  to  become  in- 
flammatory, and  to  involve  organs  not  originally  affected. 

The  evolution  of  the  teeth  is  commonly  attended  with  more  or  less 
inflammation  of  the  parts  in  relation  with  the  dental  follicles,  and  this 
turgescence  is  greater  with  some  teeth  than  with  others ;  sometimes  it 
is  present  to  such  a  degree  that  the  gums  are  greatly  swollen  and  ex- 
tremely tender,  presenting  a  very  red  appearance,  more  so  than  in 
ordinary  dentition. 

The  indications  of  the  eruption  of  the  teeth  are  an  increased  flow 
of  saliva,  which  tends  to  keep  the  mouth  moist  and  cool,  and  is  due  to 
the  irritation  of  the  trifacial  nerve,  which  gives  sensation  to  the  teeth 
and  nutrition  to  the  salivary  glands ;  an  itching  of  the  mouth,  which 
causes  the  infant  to  keep  its  fingers  on  the  gums,  as  a  slight  pressure 
evidently  gives  some  relief;  the  irritation  continuing,  the  mouth,  as  a 
result,  becomes  hot  and  dry,  and  there  is  more  or  less  febrile  excite- 
ment. Diarrhea  frequently  ensues,  which,  if  not  too  great,  is  bene- 
ficial ;  one  or  both  cheeks  may  become  unusually  red,  which  is  a  symp- 
tom of  nervous  disturbance  ;  eruptions  may  appear  on  the  face  or  head, 
and  sometimes  on  the  entire  body ;  ulceration  may  occur  on  the  lips, 
gums,  inside  of  the  cheeks,  and  on  the  tongue ;  itching  of  the  nose, 
twitching  of  the  muscles,  disturbed  sleep,  wakefulness,  dilatation  of  the 
pupils,  thirst,  loss  of  appetite,  all  indicate  an  increase  of  the  irrita- 
tion ;  the  temper  becomes  very  irritable,  and  delay  in  the  eruption  of 
a  tooth  may  cause  congestion  of  the  gum  with  swelling  of  the  cheek ; 
nausea  and  vomiting,  diarrhea,  fever,  thirst,  and  other  systemic  dis- 
turbances, such  as  convulsions,  etc.,  may  soon  succeed  these  symptoms. 
A  premature  eruption  of  the  teeth  is  more  liable  to  give  rise  to  consti- 
tutional symptoms  than  a  tardy  or  delayed  eruption. 

The  salivary  secretion,  which  is  very  scanty  prior  to  the  period  of 
the  eruption  of  the  teeth,  always  increases  as  dentition  approaches, 


l66  DENTAL   PATHOLOGY,    THERAPEUTICS. 

and  in  cases  of  difficult  dentition  becomes  very  profuse.  A  decided 
form  of  stomatitis  may  be  present,  and  in  some  cases  even  abscesses 
have  formed,  which  could  only  be  relieved  by  incisions.  As  a  general 
rule  the  degree  of  irritation  present  depends  upon  the  number  of  teeth 
erupting,  but,  owing  to  the  difference  of  susceptibility,  one  tooth  may 
give  rise  to  more  irritation  than  the  simultaneous  eruption  of  several 
teeth  will  in  other  cases. 

A  perfectly  healthy  child,  properly  cared  for,  may  erupt  its  teeth 
with  little  or  no  suffering,  although  there  may  be  some  restlessness, 
a  slight  decrease  of  appetite,  and  a  slight  elevation  of  the  tempera- 
ture of  the  mouth.  At  other  times  a  mere  local  uneasiness  may  be 
experienced,  which  will  induce  the  infant  to  place  its  finger  in  the 
mouth,  or  to  bite  upon  some  foreign  substance,  which  apparently 
affords  relief.  In  such  cases  as  these  the  processes  of  the  development 
of  the  teeth,  and  the  absorption  of  the  tissues  confining  them,  are 
equal,  and  the  result  is  that  the  teeth  perforate  the  gum  without  caus- 
ing either  pain  or  irritation.  Where,  however,  there  is  a  difference  in 
the  progress  between  the  growth  of  the  teeth  and  the  absorption  of  the 
opposing  structures,  then  these  different  forces  produce  irritation,  and 
a  difficult  dentition  results. 

When  the  eruptive  period  arrives,  the  roots  of  the  teeth  are  yet 
incomplete,  for  instead  of  a  conical  end  and  the  small  opening  or 
foramen  which  a  completed  tooth  presents,  there  is  a  voluminous  pulp 
occupying  a  cavity  with  an  incomplete  termination  almost  as  large  as 
the  root  itself;  hence  any  considerable  increase  of  vascular  and 
nervous  action  produces  a  hypersemia  of  the  pulp  which  may  cause  its 
protrusion  and  induce  thereby  constitutional  disturbance. 

The  immediate  cause  of  the  irritation  is  conceded  to  be  due  to  the 
downward  pressure  of  the  root  upon  the  nerves  and  vessels  of  the  pulp 
of  the  tooth,  such  pressure  being  caused  by  the  opposing  gum,  and 
giving  rise  to  congestion  and  swelling,  which  have  the  effect  of  increas- 
ing the  induration  of  the  opposing  tissues.  Constitutional  as  well  as 
local  symptoms  result  from  such  irritation,  some  of  which  are  of  the 
most  serious  character.  The  cerebro-spinal  system  may  become 
affected,  giving  rise  to  restlessness,  sleeplessness,  pain  in  the  head, 
convulsions,  or  paralysis  ;  also  the  respiratory  system,  a  condition  which 
is  manifested  by  cough,  catarrh,  bronchitis,  pneumonia,  or  spasmodic 
croup;  also  the  alimentary  canal,  where  there  may  be  nausea,  vomit- 
ing, loss  of  appetite,  or  diarrhea  ;  also  the  skin  may  become  affected, 
and  such  forms  of  skin  disease  may  manifest  themselves  as  eczema, 
acne,  etc.  Therefore,  the  period  of  dentition  may  be  a  dangerous 
one,  for  many  infants  die  at  this  time,  either  from  convulsions,  from 
whooping  cough,  or  cholera  infantum.     Difficult    dentition  is    more 


DENTITION.  167 

frequently  a  predisposing  than  a  direct  cause  of  infantile  convulsions. 
At  such  a  period  a  sensitive  state  of  the  nervous  system,  or  an  afflux 
of  blood  to  the  head,  may  result  in  convulsions,  although  such  an 
affection  may  be  the  direct  consequence  of  the  irritation  caused  by 
the  efforts  of  several  teeth  to  erupt  at  the  same  time,  especially  in  the 
case  of  weakly  children. 

The  premonitory  symptoms  of  convulsions  are  depression,  restless- 
ness, and  fretfulness  for  some  days  before  the  paroxysm ;  the  eyes  have 
a  wild,  unnatural  appearance,  the  sleep  is  disturbed,  and  sometimes 
there  is  unusual  heat  of  the  head,  with  a  sudden  starting  or  twitching 
of  the  limbs.  In  general  convulsions,  the  paroxysm  is  characterized 
by  a  hot  head  during  its  early  stage,  and  a  flushed  face,  while  in  sym- 
pathetic convulsions  the  head  is  cool  and  the  face  pallid ;  the  pulse  is 
accelerated,  as  well  as  the  respiration,  which  is  also  irregular,  especially 
if  the  respiratory  muscles  are  involved,  which  is  usually  the  case. 
The  muscles  of  the  face,  eyes  and  eyelids,  and  limbs  are  in  a 
state  of  rapid  involuntary  contraction  and  relaxation  ;  the  features  are 
distorted  ;  the  mouth  is  drawn  out  of  shape,  and  the  teeth  become 
tightly  closed,  owing  to  the  tonic  contraction  of  the  masseter 
muscles;  and  if  the  paroxysm  is  prolonged,  frothy  saliva  may  issue 
from  the  lips. 

The  eyelids  are  usually  open,  and  in  severe  cases  the  pupils  of  the 
eyes  are  concealed  under  the  upper  lids,  or  the  eyeballs  may  be  forci- 
bly drawn  from  side  to  side.  The  head  is  strongly  retracted,  or  turned 
to  one  side  ;  the  thumbs  and  fingers  are  convulsively  flexed,  so  that 
the  former  are  turned  across  the  palms  and  covered  by  the  fingers ;  the 
great  toe  is  adducted  and  the  other  toes  are  flexed,  and  with  the 
legs  move  spasmodically  ;  consciousness  is  lost.  The  duration  of  the 
paroxysm  varies  from  a  few  minutes  to  several  hours,  generally  averag- 
ing from  five  to  fifteen  minutes;  and  when  it  terminates  favorably,  the 
spasmodic  movements  gradually  cease,  and  are  followed  by  a  deep 
inspiration  and  quiet  or  sleep,  with  a  return  of  consciousness.  The 
temperature  and  respiration  become  natural,  although  dullness  and 
bewilderment  of  mind  may  continue  for  several  hours.  In  severe 
cases,  the  respiration  is  so  embarrassed  and  the  circulation  so  retarded 
that  congestion  of  various  organs  results.  Death  does  not  usually 
occur  from  one  paroxysm,  but  from  several  at  intervals,  during  the 
last  of  which  convulsive  movements  cease,  and  there  is  no  return  of 
consciousness ;  the  limbs  grow  cold,  the  pulse  feeble,  and  coma  super- 
venes. 

The  treatment  of  convulsions  consists  in  first  removing  the  irritation 
by  the  use  of  the  gum-lancet,  by  emesis,  purgatives,  etc.,  according  to 
the  indications ;  the  feet,  as  soon  as  possible,  may  be  put  in  hot  water. 


1 68  DENTAL   PATHOLOGY,    THERAPEUTICS. 

to  which  mustard  is  added  ;  or  a  warm  bath  may  be  used  ;  such  meas- 
ures have  a  soothing  effect  upon  the  nervous  system,  and  cause  muscu- 
lar relaxation  and  derivation  of  blood  from  the  cerebro-spinal  axis. 
They  also  prevent  passive  congestion  and  edema  of  the  brain  and 
lungs.  Antispasmodics  and  nervous  sedatives  are  indicated  after  the 
cause  of  the  irritation  has  been  removed.  Cool  applications,  in  the 
form  of  a  cloth  frequently  wrung  out  in  cold  water,  should  be  made  to 
the  head,  to  reduce  its  temperature,  which  will  have  the  effect  of  con- 
tracting the  vessels  and  membranes  of  the  head,  and  diminishing  the 
cerebral  congestion.  An  aperient  is  useful,  unless  there  has  been  pre- 
vious diarrhea.  An  enema  of  soap  and  water  will  produce  free  and 
speedy  evacuation,  as  it  is  often  necessary  to  relieve  the  digestive  canal 
of  irritating  substances. 

For  the  relief  of  the  paroxysm,  and  to  lessen  its  duration,  chloroform 
has  been  successfully  employed  as  an  anesthetic,  but  as  it  is  a  danger- 
ous agent,  the  bromid  of  potassium  is  preferable,  in  doses  of  three 
grains  for  a  child  one  year  of  age,  or  four  or  five  grains  for  a  child  of 
two  or  three  years  of  age,  dissolved  in  cold  water,  and  administered 
every  ten  minutes ;  after  the  convulsions  cease,  there  should  be  longer 
intervals  between  the  doses.  In  very  severe  cases,  where  the  bromid 
of  potassium  may  not  act  with  the  required  promptness,  the  hydrate 
of  chloral  may  be  employed  in  doses  of  five  grains  for  a  child  of  one 
year  of  age,  and  ten  grains  for  one  of  four  years  of  age,  dissolved  in 
two  or  three  drachms  of  water,  and  injected,  by  means  of  a  small 
syringe,  into  the  rectum.  The  bromid  of  potassium  may  be  com- 
bined with  the  chloral  as  follows:  R.  Potassii  bromid.  gr.  xvj ; 
Chloral,  hydrat.  gr.  iv  to  vj ;  Sodii  bicarb,  gr.  xv ;  Aquse  nienth. 
pip.  fSj.     M. 

This  remedy  is  generally  successful  in  controlling  the  spasmodic 
movements  in  five  or  ten  minutes,  unless  recovery  is  impossible. 
During  such  premonitory  symptoms  of  difficult  dentition  as  fretful- 
ness  and  nervous  excitement,  the  bromid  of  potassium  is  a  useful  and 
safe  remedy.  Demulcent  and  soothing  lotions  are  useful  to  reduce 
the  swelling  and  tenderness  of  the  gums  ;  and  an  ivory  or  rubber  ring, 
for  the  child  to  bite  upon,  will  afford  great  relief. 

The  practice  of  rubbing  the  gums  with  a  thimble  or  ring  is  injurious, 
as  the  swelling  and  tenderness  are  increased. 

Unless  the  tooth  is  on  the  point  of  protruding,  the  operation  of 
lancing  the  gum  is  by  many  thought  to  be  unnecessary,  for  the  reason 
that  the  gum  is  not  rendered  tense  by  the  pressure  of  the  advancing 
tooth,  and  too  much  importance  has  been  attached  to  the  supposed 
tension  and  resistance  of  the  gum. 

When  the  symptoms  are  local  and  the  gums  are  somewhat  congested 


DENTITION. 


169 


and  swollen,  scarifying  them  lightly  with  a  very  sharp  lancet  will 
often  afford  relief;  but  if  the  gums  are  very  tender  this  operation 
should  not  be  performed. 

Others,  again,  advocate  the  operation  of  lancing  the  gums  in  diffi- 
cult dentition,  even  when  no  single  local  indication  exists  in  the 
mouth,  by  making  free  incisions  over  the  teeth  whose  eruption  is 
anticipated,  the  cuts  extending  through  the  gum  to  the  presenting 
surface  of  the  tooth,  and  thus  affording  manifest  and  complete  relief. 
No  injury  results  to  the  erupting  tooth,  or  to  the  germ  of  the  develop- 
ing permanent  one,  if  the  lancet  is  carried  to  the  surface  of  the 
crown,  without  undue  force  is  employed.  Partially  erupted  canines 
and  molars  sometimes  require  the  use  of  the  lancet  to  relieve  the 
pressure  of  the  enclosing  band  of  gum  tissue.  Such  objections  against 
lancing  the  gums,  as  the  infliction  of  great  pain  and  uncontrollable 
hemorrhage,  are  of  little  moment,  as  is  also  the  assumed  increased 


Fig.  114. 

resistance  of  cicatricial  tissue ;  for,  although  the  wound  made  by  the 
lancet  should  heal  before  the  appearance  of  the  tooth,  this  cicatricial 
tissue  is  easier  absorbed,  and  consequently  less  resistant. 

For  lancing  the  gum  over  an  incisor,  a  single  incision  in  the  line 
of  the  arch  will  answer ;  the  molars  generally  require  a  crucial 
incision,  and  the  gum  of  the  canines,  even  after  the  point  of  the  cusp 
has  emerged,  may  require  severance  on  the  lateral,  anterior,  and  pos- 
terior surfaces,  in  order  to  relieve  the  tension  and  liberate  these  teeth. 
The  illustrations  (Fig.  114)  show  the  necessary  incisions  for  the 
different  classes  of  teeth.  Should  undue  bleeding  result  from  such  an 
operation,  it  can  be  arrested  by  means  of  a  little  finely  powdered 
alum  applied  to  the  incisions ;  should  such  a  remedy  fail,  more 
powerful  astringents  or  styptics  can  be  employed,  such  as  tannic  acid, 
styptic  colloid,  matico,  powdered  resin,  etc.  Nitrate  of  silver  and 
the  iron  preparations  are  liable  to  cause  slough  and  secondary  hemor- 
rhage ;  hence  should  never  be  employed  in  such  cases.     As  the  act  of 


170  DENTAL    PATHOLOGY,    THERAPEUTICS. 

sucking  the  gums  may  promote  persistent  bleeding,  in  such  cases  the 
child  should  be  either  placed  at  the  breast  of  the  nurse,  or  a  gag  of  soft 
linen  be  introduced  in  such  a  manner  as  will  prevent  the  infant  from 
sucking  its  gums.  Internal  remedies  in  case  of  a  hemorrhagic  diathesis 
are  indicated  to  correct  an  abnormal  or  depraved  condition  of  the 
blood  and  promote  contraction  of  the  orifices  of  the  bleeding  vessels; 
but  their  use  is  seldom  necessary. 

When  such  remedies  are  indicated,  tincture  of  the  muriate  of  iron, 
acetate  of  lead,  aromatic  sulphuric  acid,  gallic  acid,  and  turpentine 
are  the  agents  to  be  employed.  Dr.  James  W.  White  gives  the  fol- 
lowing formula  which  will  meet  all  the  indications  in  such  cases: — 

R.     Tinct.  ferri  chloridi, f^ss. 

Acid,  acetic,  dil., ^oh 

Liq.  ammonii  acet., f^j. 

Ext.  ergot,  fld., fSij- 

Syr.  simp. , f .^  ss. 

Aquae, q.  s.    ad   f^iij.  M. 

Dose,  a  teaspoonful  every  three  hours  for  a  child  six  months  old. 

It  is  not  unusual  for  some  children  to  be  affected  with  diarrhea 
during  the  period  of  dentition,  and  which  may  be  accompanied  with 
irritability  of  the  stomach.  Where  not  too  debilitating  and  pro- 
tracted, the  diarrhea  is  beneficial,  but,  on  the  other  hand,  it  must  not 
be  neglected  and  permitted  to  become  a  source  of  danger.  But  there 
are  often  other  causes  for  this  affection  than  those  which  can  be 
attributed  to  dentition,  such  as  improper  food  and  clothing,  residence 
in  unhealthy  localities,  and  exposure  to  cold. 

The  diarrhea,  when  severe,  should  be  controlled  by  proper  remedies, 
capable  of  reducing  the  number  of  evacuations  to  two  or  three  daily, 
as  a  greater  number  may  result  in  danger  to  the  child.  The  treatment 
of  the  diarrhea  of  dentition  consists  in  a  change  in  the  diet,  the 
adoption  of  hygienic  measures,  and,  when  medicines  are  necessary, 
the  administration  of  the  milder  purgatives  in  small  doses.  Where 
the  dejections  are  acid,  as  is  shown  by  the  green  color,  half  a  tea- 
spoonful  to  one  teaspoonful  of  castor  oil  or  calcined  magnesia  will 
prove  beneficial.  According  to  Dr.  West,  if  there  be  neither  much 
pain  nor  tenesmus,  and  the  evacuations,  though  watery,  are  fecal,  and 
contain  little  mucus  and  no  blood,  very  small  doses  of  the  sulphate  of 
magnesia  and  tincture  of  rhubarb  are  more  useful  than  any  other  remedy. 

R.     Magnesia  sulphatis, ^]. 

Tinct.  rhei, 3J. 

Syr.  zingiberis, 3J. 

Aquce  carui, 3  ix.  M. 

SiG. — One  dram  three  times  a  day,  for  children  one  year  old. 


DENTITION.  171 

Dr.  Christopher  Elliott  recommends  half  to  one  dram  doses  of 
the  infusion  of  chamomile-flowers  for  infantile  diarrhea  of  dentition, 
when  the  evacuations  are  greenish  in  color  or  are  slimy  and  streaked 
with  blood. 

For  the  diarrhea  of  infants  due  to  indigestion,  and  attended  with 
acidity,  Professor  J.  L.  Smith  recommends  the  following: — 

R.     Pulv.  ipecac, gr.  ss. 

Pulv.  rhei, gr-  ij- 

Sodse  bicarb., gr.  xij.  M. 

Divide  into  chart  No.  xij.     One  powder  every  four  to  six  hours,  for 
an  infant  one  year  old. 

The  same  author  also  recommends  the  following  in  the  non-inflam- 
matory diarrhea  of  infants  : — 

U.     Tinct.  opii  deodorat., gtt.  xvj. 

Bismuth,  subnitrat., gij. 

Syr.  simplic, ^ss. 

Mistur.  cretiE., ^iss.  M. 

Shake  well,  and  give  one  teaspoonful  from  three  to  four  hours. 

For  increased  excitability  of  the  intestine  due  to  dental  irritation, 
which  is  indicated  by  frequent  stools  of  semi-solid  matter  containing 
undigested  food,  Dr.  Lees  recommends  the  use  of  bromid  of  potas- 
sium in  from  three  to  five-grain  doses  every  three  or  four  hours  for  a 
child  one  year  of  age.  Persistent  constipation  may  be  treated  with 
ten-drop  doses,  three  times  daily,  of  cod-liver  oil,  increasing  the  dose 
if  necessary  to  a  half  dram. 

For  the  skin  affection  attending  dentition,  such  as  eczema  in  the 
acute  form,  with  a  watery  discharge  and  an  irritable  skin,  oxid  of 
zinc,  used  as  a  dusting  powder,  will  prove  serviceable,  but  the  parts 
should  not  be  washed  with  water. 

When  the  discharge  is  thicker  and  more  purulent,  and  forms  scabs, 
they  may  be  removed  by  bathing  the  part  with  oil  and  washing  it 
with  soap  and  water,  and  a  salve  applied,  composed  of  equal  parts  of 
vaseline  and  simple  lead  plaster  ;  or  less  of  the  lead  plaster  may  be 
used  with  the  vaseline,  if  the  salve  should  prove  too  strong ;  or  an 
ointment  may  be  employed,  composed  of  oxid  of  zinc,  five  grains, 
and  simple  salve,  one  ounce. 

When  the  gum  over  an  erupting  tooth  appears  swollen  and  con- 
gested, and  at  length  ulcerates,  even  after  the  tooth  is  protruding,  a 
condition  to  which  the  appellation  "odontitis  infantum"  has  been 
applied,  the  ulcers  may  be  touched  with  a  crystal  of  alum,  and  a 
lotion  composed  of  sage  tea  and  honey  used,  with  decided  advan- 
tage.    For  a  sloughing  condition  of  the  mucous  membrane  over  an 


172  DENTAL   PATHOLOGY,    THERAPEUTICS. 

erupting  tooth,    the  careful   application  of  strong  carbolic  acid  will 
prove  efficient. 

During  infancy,  and  especially  during  the  period  of  dentition,  the 
clothing  should  consist  of  fine,  soft  flannel  next  to  the  skin,  to  protect 
the  body  from  variations  of  temperature,  and  all  changes  be  made 
gradually.  The  food  for  some  months  after  birth  should  be  confined 
exclusively  to  milk,  that  of  the  mother  being  preferable  when  she  is 
in  good  health.  For  artificial  food,  when  such  is  necessary,  an  excel- 
lent preparation  is  that  of  Dr.  J.  F.  Meigs,  which  consists  of  equal 
parts  of  milk,  cream,  lime-water,  and  oatmeal,  barley-  or  arrowroot- 
water,  to  which  a  little  sugar  of  milk  is  added. 

SECOND    DENTITION. 

The  design  of  nature  is  to  preserve  the  deciduous  teeth  until  their 
roots  are  absorbed  and  they  become  loose,  and  are  removed  to  make 
room  for  their  permanent  successors.  But  the  eruption  of  the  per- 
manent teeth  begins  before  any  of  the  deciduous  teeth  are  removed. 
Between  the  ages  of  five  and  a  half  and  six  years,  the  first  perma- 
nent molars  make  their  appearance  ;  hence  they  are  commonly  called 
"sixth-year  molars,"  and  their  germs,  with  those  of  the  remaining 
permanent  teeth,  are  progressing  with  the  development  of  the  decidu- 
ous teeth. 

When  the  permanent  teeth  are  developing,  and  their  crowns,  on 
account  of  the  growth  of  the  roots,  are  approaching  the  alveoli  of  the 
deciduous  teeth,  a  process  of  absorption,  decalcification,  commences,  by 
which  the  roots  of  the  latter  teeth  are  gradually  destroyed,  the  dissolv- 
ing process  going  on  until  only  the  crowns  of  the  deciduous  ones  remain. 
The  process  of  absorption  affects  the  roots  of  the  deciduous  teeth  in  the 
order  corresponding  to  their  development  and  eruption  ;  the  inferior 
central  incisors  are  first  shed,  then  the  superior  central  incisors,  then 
the  lateral  incisors ;  and  this  order  is  preserved  until  all  of  the  de- 
ciduous teeth  have  been  removed  or  have  become  so  loose  that  they 
are  easily  extracted. 

The  absorptive  process  commences  in  the  alveoli  of  the  decidu- 
ous teeth,  and  then  attacks  the  apices  of  their  roots,  and  in  some 
cases  progresses  until  it  involves  a  large  portion  of  the  crowns. 
The  loss  of  substance  commences  generally  upon  the  side  of  the 
root,  near  the  apex,  toward  the  advancing  crown  of  the  permanent 
tooth,  and  the  surface  of  the  root  acted  upon  presents  pits,  grooves, 
or  irregular  facets,  with  rough  surfaces  and  sharp  edges,  such  as 
would  result  from  corrosion.  If  a  deciduous  tooth  undergoing  this 
process  of  absorption  be  extracted,  a  loose,  spongy  substance  is 
found  adherent  to  it,  which  Laforgue  and  Bourdet  supposed  to  be  an 


SECOND    DENTITION. 


173 


absorbent  organ — vascular  papilla — secreting  a  fluid  capable  of  dissolv- 
ing the  tooth-structure.  According  to  Wedl,  a  fluid  is  secreted  by  the 
cells  of  this  organ  which  dissolves  the  hard  substance,  and  referring  to 
the  theory  held  by  some,  he  says  "  that  these  cells  are  of  a  parasitic 
nature,  that  is  to  say,  that  the  dental  substances  are  eaten  up,  as  it 
were,  since  the  cells  absorb  the  latter,  and  he  remarks  that  "possi- 
bly ameboid  movements  may  be  the  occasion  of  the  wasting  of  the 
tissues;"  he  is  also  of  the  opinion  that  the  organ  of  absorption  is 
developed  from  the  connective  tissue  of  the  root  membrane  of  the 
deciduous  tooth.  According  to  a  microscopic  examination  made 
by  Mr.  Tomes,  the  surface  of  this  absorptive  organ  is  made  up  of 
peculiar  multiform  cells,  each  one  being  composed  of  several  smaller 


Fig.  115. — Illustrates  the  Jaws  of  a  Child  Between  Six  and  Seven  Years  of  Age 
Showing  the  Relations  of  the  Two  Sets  of  Teeth. 


cells,  the  number  varying  from  two  to  three  to  as  many  as  fourteen  or 
fifteen. 

Some  have  regarded  the  method  employed  by  nature  for  the  re- 
moval of  the  roots  of  the  temporary  teeth  as  sui  generis,  but  there  is 
a  better  reason  for  considering  it  to  be  the  effect  of  an  inflammatory 
process  that  brings  about  a  proliferation  of  cell-growth,  which  may  at 
one  time  act  as  an  absorbent  and  at  another  be  reparative.  As  to  the 
precise  manner  in  which  these  cells  of  the  absorbent  organ  act,  much 
remains  to  be  learned,  but  that  it  is  a  physiological  process,  and 
occasioned  by  the  action  of  cells  known  as  "  osteoclasts,"  or  "odon- 
toclasts," and  is  not  a  mechanical  force,  is  now  quite  generally 
admitted.     These   cells   secrete   what   has   been    termed    "a  soluble 


174  DENTAL    PATHOLOGY,    THERAPEUTICS. 

ferment,"  or  "  fluid  of  exudation,"  which  dissolves  out  the  lime  salts 
from  the  hard  tissues  with  which  it  comes  in  contact,  the  surface  acted 
upon  presenting  a  series  of  pits  and  cup-shaped  depressions. 

Dr.  C.  N.  Pierce,  in  an  excellent  article,  entitled  "Calcification 
and  Decalcification  of  the  Teeth,"*  and  which  is  illustrated  by  the 
following  instructive  figures  (Fig.  ii6),  in  treating  of  the  absorption 
or  decalcification  of  the  roots  of  the  deciduous  teeth,  regards  this 
process  "  as  being  both  physiological  and  somewhat  obscure,"  and  he 
further  states  :  — 

"  The  evidence  that  it  is  the  result  of  a  physiological  action  is  the 
fact  that  it  matters  not  to  what  extent  absorption  has  progressed,  the 
very  moment  vitality  of  the  pulp  ceases  that  instant  this  retrograde 
metamorphosis  terminates.  What  induces  this  molecular  dissolution 
it  is  difificult  to  state,  though  the  several  conditions  which  are  always 
present  are  readily  recognized  ;  but  the  part  they  play  is  so  obscure 
that  it  is  not  readily  ascertained.  The  manner  of  its  commencement 
when  successful — always  at  the  end  of  the  root — and  the  presence  of 
a  vascular  papilla  in  close  proximity  to  the  absorbing  surface,  are, 
with  the  retention  of  pulp  vitality,  three  essential  accompaniments, 
and  the  absence  of  any  one  of  them  would  militate  against  the  com- 
pletion of  the  process. 

"  The  statement  that  the  presence  and  pressure  of  the  permanent 
tooth  are  essential,  cannot  be  sustained,  for  frequently  the  decalcifi- 
cation of  the  deciduous  tooth  is  successfully  accomplished  in  the 
absence  of  its  successor;  and  again,  how  often  do  we  find  the  per- 
manent tooth  impacted  against  or  within  the  bifurcated  roots  of 
the  deciduous  molar,  or  pressing  down  by  the  side  of  its  single-rooted 
predecessor,  both  being  more  or  less  displaced  by  the  persistence  of 
the  deciduous  tooth  without  absorption.  That  the  organ  has  served 
its  purpose,  and  that  the  nourishment  which  had  previously  been 
appropriated  by  it  is  diverted  or  relegated  to  its  successors,  is  probably 
the  most  plausible  explanation  we  can  give  of  this  interesting  physio- 
logical process." 

The  average  time  and  order  for  the  eruption  of  the  jjermanent  teeth 
are  as  follows  :  — 

First  molars, 5  to    6  years. 

Central  incisors, 6  "     8  " 

Lateral  incisors, 7  "     9  " 

First  bicuspids, 9  "  lo  <* 

Second  bicuspids, lo  "  I2  " 

Canines, "   "  13  " 

Second  molars, 12   "  14  " 

Third  molars,  or  wisdom  teeth, 17   "  21  *' 

*  Dental  Cosmos,  August,  1884. 


175 


Fig.  ii6. 


1)6  DENTAL   PATHOLOGY,    THERAPEUTICS. 

Usually  little  or  no  difificulty  attends  the  eruption  of  the  permanent 
teeth,  with  the  exception  of  the  third  molars  of  the  lower  jaw,  which 
may  cause  considerable  trouble  and  suffering,  on  account  of  their 
being  crowded  between  the  second  molar  and  the  ramus  or  ascending 
portion  of  the  jaw,  the  space  left  being  insufficient  to  accommodate 
the  third  molar.  Inflammation  from  such  a  cause  may  extend  to  the 
soft  tissues,  such  as  the  muscles,  and  render  the  act  of  swallowing 
difficult  and  painful,  and  that  of  mastication  impossible.  The 
inflammation  thus  caused  may  also  terminate  in  suppuration,  and  the 
pus  discharge  at  remote  points,  internal  or  external.  Such  maladies 
as  neuralgia,  hysteria,  epilepsy,  St.  Vitus'  dance,  disordered  vision, 
earache,  deafness,  tetanus,  etc.,  have  been  caused  by  the  eruption  of 
the  third  molar.  Occasionally  the  eruption  of  the  molars  anterior  to 
the  third  molars  may  be  attended  with  some  constitutional  disturbance, 
such  as  headache,  slight  neu^lgic  pains,  impaired  appetite  ;  and  also 
local  symptoms,  such  as  swollen  gums,  increased  heat  of  mouth,  and  an 
increased  flow  of  saliva.  The  extraction  of  the  third  molar  may  be 
necessary  in  some  cases ;  in  others,  that  of  the  second  molar,  although 
the  removal  of  a  carious  first  molar  may  sometimes  relieve  the  crowded 
condition  of  the  arch,  when  the  trouble  is  owing  to  a  want  of  space 
between  the  second  molar  and  the  ramus  of  the  jaw.  The  lancing  of 
the  gum  over  a  third  molar  not  yet  protruded  often  relieves.  The  most 
common  period  of  suffering  from  second  dentition,  apart  from  that  of 
the  third  molar,  is  from  the  tenth  to  the  thirteenth  year,  and  it  is  char- 
acterized by  such  affections  as  obstinate  and  protracted  cough,  with 
paroxysms  of  long  duration,  also  diarrhea,  wasting  of  flesh,  ner- 
vous diseases,  loss  of  spirits,  headache,  and  morbidly  sensitive  and 
painful  eyes. 

The  obstinate  cough  disappeared  when  the  molar  teeth  pierced 
the  gums;  and  a  mixture  of  iron  and  nitric  acid  was  successful  in 
immediately  curing  a  patient  of  seven  years  of  age  in  the  practice  of 
Dr.  James  Jackson,  who  recommends  the  following  remedies  as  being 
most  useful :  — 

"  First,  a  relief  from  study  or  from  regular  tasks,  yet  using  books  so 
far  as  they  afford  agreeable  occupation  or  amusement.  Second,  exer- 
cise in  the  open  air,  preferring  the  mode  most  agreeable  to  the  patient, 
and  in  more  grave  cases  the  removal  from  town  to  country." 

Fig.  117  represents  an  instnmient,  the  invention  of  Mr.  Wood- 
house,  and  introduced  by  Dr.  L.  D.  Shepard,  designed  for  the  removal 
of  the  overlying  gum  which  covers  the  masticating  surfaces  of  the  first 
and  third  molars  very  often  for  months  after  the  cusps  have  appeared 
through  the  gum,  and  thus  promotes,  if  it  does  not  cause,  the  decay  so 
frequently  attacking  these  teeth  upon  their  eruption.     An    incision 


THIRD    DENTITION. 


177 


is  made  with  a  lancet,  through  the  gum,  along  the  anterior  margin  of 
the  tooth,  and  the  thin,  flat  blade  of  the  cutter  is  inserted ;  then,  by- 
closing  the  handles,  the  section  of  gum  the  size  of  the  blade  is 
instantly  removed.  The  operator  will  find  this  process  much  more 
effectual,  and  far  easier  to  the  patient,  than  the  usual  practice  of  cut- 
ting the  gum  in  different  directions. 


Fig.  117. 


THIRD    DENTITION. 

That  nature  sometimes  makes  an  effort  to  produce  a  third  set  of 
teeth  is  a  fact  which,  however  much  it  may  be  disputed,  is  now  so 
well  established  that  no  room  is  left  for  cavil  or  doubt. 

The  following  interesting  particulars  are  taken  from  "  Good's  Study 
of  Medicine  :  " — 

"We  sometimes,  though  rarely,  meet  with  playful  attempts  on  the 
part  of  nature  to  reproduce  teeth  at  a  very  late  period  of  life,  and 
after  the  permanent  teeth  have  been  lost  by  accident  or  by  natural 
decay. 

''This  most  commonly  takes  place  between  the  sixty-third  and  eighty- 
first  year,  or  the  interval  which  fills  up  the  two  grand  climacteric 
years  of  the  Greek  physiologist,  at  which  period  the  constitution 
appears  occasionally  to  make  an  effort  to  repair  other  defects  than  lost 
teeth.     .     .     . 

"  For  the  most  part,  the  teeth,  in  this  case,  shoot  forth  irregularly, 
few  in  number,  and  without  proper  roots,  and,  even  where  roots  are 
produced,  without  a  renewal  of  sockets.  Hence,  they  are  often  loose, 
and  frequently  more  injurious  than  useful,  by  interfering  with  the 
uniform  line  of  indurated  and  callous  gums,  which,  for  many  years. 
perhaps,  had  been  employed  as  a  substitute  for  the  teeth.  A  case  of 
this  kind  is  related  by  Dr.  Bisset,  of  Knayton,  in  which  the  patient, 
a  female  in  her  ninety-eighth  year,  cut  twelve  molar  teeth,  mostly 
12 


lyS  DENTAL    PATHOLOGY,    THERAPEUTICS. 

in  the  lower  jaw,  four  of  which  were  thrown  out  soon  afterward, 
while  the  rest,  at  the  time  of  examination,  were  found  more  or  less 
loose. 

"The  German  Ephemerides  contain  numerous  examples  of  the 
same  kind ;  in  some  of  which  teeth  were  produced  at  the  advanced 
age  of  ninety,  a  hundred,  and  even  a  hundred  and  twenty  years. 
One  of  the  most  singular  instances  on  record  is  that  given  by  Dr. 
Slade,  which  occurred  to  his  father,  who,  at  the  age  of  seventy-five, 
reproduced  an  incisor,  lost  twenty-five  years  before,  so  that,  at 
eighty,  he  had  hereby  a  perfect  row  of  teeth  in  both  jaws.  At 
eighty-two  they  all  dropped  out  successively  ;  two  years  afterward 
they  were  all  successively  renewed,  so  that  at  eighty-five  he  had  once 
more  an  entire  set.  His  hair,  at  the  same  time,  changed  from  a  white 
to  a  dark  hue  ;  and  his  constitution  seemed,  in  some  degree,  more 
healthy  and  vigorous.  He  died  suddenly,  at  the  age  of  ninety  or  a 
hundred. 

'  •  "Sometimes  these  teeth  are  produced  with  wonderful  rapidity  ;  but 
in  such  cases  with  very  great  pain,  from  the  callosity  of  the  gums 
through  which  they  have  to  force  themselves.  The  Edinburgh  Medi- 
cal Commentaries  supply  us  with  an  instance  of  this  kind.  The 
individual  was  in  his  sixty-first  year,  and  altogether  toothless.  At  this 
time  his  gums  and  jawbones  became  painful,  and  the  pain  was  at 
length  excruciating.  But  within  the  space  of  twenty-one  days  from 
its  commencement,  both  jaws  were  furnished  with  a  new  set  of  teeth, 
complete  in  number." 

A  late  physician  of  Baltimore  informed  the  author,  in  1838,  that 
an  example  of  third  dentition  had  come  under  his  own  observation. 
The  subject,  a  female,  at  the  age  of  sixty,  he  assured  him,  erupted  an 
entire  new  set  in  each  jaw. 

The  following  extract  of  a  letter  from  a  professional  friend*  de- 
scribes another  very  interesting  case  :  — 

"  I  have  just  seen  a  case  of  third  dentition.  The  subject  of  this 
'  playful  freak  of  nature,'  as  Dr.  Good  styles  it,  is  a  gentleman  residing 
in  the  neighborhoor'.  of  Coleman's  Mill,  Caroline  County,  Virginia. 
Hi  is  now  in  his  seventy-eighth  year,  and,  as  he  playfully  remarked, 
■s  just  cutting  his  teeth.'  There  are  eleven  out,  five  in  the  upper  and 
..IX  in  the  lower  jaw.  Those  in  the  upper  jaw  are  two  central  incisors, 
(;ne  lateral  and  two  bicuspids,  on  the  right  side.  Those  in  the  lower 
are  the  four  incisors,  one  cuspid  and  one  molar.  Their  appearance  is 
that  of  bone,  extremely  rough,  without  any  coating  or  enamel,  and  of 
a  dingy  brown  color." 

*  Dr.  J.  D.  McCabe. 


THIRD    DENTITION.  I  79 

Two  cases  somewhat  like  the  foregoing  have  come  under  the 
author's  observation.  The  subject  of  the  first  was  a  shoemaker,  Mr. 
M.,  of  Baltimore,  who  erupted  a  lateral  incisor  and  cuspid  at  the  age 
of  thirty.  Two  years  before  this  time  he  had  been  badly  salivated, 
and,  in  consequence,  lost  four  upper  incisors  and  one  cuspid.  The 
alveoli  of  these  teeth  exfoliated,  and  at  the  time  he  first  saw  him  were 
entirely  detached  from  the  jaw,  and  barely  retained  in  the  mouth  by 
their  adhesion  to  the  gums.  On  removing  them,  he  found  two  white 
bony  protuberances,  which,  on  examination,  proved  to  be  the  crowns 
of  an  incisor  and  cuspid.  They  were  perfectly  formed,  and  though 
much  shorter  than  the  other  teeth,  yet  up  to  1845  they  remained  quite 
firm  in  the  jaw. 

The  subject  of  the  other  case  was  a  lady  residing  near  Fredericks- 
burg, Virginia,  who  erupted  four  right  central  incisors  of  the  upper 
jaw  successively.  One  of  her  temporary  teeth,  in  the  first  instance, 
had  been  permitted  to  remain  too  long  in  the  mouth,  and  a  per- 
manent central  incisor,  in  consequence,  came  out  in  front  of  the 
dental  arch.  To  remedy  this  deformity,  the  deciduous  incisor  was, 
after  some  delay,  removed  ;  and  about  two  years  after,  the  permanent 
tooth,  not  having  fallen  back  into  its  proper  place,  was  also  extracted. 
Another  two  years  having  elapsed,  another  tooth  came  out  in  the  same 
place  and  in  the  same  manner,  and,  for  similar  reasons,  was  also 
removed.  To  the  astonishment  of  the  lady  and  her  friends,  a  fourth 
incisor  made  its  appearance  in  the  same  place,  two  years  and  a  half 
after  the  extraction  of  the  first  permanent  tooth.  When  it  had  been 
out  about  eighteen  months,  the  author  was  called  in  by  the  lady,  who 
vvished  him,  if  possible,  to  adjust  it.  Finding  that  it  could  not  be 
brought  within  the  dental  circle,  he  advised  her  to  have  it  extracted 
and  an  artificial  tooth  placed  in  the  proper  place  in  the  arch. 

In  the  second  number  of  the  eighth  volume  of  the  American 
Journal  of  Dental  Science,  the  history  of  a  case  of  four  successive 
dentitions  of  the  upper  central  incisors  is  given.* 

The  following  interesting  case  is  related  by  Dr.  B.  H.  Catching  in 
\\iQ  Southern  Dental  Journal  for  October,  1886.  The  patient  was  a 
girl,  born  August  6,  1871,  very  small  and  delicate,  having  been  a  six- 
months'  child. 

At  the  age  of  six  months  the  eruption  of  the  teeth  began,  and  at 
seven  months  she  possessed  a  full  set  of  diminutive  teeth,  all  of  which 
were  shed  within  three  months.  When  eleven  months  old,  teeth  again 
began  to  erupt,  and  at  the  age  of  fifteen  m.onths  a  second  full  set  was 
in  her  mouth.     These  soon  crumbled  away,  and  her  mouth  was  with- 

*  Dr.  W.  H.  Dwindle. 


i:i'o  DENTAL    PATHOLOGY,    THERAPEUTICS. 

out  teeth  until  she  had  arrived  at  the  age  of  two  and  a  half  years,  when 
a  third  set  began  to  erupt.  The  child  weighed  at  this  time  but  ten 
pounds,  and  this  third  set  of  teeth  caused  her  so  much  trouble  that 
the  mother  endeavored  to  have  them  extracted,  and  not  being  able  to 
induce  a  dentist  to  perform  the  operation,  she  extracted  twelve  of  the 
teeth  herself  in  order  to  give  relief  to  her  child  ;  and  all  of  the  third 
set  were  removed  prior  to  her  fourth  year  of  age.  She  remained  with- 
out teeth  until  her  eleventh  year,  when  her  last  and  permanent  set 
began  to  erupt,  nearly  all  of  which  were,  at  the  date  of  writing  this 
account,  in  her  mouth,  sound  and  firm.  Her  last  set  is  deficient  in 
one  superior  central  incisor,  one  superior  left  bicuspid,  two  inferior 
right  bicuspids,  and  an  inferior  left  cuspid  and  bicuspid.  At  seven 
years  of  age  this  child  weighed  but  thirty  pounds,  but  at  fifteen  years 
of  age  she  had  developed  into  a  stout,  strong  girl.  Dr.  T.  T.  Moore, 
of  S.  C,  verifies  this  case,  as  the  child  was  under  his  care  also,  both 
himself  and  Dr.  Catching  having  carefully  observed  the  conditions  and 
development  from  the  beginning  to  the  end. 

Concerning  the  manner  of  the  origin  and  formation  of  teeth  of  third 
dentition,  adopting  Wedl's  views,  germs  may  lie  dormant  for  many 
years  in  the  animal  organism,  until  they  are  subjected  to  favorable  con- 
ditions which  enable  them  to  develop.  The  crowns  of  such  teeth  only 
being  formed,  while  the  roots  are  stunted,  is  clearly  due  to  the  small 
depth  of  the  jaws  in  old  age. 


CHAPTER  in. 

DISEASES   OF   THE   ORAL   MUCOUS   MEMBRANE. 
STOMATITIS. 

The  diseases  of  the  mucous  membrane  lining  the  mouth,  very  com- 
mon at  the  periods  for  the  eruption  of  the  teeth  and  later  in  life,  are 
comparatively  rare  during  fetal  life,  and  differ,  as  regards  symptoms, 
in  accordance  with  the  nature  of  the  affection  and  the  part  of  the  mu- 
cous surface  in  which  it  may  have  its  origin. 

The  most  common  affection  of  the  membrane  lining  the  mouth  is 
known  by  the  general  term  stomatitis,  from  the  Greek  word  arofia, 
**  mouth,"  and //w,  a  "  suffix  denoting  inflammation,"  and  is  described 
by  Prof.  Wood  as  follows :  — 

"  Inflammation  of  the  mouth  appears  in  reddened,  somewhat  elevated 
patches,  or  occupies  large  portions  of  the  surface,  sometimes  extending 


DISEASES   OF   THE    ORAL    MUCOUS   MEMBRANE.  151 

apparently  over  the  whole  mouth.  In  some  cases  it  is  superficial,  with 
little  or  no  swelling,  and  may  be  designated  as  erythematous,  from  the 
Greek  word  spof^poi,  '  red  ;  '  in  others  it  occupies  the  whole  thickness 
of  the  membrane,  extending  sometimes  to  the  submucous  tissue,  and 
even  to  the  neighboring  structures,  as  the  sublingual  and  submaxillary 
glands,  and  the  absorbent  glands  of  the  neck,  and  occasions  consider- 
able tumefaction  in  all  these  parts.  In  the  erythematous  form  it  is 
characterized  by  redness  and  sense  of  heat,  and  sometimes  considerable 
tenderness,  but  is  not  usually  attended  with  acute  pain ;  when  deeper 
in  the  tissue  it  is  often  very  painful. 

"  Portions  of  the  epithelium  sometimes  become  opaque,  giving  an 
appearance  of  whiteness  in  streaks  or  patches.  Occasionally  this  coat- 
ing is  elevated  in  blisters,  or  even  detached,  like  the  cuticle  from  the 
skin  in  scales.  Superficial  ulcerations  not  unfrequently  occur,  which 
may  spread  over  considerable  portions  of  the  membrane.  In  certain 
states  of  the  constitution  the  ulcerative  tendency  is  very  strong  and 
deep,  and  extensive  sores  occur,  which  are  sometimes  attended  with 
gangrene. 

*'  There  is  often  a  copious  flow  of  saliva  ;  though,  in  some  instances, 
this  secretion,  as  well  as  that  of  the  mucous  follicles,  is  checked,  and 
the  mouth  is  clammy  or  dry.  The  sense  of  taste  is  usually  more  or 
less  impaired,  and  speech  and  mastication  are  often  difficult  and  pain- 
ful. When  the  tongue  is  affected,  its  surface  is,  in  general,  first 
covered  with  a  whitish  fur,  through  which  the  red  and  swollen 
follicles  may  often  be  seen  projecting.  This  fur  sometimes  breaks  off", 
leaving  the  surface  red,  smooth,  and  glossy,  with  here  and  there  promi- 
nent follicles;  or  the  surface  may  be  hard,  dry,  or  gashed  with  painful 
fissures.  When  the  gums  are  involved,  they  swell,  and  rise  up  between 
the  teeth,  around  the  necks  of  which  they  frequently  ulcerate.  In  some 
cases  this  ulceration  does  not  cease  until  it  has  extended  into  the 
sockets,  and  destroyed  altogether  the  connections  of  the  teeth,  which 
become  loosened  and  fall  out,  after  which  the  gums  will  heal. 

"Ordinary  inflammation  of  the  mouth  is  seldom  so  violent  as  to 
induce  symptomatic  fever.  This  form  of  inflammation  is  more  fre- 
quently a  complication  of  other  diseases  than  an  original  affection. 
When  of  the  latter  character,  it  is  generally  caused  by  the  direct 
action  of  irritant  bodies,  as  by  scalding  drinks,  acrid  or  corrosive  sub- 
stances taken  into  the  mouth,  or  unhealthy  secretions  from  decayed 
teeth.  The  sharp  edge  of  a  broken  tooth  sometimes  gives  rise  to  much 
inflammation,  and  even  deep  and  obstinate  ulcers,  especially  of  the 
tongue.  Inflammation  of  the  mouth  may  also  result  from  the  reaction 
which  follows  the  long  contact  of  very  cold  substances,  such  as  ice, 
with  the  interior  of  the  mouth.     It  sometimes  proceeds  from  the  propa- 


l82  DENTAL    PATHOLOGY,    THERAPEUTICS. 

gation  of  inflammation  from  the  fauces,  and  is  a  frequent  consequence 
of  gastric  irritation  produced  by  sour  or  acrid  matter  in  the  stomach. 
Drunkards  seem  peculiarly  predisposed  to  it.  Of  the  constitutional 
causes  none  are  so  frequent  as  the  state  of  fever,  which,  whatever  may 
be  its  peculiar  character,  is  very  apt  to  affect  the  mouth,  and  not  infre- 
quently occasions  inflammation." 

Catarrhal  Stomatitis. — Catarrhal  stomatitis  may  be  either  acute  or 
chronic,  and  a  simple  form  is  common  to  children  under  the  age  of 
one  year  ;  while  this  simple  form  .gives  rise  in  itself  to  no  severe 
symptoms,  yet  it  may  be  connected  with  other  serious  maladies, 
and  hence  is  often  overlooked.  Acute  catarrhal  stomatitis  first 
appears  in  the  form  of  bright-red  patches  at  the  angles  of  the  mouth 
and  on  the  inside  of  the  cheeks,  which  increase  in  size  and  some- 
times unite,  when  the  entire  mucous  surface  of  the  mouth  may  be- 
come inflamed.  While  it  is  more  intense  in  one  part  than  in  another, 
it  may  be  confined  to  the  tongue  alone,  or  be  universally  diffused  over 
the  whole  mucous  membrane  of  the  mouth.  It  is  characterized  by  an 
increase  of  the  heat  and  redness  of  the  part  affected,  rapid  prolifera- 
tion and  exfoliation  of  epithelial  cells,  and  more  or  less  dryness  of  the 
surface,  as  there  is  but  little  mucus  secreted,  with  a  high  degree  of 
sensibility,  and  pain  when  the  lips  or  tongue  are  moved.  The  pain  is 
of  a  smarting,  burning  character,  the  result  of  irritation  on  a  denuded 
surface.  Owing  to  the  limited  extent  of  connective  tissue,  the  swell- 
ing of  the  inflamed  mucous  membrane  is  generally  slight.  In  severe 
cases  the  gums  become  swollen  and  spongy,  and  bleed  readily,  and  the 
entire  surface  of  the  mouth  and  tongue  is  covered  with  a  white,  viscid 
mucus ;  there  is  an  increased  flow  of  saliva,  that  is  acrid  and  irritat- 
ing, which  may  dribble  from  the  corners  of  the  mouth,  causing  a 
greater  degree  of  congestion,  which  is  apparent  by  the  dark  red  color 
of  the  affected  membrane.  A  fetid  condition  of  the  breath  is  not 
common  to  the  acute  form  of  catarrhal  stomatitis  unless  shallow  ulcers 
are  present,  which  result  from  the  rapid  loss  of  the  superficial  cells  and 
a  failure  in  the  development  of  others  to  supply  their  places.  The 
engorgement  of  the  vessels  of  the  mucous  membrane  is  followed  by  the 
exudation  of  white  blood-corpsucles. 

The  intensity  of  this  affection  varies  in  different  cases,  sometimes 
existing  in  such  a  slight  form  as  to  cause  little  uneasiness,  and  quietly 
disappearing,  while  at  other  times  it  may  cause  intense  pain,  and  con- 
tinue for  weeks  or  months. 

In  a  severe  form  it  may  extend  to  the  esophagus  and  stomach,  or 
the  larynx  and  trachea,  and  at  last  prove  fatal,  especially  if  there  is 
present  a  decided  state  of  cachexia,  or  a  severe  co-existing  disease. 

When  it  occurs  during  the  period  of  dentition,  to  which  it   is  com- 


DISEASES    OF    THE    ORAL    MUCOUS    MEMBRANE.  185 

mon,  it  is  often  accompanied  with  fever,  and  sometimes,  especially 
when  long  continued,  by  a  profuse  flow  of  saliva  ;  occurring  previous 
to  dentition,  it  is  seldom  accompanied  with  fever. 

When  caused  by  some  disease  coincident  with  the  period  of  denti- 
tion, the  gum  over  the  erupting  tooth  becomes  inflamed,  and  the 
inflammation  may  extend  over  the  entire  buccal  surface.  But  when 
due  to  the  irritation  of  dentition,  this  form  of  stomatitis  is  generally 
more  circumscribed  than  when  it  arises  from  a  constitutional  cause. 
It  may  also  result  from  a  mercurial  course  of  treatment,  exposure  to 
cold,  hot  and  stimulating  food,  or  a  diseased  condition  of  the  alimen- 
tary canal. 

In  adults  catarrhal  stomatitis  may  result  from  long-continued  irrita- 
tion of  the  mucous  membrane  of  the  mouth,  or  from  injuries  to  the 
gums,  such  as  may  result  from  laceration  in  the  extraction  of  teeth  ; 
also  from  the  sharp  edges  of  fractured  teeth  and  roots,  and  constitutional 
derangement. 

In  very  young  children,  among  the  early  symptoms  are  restlessness 
and  fretfulness,  with  refusal  to  take  food,  or,  when  attempting  to  do  so, 
suddenly  ceasing  on  account  of  the  pain  experienced. 

Chronic  catarrhal  stomatitis  is  characterized  by  the  structural 
changes  which  ensue  on  account  of  the  stroma  becoming  affected. 
The  mucous  surface  affected  becomes  indurated  and  thickened,  the 
mucous  glands  are  obstructed,  and,  as  a  result  of  their  secretion  being 
arrested,  they  become  encysted  and  present  a  granular  appearance 
on  the  surface  of  the  membrane.  The  breath  is  more  or  less  fetid, 
owing  to  the  secretions  of  the  mouth  becoming  vitiated,  and  the 
teeth  are  coated  with  sordes.  The  papillae  of  the  tongue  become 
hypertrophied,  but  the  substance  beneath  is  less  affected  than  in  the 
acute  form  of  this  affection.  The  duration  of  the  acute  form  is 
from  three  to  six  days,  as  a  general  rule,  while  the  chronic  form  is 
more  persistent. 

Simple  stomatitis  of  children  is  readily  relieved  by  means  of 
emollient  washes,  such  as  solutions  made  from  the  slippery  elm  bark  or 
the  pith  of  sassafras,  in  cold  water.  When  severe,  a  leech  or  two 
applied  to  the  angle  of  the  jaws  will  prove  serviceable,  and  as  a  wash, 
the  acetate  of  lead,  in  a  solution  composed  of  three  grains  to  one 
fluidounce  of  water.  A  few  doses  of  bromid  of  potassium  may  relieve 
the  nervous  excitement  and  fretfulness.  One  part  of  borax  to  three  of 
honey,  or  a  dram  of  borax  to  an  ounce  of  glycerin  and  water,  or  a 
weak  solution  of  alum,  may  prove  useful  local  remedies. 

The  treatment  of  catarrhal  stomatitis  consists  in  first  removing  the 
cause  of  irritation,  when  such  is  present,  and  the  use  of  alkaline 
washes,  or,  in   more  obstinate  cases,  a  solution  of  either  chlorid  of 


l84  DENTAL    PATHOLOGY,    THERAPEUTICS. 

zinc  or  nitrate  of  silver,  one  grain  to  the  ounce  of  water.  Phenol 
sodique  or  phenate  of  soda  will  correct  the  fetor  of  the  breath,  when 
used  in  the  form  of  spray.  For  the  chronic  form  the  following  may  be 
applied  to  the  inflamed  mucous  surface,  either  in  the  form  of  a  gargle 
or  spray : — 

R.    Acidi  carbolici, ^j. 

Olei  gaultherise, ^ij. 

Glycerini, gij. 

Olei  menthae  piperitae, 3;iij.  M. 

When  the  inflammation  of  the  mouth  is  symptomatic  of  a  diseased 
condition  of  the  alimentary  canal,  the  remedies  adapted  to  such  a  con- 
dition are  necessary. 

Ulcerous  Stomatitis,  also  known  as  "  Noma,"  is  another  affection  of 
the  mouth  which  is  common  to  childhood,  the  premonitory  symptoms 
being  the  same  as  in  simple  stomatitis.  The  inflammation  usually 
begins  upon  the  gums  and  extends  along  the  buccal  surface.  An  ex- 
amination of  the  mouth,  however,  at  this  stage  of  the  disease,  reveals 
one  or  more  small,  inflamed,  and  slightly  elevated  points  or  pimples, 
which,  sometimes  within  a  few  hours,  but  more  commonly  after  one  or 
two  days,  present  a  softened  and  yellowish  apex,  and  at  length  a  small 
ulcer,  superficial  at  first,  but  gradually  becoming  deeply  excavated, 
with  often  an  inflamed  and  elevated  margin.  The  surfaces  of  these 
ulcers  are  covered  with  an  ash-colored  or  a  yellowish  matter,  in  the 
majority  of  cases  ;  but  sometimes,  instead  of  being  thus  covered,  their 
surfaces  are  bare,  and  bleed  readily. 

Some  of  the  ulcers  may  unite  and  form  large,  irregular  ulcerations, 
while  others  remain  isolated.  The  ulceration,  when  severe,  gives  rise 
to  considerable  swelling,  especially  around  the  ulcers,  and  the  swollen 
part  is  soft,  and  not  very  tender  on  pressure.  The  soft,  yielding 
nature  of  the  swelling  enables  this  form  to  be  distinguished  from 
gangrenous  ulceration,  as  there  is  more  induration  in  the  latter  affec- 
tion. These  ulcers  result  from  acute  phlegmonous  inflammation,  and 
may  attack  any  part  of  the  mucous  membrane  lining  the  mouth,  but 
are  most  commonly  found  on  the  sides  of  the  frenum,  along  the  in- 
ferior margin  and  edges  of  the  tongue,  and  inside  the  lips. 

It  is  but  seldom  that  they  are  found  on  the  upper  surface  of  the 
tongue  ;  but  when  they  do  appear  on  this  surface,  they  are  generally 
superficial,  and  not  deeply  excavated. 

When  the  ulcers  in  this  form  of  stomatitis  are  fully  formed,  there 
is  usually  a  profuse  flow  of  saliva  and  a  decrease  of  the  febrile  ex- 
citement. The  bowels,  which  in  the  first  stage  of  the  disease  are 
costive,  now  become  loose,  and  often  very  much  so  during  its  con- 


DISEASES    OF    THE    ORAL    MUCOUS    MEMBRANE.  1S5 

tinuance.  A  simple  form  of  ulcerous  stomatitis  is  characterized  by 
but  one  or  two  small  ulcers,  which  in  a  little  time  fill  up  with 
granulations  and  soon  heal  over.  In  a  more  severe  form  of  this 
disease  a  considerable  number  of  these  ulcers  exist,  in  some  cases 
covering  almost  the  whole  of  the  mucous  membrane  of  the  gums,  the 
inside  of  the  cheeks,  arch  of  the  palate,  sides  and  inferior  surface  of 
the  tongue. 

During  the  early  stage  of  ulcerous  stomatitis  the  mouth  becomes  hot 
and  painful  and  the  submaxillary  glands  swollen  and  tender.  The 
breath  becomes  very  offensive  as  soon  as  the  ulceration  is  well  estab- 
lished, and  there  is  a  tendency  to  keep  the  mouth  open. 

Another  form  of  this  disease  is  sometimes  met  with  where  but  one 
or  two  ulcers  exist,  but  which  gradually  extend  over  the  mucous  sur- 
face, at  the  same  time  increasing  in  depth,  and  with  no  appearance  of 
healing.  This  form  of  the  affection  is  attended  with  hectic  fever,  the 
exacerbations  occurring  night  and  morning,  and  rapidly  wearing  away 
the  strength. 

There  is  yet  another  form  of  ulcerous  stomatitis  occasionally  met 
with,  which  consists  of  a  softening  of  the  mucous  membrane  of  the 
palate  in  its  centre,  either  on  the  median  line  or  outside  this  line. 
The  membrane  appears  to  be  softened  into  a  kind  of  pulp,  of  a  red  or 
fawn  color,  which,  on  its  removal,  discloses  an  ulcer  with  perpendicular 
walls  ;  the  bone,  however,  forming  its  base  is  found  to  be  perfectly 
healthy.  It  is  the  opinion  of  some  that  ulcerous  stomatitis  is  conta- 
gious ;  that  is,  that  it  may  be  communicated  by  using  the  same  spoon 
in  eating,  and  also  that  it  is  endemic  and  epidemic.  Ulcerous  stomatitis 
is  common  to  the  period  of  dentition,  especially  when  there  is  disorder 
of  the  digestive  organs. 

The  causes  of  ulcerous  stomatitis  are  uncleanliness,  poor  food,  resi- 
dence in  damp,  dirty  places,  mercury,  a  cachectic  condition,  enfeebled 
system,  and  contagion. 

The  treatment  of  ulcerous  stomatitis  consists  in  a  change  of  resi- 
dence and  diet,  cleanliness,  the  use  of  tonics,  ferruginous  or  vege- 
table, such  as  the  liquor  ferri  nitratis,  with  tincture  of  calumba, 
given  in  simple  syrup,  tincture  of  chlorid  of  iron,  and  sulphate  of 
quinin,  or  cod-liver  oil,  and  such  local  remedies  as  dilute  chlorid 
of  zinc,  carbolic  acid,  nitrate  of  silver,  muriatic  acid,  with  an  alter- 
nate wash  of  honey  and  borax,  equal  parts  ;  or  the  chlorid  of  lime 
applied  dry  to  the  ulcerated  surface  twice  daily,  and  simple  water 
used  during  the  interval,  and  continued  until  a  healthy  appearance 
is  apparent,  when  a  weak  solution  of  chlorid  of  lime,  one  grain  to 
forty-five  of  water,  is  employed.  Chlorid  of  lime  one  dram,  with 
honey  one  ounce,  is  also  recommended.     Chlorate  of  potassium  often 


l86  DENTAL    PATHOLOGY,    THERAPEUTICS. 

acts  like  a  specific,  employed  internally  and  externally,  the  dose 
of  which  is  two  or  three  grains,  dissolved  in  water  with  sugar,  or  in 
syrup. 

The  following  formula  may  be  employed  : — 

R.     Potass,  chlorate, ^ss  to  j. 

Mellis, ^ss. 

AquDe, ^ij.  M. 

•       One  teaspoonful  every  two  hours,  and  also  applied  as  a  lotion. 

Dr.  Condie  recommends  the  following  treatment  where  the  ulcers 
are  slow  in  healing  :  A  solution  of  borax,  gr.  xv  to  the  ounce  of  water, 
or  a  weak  solution  of  the  nitrate  of  silver,  gr.  j  to  the  ounce  of  water, 
or  sulphate  of  copper,  gr.  v  to  the  ounce  of  water,  or  acidum  nitricum 
dilutum  applied  by  means  of  a  camel's  hair  pencil  to  the  whole  of  the 
ulcerated  surface,  which  will  improve  the  character  of  the  ulceration 
and  arrest  its  progress. 

"Any  apparent  cause  of  irritation,  such  as  a  decayed  tooth,  should 
be  removed."  When  there  is  great  derangement  of  the  alimentary 
canal  accompanying  ulcerous  stomatitis,  or  this  disease  occurs  during 
the  course  of  other  acute  and  chronic  diseases,  such  as  pneumonia, 
scarlet  fever,  smallpox,  etc.,  the  proper  remedies  adapted  to  the  removal 
of  these  diseases  are  necessary. 

Aphthous  Stomatitis. — This  form  of  stomatitis,  sometimes  called 
'follicular  stomatitis,"  and  also  "  canker  sore  mouth,"  although  it 
is  not  confined  to  the  seat  of  the  follicles,  is  common  to  all  ages,  but 
is  most  frequent  during  childhood.  The  seat  of  the  aphthae  is  asually 
the  inner  surfaces  of  the  lips  and  cheeks,  the  gums,  the  tongue,  and 
sometimes  the  roof  of  the  mouth.  They  commence  with  a  vascular 
injection,  which  is  followed  in  a  few  hours  by  a  whitish  exudation 
immediately  below  the  epithelium  and  upon  thecorium,  in  the  form  of 
small,  round  or  oval,  isolated  spots,  the  smallest  being  of  the  size  of 
a  pin's  head,  but  the  greater  number  of  a  diameter  of  one  or  two 
lines,  causing  slight  vesicle-shaped  elevations  on  the  surface  of  the 
mucous  membrane.  The  vesicles  have  a  whitish  appearance  with  an 
inflamed  ring  about  their  base  ;  after  their  rupture  an  irregular  gray 
surface  is  exposed,  and  the  ulcers  resulting  are  shallow  and  painful. 
After  a  few  days  the  exudation  softens,  and  the  points  become  denuded 
of  epithelium,  presenting  superficial,  painful  ulcers,  but  without  in- 
durated edges.  After  an  existence  of  one  or  two  weeks  the  aphthae 
disappear,  leaving  red  spots,  which,  however,  soon  fade.  Besides 
being  very  painful  to  the  touch,  and  also  to  foods  and  liquids,  they 
are  attended  with  an  increased  secretion  of  saliva. 

Two  or  more  of  the  ulcers  may  coalesce,  forming  one  large  ulcerated 


DISEASES    OF    THE    ORAL    MUCOUS    MEMBRANE.  iSy 

patch,  to  the  edges  of  which  vegetable  fungi  may  adhere ;  in  rare 
cases,  it  may  become  gangrenous,  when  the  affection  is  usually  compli- 
cated with  gastro-intestinal  disease.  The  constitutional  symptoms  are 
generally  slight,  except  when  there  is  a  tendency  to  gangrene,  which 
may  cause  a  feeble  pulse,  pallid  countenance,  wasted  body  and  limbs, 
and  great  prostration. 

The  causes  of  aphthous  stomatitis  may  be  bad  hygienic  conditions, 
uncleanliness,  and  privation,  but  is  usually  owing  to  some  derange- 
ment of  the  digestive  organs,  when  it  may  also  be  accompanied  with 
diarrhea.  It  differs  from  ulcerous  stomatitis  in  form  of  the  aphthze, 
and  the  inflammation  being  confined  to  the  immediate  vicinity  of  the 
ulcers,  and  not  extending  over  the  mouth. 

The  treatment  of  aphthae  consists  in  the  application  of  demulcent 
drinks,  such  as  the  mucilage  of  gum  acacia,  flaxseed,  or  marsh- 
mallow.  Mel-boracis,  honey  of  borax,  is  an  efficient  application 
applied  with  a  camel's-hair  pencil,  and  a  small  quantity  of  some 
opiate  to  relieve  the  tenderness  of  the  ulcers  and  the  restlessness. 
When  the  ulcers,  besides  being  painful,  are  not  disposed  to  heal, 
they  may  be  touched  with  nitrate  of  silver  or  with  hydrochloric 
acid  in  honey  of  roses,  or  nitric  acid  applied  on  the  sharpened  end  of 
a  stick  of  orange  wood.  The  application  of  chlorate  of  potassium  is 
also  effective  in  some  cases.  The  constitutional  treatment  consists  in 
the  administration  of  citrate  of  magnesia  or  rhubarb  to  correct  the 
intestinal  trouble,  and  tonics  of  sulphate  of  quinin  or  other  vegetable 
bitters,  or  of  the  tincture  of  the  chlorid  of  iron,  to  keep  up  the 
strength.  When  there  is  a  great  number  of  the  ulcers,  with  consider- 
able fever,  and  symptoms  of  cerebral  congestion  or  of  convulsions, 
the  administration  of  laxatives  and  the  bromids,  with  a  warm  foot- 
bath, will  prove  beneficial. 

Thrush. — This  affection,  also  known  as  "sprue  "  and  "  muguet,"  is 
characterized  by  a  form  of  inflammation  which  consists  of  points  and 
patches  of  a  curd-like  appearance  on  the  surface  of  the  mucous  mem- 
brane of  the  mouth,  its  common  seat,  as  the  fauces,  pharynx,  and 
esophagus  are  only  occasionally  affected. 

Thrush  commences  as  simple  inflammation  of  the  mucous  sur- 
face, which  is  followed  by  the  appearance  of  minute  semi-trans- 
parent points  or  granules,  which  soon  become  white  and  opaque. 
While  some  remain  as  points,  others  extend,  and  by  coalescing 
form  patches,  the  surfaces  of  which  are  not  uniform,  but  unequally 
elevated. 

The  central  part  of  the  points  and  patches  project  but  little  above 
the  surrounding  epithelial  surface,  being  not  more  than  a  line  in 
height.     They  resemble  in  color  and  consistence  portions  of  curdled 


l88  DENTAL   PATHOLOGY,    THERAPEUTICS. 

milk,  for  which  they  may  be  mistaken.  Being  very  easily  detached, 
they  are  rapidly  reproduced,  and  their  white  color  may  change  to  a 
yellow  hue. 

Composed  of  epithelial  cells  and  a  parasitic  vegetable  growth,  of 
the  oidium  albicans  variety,  each  point  consists  of  roots,  branches, 
and  sporules,  the  roots  being  transparent,  and  penetrating  the 
epithelial  layer,  and  sometimes  even  as  far  as  the  basement  mem- 
brane. The  branches  divide  and  subdivide,  and  consist  of  elon- 
gated cells  with  one  or  two  nuclei.  Around  the  branches  are  numerous 
sporules.  Thrush,  in  its  mildest  form,  appears  in  points  or  small 
patches ;  and  if  the  patches  are  of  large  extent,  which,  however, 
rarely  occurs,  the  affection  is  attended  by  a  state  of  great  prostration 
and  danger  from  some  concomitant  disease.  Often  it  occurs  as  the 
sequel  of  pneumonia  or  gastro-intestinal  inflammation,  in  the  latter 
case  being  caused  by  neglect,  improper  food,  or  a  deprivation  of  the 
maternal  milk.  In  the  mildest  cases  the  symptoms  are  similar  to  those 
of  simple  stomatitis.  When  the  inflammation  is  more  extensive,  and 
especially  if  the  fauces  and  esophagus  are  involved,  the  inflamed 
surface  becomes  very  hot,  red,  and  painful,  and  there  is  fretfulnessand 
fever.  In  the  severest  forms,  the  surface  becomes  dry  and  parched,  the 
inflammation  more  extensive,  and  there  is  thirst,  loss  of  appetite,  vom- 
iting, and  frequently  diarrhea,  with  an  anxious,  pallid  countenance, 
rapid  emaciation,  and  extreme  prostration. 

When  thrush  is  complicated  with  aphthae,  small,  white,  flocculent 
patches  appear  on  the  surface  of  the  mucous  membrane,  which  in- 
crease in  size  and  finally  coalesce.  In  such  patches  some  form  of 
vegetable  parasite  exists,  more  commonly  that  known  as  oidium 
albicans. 

The  causes  of  thrush  are  bad  hygienic  conditions,  constitutional 
feebleness,  indigestion,  and  improper  food.  It  is  common  among 
emaciated  children  in  crowded  institutions,  or  where  there  is  expos- 
ure to  dampness.  Foul  nursing-bottles  are  also  a  common  cause 
of  this  affection.  It  appears  to  be  more  prevalent  during  the  sum- 
mer months,  and  to  occur  more  frequently  under  the  age  of  three 
months. 

Even  children  of  eighteen  months,  sufi"ering  from  debilitating 
diseases,  are  subject  to  it.  The  stools  are  greenish  and  acrid,  giving 
rise  to  excoriations  of  the  parts  with  which  they  come  in  contact. 
When  this  disease  occurs  in  adults,  it  is  attended  with  an  increased 
flow  of  saliva  and  a  dry,  hot  state  of  the  mouth,  rendering  deglutition 
painful. 

The  treatment  of  thrush  should  commence  with  an  improvement  in 
the  diet  and  locality,  if  these  are  at  fault,  and  the  administration  of 


DISEASES    OF    THE    ORAL    MUCOUS    MEMBRANE.  1 89 

an  alkali  to  correct  the  acidity  of  the  secretions  which  is  usually 
present.  Saccharate  of  lime  added  to  the  milk  is  very  beneficial.  The 
following  combination  is  recommended  by  Dr.  Sudduth  : — 

R.     Infusi  rhei, S^J* 

Potassi  bicarb., 2J- 

Tincturse  cinnamomi,  , 2'j- 

Syrupi  simp., gvj.  M. 

Dose.     A  teaspoonful  every  three  hours  for  an  adult. 

Quinin  in  one-grain  doses  every  three  hours  will  prove  beneficial  for 
infants.  The  quinin  may  be  combined  with  tincture  of  the  chlorid 
of  iron  to  produce  a  tonic  effect,  one  dram  of  the  quinin  with 
one  ounce  of  the  iron,  in  doses  of  fifteen  drops  every  three  hours.  Dr. 
Trousseau  recommends  the  following  alterative  tonic,  which  is  very 
effective :  — 

B  .     Hydrarg.  chloridi  corrosivi, gr.  j-ij. 

Liq.  arsenici  chloridi, f  Jj. 

Tinct.  ferri  chloridi, 

Acid,  hydrochlorici  dil.,     .    .    .    .  aa f^iv. 

Syrupi, f|iij. 

Aquam, ad  .    .  f^vj.  M. 

Dose.     One  dessertspoonful  in  a  wineglassful  of  water  after  each  meal. 

The  local  treatment  consists  in  the  application  of  borax  with  honey — 
mel-boracis — or  borax  with  powdered  sugar,  or  dissolved  in  water. 
Some  object  to  the  use  of  sugar,  as  it  promotes  the  growth  of  the  para- 
site.    Prof.  J.  L.  Miller  recommends  the  following: — 

R.     Sodii  borat., ^j. 

Glycerinae, gij. 

Aquae, ^vj.  M. 

SiG. — To  be  applied  with  a  camel's-hair  pencil  four  or  five  times  a  day. 

If  such  an  application  fails,  which  is  rarely  the  case,  then  recourse 
must  be  had  to  a  solution  of  nitrate  of  silver  or  sulphate  of  zinc. 

R  .     Zinci  sulph., gr.  ij-iv. 

Aquae  rosse,      ^ij.  M. 

When  thrush  is  complicated  with  other  diseases,  the  proper  treat- 
ment for  such  diseases  may  render  its  treatment  easy  and  effectual. 

Gangrene  of  the  Mouth. — This  disease,  characterized  by  such  names 
as  "  Cancrum  Oris,"  "  Gangrenopsis,"  "Canker  of  the  Mouth," 
"Water  Canker,"  is  common  to  children  of  debilitated  constitutions 
and  a  decided  lymphatic  temperament,  the  result  of  scanty  nourish- 
ment, improper  clothing,   and  damp,  unhealthy  places  of  abode,  or 


190  DENTAL    PATHOLOGY,    THERAPEUTICS. 

where  many  children  are  crowded  together  in  charitable  institutions. 
There  are  several  forms  of  this  affection,  the  most  common,  perhaps, 
being  preceded  by  inflammation  of  the  gums,  with  such  premonitory 
symptoms  as  great  languor  and  listlessness,  indisposition  to  any  exer- 
cise, irritable  temper,  loss  of  sleep  and  appetite,  and  increase  of  thirst. 
The  countenance  becomes  pale  and  dejected,  and  a  peculiar  puckering 
of  the  cheeks  is  observed  about  the  corners  of  the  mouth.  Emaciation 
and  night-sweats  are  not  uncommon. 

These  premonitory  symptoms  may  continue  for  several  days,  or 
even  weeks,  when  an  acute  pain  is  felt  in  the  mouth  and  gums,  with  a 
sense  of  heat  and  itching  about  their  margins,  the  free  edges  of  which 
become  congested  and  thickened,  spongy,  and  of  a  dark  red  or  purple 
hue,  bleeding  readily. 

The  flow  of  saliva  increases  greatly,  and  is  frequently  mixed  with 
blood.  From  about  the  necks  of  the  teeth  a  muco-purulent  matter 
is  discharged,  which  after  a  time  becomes  thin,  watery,  and  acrid, 
rendering  the  breath  very  ofi"ensive.  In  the  majority  of  cases  this 
disease  is  confined  to  one  side  of  the  mouth  and  to  the  lower  jaw, 
and  if  allowed  to  progress,  the  gums  separate  from  the  necks  of  the 
teeth  and  alveolar  processes,  and  become  ragged,  flabby,  and  livid  ; 
the  teeth  on  the  affected  side  loosen,  and  at  length  drop  out,  and  at 
this  stage  there  is  an  increase  of  the  febrile  symptoms  and  night- 
sweats.  In  such  a  state  the  gums  may  continue  for  weeks  or  even 
months,  but  usually  after  a  few  days  a  number  of  ash-colored 
vesicles  make  their  appearance,  which  rapidly  increase  in  size  and 
become  confluent,  the  divided  gum  presenting  a  gangrenous  ap- 
pearance. The  dead  portions  separate,  a  gangrenous  ulcer  follows, 
and  soon  the  entire  part  is  destroyed  and  the  inferior  maxillary  bone 
exposed.  The  ulceration  is  more  common  to  the  labial  surface  than  to 
the  lingual,  and  commences  in  the  front  part  of  the  mouth,  extending 
to  posterior  parts.  The  ulcers,  before  becoming  gangrenous,  are 
covered  with  a  yellow  or  gray  secretion,  which,  on  being  removed, 
exposes  many  small,  red  papillae,  which  correspond  to  imperfect  granu- 
lations. After  a  time  the  gangrenous  ulceration  extends  to  the 
mucous  membrane  of  the  cheek  and  lips,  causing  pain  and  difficulty  in 
attempting  to  open  the  mouth,  which  is  sometimes  impossible. 

In  a  short  time  the  whole  of  the  mouth  becomes  affected,  and  death 
usually  occurs  at  about  the  eighth  or,  at  the  furthest,  upon  the  four- 
teenth day  from  the  commencement  of  the  gangrene. 

Mr.  Tomes  remarks  that  although  the  disease  is  usually  confined  to 
children  during  the  shedding  of  the  temporary  teeth,  yet  adults  are 
not  wholly  exempt  from  its  attacks. 

There    is   another   form  of  this  disea.se  which  differs  considerably 


DISEASES    OF    THE    ORAL    MUCOUS    MEMBRANE.  IQI 

from  that  just  described,  from  the  fact  that  it  is  not  preceded  by 
inflammation  of  the  gums,  but  commences  in  the  cheek,  usually  at  the 
angle  of  the  lips,  and  comes  on  abruptly,  without  the  premonitory 
symptoms  characteristic  of  the  first  form  described. 

There  is  first  seen  a  hard,  indolent  tumor,  about  the  size  of  an 
almond,  in  some  part  of  the  lips  or  cheek,  which  is  deeply  seated,  the 
skin  covering  it  being  somewhat  redder  than  natural.  This  tumor 
gradually  increases  in  size  for  a  few  days,  when  the  mucous  membrane 
covering  it  presents  a  gangrenous  appearance,  with  an  offensive  odor. 
Before  this  occurs,  however,  the  external  redness  of  the  skin  covering 
the  tumor  becomes  pale,  then  livid,  then  of  a  grayish  hue,  surrounded 
by  a  red  circle,  which  spreads  rapidly  and  in  a  few  hours  changes  to  a 
black  color. 

The  gums  nearest  to  this  tumor  then  become  gangrenous,  and  the 
teeth  loosen  and  at  length  fall  out.  Death  usually  occurs  before  the 
death  of  the  bone  of  the  jaw.  There  is  also  a  superficial  form  of 
gangrene  sometimes  met  with  in  the  form  of  spots  of  a  dark-brown 
color  surrounded  by  a  red  margin,  which  vary  in  size,  and  have  for 
their  seat  the  corners  of  the  lips  and  inner  surfaces  of  the  cheeks. 
These  spots  may  first  appear  in  the  form  of  slightly  reddened  patches, 
but  in  this  mild  form  are  always  superficial,  confined  to  the  mucous 
membrane  alone,  the  sloughs  separating  with  little  loss  of  substance, 
soon  to  be  followed  by  healthy  granulations  and  cicatrization. 

Gangrene  of  the  mouth  may  occur  at  any  period  between  the  first 
and  tenth  year  of  age,  but  is  more  common  between  the  second  and 
fourth  years  ;  and  the  children  subject  to  it  are  those  of  a  lymphatic 
temperament,  delicate  constitution,  soft,  flaccid  muscles,  pale  skin,  and 
whose  digestive  organs  are  deranged.  It  usually  occurs  in  those  whose 
systems  are  much  reduced  or  cachectic,  and  is  more  common  to 
children  crowded  together  in  asylums  and  those  deprived  of  pure  air 
and  proper  nourishment,  or  enfeebled  by  disease.  It  sometimes  follows 
the  eruptive  fevers,  and  such  diseases  as  pneumonia,  scrofiila,  whoop- 
ing-cough, typhus  fever,  ague,  etc. 

In  the  treatment  of  gangrene  of  the  mouth  no  little  depends  upon 
the  time  this  is  instituted.  Before  the  gangrene  makes  its  appearance 
much  may  be  done  in  the  way  of  preventive  treatment,  in  order  to 
remove  the  existing  predisposition.  A  dry,  pure  air,  cleanliness,  and 
a  nourishing  diet  adapted  to  the  condition  of  the  digestive  organs  are 
very  essential.  The  preparations  of  iron  and  bitter  vegetable  tonics 
are  required. 

The  administration  of  the  sulphate  of  quinin,  and  the  local  appli- 
cation of  a  strong  decoction  of  white  oak  bark,  is  thought,  by  Dr. 
Condie,  to  be  beneficial  in  preventing  gangrene  of  the  mouth  in  cases 


192  DENTAL    PATHOLOGY,    THERAPEUTICS. 

in  which  there  is  every  reason  to  anticipate  its  speedy  occurrence. 
For  local  treatment  solution  of  sulphate  of  zinc  (one  dram  to  the 
ounce  of  water),  to  which  is  added  honey  and  tincture  of  myrrh,  two 
drams  of  each,  will  prove  serviceable.  Nitrate  of  silver,  either  in 
the  solid  form  or  in  solution,  applied  to  the  affected  part,  has  been 
successfully  employed  in  a  large  number  of  cases. 

When  the  disease  is  established,  the  first  indication  in  the  local 
treatment  is  to  arrest  the  progress  of  the  gangrene  and  hasten  the 
detachment  of  the  slough,  and  for  such  purposes  highly  stimulating  or 
escharotic  agents  are  required.  The  affected  parts  should  be  well 
cleansed,  and  then  sprayed  with  carbolized  water  and  strong  acetic, 
sulphuric,  nitric,  or  hydrochloric  acids,  nitrate  of  silver,  acid  nitrate 
of  mercury,  or  chlorid  of  antimony,  applied,  by  means  of  a  brush, 
on  and  about  the  slough,  to  be  at  once  followed  by  the  application  of 
dry  chlorid  of  lime,  when  the  mouth  is  to  be  thoroughly  washed  out 
with  water,  by  means  of  a  syringe.  By  such  applications  to  the  edges 
of  the  ulcers,  the  diseased  tissue  is  destroyed  and  healthy  granulations 
promoted. 

After  the  separation  of  the  slough  the  escharotic  is  to  be  discon- 
tinued and  the  chlorid  of  lime  alone  employed.  Some,  however, 
prefer  milder  remedies  than  the  strong  acids,  such  as  the  nitrate  of 
silver,  if  the  slough  is  small  in  extent ;  if  larger,  muriated  tincture 
of  iron  is  applied,  undiluted,  and  after  the  progress  of  the  gangrene  is 
arrested  the  use  of  astringent  stimulants,  such  as  tincture  of  myrrh  or 
the  French  aromatic  wine. 

Dr.  Coates  found  sulphate  of  copper,  according  to  the  following 
formula,  to  be  successful :  — 

R.     Cupri  sulph., 5jij. 

Pulv.  cinchonae,  Jss. 

Aquse,      ^iv.  M. 

To  be  applied  twice  a  day  to  the  entire  ulcerations  and  excoriations. 

In  milder  cases  a  solution  of  sulphate  of  zinc,  5J  to  an  ounce  of 
water,  by  itself  or  combined  with  tincture  of  myrrh,  is  found  to  be 
useful.  If  the  milder  agents,  after  two  or  three  days'  use,  do  not 
prevent  the  gangrene  from  spreading,  strong  hydrochloric  acid, 
applied  by  a  camel's-hair  pencil,  may  prove  efficacious,  and  its  use 
immediately  followed  by  lime-water  made  turbid  by  lime.  To  cor- 
rect the  fetor,  chlorin  or  carbolic  acid,  properly  diluted,  may  be 
employed  alternately  with  the  sulphate  of  copper,  or  Labarraque's 
solution  of  chlorinated  soda,  one  part  to  eight  or  ten  parts  of  water. 
The  tincture  of  myrrh,  with  tonics  and  a  nutritious  diet,  should  com- 
plete the  treatment. 


DISEASES    OF   THE    ORAL   MUCOUS    MEMBRANE.  1 93 

Dr.  Condie  recommends  the  administration  of  sulphate  of  quinin 
during  the  time  the  local  remedies  are  being  applied,  as  follows  : — 

R.   Quinise  sulphat. , gr.  x. 

Acid,  sulph.  dil., n\^x. 

Sacch.  alb., giv. 

Aq.  cinnamora. , ^  iv.  M. 

Dose  :  A  teaspoonful  every  three  hours. 

The  free  internal  use  of  the  chlorate  of  potassa,  one  to  three  scruples 
in  twelve  hours,  according  to  the  age  of  the  child,  has  been  employed 
with  advantage. 

For  the  diarrhea  accompanying  the  disease,  and  especially  when  it  is 
profuse,  Dr.  Condie  recommends  acetate  of  lead,  as  follows  : — 

R.   Acetat.  plumbi gr.  xvj. 

Cretae  praep. ,      5  ''^^■ 

Ipecacuanhae, gr.  iv. 

Opiipulv., gr-  ij-         M. 

To  be  divided  in  xvj  portions  ;  one  to  be  given  every  three  or  four  hours. 

Syphilitic  Ulceration  of  the  Mouth. — Syphilitic  ulcers  are  the  secon- 
dary results  of  constitutional  syphilis,  and  are  usually  found  on  the 
tongue,  the  lips,  or  the  tonsils.  Although  the  syphilitic  ulcer  is 
usually  superficial,  little  irritating,  and  attended  with  the  discharge  of 
a  small  amount  of  pus,  it  is  occasionally  phagedenic  in  character. 
Such  ulcers,  as  a  result  of  constitutional  syphilis,  may  be  incited  by 
abrasions  and  injuries  caused  by  fractured  and  carious  teeth  upon  the 
sides  of  the  tongue,  and  they  may  appear  on  the  lip  as  the  result  of 
kissing.  These  ulcers  also  appear  upon  the  tonsils  and  pharynx. 
These  syphilitic  ulcers  may  be  distinguished  from  more  malignant 
ones  by  their  improvement  under  specific  medication  and  the  other 
indications  of  constitutional  syphilis  generally  present  and  recogniz- 
able. The  glands  of  the  neck  are  often  found  enlarged  when  syphi- 
litic ulcers  exist  in  the  mouth  or  on  the  lips.  Local  and  constitutional 
treatment  is  required  in  the  majority  of  cases.  The  local  treatment 
consists  in  the  application  of  a  solution  of  chromic  acid — ten  grains 
to  the  ounce  of  water — by  means  of  a  camel's-hair  brush,  three  times 
a  day.  When  such  applications  fail,  the  administration  of  mercury 
is  necessary ;  and  in  all  cases  a  total  abstinence  from  alcoholic  drinks 
and  tobacco  is  required- 

Mercurial  Stomatitis. — The  employment  of  mercury  as  a  medicinal 
agent  causes  increased  watery  evacuations,  increased  flow  of  bile  and 
saliva,  and,  as  a  consequence,  increases  the  flow  of  blood  to  the  secret- 
ing part.  But  when  administered  in  excess  other  effects  follow.  It  is 
13 


194  DENTAL  PATHOLOGY,  THERAPEUTICS. 

capable  of  producing  inflammation,  especially  the  acute,  phlegmonous, 
adhesive  variety.  The  effects  of  its  use  depend  upon  the  quantity 
administered  and  the  susceptibility  of  the  patient  to  its  action.  When 
carried  to  excess,  the  mucous  membrane  of  the  mouth  becomes  tender, 
red,  and  swollen,  the  glands  beneath  the  jaw  become  painful,  and  at 
length  ulceration  occurs,  which  spreads  from  the  gums — where  the 
effects  of  the  drug  are  first  observed — to  fauces  and  throat,  and,  in 
extreme  cases,  the  parts  affected  may  perish. 

Prof.  Wood  describes  the  disease  as  follows  :  "  Among  the  first  indi- 
cations of  the  action  of  mercury  are  often  a  metallic  taste  in  the 
mouth,  like  that  of  brass  or  copper,  and  some  increase  of  saliva.  At 
the  same  time  a  close  examination  will  detect  a  slight  redness  and 
swelling  of  the  gums,  particularly  about  the  necks  of  the  lower  incisors, 
while  somewhat  below  their  edge  a  broad,  white  line  may  be  observed, 
depending  on  opacity  of  the  epithelium. 

"The  patient  soon  begins  to  feel  some  uneasiness,  complaining  of 
soreness  when  the  gums  are  pressed,  and  of  pain  when  the  teeth  are 
forcibly  closed  together.  There  is  also  a  sense  of  stiffness  about  the 
jaws  when  the  mouth  is  opened,  and  they  feel  as  if  projecting  above  their 
proper  level.  The  flow  of  saliva  increases,  the  inflammation  extends, 
the  gums  and  palate  become  obviously  swollen,  and  the  tongue  covers 
itself  with  a  yellowish-white  or  brownish  fur,  and  is  often  so  much 
enlarged  as  to  exhibit  the  impression  of  the  teeth  upon  being  projected 
from  the  mouth.  The  throat  frequently  becomes  sore,  and  the  cheeks 
and  salivary  and  absorbent  glands  swollen  and  painful.  There  is  often 
severe  toothache  or  pain  in  the  jaws.  A  whitish  exudation  along  the 
edges  of  the  gums  is  very  common, 

"  The  breath,  which  sometimes  from  the  beginning,  and  sometimes 
even  before  the  appearance  of  any  one  of  the  symptoms  mentioned, 
has  a  peculiar,  disagreeable  odor,  now  becomes  extremely  offensive,  and 
in  bad  cases  almost  intolerable.  Ulceration  often  occurs,  especially 
about  the  necks  of  the  teeth,  which  are  consequently  loosened,  and  in 
the  cheeks,  lips,  and  fauces.  The  ulcers  often  have  their  origin  in  a 
vesicular  eruption.  The  whole  mouth  with  its  appendages  is  some- 
times so  swollen  that  it  can  scarcely  be  opened,  and  the  tongue  so 
much  enlarged  as  to  project  beyond  the  lips. 

"  The  patient  is  now  nearly  or  quite  unable  to  articulate  or  to  mas- 
ticate his  food,  and  sometimes  can  scarcely  swallow.  Hemorrhage  is 
not  an  unfrequent  attendant  upon  the  bad  cases,  and  is  sometimes  so 
profuse  as  to  be  alarming.  Sloughing  also  takes  place,  and  portions 
of  the  jawbone  are  occasionally  laid  bare.  There  is  always  in  the 
severe  cases  more  or  less  fever,  which  is  partly  symptomatic  of  the  local 
affection  and   partly  the  direct  effect  of  the  mercury.     Death,  from 


DISEASES    OF    THE    ORAL    MUCOUS    MEMBRANE.  1 95 

the  exhausting  influence  of  the  irritation,  want  of  nourishment,  and 
hemorrhage,  has  occurred  in  numerous  instances,  but  the  patient  usually 
recovers  from  the  worst  forms  of  the  affection,  though  sometimes 
with  a  deformed  mouth. 

"  The  tongue  and  cheeks  have  occasionally  adhered  at  points  where 
their  ulcerated  surfaces  were  in  contact,  and  a  surgical  operation  has 
been  necessary  to  remove  the  evil." 

For  the  treatment  of  mercurial  stomatitis,  see  ''Treatment  of  Mer- 
curial Inflammation  of  the  Gums." 

Scurty-Scorbutus  is  a  disease  characterized  by  spongy  gums,  offensive 
breath,  livid  spots  on  the  skin,  great  general  debility,  and  a  pale, 
bloated  countenance. 

"  Scurvy,"  remarks  Prof.  Wood,  "  is  generally  very  gradual  in  its 
approach,  so  that  it  is  scarcely  possible  to  say,  in  any  particular  case, 
what  was  its  precise  time  of  attack.  Attention  is  commonly  first 
attracted  by  an  unhealthy  paleness  of  complexion,  a  feeling,  on  the 
part  of  the  patient,  of  languor  and  despondency,  with  an  indisposition 
to  bodily  action,  and  unusual  fatigue  after  exercise  ;  a  sensation  of 
weariness  and  aching  in  the  limbs,  as  from  over-exertion,  though  the 
patient  may  have  been  at  rest ;  and  some  swelling,  redness,  and  tender- 
ness of  the  gums,  with  a  tendency  to  bleed  from  slight  causes.  With  the 
advance  of  the  disease,  the  face  becomes  paler,  and  assumes  a  some- 
what sallow  or  dusky  hue,  and  often  a  degree  of  puffiness ;  the  lip£ 
and  tongue  become  pallid  and  contrast  strikingly  with  the  gums, 
which  are  purple  or  livid,  especially  at  their  edges,  rise  up  between 
and  around  the  teeth,  are  soft  and  spongy,  and  bleed  from  the  slightest 
touch ;  the  breath  is  offensive ;  purplish  spots  or  blotches  appear 
upon  various  parts  of  the  surface,  beginning  usually  upon  the  lower 
extremities,  and  afterward  extending  to  the  trunk,  arms,  and  neck, 
though  seldom  affecting  the  face ;  hemorrhage  frequently  occurs,  most 
commonly  from  the  nose,  gums,  and  mouth,  but  sometimes  from  the 
stomach,  bowels,  and  urinary  passages  ;  the  feet  become  edematous 
and  the  legs  swollen  and  painful ;  the  general  debility  increases,  and 
muscular  exertion  is  apt  to  be  attended  with  palpitation  of  the  heart, 
panting,  vertigo,  dizziness,  and  a  feeling  of  faintness.  The  petechial 
spots  are  evidently  owing  to  the  extravasation  of  blood  within  the 
cutaneous  tissue.  Occasionally  portions  of  the  surface  look  as  if 
bruised  without  having  suffered  any  violence  ;  and  blows  which,  under 
ordinary  circumstances,  would  produce  no  effect,  now  give  rise  to 
extensive  ecchymosis.  Should  the  disease  continue,  all  the  symptoms 
become  aggravated  ;  the  complexion  assumes  often,  with  its  paleness, 
a  livid  or  leaden  hue  ;  the  gums  swell  greatly,  and  put  forth  a  blackish, 
fungous   growth,  so  as  sometimes  to  conceal  the  teeth  ;  blood  con- 


196  DENTAL   PATHOLOGY,    THERAPEUTICS. 

tinually  oozes  from  them  ;  sloughing  occasionally  takes  place,  laying 
bare  the  necks  of  the  teeth,  and  extending,  in  very  bad  cases,  even  to 
the  cheek. 

"  The  teeth  become  loose  and  sometimes  fall  out;  the  patient  is 
unable  to  chew  solid  food,  in  consequence  of  the  state  of  his  gums. 
The  breath  becomes  intolerably  offensive;  hard  and  painful  tume- 
factions occur  in  the  calves  of  the  leg,  among  the  muscles  of  the 
thigh,  upon  the  tibiae  and  lower  jaw,  and  in  the  hand,  with  stiffness 
and  contraction  of  the  joints,  especially  the  knee,  and  severe  pain 
in  the  extremities  upon  every  attempt  at  movement ;  and  the  de- 
bility, before  so  prominent  a  feature  in  the  case,  now  becomes  ex- 
cessive, so  that  the  least  exertion  is  dangerous,  and  the  patient 
sometimes  dies  suddenly  upon  rising  from  bed  or  upon  being  con- 
veyed, without  great  caution,  from  one  place  to  another.  Wounds, 
even  slight  scratches,  degenerate  into  unhealthy  ulcers;  old  cicatrices 
break  out  afresh,  and  existing  ulcers  assume  a  new  and  much  worse 
aspect.  The  bones  are  said  to  be  softened,  united  fractures  are  again 
opened,  and  in  the  young  the  epiphyses  separate  sometimes  from  the 
shaft. 

"  Throughout  the  complaint  the  tongue  is  usually  clean  and  moist ; 
and  the  appetite  and  digestion  remain  unimpaired  almost  to  the  last, 
unless  the  disease,  as  sometimes  happens,  should  be  complicated  with 
fever.  Indeed,  there  is  often  a  craving  for  food,  especially  for  fresh 
vegetables  and  fruits  ;  occasionally,  however,  there  is  vomiting,  with 
epigastric  distress  and  other  evidences  of  stomachic  disorder.  The 
bowels  are  mostly  costive,  and  in  some  cases  obstinately  so,  but 
diarrhea  not  unfrequently  intervenes,  with  black  or  bloody  and  offen- 
sive evacuations.  The  pulse  is  generally  small,  feeble,  and  slow ;  but 
cases  occur  in  which  it  becomes  very  frequent,  and  the  surface  of  the 
skin  febrile,  probably  from  the  sympathy  of  the  system  with  various 
local  irritative  congestions, 

' '  Great  emaciation  usually  attends  the  disease  when  severe  or  lasting, 
but  not  invariably.  Little  cerebral  disturbance  is  ordinarily  observ- 
able, and  the  patient  often  retains  full  possession  of  his  senses  and 
intellect  to  the  last." 

In  regard  to  the  cause  of  scurvy,  it  is  the  general  belief  that  it  results 
from  the  absence  of  fresh  vegetables  and  fruits.  Prof.  Hamilton  says  : 
"  In  regard  to  the  pathology  of  scurvy,  the  belief  prevails  that  it  is 
due  essentially  to  the  absence  of  certain  staminal  principles  from  the 
blood,  and  especially  potash,  as  all,  or  nearly  all,  the  remedies  which 
have  been  employed  successfully  in  the  prevention  or  cure  of  scurvy 
contain  potash,  such  as  potatoes,  cabbage,  celery,  lettuce,  lime, 
lemon,  and   orange  juice."     As  regards   the  treatment,  both   local 


DISEASES    OF    THE    GUMS.  I97 

and  constitutional  are  required.  The  local  treatment,  being  the 
same  as  is  recommended  for  ''  Mercurial  Stomatitis,"  need  not  be  re- 
peated. The  constitutional  treatment  consists  in  the  administration 
of  the  vegetable  acids,  such  as  lemonade,  for  example.  Turner's  anti- 
dote, composed  of  potassse  nitratis  5ij»  ^^^  acidi  acetici  ^viij,  in 
tablespoonful  doses,  three  times  a  day,  is  a  favorite  remedy.  In  con- 
nection with  this.  Dr.  Garretson  recommends  saturating  a  sheet  with 
water  moderately  warm  and  moderately  salt,  which  is  thrown  around 
the  body  each  morning  immediately  on  rising,  and  rubbed  against  the 
flesh  until  a  ruddy  glow  is  excited. 


CHAPTER  IV. 
DISEASES   OF   THE   GUMS.  ' 

The  gums  frequently  assume  various  morbid  conditions,  but  as 
many  of  the  lesions  which  affect  the  oral  mucous  membrane  have  been 
described  under  "  Diseases  of  the  Oral  Mucous  Membrane,"  it  will  only 
be  necessary  to  refer  to  such  affections  as  are  confined  to  the  gums. 

The  diseases  of  the  gums  are  divided  into  two  classes :  those  which 
are  the  result  of  local  irritation,  and  those  which  arise  from  constitu- 
tional causes. 

Were  it  not  for  local  irritation  in  these  parts,  the  constitutional 
tendencies  to  disease  would  rarely  manifest  themselves ;  and,  on  the 
other  hand,  were  it  not  for  constitutional  tendencies,  the  effects  of 
local  irritation  would  seldom  be  of  a  serious  character. 

Each  constitution  has  its  peculiar  tendency ;  or,  in  other  words,  is 
more  favorable  to  the  development  of  some  form  of  disease  than 
others  ;  and  this  tendency  is  always  increased  or  diminished  according 
to  the  healthy  or  unhealthy  performance  of  the  functional  operations 
of  the  body  generally.  Thus,  derangement  of  the  digestive  organs  in- 
creases the  tendency,  in  an  individual  of  a  mucous  habit,  to  certain 
forms  of  diseased  action  in  particular  organs,  and  especially  in  the 
gums.  A  local  irritant,  which  would  otherwise  produce  only  a  slight 
inflammation  of  the  margins  of  the  gums,  would  now  give  rise  to 
turgidity  and  sponginess  of  their  whole  structure.  The  same  may  be 
said  with  regard  to  a  person  of  a  scrofulous  or  scorbutic  habit. 

The  susceptibility  of  the  gums  to  the  action  of  morbid  irritants  is 
always  increased  by  enfeeblement  of  the  vital  powers  of  the  body. 
Hence,  persons  laboring  under  excessive  grief,  melancholy,  or  any 
other  affection  of  the  mind,  or  under  constitutional  disease  tending  to 


I9S  DENTAL    PATHOLOGY,    THERAPEUTICS. 

enervate  the  vital  energies  of  the  system,  are  exceedingly  subject  to 
inflammation,  sponginess,  and  ulceration  of  the  gums.  But,  notwith- 
standing the  increase  of  susceptibility  which  the  gums  derive  from 
certain  constitutional  causes  and  states  of  the  general  health,  these 
influences  may,  in  the  majority  of  cases,  be  counteracted  by  a  strict 
observance  of  the  rules  of  dental  hygiene;  or,  in  other  words,  by  con- 
stant and  regular  attention  to  the  cleanliness  of  the  teeth. 

A  local  disease,  situated  in  a  remote  part,  often  has  the  effect  of 
diminishing  the  tendency  in  the  gums  to  disease;  but  when,  from  its 
violence  or  long  continuance,  the  general  health  becomes  implicated, 
the  susceptibility  of  these  parts  is  augmented. 

Although  deriving  their  predisposition  to  disease  from  a  specific, 
morbid  constitutional  tendency,  they,  nevertheless,  when  diseased, 
contribute  in  no  small  degree  to  derange  the  whole  organism.  Their 
unhealthy  action  vitiates  the  fluids  of  the  mouth  and  renders  them  unfit 
for  the  purposes  for  which  they  are  designed  ;  hence,  when  these  parts 
are  restored  to  health,  whether  from  the  loss  of  diseased  teeth  or  the 
treatment  to  which  they  may  have  been  subjected,  the  condition  of 
the  general  health  is  always  immediately  improved. 

Thus,  while  the  susceptibility  of  the  gums  to  morbid  impressions  is 
influenced  by  the  state  of  the  general  health,  the  latter  is  equally  in- 
fluenced by  the  condition  of  the  former  And  not  only  is  a  healthy 
condition  of  the  gums  essential  to  the  general  health,  but  it  is  also 
essential  to  the  health  of  the  teeth  and  alveolar  processes.  From  the 
intimate  relation  that  subsists  between  the  former  and  the  latter,  dis- 
ease cannot  exist  in  one  without  in  some  degree  affecting  the  other. 
Caries  of  the  teeth,  for  example,  often  gives  rise  to  inflammation  of 
the  gums  and  peridental  membrane  ;  on  the  other  hand,  inflammation 
of  these  parts  vitiates  the  fluids  of  the  mouth  and  causes  them  to  exert 
a  deleterious  action  upon  the  teeth,  and  also  excites  more  or  less  con- 
stitutional derangement. 

The  gums  appear  bloodless  and  pale  in  general  anemia,  or  chlorosis  ; 
also  edematous  as  a  result  of  catarrhal  stomatitis,  or  after  typhoid 
fever,  or  during  pregnancy.  The  gums  also  become  hyperemic, 
assuming  a  bluish-red  color,  and  bleeding  from  the  slightest  injury,  a 
condition  which  may  also  arise  during  pregnancy,  or  result  from  mer- 
curial poisoning,  or  exposure  to  the  irritating  action  of  acids  and  other 
poisons. 

INFLAMMATION    OF    THE    GUMS.  —  ULITIS. 

Acute  inflammation  of  the  gums  frequently  occurs  in  connection 
with  stomatitis,  or  general  inflammation  of  the  mucous  membrane  of 
the  buccal  cavity,  which  appears  under  a  great  variety  of  forms.  In 
this  case  the  inflammatory  action  does  not  always  extend  to  the  sub- 


DISEASES    OF   THE    GUMS.  I99 

jacent  fibrocartilaginous  structure ;  but  the  local  disease  is  often  com- 
plicated with  other  disorders,  the  treatment  of  which  comes  more 
properly  within  the  province  of  the  medical  than  that  of  the  dental 
practitioner.  Ulitis,  or  acute  inflammation  of  the  gums,  is,  in  most 
cases,  a  purely  local  disease,  arising  from  mechanical  injury,  such  as 
the  irritation  of  artificial  teeth,  etc.  Other  common  causes  are  the 
accumulation  of  salivary  calculus  on  the  necks  of  teeth,  decomposing 
particles  of  food  at  the  borders  of  the  gums  and  in  the  space  between 
the  gum  and  the  neck  of  the  tooth,  and  the  accumulation  of  micro- 
organisms. Ulitis  also  arises  from  the  presence  of  carious,  dead,  loose 
teeth,  and  teeth  irregularly  placed.  When  the  gums  are  in  contact 
with,  or  overlap  the  edges  of  carious  cavities,  they  become  irritated 
and  inflamed,  and  in  many  instances  protrude  into  such  cavities  in  the 
form  of  lobulated  tumors  of  such  a  size  as  to  more  or  less  fill  up  the 
cavity.  A  vitiated  condition  of  the  fluids  of  the  mouth  will  also 
cause  ulitis;  it  may  also  arise  from  the  irritation  of  dentition  or  as  a 
consequence  of  periodontitis.  It  often  extends  to  the  submaxillary 
glands  and  muscles  of  the  face,  and  is  attended  by  swelling  and  other 
morbid  phenomena.  But  as  this  form  of  inflammation  of  the  gums  is 
treated  of  in  connection  with  Stomatitis,  it  will  not  be  necessary  to 
repeat  what  we  have  said  elsewhere  concerning  it. 

The  chronic  form  of  ulitis  may  exist  for  years  without  being  at- 
tended with  suppuration  or  recession  of  their  margins  from  the  necks 
of  the  teeth  ;  but  these  phenomena  are  sooner  or  later  developed, 
according  to  the  amount  of  local  irritation  and  the  state  of  the  consti- 
tutional health  and  habit  of  the  body.  With  the  occurrence  of  inflam- 
mation the  margins  of  the  gums  gradually  lose  their  festooned  appear- 
ance, become  thick,  spongy,  and  rounded,  and  ultimately,  on  being 
pressed,  purulent  matter  is  discharged  from  between  them  and  the 
necks  of  the  teeth.  Their  sensibility  is  increased  and  they  bleed  from 
the  most  trifling  injury. 

The  diseased  action  usually  first  develops  itself  in  the  gums  around 
the  lower  front  teeth  and  the  upper  molars,  opposite  the  mouths  of  the 
salivary  ducts,  also  in  the  immediate  vicinity  of  aching,  decayed,  dead, 
loose,  or  irregularly  arranged  teeth,  or  in  the  neighborhood  of  roots  of 
teeth  ;  from  thence  it  extends  to  the  other  teeth.  The  rapidity  of  its 
progress  depends  on  the  age,  state  of  the  general  health,  temperament 
and  habit  of  body  of  the  individual,  and  the  character  of  the  local 
irritant  which  has  given  rise  to  it.  It  is  always  more  rapid  in  persons 
addicted  to  the  free  use  of  spirituous  liquors,  and  in  individuals  in 
whom  there  exists  a  scorbutic  tendency,  or  who  have  suffered  from 
venereal  disease,  or  from  the  constitutional  effects  of  a  mercurial 
treatment  used  to  cure  this  or  other  diseases. 


200 


DENTAL    PATHOLOGY,     1 HERAPEUTICS. 


Fig.  ii8. 


The  inflammation  may  be  confined  to  the  gums  of  two  or  three 
teeth,  or  it  may  extend  to  the  gums  of  all  the  teeth  in  one  or  both 
jaws. 

As  the  disease  advances,  the  gums  begin  to  recede  from  the  necks 
of  the   teeth,  and  the   alveoli  to  waste,  and  the  teeth,  as  they  lose 

their  support,  loosen  and  ultimately 
drop  out.  In  Fig.  ii8  is  repre- 
sented a  case  in  which  nearly  one- 
half  of  the  roots  of  the  lower 
incisors  have  become  exposed  by 
this  devastating  process. 

But  the  loss  of  the  teeth,  though 
it  puts  a  stop  to  the  local  disease, 
is  not  the  only  bad  effect  that  re- 
sults from  it.  Constitutional  symp- 
toms often  supervene,  more  vital  organs  become  implicated,  and  the 
health  of  the  general  system  is  sometimes  very  seriously  impaired. 
Hence,  the  improvement  often  observed  after  the  loss  of  the  teeth  in 
the  general  health  of  persons  whose  mouths  have  for  a  long  time  been 
affected  with  this  disease. 

The  loss  of  the  teeth,  from  the  wasting  of  the  gums  and  alveolar 
processes,  although  occurring  frequently  in  advanced  life,  is  not  a 
necessary  consequence  of  senility,  for  we  occasionally  see  persons  of 
seventy,  and  even  eighty  years  of  age,  whose  teeth  are  as  firmly  fixed 
in  their  sockets,  and  their  gums  as  little  impaired,  as  in  individuals  at 
twenty.  But  it  is  of  little  importance  whether  it  be  the  result  of  old 
age,  a  constitutional  tendency,  functional  derangement  of  some  other 
part,  or  local  irritation,  since  the  consequences  resulting  from  such  loss 
are  always  the  same. 

The  gums,  after  having  been  once  the  seat  of  chronic  inflamma- 
tion, are  ever  after  more  susceptible  to  the  action  of  morbid  irritants. 

In  scrofulous  diatheses,  the  gums,  instead  of  being  purple  and 
swollen,  may  become  pale  and  harder  than  ordinary,  and,  on  being 
pressed,  discharge  muco-purulent  matterof  a  dingy  white  color.  They 
often  remain  in  this  condition  for  years  without  appearing  to  undergo 
any  structural  alteration  or  to  affect  the  alveolar  processes.  It  rarely 
occurs  before  the  age  of  eighteen  or  twenty,  and  it  seems  to  be  the 
result  of  impaired  nutrition.  The  gums  exhibit  no  signs  of  inflamma- 
tory action ;  on  the  contrary,  they  are  paler,  less  sensitive,  and  possess 
less  warmth  than  usual.  It  is  never  attended  with  tumefaction  or 
absorption,  except  in  its  advanced  stages. 

Treatment. — In  the  treatment  of  ulitis,  the  first  thing  claiming  the 
attention  is  the  removal  of  the  exciting  causes.     If  there  are  dead  or 


DISEASES    OF   THE   GUMS.  201 

loose  teeth  in  the  mouth,  or  teeth  which,  from  their  position,  act  as 
mechanical  irritants,  they  should  be  at  once  extracted.  The  remaining 
teeth  should,  at  the  same  time,  be  freed  from  salivary  calculus  and  all 
other  irritating  depositions,  in  such  a  thorough  manner  as  to  permit  none 
to  remain,  either  about  the  necks  or  beneath  the  margins  of  the  gums; 
and,  if  necessary,  all  deposits  should  be  removed  from  about  the  very 
ends  of  the  roots  of  the  teeth,  so  far,  at  least,  as  the  separation  of  the 
gums  from  the  teeth  extends.  All  necrosed  portions  of  process  should 
also  be  removed,  and  the  entire  surfaces  of  the  exposed  portions  of  the 
roots  of  the  teeth  be  well  polished.  Besides  removing  the  tartar, 
if  the  gums  are  much  congested  they  should  be  scarified  around  the 
necks  of  the  teeth  and  all  hypertrophied  growths  in  the  interstices  cut 
away.  The  bleeding  which  follows  such  operations  should  be  pro- 
moted by  frequently  rinsing  the  mouth  with  warm  water. 

It  is  essential,  in  the  treatment  of  the  disease  under  consideration, 
that  a  decided  impression  be  made  upon  it  at  once  ;  consequently,  no 
time  should  be  lost  in  the  removal  of  local  exciting  causes. 

Several  sittings  are  often  required  for  the  complete  removal  of  calcic 
deposits  when  present. 

The  cure  may  be  hastened  by  washing  the  mouth  several  times  a  day 
with  some  tonic  and  astringent  lotion.  The  author  has  found  combi- 
nations of  powd.  nutgalls,  cinchona,  and  orris  root  in  infusion  of 
roses,  to  be  very  serviceable ;  also  as  gargles,  combinations  of  chlorate 
of  potassium  and  borax,  in  water  ;  also,  tannic  acid,  chlorate  of  potas- 
sium, with  honey  of  roses  and  water;  also,  tinct.  of  capsicum,  cologne 
water,  borax,  tinct.  of  cinchona,  and  tincture  of  pyrethrum  with  water. 
When  there  is  much  soreness,  a  combination  of  borax,  honey  and  sage 
tea  will  prove  soothing  and  healing. 

The  pleasantest,  and  at  the  same  time  the  most  efficacious,  mouth- 
wash which  the  author  has  ever  employed  is  the  following  : — 

B  .    South  American  soap  bark, 8  ounces. 

Pyrethrum,      1 

Orris  root,         I 

Benzoic  acid, 

Cinnamon, 

Tannic  acid, 4  drachms. 

Borax, 4  scruples. 

Oil  of  wintergreen, 2  fluidrachms. 

Oil  of  peppermint,      4  " 

Cochineal,    . 3  drachms. 

White  sugar, I  pound. 

Alcohol, 3  pints. 

Pure  water, 5      " 

Mix  ingredients  thoroughly,  digest  for  six  days,  and  filter. 


each 


202  DENTAL    PATHOLOGY,    THERAPEUTICS. 

The  following  combinations  are  also  serviceable  : — 

R .    Acid  carbolic, gtt.  v. 

Glycerini,      ^j. 

Ol.  caryophylli, gtt.  v.  M. 

R.    Sod£e  sulphis, _^j. 

Glycerini,       ^j.  M. 

R.    Acid  carbolic, ^ss. 

Glycerini, 3  x^-  M. 

R.    Sodee  boras gij. 

Glycerini,      ^j. 

Aquae,       ^iv.  M. 

In  mild  cases  of  inflammation  of  the  gums  and  mucous  membrane 
of  the  mouth,  iodin  in  glycerin — saturated  solution — is  an  excellent 
application. 

For  ulceration  of  the  gums  and  mucous  membrane  of  the  mouth  see 
"  Ulcerous  Stomatitis." 

For  soft,  swollen,  and  spongy  gums,  the  French  prejmration  known 
as  Phenol  Sodiqiie — phenate  of  soda — a  teasj)oonful  to  a  tumbler  of 
water,  will  prove  beneficial. 

If,  notwithstanding  the  use  of  the  means  here  recommended, 
matter  still  be  discharged  from  around  the  necks  of  the  teeth,  and 
should  the  gums  continue  spongy  and  manifest  no  disposition  to  heal, 
their  edges  may  be  touched  with  a  solution  of  the  chlorid  of  zinc  or 
nitrate  of  silver.  This  will  seldom  fail  to  impart  to  them  a  healthy 
action.  Either  remedy  may  be  used  in  the  proportion  of  from  one  to 
three,  or  even  six  grains  to  one  ounce  of  water.  The  most  conve- 
nient mode  of  applying  them,  is  with  a  camel's-hair  pencil,  and  they 
will  often  succeed  when  other  remedies  fail.  In  those  cases  where  the 
matter  discharged  from  the  edge  of  the  gum  has  a  nauseating  and  dis- 
agreeable odor,  a  preparation  composed  of  carbolic  acid  f^ij  ;  oil  of 
gaultheria,  f^ij,  and  aqua  ros?e,  fgiij,  of  which  ten  to  twenty  drops  may 
be  added  to  a  wineglass  of  water  and  used  as  a  gargle,  or  applied  on 
lint  to  the  inflamed  surface,  is  an  excellent  remedy  for  rendering  the 
mouth  comfortable.  An  excellent  disinfectant  in  such  cases  is  a  gargle 
made  by  diluting  a  teaspoonful  of  chlorinated  soda  (Labarraque's 
solution)  in  four  or  eight  ounces  of  water.  Or  it  may  be  used  much 
stronger,  and  applied  with  a  small  mop  to  the  diseased  parts  ;  phenol 
sodique  is  also  an  excellent  disinfectant. 

While  the  means  here  directed  for  the  cure  of  the  disease  are  being 
employed,  a  recurrence  of  its  exciting  causes  must  be  studiously 
guarded  against.     Tartar  and  foreign  matter  of  every  kind  should  be 


DISEASES    OF   THE    GUMS.  203 

prevented  from  accumulating  on  the  teeth,  by  a  free  and  frequent  use 
of  a  suitable  brush  and  waxed  floss-silk,  until  a  healthy  action  be  im- 
parted to  the  gums  ;  these  should  be  used  at  least  five  times  a  day — im- 
mediately after  rising  in  the  morning,  after  each  meal,  and  before 
retiring  at  night.  The  application  of  the  brush  may  at  first  occasion 
some  pain  ;  but  its  use  should  nevertheless  be  persisted  in,  for,  without 
it,  all  the  other  remedies  will  be  of  little  avail.  The  friction  produced 
by  it,  besides  keeping  the  teeth  clean,  is  of  great  service  to  the  gums, 
in  imparting  to  them  a  healthy  action. 

The  treatment  necessary  in  that  form  of  disease  which  we  noticed 
as  being  characterized  by  preternatural  paleness  and  discharge  of 
muco-purulent  matter  from  between  the  edge  of  the  gum  and  the  neck 
of  the  tooth,  consists  of  the  use  of  tonics,  free  exercise  in  the  open  air, 
and  the  application  to  the  edges  of  the  gums  of  nitrate  of  silver, 
followed  by  the  daily  use  of  an  astringent  mouth-wash. 

HYPERTROPHY,    OR     MORBID    GROWTH    OF    THE    GUMS. 

The  structural  changes  which  take  place  in  the  gums  as  a  conse- 
quence of  increased  vascular  action  are  almost  as  various  as  are  the 
constitutional  tendencies  of  different  individuals.  The  affection  of 
which  we  are  now  about  to  treat  is  characterized  by  a  morbid  growth, 
which  is  sometimes  so  considerable  that  it  almost  covers  the  crowns  of 
the  teeth,  thus  interfering  very  seriously  with  the  function  of  mastica- 
tion. When  thus  affected,  the  gums  have  a  dark  purple  color,  with 
thick,  smooth,  and  rounded  margins,  and  discharge  almost  constantly 
from  their  inner  surface,  a  thin, 
purulent  matter,  which  exhales 
an  exceedingly  offensive  odor. 
They  bleed  profusely  from  the 
slightest  injury,  and  are  so  sen- 
sitive that  the  pressure  even  of 
the  lips  is  sometimes  attended 
with  pain.  They  are  also  af- 
fected with  a  peculiar  itching 
sensation,  which  at  times  is  a 
source  of  great  annoyance.  Mi- 
croscopic    investigation    shows 

the  fibrous  stroma  of  the  gum  tissue  to  be  unduly  increased,  but 
without  the  presence  of  any  new  glandular  or  epithelial  ele- 
ments. 

The  accompanying  engraving  (Fig.  119)  will  convey  to  the  reader 
a  more  correct  idea  of  the  appearance  of  the  gums  when  thus  affected, 
than  any  description  which  can  be  given.     It  will  be  perceived  from 


204  DENTAL    PATHOLOGY,    THERAPEUTICS. 

this  that  the  morbid  growth  extends  to  the  gums  of  all  the  teeth,  as  it 
usually  does  in  this  variety  of  diseased  action. 

Among  the  local  and  constitutional  effects  arising  from  the  dis- 
ease are  offensive  breath,  vitiated  saliva,  destruction  of  the  alveoli, 
with  loosening  and  ultimate  loss  of  the  teeth,  impaired  digestion, 
with  all  its  disagreeable  concomitants,  enlargement  of  the  tonsils 
and  bronchitis,  together  with  a  long  train  of  other  phenomena. 

Causes. — The  exciting  cause  of  this  peculiar  affection  is  local  irrita- 
tion, produced  by  salivary  calculus,  dead,  diseased,  or  irregularly 
arranged  teeth  ;  but  the  character  of  the  structural  alteration  is 
evidently  determined  by  some  cachectic  habit  of  body  or  constitutional 
tendency.  It  often  attacks  the  gums  of  individuals  whose  teeth  are 
sound  and  well  arranged  ;  but  the  author  has  never  met  with  a  case  in 
which  salivary  calculus  was  not  present,  though  in  some  instances  the 
quantity  was  so  small  as  almost  to  lead  one  to  doubt  whether  it  could 
have  had  much  agency  in  the  production  of  the  disease.  But  the  suscepti- 
bility of  the  gums  to  morbid  impressions  in  individuals  liable  to  this 
affection  is  usually  so  great  that  an  irritant  which  under  other  circum- 
stances would  scarcely  excite  an  increase  of  vascular  action,  gives  rise, 
in  cases  of  this  sort,  to  the  rapid  development  of  an  aggravated  form 
of  disease. 

Treatment. — The  first  thing  to  be  attended  to  in  the  treatment  of 
this  disease  is  the  removal  of  all  dead  teeth,  and  such  others  as  may 
in  any  way  irritate  the  gums.  The  morbid  growth  should  be  next 
removed  by  making  a  horizontal  incision  entirely  through  the  diseased 
gums  to  the  crowns  of  the  teeth.  This  should  be  carried  as  far  back 
as  the  morbid  growth  extends.  After  this  the  gums  should  be  freely 
scarified  by  passing  a  lancet  between  the  teeth  down  to  the  alveoli,  in 
order  that  the  vessels  may  be  completely  divided  and  discharge  their 
accumulated  blood.  This  should  be  repeated  several  times,  at  inter- 
vals of  four  or  five  days.  Meanwhile  the  mouth  may  be  washed  three 
or  four  times  a  day  with  some  astringent  and  detergent  lotion,  and 
occasionally  mopped  with  a  weak  solution  of  chlorid  of  zinc  or  nitrate 
of  silver,  one  grain  to  the  ounce  of  water.  Phenol  sodique — phenate 
of  soda — either  in  its  full  strength  or  diluted  with  from  one  to  twelve 
rimes  its  bulk  of  water,  according  to  indications,  proves  very  service- 
able as  a  lotion,  causing  the  rapid  absorption  of  the  extravasated  blood, 
preventing  fetor,  and  speedily  healing  and  hardening  the  gums.  The 
salivary  calculus  should  be  removed  as  soon  as  the  gums  have  suffi- 
ciently collapsed  to  admit  of  the  operation. 

In  severe  cases  a  permanent  cure  cannot  be  effected  by  the  local 
treatment  above  described,  for,  in  addition  to  the  removal  of  the  en- 
larged gum  tissues,   it  may  be  necessary  to  excise  the  edge  of  the 


DISEASES    OF   THE    GUMS.  205 

alveolus,  especially  if  there  is  necrosis  of  the  margins  present,  or  ex- 
pansion of  the  alveolar  border.  Particular  attention  should  be  paid  to 
the  regimen  of  the  patient  and  such  general  remedies  prescribed  as  the 
peculiar  nature  of  the  case  may  indicate.  Excess  and  intemperance  of 
every  kind  must  be  avoided.  In  cases  of  an  inflammatory  type,  the 
diet  should  be  chiefly  vegetable  ;  but  where  there  is  debility  or  other 
cachexia,  animal  food  should  be  used,  taking  care  to  avoid  all  young 
meats,  as  veal  or  lamb,  all  gross  meats,  such  as  pork,  and  all  salt  meats 
or  shell-fish.  Fruits  and  acid  beverages,  such  as  infusions  of  malt  and 
vinegar,  lemon-juice,  spruce  beer,  etc.,  may  be  used  with  advantage. 

The  teeth  should  be  kept  perfectly  and  constantly  clean.  Not  a 
particle  of  foreign  matter  should  be  permitted  to  remain  between  them 
or  along  the  edges  of  the  gums.  A  scrupulous  attention  to  this  pre- 
caution is  indispensably  necessary,  as  it  constitutes  one  of  the  most 
important  remedial  indications. 

MERCURIAL    INFLAMMATION   OF   THE   GUMS. 

Small  and  repeated  doses  of  mercury,  when  carried  to  the  point  of 
salivation,  frequently  give  rise  to  the  development  of  peculiar  morbid 
phenomena  in  the  gums  and  other  parts  of  the  mouth.  The  first  indi- 
cation of  the  specific  action  of  this  powerful  medicinal  agent  upon  the 
animal  economy  consists  in  a  slightly  increased  redness  and  tumefac- 
tion of  the  free  edge  of  the  gums,  around  the  necks  of  the  inferior 
incisors.  There  is  a  characteristic  bluish  color  along  the  edge  of  the 
gums,  while  the  investing  mucous  membrane  of  the  adherent  portion, 
a  little  lower  down,  often  assumes  a  white  color,  owing  to  the  opacity 
of  the  epithelium.  These  appearances  are  followed  by  increased 
secretion  of  saliva ;  a  strong  metallic  taste  ;  soreness  of  the  teeth  and 
gums ;  inflammation  and  swelling  of  the  mucous  membrane  of  the 
roof  of  the  mouth,  fauces  and  cheeks,  and  the  salivary  glands ;  a  swell- 
ing of  the  tongue,  with  increased  redness  of  its  edges,  and  a  pecu- 
liarly offensive  odor  of  breath.  In  the  meantime,  the  edges  of  the 
gums  about  the  necks  of  the  teeth  swell  and  assume  an  increase  of 
redness ;  the  saliva  becomes  viscid,  and  is  secreted  in  such  abundance 
as  to  flow  from  the  mouth,  and  the  movements  of  the  jaws  are  attended 
with  pain.  The  alveolo-dental  periosteum  is  thickened,  and  the  teeth 
raised  from  their  sockets  and  loosened.  A  vesicular  eruption  some- 
times appears,  followed  by  ulceration  and  sloughing  of  the  gums,  and 
very  frequently  by  necrosis  of  large  portions  of  the  alveolar  pro- 
cess and  maxilla.  We  were  shown,  a  few  years  since,  the  entire 
alveolar  border  of  both  jaws,  the  necrosis  and  exfoliation  of  which  had 
been  occasioned  by  severe  mercurial  salivation ;  and  we  have  fre- 
quently had  occasion  to  remove  portions  both  of  the  superior  and  in- 


2o6  DENTAL   PATHOLOGY,    THERAPEUTICS. 

ferior  maxillary  bones — the  necrosis  having  been  occasioned  by  the 
use  of  this  medicine. 

By  the  prudent  administration  of  mercury,  salivation  may  be  in- 
duced without  causing  the  deplorable  effects  just  described.  But  the 
specific  action  of  this  agent  upon  the  constitution  is  always  attended 
by  more  or  less  tumefaction  and  sponginess  of  the  gums,  and  when 
once  brought  under  its  influence,  however  perfectly  its  effects  may  have 
subsided,  they  are  ever  after  more  susceptible  to  morbid  impressions. 
Again,  it  should  be  remembered  that  very  many  of  these  deplorable 
symptoms  follow  the  use  of  mercurials,  even  where  there  is  no  intention 
to  salivate.  It  is  a  powerful  agent,  capable  of  much  good,  but  one 
which  has  been  productive  of  untold  mischief,  especially  upon  the 
mouth  and  teeth.  Doubtless  life  must  be  saved  at  the  expense, 
if  necessary,  of  the  teeth;  but  the  peculiar  specific  action  of  this 
medicine  should  forbid  its  constant  and  indiscriminate  employment. 

Treatment. — It  is  scarcely  necessary  to  say,  that  until  the  use  of  the 
mercury  is  discontinued  it  will  be  impossible  to  control  or  even  coun- 
teract its  effects  upon  the  gums  ;  but  in  mild  cases  these  usually  soon 
disappear  after  the  action  which  it  has  produced  on  the  general  system 
has  completely  subsided.  When  the  gums  continue  spongy,  the 
bowels  should  be  kept  open  with  Seidlitz  powders  or  other  saline 
cathartics,  the  patient  restricted  to  a  fluid  farinaceous  diet,  and  the 
mouth  gargled  several  times  a  day  with  mild  astringent  lotions,  to 
which  it  may  sometimes  be  advisable  to  add  a  little  laudanum.  Benefit 
may  be  derived  from  the  application  of  the  official  tincture  of  iodin 
in  a  solution  composed  of  one-half  water.  For  internal  use  chlorate 
of  potash  and  iodid  of  potassium  are  considered  the  best  remedies  in 
mercurial  poisoning. 

The  chlorate  of  potash  is  also  of  very  great  service  as  a  lotion,  in 
the  strength  of  one  dram  to  the  ounce  of  water. 

For  internal  use,  ten  grains  of  the  chlorate  of  potash  may  be  dis- 
solved in  half  an  ounce  of  water,  and  administered  in  four  or  five 
doses  during  the  day.  For  an  adult.  Dr.  Garretson  recommends  the 
following  lotion  as  very  beneficial  in  cases  where  the  tumefaction  is 
very  great  and  indolent  looking  :  — 

B  .    Potassae  chloras,       3  ss. 

.Sodas  boras, 

Alumen  pulv., &a ^ij. 

Potass,  pemiang., grs.  xxv. 

Aqua  cologn., .?  ss. 

Tinct.   cinchonx, ^  ij. 

Tinct.  myrrhse, '^'). 

Infus.  quercus  (fort.), S '^'  ^' 

SiG.  — Ciargle  the  mouth  pro  re  nata. 


DISEASES    OF   THE    GUMS.  207 

The  iodid  of  potassium  may  be  given  in  doses  of  from  three  to  five 
grains,  three  times  a  day,  in  some  bitter  infusion  ;  also,  dikited  sul- 
phuric acid  combined  with  bitter  tonics  ;  also  the  tincture  of  bella- 
donna in  five-drop  doses  three  or  four  times  daily. 

The  following  gargle  will  be  found  very  serviceable  in  mercurial 
salivation  :  — 

R  .    Tinct.  iodinii,       ^:^iij  tovj. 

Potassse  iodidi, grs.  xv.  to  xxx. 

Aquas, Oss.  M. 

Astringent  washes  of  tannic  acid,  borax,  or  dilute  alcohol,  are  also 
serviceable. 

After  the  action  of  the  medicine  upon  the  system  has  subsided,  and 
the  disease  assumes  a  chronic  form,  the  useof  astringent  washes  should 
be  continued,  and  if  there  are  any  teeth  which,  from  the  loss  of  their 
vitality  or  from  having  become  very  much  loosened  by  the  partial 
destruction  of  their  sockets,  act  as  irritants  they  should  be  removed  ; 
but  teeth  should  not  be  sacrificed  merely  on  account  of  their  loosened 
condition,  as  they  may  become  firmly  fixed  on  the  subsidence  of  the 
disease. 

For  correcting  the  fetor  arising  from  the  ulcerated  surfaces,  a  gargle 
may  be  used  composed  of  two  or  three  drams  of  charcoal  suspended 
by  agitation  in  a  tumbler  of  water.  After  retaining  a  portion  of  this 
gargle  for  a  short  time,  the  mouth  should  be  rinsed  with  warm  water  to 
remove  the  particles  of  charcoal. 

A  solution  of  the  permanganate  of  potash,  in  the  strength  of  from 
two  to  ten  grains  to  the  ounce  of  water,  as  a  gargle,  or  of  phenol 
sodique  in  the  form  of  spray,  will  also  prove  effective  for  the  removal 
of  the  fetor  ;  also  washes  made  from  chlorinated  soda  or  lime,  and 
solutions  of  listerine  or  borine. 

ULCERATION    OF    THE    GUMS  OF   CHILDREN,    ATTENDED   WITH    EXFOLIA- 
TION   OF    THE    ALVEOLAR    PROCESSES. 

The  gums  and  alveolar  processes  of  children  are  occasionally 
attacked  by  a  very  peculiar  form  of  disease,  which  occurs  more  fre- 
quently during  the  shedding  of  the  temporary  and  the  eruption  of  the 
permanent  teeth  than  at  any  other  period  of  childhood.  We  have 
never  known  adults  to  be  affected  with  it,  and  to  the  ordinary  spongy, 
inflamed,  and  ulcerated  gums  it  does  not  appear  to  be  at  all  analogous. 
It  bears  a  much  closer  resemblance  to  cancrum  oris,  yet  differs  in  many 
particulars  from  this  disease. 

Among  the  symptoms  which  characterize  the  affection  are  itching 
and  ulceration  of  the  gums  and  their  separation  from  the  necks  of  the 


2o8  DENTAL   PATHOLOGY,    THERAPEUTICS. 

teeth  and  alveolar  processes ;  there  is,  at  first,  a  discharge  of  muco- 
purulent matter  from  between  the  gums  and  necks  of  the  teeth,  which 
ultimately  becomes  ichorous  and  fetid.  The  teeth  loosen,  and  the 
alveoli  lose  their  vitality  and  exfoliate.  Ulcers  are  formed  in  various 
parts  of  the  mouth,  and  the  gums  and  lips  assume  a  deep  red  or  purple 
color.  In  the  exfoliation  of  the  alveolar  processes  the  temporary,  and 
sometimes  the  crowns  of  the  permanent  teeth,  are  carried  away.  The 
constitutional  symptoms  are  :  skin,  for  the  most  part,  dry  ;  pulse,  small 
and  quick  ;  the  bowels  generally  constipated,  though  sometimes  there 
is  diarrhea  ;  and  to  these  symptoms  may  be  added  lassitude  and  a  dis- 
position to  sleep. 

These  may  be  regarded  as  the  prominent  phenomena  of  the  disease 
in  its  most  aggravated  form.  When  exfoliation  of  the  alveolar  pro- 
cesses takes  place,  the  symptoms  usually  abate,  and  sometimes  wholly 
disappear. 

In  the  majority  of  cases  the  disease  is  confined  to  one  jaw  and  to  one 
side,  though  sometimes  both  are  affected  by  it.  The  effect  on  the  per- 
manent teeth,  in  all  the  cases  which  have  fallen  under  the  notice  of 
the  author,  was  injurious. 

Causes. — The  disease  seems  to  be  the  result  of  general  debility  or 
defective  nutrition  and  a  cachectic  habit  of  body.  It  appears  to  be 
almost  wholly  confined  to  children  of  the  poor  and  destitute,  and,  so 
far  as  the  author's  observations  extend,  to  those  who  reside  in  cellars  or 
small  and  confined  apartments.  Children  of  scorbutic  habit  seem  to 
be  the  most  subject  to  it.  From  the  great  debility  of  all  the  organs 
of  the  body,  their  functions  are  languidly  and  imperfectly  performed. 
That  the  disease  is  determined  by  general  enfeeblement  of  the  func- 
tions of  the  body  there  is,  we  think,  little  doubt ;  but  whether  it 
would  develop  itself  independently  of  any  local  cause,  is  a  question 
which  we  do  not  feel  ourselves  able  satisfactorily  to  answer.  It  is  not 
at  all  improbable  that  local  irritants  are  the  exciting  cause  ;  and  we 
are  the  more  inclined  to  this  belief  from  the  fact  that  in  all  the 
cases  which  have  fallen  under  our  observation  the  teeth  were  con- 
siderably decayed  and  had  previously  given  rise  to  pain,  and  in 
some  instances  they  were  coated  with  tartar.  While,  therefore,  the 
character  of  the  affection  is  determined  by  some  peculiar  constitu- 
tional tendency  and  general  enfeeblement  of  the  vital  powers  of  the 
body,  it  is  not  unlikely  that  local  irritation  is  the  immediate  cause  of 
its  development. 

Treatment. — The  local  treatment  should  consist  of  acidulated  and 
astringent  gargles.  The  ulcerated  parts  may  be  occasionally  touched 
with  a  solution  of  the  nitrate  of  silver,  or  chlorid  of  zinc,  from  three 
to  eight  grains  to  the  ounce  of  water  ;  phenol  sodique  or  permangan- 


DISEASES   OF   THE   GUMS.  209 

ate  of  potash  solution  may  be  employed  to  correct  the  fetor.  As  soon 
as  the  alveolar  process  exfoliates,  it  should  be  removed.  After  this 
takes  place  a  cure  is  generally  speedily  effected  under  proper  constitu- 
tional treatment.  This  last  may  consist  of  mild  alteratives,  a  generous 
nutritive  diet,  consisting  of  succulent  vegetables,  and,  in  the  absence 
of  fever,  of  wholesome  meats,  tonics,  and  exercise  in  the  open  air. 
(See  "Ulcerous  Stomatitis.") 

ADHESIONS    OF   THE   GUMS   TO   THE    CHEEKS. 

The  gums  and  inner  w^alls  of  the  cheeks  sometimes  contract  adhe- 
sions which  interfere  seriously  with  the  functions  of  the  mouth.  The 
affection  may  be  congenital,  but  in  the  majority  of  cases  it  occurs  sub- 
sequently to  birth.  The  extent  of  the  adhesion  may  be  small,  or  it  may 
occupy  the  gums  of  the  entire  alveolar  border  of  one  or  both  sides  of 
the  mouth  and  of  one  or  both  jaws.  Desirabode  relates  the  case  of  a 
young  man,  who,  in  consequence  of  a  venereal  ulcer,  had  his  upper 
lip  united  to  the  gums  of  the  four  incisors  in  such  a  way  as  to  form  a 
sort  of  loop  above  the  teeth,  which,  by  the  retraction  of  the  lip,  were 
caused  to  project  outward. 

Adhesion  of  the  gums  to  the  cheek  or  lips  results  from  ulceration, 
caused  either  by  constitutional  disease  or  local  lesions.  But  that  it 
arises  more  frequently  as  a  consequence  of  the  immoderate  use  of 
mercury  than  from  any  other  cause  is  a  universally  admitted  fact. 
The  author  has  met  with  several  cases,  however,  in  which  the  affection 
has  resulted  from  ulceration  of  the  gums  around  necrosed  temporary 
teeth  and  of  the  corresponding  wall  of  the  cheek,  caused  by  excoria- 
tion of  the  mucous  membrane,  produced  by  the  sharp  points  of  the 
protruding  roots.  But  the  extent  of  the  adhesion,  in  cases  of  this 
sort,  is  never  very  considerable. 

The  proper  remedy  is  to  separate  the  parts  which  have  grown  to- 
gether with  a  sharp  bistoury.  This  done,  reunion  should  be  prevented 
by  keeping  a  pledget  of  cotton  or  lint  in  the  wound,  until  the  process 
of  cicatrization  is  completed. 


2IO  DENTAL   PATHOLOGY,    THERAPEUTICS. 

CHAPTER  V. 

DISEASES  OF  THE  PERIDENTAL  MEMBRANE. 

PERIODONTITIS. 

Periodontitis,  pericementitis,  alveolo-dental  periostitis,  peri- 
dentitis,  as  the  affection  is  variously  named,  denotes  inflammation  of 
the  investing  or  peridental  membrane  of  the  roots  of  the  teeth,  a 
tissue  highly  vascular  and  very  susceptible  to  inflammatory  conditions, 
and  which  may,  in  many  cases,  be  regarded  as  a  premonitory  stage  of 
alveolar  abscess. 

Although  the  death  of  the  pulp  generally  precedes  the  form  of  in- 
flammation of  the  peridental  membrane  which  aff"ects  the  apical  space, 
yet  there  are  other  forms  of  periodontitis  which  exist  independent  of 
the  dental  pulp;  for  example, — an  acute,  non-purulent  form  which 
occurs  around  the  necks  of  the  teeth;  an  acute,  non-purulent,  circum- 
scribed form  which  affects  one  side  of  the  root-membrane,  or  may 
encircle  the  root  about  its  middle  portion.  There  are  also  other 
forms  of  this  affection,  such  as  an  acute  non-purulent  form  which  may 
originate  in  and  be  confined  to  the  apical  space ;  an  acute  non-puru- 
lent form  which  may  arise  in  the  apical  space  and  extend  over  the 
greater  part  of  the  peridental  membrane  below  the  marginal  por- 
tion ;  an  acute  purulent  form  which  involves  the  apical  space  only ; 
an  acute  purulent  form  which  may  arise  in  the  apical  space  as  a 
result  of  the  apical  form,  and  extend  over  a  considerable  portion  of 
the  peridental  membrane.  Chronic  forms  of  periodontitis  also  exist, 
which  differ  from  the  acute  forms  in  the  character  of  their  phe- 
nomena, which  are  not  so  intense  as  those  of  the  latter.  The  peri- 
dental membrane  is  confined  between  the  walls  of  the  alveolar  cavity 
and  the  root  of  the  tooth,  and  as  a  consequence  is  incapable  of  expan- 
sion when  its  vessels  are  engorged  with  blood,  and  being  endowed  with 
a  large  supply  of  nerves,  which  render  the  membrane  very  sensitive 
even  in  a  normal  condition,  it  becomes  excruciatingly  painful  when 
inflamed. 

Inflammation  of  the  peridental  membrane  of  a  tooth  may  therefore 
je  acute  or  chronic,  the  acute  forms  being  generally  due  to  direct  local 
irritation  and  the  chronic  forms  to  the  result  of  the  acute  forms,  or  to 
systemic  influences.  Each  variety  is  modified  in  its  character  by  the 
state  of  the  constitutional  health  and  by  the  causes  concerned  in  its 
production,  and  also  its  location,  extent,  etc.  The  premonitory 
symptoms  of  the  acute  varieties,  especially  when  they  are  apical  or 
diffuse,  are  a  slight  sensation  of  uneasiness  and  tension,  a  feeling  of 


PERIODONTITIS.  211 

fullness  about  the  affected  part,  and  a  desire  to  press  the  teeth 
together.  Pressure  appears  to  afford  temporary  relief,  but  the  uneasy 
feeling  returns  on  the  pressure  being  withdrawn. 

These  symptoms  are  soon  followed  by  a  dull,  heavy,  and  continuous 
pain,  and  the  affected  tooth  appears  to  be  longer  than  the  adjoining 
ones,  and  is  really  so,  owing  to  the  increased  thickness  of  the  investing 
membrane  of  the  root.  Occlusion  of  the  teeth  gives  rise  to  severe 
pain,  and  there  is  an  inclination  to  keep  the  jaws  apart.  The  appear- 
ance of  the  gums  at  this  stage  of  the  affection  also  indicates  the  exist- 
ence of  disease  in  the  peridental  membrane  ;  they  become  very  tender 
and  swollen,  and  change  from  a  pale  rose  color  to  a  deep  red  or  purple 
opposite  the  root  of  the  affected  tooth. 

At  first  the  inflammation  is  circumscribed,  but  soon  it  becomes  more 
general,  until  the  whole  of  the  gum  about  the  root  of  the  tooth  is 
involved.  Although  the  pain  increases  in  severity,  it  yet  preserves 
the  same  character,  and  even  when  not  continuous,  it  seldom  ceases 
for  any  great  length  of  time.  At  length  suppuration  occurs,  and  we 
have  the  condition  known  as  alveolar  abscess,  this  process  sometimes 
extending  to  nearly  every  part  of  the  periosteum,  causing  the  entire 
death  of  the  tooth,  and  often  followed  by  erosion  of  the  root  and 
necrosis  of  the  alveolus.  When  favored  by  a  cachectic  habit  of  body, 
it  often  extends  to  the  periosteum  of  the  jaw,  followed  by  suppuration 
and  necrosis. 

The  inflammation  of  the  peridental  membrane  has  been  classified 
according  to  its  location,  symptoms,  causes,  and  results,  such  as  acutt 
cervical  periodontitis ;  acute  circumscribed  periodontitis ;  acute  apical 
periodontitis,  and  acute  diffuse  periodontitis.  When  the  inflammation 
of  this  membrane  terminates  in  suppuration,  such  forms,  according  to 
their  location,  causes,  symptoms,  and  results,  may  properly  be  classified 
as  forms  of  alveolar  pyorrhea  and  alveolar  abscess 

Acute  cervical  periodontitis  is  characterized  by  an  area  of  bright  red 
gum,  corresponding  in  extent  to  the  area  of  inflamed  peridental  mem- 
brane about  the  neck  of  the  tooth.  The  gum  is  detached  from  the 
neck  of  the  affected  tooth  to  a  greater  or  less  degree  ;  and  when  sali- 
vary calculus  is  present,  the  margin  of  the  gum  assumes  a  bluish  color. 
The  pain  resulting  from  this  cervical  form  is  seldom  acute,  but  more 
frequently  consists  of  an  annoying  sensation  ;  the  tooth  is  sensitive  to 
pressure,  and  sometimes  to  thermal  changes,  unless  the  cause  is  due  to 
salivary  calculus,  when  a  soreness  instead  of  a  decided  pain  is  experi- 
enced about  the  neck  of  the  affected  tooth. 

Acute  circumscribed  periodontitis  is  usually  confined  to  that  portion 
of  the  peridental  membrane  which  is  midway,  or  thereabouts,  between 
the  cervical  and  apical  portions.     This  form  of  the  disease  may  en- 


212  DENT>AL    PATHOLOGY,    THERAPEUTICS. 

circle  the  root  of  the  tooth  or  be  confined  to  the  lingual  surface  of 
the  root.  Pressure  from  the  opposite  side  causes  pain,  and  percussion 
elicits  a  dull  sound.  When  due  to  a  local  irritant  or  injury,  this  form 
may  continue  for  from  one  to  three  days ;  whereas  if  it  is  caused  by 
constitutional  derangement,  it  is  liable  to  assume  a  chronic  character 
and  be  more  persistent. 

Acute  apical  periodontitis  is  first  characterized  by  soreness  of  the 
tooth,  and  light  redness  of  the  overlying  gum.  The  affected  tooth  at 
length  becomes  loose,  and  is  elevated  in  its  cavity  above  the  level  of 
the  adjoining  teeth,  owing  to  the  thickening  of  the  peridental  mem- 
brane by  the  effusion  of  watery  liquid  from  the  blood  into  the  affected 
tissue.  The  pain  resulting  from  this  apical  form  is  acute  and  pulsat- 
ing, and  often  extends  to  the  entire  side  of  the  face,  becoming  more 
severe  toward  evening,  especially  when  the  sufferer  assumes  a  recum- 
bent position  ;  active  exertion  and  the  use  of  alcoholic  stimulants 
aggravate  the  pain.  The  tooth  is  also  very  sensitive  to  cold,  and  the 
gum  over  the  root  is  quite  hot.  Mastication  is  exceedingly  painful, 
and  in  some  cases  closure  of  the  jaws  is  difficult.  Percussion  elicits  a 
very  dull  sound  in  the  affected  tooth.  This  acute  apical  form  comes 
on  gradually  during  one  or  two  days  or  more  before  it  is  fully  devel- 
oped, and  may  then  continue  for  four  or  five  days,  or  even  longer, 
when  it  may  assume  a  chronic  character  which  is  indicated  by  an 
abatement  of  the  symptoms. 

Acute  diffuse  periodontitis  is  usually  a  result  of  the  extension  of  the 
inflammation  of  the  peridental  membrane  from  the  apical  space  over 
the  greater  portion  of  the  membrane,  although  it  may  not  involve  the 
cervical  portion.  While  the  symptoms  of  the  diffuse  form  resemble 
those  of  the  apical  form,  they  manifest  themselves  with  greater  severity. 
The  tooth  affected  with  the  diffuse  form  of  periodontitis  becomes  very 
loose  in  its  cavity,  is  greatly  elevated  above  the  adjoining  teeth, 
and  elicits  an  exceedingly  dull  sound  on  percussion  ;  it  is  also  very 
sensitive  to  pressure  from  any  direction,  and  mastication  and  closure 
of  the  jaws  are  impossible.  The  gum  over  the  root  of  the  affected  tooth 
is  very  much  swollen  and  of  a  dark  red  color.  The  pain  experienced 
is  of  a  very  severe,  throbbing  character,  and  these  severe  symptoms  may 
continue  for  three  or  four  days  or  even  a  week,  when  they  abate,  or 
the  inflammation  assumes  a  chronic  form. 

Acute  inflammation  of  the  peridental  membrane  having  terminated 
in  suppuration,  sometimes,  instead  of  subsiding  altogether,  degenerates 
into  a  chronic  form,  and  when  favored  by  some  constitutional  vice,  as 
the  scorbutic,  venereal,  or  scrofulous,  it  often  gives  rise  to  the  destruc- 
tion of  the  socket  and  loss  of  the  tooth. 

The  acute  form  of  periodontitis  is  readily  diagnosed  by  the  pain 


PERIODONTITIS.  213 

caused  by  pressure  on  the  affected  tooth,  which  distinguishes  it  from 
such  diseases  of  the  dental  pulp  as  irritation  and  inflammation  oi 
pulpitis.  Besides,  the  pain  of  periodontitis  can  always  be  definitely 
located,  whereas  in  pulpitis  its  exact  location  is  often  doubtful ;  again, 
the  dental  pulp  is  influenced  by  thermal  changes  to  such  a  degree 
as  to  very  greatly  increase  its  sensibility  when  diseased,  whereas  the 
peridental  membrane  is  not  so  influenced,  and  its  sensitiveness  is  not 
increased  to  any  marked  degree  by  thermal  changes,  except  when  the 
pulp  cavity  contains  gas,  which  expands  from  heat  and  induces  pressure 
on  the  tissues  beyond  the  apical  foramen. 

Chronic  inflammation  of  the  peridental  membrane  is  generallv  pre- 
ceded by  the  active  form  of  the  disease,  but  it  may  assume  the  chronic 
form  at  the  commencement.  In  this  case  it  is  complicated  with  tume- 
faction of  the  gums  and  discharge  of  puriform  matter  from  between 
their  edges  and  the  necks  of  the  teeth.  Chronic  periodontitis  is  there- 
fore but  a  modified  form  of  the  acute,  and  is  manifested  by  soreness  of 
a  tooth,  which  may  either  be  so  slight  as  to  occasion  very  little  annoy- 
ance, or  be  very  considerable,  with  apparent  congestion  of  the  gum 
about  the  tooth,  and  sensitiveness  of  a  greater  or  less  degree  when  the 
organ  is  pressed  upon. 

After  the  loss  of  vitality  in  the  pulp  of  a  tooth,  the  peridental  mem- 
brane is  very  susceptible  to  inflammation,  owing  to  the  irritation  to 
which  it  is  subjected,  and  also  to  the  weakened  condition  of  this  mem- 
brane and  its  increased  function  in  supplying  the  cementum  and 
dentine  with  nourishment. 

Causes. — Acute  cervical  periodontitis  is  caused  by  chemical  and 
mechanical  irritants,  such  as  decomposing  food  and  other  matters 
retained  about  the  neck  of  a  tooth,  and  in  connection  with  the  peri- 
dental membrane ;  also  the  bristles  of  tooth-brushes,  small  particles 
of  bone,  and  other  foreign  substances  forced  under  the  gum  in  masti- 
cation, etc.  ;  also  improperly  fitting  bands,  metal  crown-caps,  over- 
lapping fillings,  and  salivary  calculus. 

Acute  circumscribed  periodontitis  is  the  result  of  mechanical  injury 
or  of  constitutional  derangements,  the  latter  cause  being  first  noticed 
in  a  former  edition  of  this  work. 

Acute  apical  periodontitis  is  of  frequent  occurrence,  and  is  generally 
the  result  of  pulpitis  caused  by  chemical  and  mechanical  irritants.  A 
putrescent  or  gangrenous  condition  of  the  pulp  of  a  tooth  is  a  common 
cause  of  this  form  of  the  disease  ;  also  filling  materials  and  irritating 
agents  used  for  disinfecting  and  antiseptic  purposes,  forced  through 
the  apical  foramen  into  the  apical  space;  broken  nerve  instruments; 
metallic  fillings  built  too  high  upon  the  grinding  surfaces  of  a  tooth; 
too  rapid  wedging  and  too  rapid  regulating  of  teeth  ;  severe  malleting; 


214  DENTAL  PATHOLOGY,  THERAPEUTICS. 

improperly  filled  cap-crowns  and  bridge-work,  and  badly  antagonized 
artificial  teeth  exercising  undue  pressure  on  a  natural  tooth. 

Acute  diffuse  periodontitis  is  caused  by  inflammation  of  the  pulp, 
chemical  and  mechanical  irritation  of  the  membrane  lining  the  apical 
space,  and  constitutional  derangements.  Acute  pulpitis  and  a  putres- 
cent condition  of  the  pulp  are  frequent  causes.  Inflammation  of  the 
pulp  from  any  cause  may  involve  the  peridental  membrane  of  the 
apical  space  and  thus  establish  periodontitis. 

Constitutional  derangements  may  consist  of  a  syphilitic  taint 
through  an  infiltration  of  lymph  and  serum  into  the  peridental  mem- 
brane, or  between  it  and  the  root  of  the  tooth  or  alveolar  walls  of  the 
socket ;  also  rheumatism,  especially  in  those  who  have  been  subjected 
to  an  excess  of  mercury,  and  also  scrofula.  This  affection  may  also 
extend  from  the  peridental  membrane  of  one  tooth  to  that  of  adjoin- 
ing teeth. 

Treatment. — The  treatment  of  the  different  forms  of  periodontitis 
will  depend  upon  the  location,  the  causes  producing  and  influencing 
the  disease,  and  the  condition  of  the  general  system. 

The  treatment  of  the  acute  cervical  form  consists  in  the  removal 
of  the  irritant,  the  disinfection  of  the  mouth,  and  the  use  of  an 
astringent  or  antiphlogistic  lotion. 

The  mouth  may  be  disinfected  by  pyrozone  (30  per  cent,  solution) 
in  the  form  of  a  mouth  wash,  or  by  iodoform,  iodol,  eucalyptus,  iodin, 
europhen,  salicylic  acid,  glycozone,  listerine,  resorcin,  and  a  number 
of  other  disinfectants  and  antiseptics  all  in  proper  solution. 

The  treatment  of  the  acute  circumscribed  form,  when  originating 
from  mechanical  violence,  consists  in  the  application  of  antiphlogistic 
lotions,  of  which  the  following  is  an  example  :  — 

R  .     Plumbi  acetas 3J- 

Tinct.  opii, ^ss. 

AquLV, ^  viij  to  x. 

Sign  A. — Apply  as  a  lotion  on  lint  or  cotton  to  the  gum  surface  about 
the  affected  roots. 

When  this  form  of  periodontitis  is  due  to  other  causes,  the  local 
application  of  equal  parts  of  tinct.  of  iodin  and  tinct.  of  aconite  will 
prove  serviceable.  When  depending  upon  constitutional  derange- 
ments, constitutional  treatment  for  the  i)articular  disease  present  is 
indicated. 

The  treatment  of  the  acute  apical  fortn  of  periodontitis  when  this 
form  of  the  disease  is  due  to  external  violence  or  irritation,  consists  in 
the  removal  of  the  irritant  and  the  application  of  antiphlogistic  or 
counter-irritant    applications.       The   antiphlogistic    combination  of 


PERIODONTITIS.  215 

acetate  of  lead,  tincture  of  opium,  and  water,  or  the  counter-irritant 
combination  of  aconite  and  iodin  often  prove  serviceable. 

When  due  to  pulpitis  or  to  foreign  substances  forced  through  the  apical 
foramen  or  the  side  of  the  root  of  the  tooth,  the  prognosis  is  more 
unfavorable,  and  the  destruction  of  the  vitality  of  the  pulp  and  its 
complete  removal,  or  the  removal  of  foreign  matters  from  the  pulp 
canal  and  the  use  of  disinfectants,  is  necessary. 

The  treatment  of  the  acute  diffuse  form  of  periodontitis  is  similar 
to  that  of  the  acute  apical  form,  and  the  prognosis  is  yet  more  un- 
favorable for  the  preservation  of  the  vitality  of  the  pulp.  This  form 
is  very  prone  to  degenerate  into  a  purulent  inflammation,  when  it  may 
be  classed  as  alveolar  abscess,  the'  treatment  of  which  demands  the 
opening  of  the  apical  foramen  by  means  of  a  fine  broach,  and  entrance 
into  the  abscess  to  evacuate  the  pus,  followed  by  the  proper  disin- 
fectant and  antiphlogistic  treatment  and  the  filling  of  the  pulp-canal 
and  crown-cavity  of  the  tooth. 

The  first  thing  to  be  attended  to  in  cases  where  the  prognosis  is 
unfavorable  to  the  preservation  of  the  pulp  is  its  devitalization  and 
the  removal  of  all  irritants  from  the  pulp-cavity,  such  as  an  inflamed  : 
or  decomposing  pulp,  after  which  the  congestion  of  the  affected  part 
maybe  relieved  by  the  use  of  such  agents  as  produce  counter-irritation, 
or  by  depletion. 

When  the  pulp  of  the  tooth  is  inflamed  it  should  receive  imme- 
diate attention,  and  when  the  pulp  is  dead,  all  the  debris  should  be 
removed  from  its  pulp-cavity  by  means  of  nerve  instruments  and 
syringing  with  tepid  water.  All  deposits  of  calculus  should  be  re- 
moved from  the  teeth,  and  also  all  dead  teeth  and  roots  which  are 
useless  and  cause  irritation,  should  be  removed  from  the  mouth. 
The  pulp-cavity  should  then  be  thoroughly  disinfected  by  iodoform, 
or  eucalyptus,  iodin,  carbolic  acid,  salicylic  acid,  sanitas,  etc.  After 
the  application  of  the  disinfecting  agent,  the  pulp-cavity  should  be 
loosely  filled  with  cotton  saturated  with  an  antiseptic  agent,  but 
sufficiently  close  to  prevent  the  entrance  of  fluids.  If  a  secretion 
of  pus  is  present  the  application  may  be  frequently  changed,  and 
thus  prevent  the  pressure  of  the  secretion  from  causing  pain.  In 
severe  cases  where  the  above  treatment  does  not  prove  effectual, 
counter  irritation  may  be  resorted  to;  the  gums  may  be  scarified, 
or  such  agents  be  applied  as  iodin  and  creasote,  tincture  of  capsicum, 
and  tincture  of  iodin.  An  excellent  application  is  composed  of 
equal  parts  of  the  official  tincture  of  iodin  and  tincture  of  aconite 
root  applied  to  the  gum  two  or  three  times  daily,  in  the  acute  form 
of  the  affection.  Previous  to  the  application,  the  gum  should  be 
dried,  and  afterward  the  cheek  kept  from  coming  in  contact  with  it 


2l6  DENTAL   PATHOLOGY,    THERAPEUTICS. 

until  a  metallic  pellicle  is  formed.  Cantharidal  collodion  is  also  an 
excellent  counter-irritant,  and  is  applied  to  the  gum,  after  the  surface 
is  dried  with  a  napkin,  by  means  of  a  camel's-hair  brush,  taking  care 
to  protect  the  lip,  and  to  prevent  moisture  from  interfering  before  the 
ether  in  the  preparation  evaporates  and  an  artificial  cuticle  is  formed. 
Within  a  few  hours  blistering  results,  and  the  periodontitis  is  effectually 
relieved.  Another  method  of  producing  counter-irritation  is  to  make 
a  deep  incision  in  the  gum  over  the  affected  root,  and  to  introduce 
into  this  a  small  pellet  of  cotton  or  lint  saturated  with  creasote  or 
carbolic  acid,  which  is  retained  for  from  one  to  five  days,  the  time 
depending  upon  the  persistence  of  the  inflammation,  taking  the  pre- 
caution to  change  the  dressing  every  day.  The  application  of  a 
solution  composed  of  equal  parts  of  tincture  of  aconite,  tincture  of 
opium,  and  chloroform,  is  often  very  serviceable  ;  also  a  small  linen 
bag  containing  capsicum,  one  side  of  the  bag  being  covered  with 
leather,  to  protect  the  cheek.  Lead-water,  in  the  proportion  of  a 
fluidounce  to  two  fluidrams  of  laudanum,  applied  in  the  same  manner 
as  the  agent  before  named,  has  also  been  successfully  used.  Depletion 
may  be  accomplished  by  means  of  the  gum  lancet,  or  by  the  use  of 
leeches  or  cups. 

Hypodermic  injections  of  morphine  have  also  been  resorted  to  for 
the  relief  of  the  intense  pain  of  this  affection,  such  as  a  solution  of 
morphine  or  tincture  of  opium,  some  ten  to  twenty  drops  of  the  latter 
being  injected  with  a  suitable  syringe  beneath  the  mucous  membrane  ; 
also,  with  good  effect,  the  application  of  rhigolene  or  ether  spray  until 
the  gum  about  the  affected  tooth  is  blanched.  As  a  topical  applica- 
tion, rhigolene  has  been  recommended,  applied  to  the  gum  on  a  pellet 
of  cotton  after  free  scarification. 

Constitutional  treatment  is  also  serviceable,  such  as  the  adminis- 
tration of  saline  cathartics.  Bromid  of  potassium  in  a  dose  of  twenty- 
five  grains,  or  the  same  quantity  of  the  bromid  combined  with  five 
drops  of  the  tincture  of  veratrum  viride,  and  repeated  every  four 
hours,  will  often  prove  serviceable  in  incipient  alveolar  periodontitis. 
A  preparation  known  as  merctirius  vivus,  the  third  decimal  trituration, 
given  in  small  doses  two  or  three  times  a  day,  has  been  recommended 
by  Prof.  Chase  and  used  successfully  by  others  in  relieving  acute 
periodontitis.  During  the  treatment,  a  cap  of  gutta-percha,  molded 
to  the  crowns  of  one  or  two  teeth  on  the  opposite  side  of  the  jaw, 
will  protect  the  affected  tooth  from  any  irritation  which  may  be 
caused  by  the  occlusion  of  the  opposing  ones,  and  thus  facilitate  the 
restoration.  For  the  treatment  of  the  chronic  variety  of  periodontitis, 
the  reader  is  referred  to  "  Chronic  Inflammation  and  Tumefaction  of 
the  Gums. ' ' 


ALVEOLAR   ABSCESS.  21  7 

ALVEOLAR    ABSCESS. 

An  alveolar  abscess  is  a  collection  of  pus  in  a  sac  attached  to  and 
closely  embracing  the  root  of  a  tooth,  and  is  the  result  of  inflammation 
of  the  tissues  of  the  apical  space,  where  its  inception  invariably  occurs. 
The  peridental  membrane  having  become  the  seat  of  acute  inflamma- 
tion, plastic  lymph  is  effused  at  the  extremity  of  the  root.  This  is 
condensed  into  a  sac  or  cyst,  which  closely  embraces  the  root  near  its 
apex,  the  walls  of  lymph  become  vascular,  and  perform  the  functions 
of  secretion  and  absorption,  and  as  suppuration  takes  place,  pus  is 
formed  in  the  centre  of  the  sac.  The  inflammation  in  the  meantime 
having  extended  to  the  gums  and  neighboring  parts,  they  swell  and 
become  painful,  and  as  the  pus  accumulates  in  the  sac,  it  distends  and 
presses  upon  the  surrounding  walls  of  the  alveolus,  which,  by  a 
chemico-vital  process,  are  gradually  broken  down.  By  absorption, 
through  pressure,  an  opening  is  ultimately  made  through  one  side  of  the 
alveolar  cavity,  when  the  pus,  coming  in  contact  with  the  investing 
soft  structures,  presses  upon  them  and  causes  their  absorption  also,  or 
it  may  follow  the  side  of  the  root  to  the  margin  of  the  gum,  and  thus 
outlets  are  effected  for  the  escape  of  the  accumulated  matter. 

In  some  cases  the  pus  may  separate  the  periosteum  from  the  bone 
of  the  alveolar  cavity  and  form  a  receptacle  for  itself  between  the 
membrane  and  alveolar  wall,  and  if  not  promptly  discharged  may 
cause  necrosis  of  the  bone. 

The  pus  of  an  alveolar  abscess,  in  the  case  of  young  persons,  usually 
finds  an  exit  through  the  root  canal  of  the  tooth,  especially  when  the 
abscess  is  formed  upon  the  apex  of  the  root,  owing  to  the  large  size  of 
the  foramen  of  a  deciduous  tooth.  In  adult  persons  the  escape  of  the 
pus  generally  takes  place  through  the  alveolar  wall  and  the  soft  tissues 
opposite  the  root  of  the  affected  tooth. 

The  secretion  of  an  alveolar  abscess,  especially  when  an  inferior 
molar  is  affected,  may  find  its  way  to  the  surface  of  the  cheek  or  neck, 
and  considerable  deformity  be  caused  from  the  cicatrix  resulting.  In 
some  cases  the  sinus  of  an  abscess  may  invade  the  duct  of  a  salivary 
gland  and  necessitate  the  operation  for  salivary  fistula  before  a  cure 
can  be  effected ;  but  the  secretion  may  escape  from  a  more  remote 
point.  It  may  make  for  itself  an  opening  through  the  cheek  or 
through  the  base  of  the  lower  jaw,  and  be  discharged  externally  ;  or  it 
may  pass  up  into  the  maxillary  sinus,  or  through  the  nasal  plate  of  the 
superior  maxilla,  or  form  a  passage  between  the  two  plates  of  the  bone, 
and  escape  from  the  centre  of  the  roof  of  the  mouth. 

The  formation  of  abscess  in  the  alveolus  of  an  inferior  dens  sapi- 
entiae  is  sometimes  attended  with  inflammation  and  swelling  of  the  ton- 


2l8  DENTAL    PATHOLOGY,    THERAPEUTICS. 

sils  and  of  the  muscles  of  the  cheek  and  neck.     The  author  has  known 
trismus  to  result  from  this  cause. 

The  pain  attending  the  formation  of  alveolar  aoscess  is  deep-seated, 
throbbing,  and  often  so  excruciating  as  to  be  almost  insupportable. 
But  as  soon  as  suppuration  takes  place,  it  loses  its  severity,  and  with 
the  escape  of  the  pus  nearly  or  altogether  ceases ;  but  the  tooth,  from 
the  thickened  condition  of  the  peridental  membrane  particularly  at 
the  apex  of  the  root,  often  remains  sore  and  sensitive  to  the  touch 
for  several  days.  The  energies  of  the  disease,  however,  having  been 
expended,  the  secretion  of  the  pus  in  the  majority  of  cases  wholly 
ceases,  and  the  opening  in  the  gums  closes.  From  the  increased  sus- 
ceptibility of  the  peridental  membrane  to  morbid  impressions, 
occasioned  by  the  presence  of  a  tooth  deprived  of  a  large  portion  of 
its  vitality,  a  recurrence  of  the  inflammation  is  liable  to  take  place, 
when  pus  will  be  again  formed  and  the  passage  for  its  escape  re- 
established. But  the  pain  attending  any  subsequent  attack  is  seldom 
so  severe  as  in  the  first  instance. 

There  are  some  cases,  however,  in  which  the  inflammation,  instead 
of  subsiding  altogether,  degenerates  into  a  chronic  form  of  abscess.  In 
this  case,  the  sac  at  the  extremity  of  the  root  continues  to  secrete  pus, 
though  the  quantity  is  usually  small,  and  the  opening  in  the  gums  re- 
mains unclosed. 

Persons  of  a  scrofulous  diathesis  are  very  liable  to  this  affection, 
which,  in  these  cases,  very  soon  assumes  a  chronic  form. 

In  the  extraction  of  a  tooth  which  has  given  rise  to  the  formation 
of  abscess,  the  sac  is  often  brought  away  with  it.  Two  teeth  in  which 
this  had  happened,  taken  from  the  upper  jaw — 
one  a  cuspid  and  the  other  a  first  molar — are  repre- 
sented in  the  accompanying  cut  (Fig.  120).  In 
the  case  of  the  molar  the  sac  is  attached  to  the 
palatine  root.  Both  of  these  teeth  were  extracted 
previously  to  the  formation  of  an  external  opening 
for  the  escape  of  the  matter. 

Although  in  the  majority  of  cases  the  sac  is 
attached  to  the  apex  of  the  root,  yet  it  is  not 
unusual  for  the  point  of  attachment  to  be  on  the 
side  of  the  root,  as  in  the  case  of  the  superior  front  teeth  and  bicus- 
pids, or  in  the  bifurcation  of  the  roots,  in  the  case  of  the  molars,  for 
example.  When  the  sac  is  situated  upon  the  side  of  the  root  of  a 
superior  front  tooth,  it  is  generally  upon  the  labial  surface,  and  when 
it  is  situated  at  the  apex  of  the  root  of  a  molar  tooth  the  palatine 
root  is  the  one  generally  affected.  The  temporary  teeth  are  much 
more   liable    to   this   disease    than    the    permanent    teeth,    and    the 


ALVEOLAR    ABSCESS.  219 

superior  incisors  more  susceptible  than  the  inferior  teeth  of  the  same 
class. 

But  the  treatment  of  inferior  teeth  affected  with  abscess,  especially 
the  bicuspids  and  molars,  is  often  more  difficult  than  that  of  the 
superior,  on  account  of  the  gravitation  of  the  pus  and  the  impossibility 
in  many  cases  of  making  an  opening  through  the  alveolar  process  so 
low  as  the  extremity  of  the  root,  owing  to  the  muscular  attachment 
being  so  high  on  the  ridge. 

The  character  of  the  secretion  differs  considerably  in  different 
cases  ;  instead  of  the  yellowish-white  appearance  that  pure  or  laudable 
pus  presents,  and  which  may  be  present  in  some  cases  of  alveolar  ab- 
scess in  good  constitutions,  a  highly  vitiated,  acrid  fluid,  with  either  a 
diminished  supply  of  pus  corpuscles  or  an  entire  absence  of  such  cor- 
puscles, usually  distinguishes  the  secretion,  which  sometimes  becomes 
very  irritating  in  its  effect  upon  living  tissue.  The  systemic  condition 
of  the  patient  modifies  the  character  of  the  secretion,  as  also  does  the 
nature  of  the  local  irritants. 

The  time  required  for  the  formation  of  alveolar  abscess  varies  from 
three  to  ten  or  fifteen  days,  according  to  the  violence  of  the  inflamma- 
tion. But  a  collection  of  pus  may  be  detected  by  fluctuation  under 
the  finger,  if  applied  to  the  tumefied  gum  one  or  two  days  before  an 
external  opening  is  spontaneously  formed  for  its  escape. 

The  size  of  the  cavity  formed  by  an  alveolar  abscess  depends  upon 
the  severity  of  the  disease  and  the  susceptibility  of  the  parts  involved. 
In  some  cases  it  is  quite  small  and  confined  to  the  point  of  irrita- 
tion, while  in  others  it  may  be  very  extensive.  Very  severe  pain 
accompanies  this  affection  when  the  abscess  is  rapidly  formed,  owing 
to  the  distention  occasioned  and  the  inability  of  the  secreting  pus  to 
escape.  As  soon  as  an  opening  is  effected,  however,  the  tension  is 
relieved  and  the  pain  subsides.  A  great  susceptibility  to  alveolar 
abscess  exists  in  case  of  an  inflammatory  diathesis,  and  after  a  time 
it  may  assume  a  chronic  character,  when  the  secretion  and  discharge 
of  the  pus  is  continuous.  Although  the  pain  of  chronic  abscess  may 
not  be  more  than  a  slight  uneasiness,  the  acute  form  is  productive 
of  intense  pain.  There  is  also  a  difference  in  the  extent  of  the 
inflammation  affecting  neighboring  tissues,  depending  upon  the 
activity  of  the  irritants  present,  and  in  some  cases  of  alveolar  abscess 
the  inflammation  of  adjacent  parts  may  be  very  limited,  while  in 
others  it  may  be  very  extensive. 

The  inflammation  and  pain  attending  the  formation  of  abscess  in 
the  alveolar  cavity  of  a  tooth  often  give  rise  to  general  febrile  symp- 
toms, headache,  and  constipation  of  the  bowels.  In  the  acute  form 
of  this  disease  the  pain  is  intense,  while  in  the  chronic  form,  where  the 


2  20  DENTAL    PATHOLOGY,    THERAPEUTICS. 

pus  is  const;antly  secreting  and  discharging,  the  sensation  experienced 
is  soreness  and  an  uneasy  feeling,  with  a  slight  pain  upon  a  change  of 
temperature. 

Chronic  alveolar  abscess  generally  follows  the  acute  form,  and 
results  from  a  subsidence  of  the  acute  symptoms  into  others  less  pain- 
ful, but  more  persistent.  The  chronic  form  is  generally  accompanied 
with  a  fistulous  opening  which,  in  its  position  and  the  direction  of  the 
canal,  presents  quite  a  variety  of  forms.  The  fistulous  opening  is 
usually,  however,  upon  the  gum  over  the  root  of  the  affected  tooth  ; 
but  in  some  cases  the  fistulous  opening  may  close  and  the  secretion 
from  the  abscess  appear  at  a  different  point  some  distance  from  the 
original  one.  In  other  cases  a  chronic  abscess  may  again  assume 
acute  symptoms,  which  may  continue  until  a  new  exit  for  the  secre- 
tion manifests  itself  at  a  more  remote  point.  These  chronic  cases 
often  cause  a  feeling  of  stiffness,  caused  by  the  pus  burrowing 
through  muscular  tissue,  as  the  secretion  will  generally  follow  a 
course  which  presents  the  least  resistance.  The  direction  of  the  pus 
is  also  influenced  by  gravitation,  especially  in  abscesses  connected 
with  the  inferior  teeth.  Abscesses  connected  with  the  inferior  molar 
teeth  sometimes  discharge  into  the  antrum  and  produce  serious 
complications.  Abscesses  discharging  on  the  face  are  generally  con- 
nected with  the  inferior  molar  teeth  and  are  influenced  in  this  respect 
by  gravitation,  and  the  least  resistance  the  pus  in  its  burrowing  course 
may  meet  with.  The  closure  of  a  fistulous  opening  of  a  chronic 
alveolar  abscess  may  lead  to  the  retention  of  the  pus,  which,  on 
account  of  gravitation,  in  the  case  of  an  inferior  tooth,  penetrates  to 
the  surface  along  the  border  of  the  lower  jaw.  Abscesses  connected 
with  the  superior  teeth,  when  pointing  on  the  face,  generally  discharge 
beneath  the  prominence  of  the  malar  bone,  and  the  deformity 
resulting  after  the  healing  of  the  fistula  is  caused  by  the  formation  of 
a  dense  cord  of  new  tissue  which  binds  the  skin  permanently  to 
the  bone,  and  which  must  be  severed  in  the  treatment  for  correcting 
such  a  deformity. 

Causes. — The  immediate  cause  of  alveolar  abscess  is  inflammation  of 
the  peridental  membrane,  which  is  frequently  incited  by  inflammation 
of  the  pulp  and  its  subsequent  death  and  decomposition,  irritating 
matter  being  thus  formed,  which  sooner  or  later  affects  the  tissues  of 
the  apical  space  through  the  apical  foramen  of  the  tooth.  Such  a  con- 
dition is  often  the  result  of  filling  the  cavity  in  the  crown  of  a  tooth, 
and  permitting  a  dead  and  decomposing  pulp  to  remain  in  the  pulp- 
cavity.  It  may  also  be  produced  by  mechanical  violence,  the  irrita- 
tion of  a  dead  tooth,  or  by  a  drill  accidentally  passing  from  the  canal 
through  the  side  of  the  root  into  the  peridental  membrane,  or  by  the 


ALVEOLAR   ABSCESS. 


221 


presence  of  a  portion  of  a  filling,  a  broken  broach,  or  other  foreign  mat- 
ter, or  irritating  medicinal  agent,  forced  through  the  root  of  a  tooth. 

Treatment. — The  treatment  of  alveolar  abscess  should  be  preventive 
rather  than  curative,  for  it  often  happens,  after  it  has  occurred,  that 
the  integrity  of  the  parts  is 
so  impaired  as  to  cause  a 
recurrence  of  the  affection. 
Although  the  secretion  of 
pus  may  cease  for  a  time, 
and  the  opening  in  the  gums 
become  obliterated,  the 
tooth,  being  deprived  of  a 
large  portion  of  its  vitality, 
is  liable,  whenever  the  ex- 
citability of  the  peridental 
membrane  is  increased  by 
any  derangement  of  the 
general  system,  to  give  rise 
to  a  recurrence  of  the  dis- 
ease. Especially  is  this  the 
case  when  the  disease  has 
assumed  the  chronic  form. 
The  formation  of  an  abscess, 
therefore,  should,  if  possible, 
be  prevented  by  the  use  of 
such  means  as  are  referred 
to  in  the  treatment  of 
''periodontitis,"  a  common 
termination  of  this  disease 
being  alveolar  abscess.  But 
should  these  means  fail  to 
prevent  the  formation  of 
pus,  we  then  have  to  resort 
to  either  therapeutic  or  sur- 
gical treatment,  consisting 
in  the  removal  of  the  irritant 
matter  from  the  pulp-cavity. 

An  alveolar  abscess  of 
recent  origin  will  yield 
more  readily  to  treatment 
than  one  of  long  continuance,  and  the  chronic  form  is  much  more 
difficult  to  arrest,  especially  after  the  adjacent  parts  have  become 
involved,  than  the  acute  form. 


Fig.  121. 


222  DENTAL    PATHOLOGY,    THERAPEUTICS. 

When  constitutional  derangement  is  present,  general  treatment, 
such  as  the  particular  condition  indicates,  must  be  resorted  to.  The 
local  or  surgical  treatment  consists  in  breaking  up  the  sac  of  the 
abscess,  and  the  evacuation  of  the  pus  as  soon  as  possible,  and  ready 
access  must  be  had  to  the  point  of  accumulation  in  order  to 
successfully  accomplish  such  a  result. 

A  sharp-pointed  bistoury  or  small  trephine  may  be  employed  to 
enlarge  the  fistulous  canal  when  the  pus  has  made  an  opening  through 
the  process  and  gum  to  the  surface  opposite  the  root  of  the  tooth, 
and  the  sac  broken  up  by  means  of  nerve  instruments,  its  remains 
being  thrown  off  and  healthy  granulations  developing  without  further 
treatment.  In  many  cases,  however,  therapeutic  treatment  must  follow 
the  surgical  before  a  perfect  cure  is  accomplished.  The  therapeutic 
treatment  consists  in  first  removing  all  irritating  substances  from  the 
pulp-cavity,  which  should  be  freely  opened  to  the  apex  of  the  root,  and 
the  application  of  disinfectant  and  antiseptic  remedies.  For  cleansing 
the  root,  peroxid  of  hydrogen,  chlorid  of  sodium,  etc.,  injected  into  the 
canal  answers  a  good  purpose,  to  be  followed  by  such  agents  as  will 
cause  the  absorption  or  destruction  of  the  sac  secreting  the  pus,  such 
as  creasote,  carbolic  acid,  mercuric  chlorid,  followed  by  alcohol, 
peroxid  of  sodium,  salicylic  acid  (applied  in  the  solid  form),  nitrate 
of  silver,  iodin,  etc.  When  a  tumor  appears  on  the  gum  from  the 
presence  of  the  pus  which  has  penetrated  the  bone,  the  contents  of 
the  abscess  should  first  be  discharged  by  making  an  opening  in  the 
tumefied  gum  with  a  sharp  lancet,  provided  the  disease  has  been 
allowed  to  progress  to  such  a  degree  as  to  render  this  operation 
necessary.  The  opening  in  the  gum  should  not  be  allowed  to  close 
until  the  pulp  cavity  has  been  exposed  and  the  decomposed  contents 
removed,  when  this  cavity  should  be  thoroughly  disinfected  by  such 
agents  as  mercuric  chlorid,  followed  by  alcohol,  peroxid  of  sodium, 
iodoform,  iodol,  aristol,  sulphuric  acid,  etc.,  etc.  If  no  opening  has 
been  formed  through  the  alveolar  process  the  decay  in  the  crown 
cavity  should  be  removed,  and  the  orifice  of  the  pulp  canal  be  so  en- 
larged as  to  admit  a  nerve  instrument  or  small  broach,  by  means  of 
which  it  can  be  cleaned  out,  and  thus  allow  the  matter  to  escape 
through  the  tooth.  Tepid  water  should  then  be  injected  into  the 
pulp  canal  by  means  of  a  small  syringe,  until  all  decomposed  matter 
is  removed,  when  one  of  the  remedial  agents  mentioned  above  may  be 
substituted  for  the  tepid  water,  or  applied  on  a  strand  of  floss  silk, 
which  is  carried  to  the  apex  of  the  root  by  means  of  a  nerve  instru- 
ment or  broach.  At  the  end  of  twenty-four  or  forty-eight  hours, 
according  to  the  character  of  the  symptoms,  this  treatment  is  repeated, 
the  crown  cavity  during  the  interval   being  filled  with  cotton.     A 


ALVEOLAR    ABSCESS.  223 

combination  of  several  of  the  remedial  agents  is  serviceable  in 
obstinate  cases,  such  as  creasote  and  tincture  of  iodin,  carbolic  acid 
and  tincture  of  iodin,  or  creasote  and  tannin  in  alcohol,  aristol  and 
chloroform,  iodoform  and  eucalyptol,  etc.,  etc.,  which  can  be  applied 
on  floss  silk,  introduced  daily  for  two  or  three  days,  until  the  discharge 
ceases. 

Fig.  121  represents  an  abscess  syringe,  of  improved  form,  with  two 
gold  points — straight  and  curved — and  one  hyi)odermic  point.  The 
metal  case  is  slotted  to  expose  the  glass  barrel,  and  provided  with 
finger-holds. 

The  application  of  the  vapor  of  crystals  of  non-agglutinized  iodo- 
form, as  recommended  by  Dr.  Peaboay,  so  that  it  may  be  forced  into 
the  canal,  thoroughly  permeating  it  and  filling  thetubuli,  a  precipitate 
being  thus  deposited  which  forms  a  solid,  insoluble  filling,  is  also  very 
effective.  The  cylinder  of  a  hot-air  syringe  is  partly  filled  with  the 
crystals  and  heated  over  a  flame  until  they  are  fused.  This  vapor  also 
penetrates  the  apical  foramen  and  subdues  the  irritation  and  inflamma- 
tion of  the  peridental  membrane. 

The  following  solution  of  Dr.  Percy  Boulton  possesses  therapeutic 
virtues  of  superior  efficiency,  especially  after  creasote,  carbolic  acid, 
eucalyptus,  iodoform,  iodin  or  salicylic  acid  have  been  employed  to 
stimulate  and  disinfect  the  secreting  surfaces  to  a  healthy  action  :  — 

R.     Tr.  iodin  comp., n\,xiv. 

Acid,  carbolic,  cryst.  (fusa), ^^j- 

Glycerina', .?^"j- 

Aq.  destillat., ^v.  M. 

This  solution  possesses  antiseptic  and  stimulant  properties. 

The  surgical  treatment  consists  in  making  an  opening,  or  enlarg- 
ing the  fistulous  one,  through  the  alveolus,  opi)osite  the  extremity  of 
the  affected  root,  by  means  of  a  small  trephine,  drill,  or  chisel,  first 
making  a  vertical  incision  in  the  gum  with  the  lancet,  and  thus  gaining 
access  to  the  .seat  of  the  disease.  The  attaclnnent  of  the  sac  to  the 
root  is  then  broken  up  by  means  of  a  delicate  instrument  which  per- 
mits of  being  passed  about  the  extremity  of  the  root,  and  the  wound 
in  the  gum  kept  ojjen  for  a  few  days  by  inserting  a  tent,  in  order  that 
the  remains  of  the  sac  may  escape,  and  such  agents  as  tannin  and 
glycerin,  carbolic  acid  and  glycerin,  etc.,  or  the  Boulton  formula,  may 
be  applied.  It  rarely  happens  that  this  surgical  treatment  can  be  made 
through  the  pulp  canal  of  the  root  and  without  an  opening  in  the  alveo- 
lar process.  During  treatment,  to  prevent  the  occlusion  of  the  teeth, 
where  this  may  be  necessary,  a  cap  of  gutta  percha  can  be  molded  over 
the  adjoining  teeth  by  first  softening  this  material  in  warm  water. 


224  DENTAL   PATHOLOGY,    THERAPEUTICS. 

The  excision  of  the  apices  of  the  roots  of  teeth,  by  means  of  a  small  tre- 
phine, and  thus  bringing  away  the  sacs  also,  has  been  recommended 
as  successful  surgical  treatment  of  alveolar  abscess. 

Dilute  aromatic  sulphuric  acid  is  a  very  reliable  application,  either 
alone  or  combined  with  a  small  quantity  of  tincture  of  capsicum,  in 
chronic  cases  of  alveolar  abscess  of  long  standing  associated  with  a 
necrosed  condition  of  the  margins  of  the  processes.  The  use  of  sul- 
phuric acid  is  also  recommended  for  opening  root-canals  to  gain 
access  to  the  pus-sac. 

Replantation  is  also  resorted  to,  and  in  many  cases  may  prove  effi- 
cient, if  care  is  exercised  to  remove  all  coagulated  lymph  and  diseased 
membrane,  and  also  to  fill  the  canal  permanently  before  returning  the 
tooth  to  its  cavity.  Under  favorable  circumstances  a  tooth  thus 
treated  may  become  firmly  attached  within  a  few  days. 

When  escharotic  agents  are  injected  into  the  pulp-cavity  and 
through  the  fistulous  opening  in  the  process  and  gum,  their  contact 
with  the  mucous  membrane  may  be  prevented  by  applying  the  rubber 
dam,  or  by  the  introduction  of  a  Hill's  stopping  filling  in  the  crown 
cavity,  in  the  center  of  which  an  opening  is  made  to  admit  closely 
the  point  of  the  syringe,  while  at  the  same  time  the  parts  about  the 
fistulous  opening  are  protected  by  bibulous  paper,  cotton,  and  napkins. 
When  there  is  a  tendency  of  the  accumulated  pus  in  the  sac  of  an  ab- 
scess upon  one  of  the  inferior  teeth  to  discharge  through  an  external 
opening  in  the  cheek,  or  beneath  the  jaw,  this  result  may  be  prevented 
by  a  free  incision  in  the  gum  opposite  the  root  of  the  affected  tooth  ; 
should  the  discharge,  however,  through  an  external  opening  be  in- 
evitable, the  immediate  extraction  of  the  tooth  is  necessary. 

The  application  of  fomentations  and  emollient  poultices  externally 
are  rarely  productive  of  any  advantage,  and  may  do  harm  by  pro- 
moting the  discharge  of  matter  through  the  cheek  or  lower  part  of 
the  face.  When  this  occurs  a  depression,  with  puckering  of  the  skin, 
is  apt  to  remain  after  the  escape  of  pus  through  the  opening  ceases 
and  the  orifice  has  closed,  causing  disfiguration  of  the  face,  which  is 
caused  by  the  formation  of  a  strong  cord  of  new  tissue  which  binds 
the  skin  firmly  to  the  bone. 

It  rarely  happens,  however,  that  anything  more  is  necessary  for  the 
cure  of  the  external  opening  than  the  extraction  of  the  tooth  which 
has  given  rise  to  the  formation  of  the  abscess. 

The  formation  of  an  abscess  in  the  alveolus  of  a  lower  wisdom  tooth 
is  sometimes  productive  of  very  serious  and  even  alarming  consequences, 
such  as  obstructed  deglutition,  fever,  difficult  respiration,  rigidity  of 
muscles  of  jaw,  and  inability  to  open  the  mouth. 

The  late  Prof.  Thomas  E.  Bond  recorded  the  case  of  a  superior  can- 


ALVEOLAR   ABSCESS.  225 

tral  incisor  affected  with  a  chronic  alveolar  abscess  where  the  discharge 
of  pus  occurred  from  behind  the  curtain  of  the  palate,  and  which 
ceased  on  the  removal  of  the  affected  tooth  after  continuing  for  over 
twelve  months  ;  and  another  case  was  recorded  by  Prof.  Chapin  A. 
Harris,  where  the  discharge  of  pus  from  an  abscessed  superior  first 
molar  passed  up  into  the  posterior  nares,  and  found  exit  behind  the 
velum  palati. 

Inflammation  of  the  investing  membrane  of  the  roots  of  an  inferior 
dens  sapientiae  may  produce  equally  serious  effects,  without  occasioning 
the  formation  of  an  abscess  in  the  alveolus.  The  eruption  of  these 
teeth  is  sometimes  attended  with  like  consequences.  The  irritation 
has,  in  some  instances,  extended  to  the  lungs,  and  even  been,  in  such 
diatheses,  the  exciting  cause  of  consumption. 

The  occurrence  of  alveolar  abscess  in  the  cavity  of  a  temporary  tooth 
is  often  followed  by  exfoliation  of  the  sockets  of  several  teeth,  and 
sometimes  of  considerable  portions  of  the  jaw-bone,  seriously  injuring 
the  rudiments  of  permanent  teeth  and  sometimes  causing  their  destruc- 
tion. The  author  saw  a  case,  a  few  years  since,  in  which  an  abscess  of 
the  alveolus  of  the  first  lower  temporary  molar  had  occasioned  exfolia- 
tion of  the  sockets  of  a  cuspid  and  two  molars.  About  one-half  of 
the  alveolar  cells  of  the  two  bicuspids  and  the  cuspid  of  the  second 
set  were  also  exfoliated,  thus  leaving  their  imperfectly  formed  crowns 
entirely  exposed. 

The  treatment  of  the  chronic  form  of  alveolar  abscess  is  generally 
confined  to  the  removal  of  the  cause  of  the  affection,  or  at  least  to  that 
of  the  secretion,  which  in  simple  cases  consists  in  the  cleansing  of  the 
pulp-cavity  of  all  irritating  matter,  which  by  its  decomposed  condi- 
tion promotes  the  formation  of  pus.  The  application  of  disinfecting 
agents  is  then  indicated,  such  as  peroxid  of  hydrogen;  mercuric  chlorid 
followed  by  alcohol,  peroxid  of  sodium,  eucalyptus,  iodoform,  iodin 
carbolic  acid,  salicylic  acid,  etc. 

Peroxid  of  hydrogen  or  sulphuric  ether  answer  as  good  cleansing 
fluids  in  the  form  of  injections  by  means  of  an  abscess  syringe.  The 
entire  tract  of  the  abscess  and  fistulous  opening  should  be  subjected  to 
the  action  of  the  disinfectant.  Dr.  G.  V.  Black  has  successfully  em- 
ployed a  combination  of  carbolic  acid  two  parts,  oil  of  cinnamon  one 
part,  and  oil  of  gaultheria  three  parts,  in  the  form  of  an  injection 
as  a  stimulant  disinfectant.  The  presence  of  sanguinary  calculus  on  the 
root  of  a  tooth  affected  with  the  chronic  form  of  alveolar  abscess  may 
retard  or  prevent  the  successful  treatment  until  such  an  irritant  is 
removed. 


X5 


226  DENTAL  PATHOLOGY,  THERAPEUTICS. 

ALVEOLAR  PYORRHEA. 

Alveolar  Pyorrhea,  commonly  designated  "  Riggs'  disease,"  de- 
notes suppurative  inflammation  of  the  gums  and  peridental  membranes, 
attended  with  the  destruction  of  the  alveolar  processes.  It  usually 
commences  with  an  uneasy  sensation  in  the  gums  and  teeth,  which 
soon  become  painful. 

At  an  early  stage  of  this  disease  the  margin  of  the  gum  presents  de- 
cided inflammatory  action  and  bleeds  from  slight  causes. 

As  the  disease  progresses,  the  inflammation  extends  deeper  into  the 
substance  of  the  gum,  which  becomes  greatly  congested  with  venous 
blood,  swollen,  and  exhibits  a  tendency  to  separate  from  the  necks  of 
the  teeth,  which  gives  rise  to  the  formation  of  small  sulci  filled  with 
pus.  There  is  also  a  loss  of  substance  of  the  gum,  and  the  destruc- 
tion of  the  margins  of  the  alveolar  processes  is  followed  by  the  death 
of  the  thicker  portions  beneath,  and,  as  a  consequence,  the  teeth  be- 
come loose  and  change  their  positions.  There  is  frequently  a  separa- 
tion and  protrusion  of  the  superior  and  inferior  front  teeth,  with  a 
thick,  fetid  discharge  from  about  their  necks,  which  causes  a  disagree- 
able taste  and  a  very  offensive  breath.  The  gum  at  this  stage  of  the 
disease  is  of  a  dark  purple  or  livid  hue,  with  a  congested  margin,  and 
in  some  cases,  on  account  of  its  being  denuded  of  its  epithelium,  its 
surface  presents  a  polished  appearance ;  it  may  also  become  granular 
and  covered  with  fungous  excrescences.  At  an  extreme  stage  of  the 
disease,  complete  destruction  of  the  alveoli  and  of  a  considerable  por- 
tion of  the  gum  occurs,  and  the  teeth  are  held  in  place  by  a  tough, 
ligamentous  attachment,  which  was  formerly  the  peridental  mem- 
brane. The  roots  of  the  teeth  become  coated  with  a  layer  of  calculus, 
often  of  a  greenish-brown  color  and  great  hardness,  which  adheres 
tenaciously,  rendering  its  removal  very  difficult. 

Although  the  two  forms  of  calculus,  the  salivary,  which  is  derived 
from  the  saliva,  and  the  sanguinary,  from  the  serum  that  exudes  from 
the  gums  when  diseased,  cause  inflammation  of  the  peridental  mem- 
brane, yet  the  latter  form  of  calculus  appears  to  be  more  commonly 
associated  with  this  suppurative  inflammation  than  the  former. 

The  congestion  and  consequent  recession  of  the  gum  from  about 
the  necks  of  the  teeth  permits  the  salivary  form  of  calculus  to  be  de- 
posited on  the  roots,  by  the  ready  access  afforded  to  the  fluids  of  the 
mouth ;  while  the  pathological  condition  of  the  ti.ssues  in  connection 
with  the  teeth  causes  a  serous  exudation,  the  result  of  which  is  the 
deposit  of  the  harder  variety  of  calculus. 

The  nature  of  this  calcic  deposit  is  no  doubt  modified  by  the  serous 
fluid  from  the  gum. 


ALVEOLAR    PYORRHCEA.  2  2? 

Causes. — Although  one  form  of  alveolar  pyorrhea  is  a  disease  which 
may  depend  almost  wholly  upon  local  causes,  such  as  the  irritation  of 
salivary  and  sanguinary  calculus,  and  especially  this  latter  form  of  cal- 
cic deposit,  and  a  perverted  condition  of  the  secretions,  yet  the  pecu- 
liar manifestations  of  another  form  often  depend  upon  some  unfavor- 
able diathesis,  which  enables  the  local  causes  to  produce  more  serious 
effects  than  might  be  possible  in  better  systemic  conditions.  If  the 
teeth  are  perfectly  free  from  irritating  accretions,  and  present  smooth, 
polished  surfaces  at  points  where  the  more  highly  vitalized  surround- 
ing structures  come  in  contact  with  them,  no  inflammatory  action  will 
occur  in  such  structures.  On  the  other  hand,  if  the  teeth,  on  account 
of  calcic  deposits  about  the  margin  of  the  gum  and  along  their  roots, 
act  as  irritants,  inflammatory  action,  followed  by  such  effects  as  one 
form  of  the  disease  under  consideration  presents,  may  ensue.  And 
again,  if  a  gouty  diathesis  is  present  due  to  a  superabundance  of  uric 
acid  in  the  system,  the  aggravated  symptoms  of  another  form  of  this 
affection  manifest  themselves.  Low  vitality  and  all  diseases  which  af- 
fect the  circulation  may  be  named  as  predisposing  causes  of  alveolar 
pyorrhea. 

Dr.  Black,  in  describing  this  disease  under  the  title  of  "  phage- 
denic pericementitis,"  maintains  that  it  is  of  local  orgin,  while  Dr. 
Atkinson  ascribes  it  to  constitutional  causes.  There  is  good  reason, 
however,  for  believing  that  there  are  both  predisposing  and  exciting 
causes  for  this  disease.  Prof.  C.  N.  Peirce  believes  that  it  is  princi- 
pally due  to  a  gouty  diathesis  of  the  system,  and  he  defines  two  forms 
of  this  affection  :  in  one  the  origin  of  the  calcic  salt  is  the  saliva,  and 
in  the  other  the  blood.  The  former  he  designates  2^^  pt\aloge?iic  calcic, 
its  origin  being  local  and  salivary ;  the  latter  hematogenic  calcic,  its 
origin  being  constitutional,  and  associated  with  some  modifications  of 
the  normal  composites  of  the  blood  plasma.  The  calcic  pericementitis 
may  have  its  origin  at  the  gingival  border,  the  salivary  calculus  acting 
as  a  local  and  mechanical  irritant  with  such  concomitants  as  irritation, 
inflammation,  suppuration,  absorption  of  gum  and  alveolar  process. 
He  says  :  "  We  have  three  distinct  abnormal  conditions  affecting  the 
gums,  peridental  membrane,  and  alveolar  processes.  The  first  is  gum 
inflammation  and  destruction,  caused  by  a  mechanical  irritant ;  sec 
ond,  inflammation  of  the  gingival  borders  without  the  presence  of  sal- 
ivary calculus.  The  third  is  pericemental  irritation  commencing  at 
or  near  the  apical  extremity  of  the  root,  due  to  the  presence  of  some 
morbid  composite  of  the  blood  exuded  with  the  plasma  and  infiltrat- 
ing the  peridental  membrane,  and  frequently  deposited  or  precipitated 
upon  the  root  of  the  tooth  near  its  apex.  This  latter  I  designated 
true  pyorrhea  alveolaris,   or  hematogenic  pericementitis,  and   so  in- 


228  DENTAL    PATHOLOGY,    THERAPEUTICS. 

timately  is  it  associated  with  some  other  local  manifestation  of  a  gouty 
diathesis,  that  I  believe  it  to  be  another  local  expression  of  that  sys- 
temic condition."  That  a  superabundance  of  uric  acid  in  the  system 
may  assist  in  producing  alveolar  pyorrhea  is  the  general  opinion,  but 
from  the  fact  that  uric  acid  may  be  present  in  the  system  without 
producing  either  gout  or  rheumatism,  Drs.  Bodecker,  Darby,  James, 
Truman,  Rhein,  and  others  dissent  from  the  views  of  Dr.  Peirce  and 
assert  that  uric  acid  will  not  exert  more  influence  in  producing 
alveolar  pyorrhea  than  consumption,  anemia,  kidney  and  liver  affec- 
tions, syphilis,  chronic  nervous  diseases,  etc.,  which  are  often  associated 
with  alveolar  pyorrhea;  and  they  assert  that  the  cause  of  this  disease 
is  a  more  or  less  chronic  general  ailment  and  not  due  to  any  particular 
form  ;  also  that  many  cases  of  alveolar  pyorrhea  can  be  attributed  to 
nothing  but  heredity. 

Treatment. — In  the  early  stage  of  alveolar  pyorrhea  all  calcic  de- 
posits should  be  carefully  removed  and  the  surfaces  beneath  well 
polished  ;  a  decided  change  for  the  better  may  occur  in  a  very  short 
time,  as  the  inflamed  gum  will  lose  its  congested  appearance,  and  as- 
sume a  lighter  color  and  a  firmer  consistence,  and  become  reduced 
to  its  normal  thickness.  In  the  more  advanced  stages  of  this  disease 
the  treatment  consists  in  reaching,  by  means  of  narrow,  sharp  instru- 
ments, the  extreme  limits  of  the  diseased  action,  removing  all  deposits, 
and  breaking  up  the  diseased  tissue  and  necrosed  bone,  and  polishing 
the  surfaces  roughened  by  depositions  of  calculus. 

The  diseased  margin  of  the  alveolar  process  must  be  removed  to 
such  an  extent  that  the  firm  and  resistant  bone  is  reached  by  the  edge 
of  the  cutting  instrument,  which  a  nice  sense  of  touch  will  determine. 

A  nice  sense  of  touch,  only  acquired  by  practice,  will  enable  the 
operator  to  distinguish,  with  the  instrument,  foreign  and  dead  sub- 
stance from  tooth  structure  and  living  bone.  It  is  especially  necessary 
that  every  particle  of  calculus  and  necrosed  bone  should  be  removed, 
as  their  presence  will  be  indicated  by  a  reddened  patch  of  tissue, 
somewhat  larger  than  the  irritant  beneath.  As  the  removal  of  such 
irritants  causes  both  pain  and  hemorrhage,  such  an  operation  will  re- 
quire several  sittings  and  the  frequent  application  of  carbolic  acid  by 
means  of  a  properly  shaped  piece  of  orange  wood.  After  this  opera- 
tion is  completed  an  application  of  dilute  aromatic  sulphuric  acid  will 
prove  serviceable.  The  effect  of  such  treatment  is  to  promote  the  re- 
production of  new  bone,  and  cause  the  gum  to  become  firmly  attached 
to  it,  and  thus  restore  the  stability  of  the  teeth,  and  in  many  cases 
the  only  after  therapeutic  treatment  necessary  will  be  the  use  of  an  as- 
tringent wash,  such  as  tincture  of  myrrh  in  its  full  strength,  applied 
to  the  gum  about  the  neck  of  the  teeth.     When  constitutional  disturb- 


ALVEOLAR    PYORRHEA. 


229 


ance  exists  in  connection  with  the  local  effects,  after  perfectly  remov- 
ing all  irritants  a  dilute  solution  of  chlorid  of  zinc  may  be  applied 
to  the  ulcerating  surfaces  by  passing  it  under  the  gum,  about  the  necks 
and  roots  of  the  teeth,  by  means  of  cotton  wound  on  a  broach,  and 
alternating  with  dilute  aromatic  sulphuric  acid  and  tincture  of  iodin, 
applied  to  the  surface  of  the  gum.  Chlorate  of  potash  solution  should 
be  used  as  a  mouth-wash  after  each  meal  and  at  night,  with  as  thor- 
ough use  of  the  brush  as  the  condition  of  the  gums  will  permit.  The 
use  of  a  solution  of  common  salt  is  recommended  during  the  intervals 
between  the  applications  of  the  more  powerful  remedies  ;  also  phenol 
sodique. 

For  the  worst  stage  of  this  disease,  where  the  teeth  are  held  in  the 
mouth  by  means  of  the  tough,  ligamentous  attachments  only,  their  re- 
moval is  inevitable. 

The  illustration  (Fig.  122)  represents  Dr.  J.  M.  Riggs's  set  of  instru- 


FiG.  122. 


ments  for  the  thorough  removal  of  all  salivary,  sanguinary,  and  other 
deposits  from  the  roots  of  the  teeth,  in  the  treatment  of  this  disease. 

Some  prefer  instruments  with  slender  points,  which  require  a  push- 
ing motion,  instead  of  the  curved  hook  or  hoe-shaped  instruments  so 
commonly  used  for  the  removal  of  calcic  deposits  from  the  teeth,  and 
which  necessitate  a  motion  toward  the  hand. 

Whatever  form  of  instrument  is  used,  the  thorough  removal  of  all 
concretions  from  the  teeth  is  absolutely  necessary  in  this  treatment, 
as  all  soft  tissues  are  rendered  unhealthy  by  the  contact  of  calcic  de- 
posits. Dr.  Cushing's  set  of  scalers  (Fig.  123)  are  well  adapted  for 
the  removal  of  all  calcic  deposits  from  the  teeth. 

For  the  removal  of  slight  deposits  in  the  form  of  thin  scales,  Dr. 
Gilmer  recommends  that  the  gum  be  first  expanded,  so  that  it  may 
stand  off  from  the  tooth,  by  packing  under  its  free  margin  salicylized 
cotton,  which  is  allowed  to  remain  for  twenty-four  hours. 


230 


DENTAL    PATHOLOGY,    THERAPEUTICS. 


Fig.  123. 


A  method  of  treatment  recently  recommended  by  Dr.  A.  W.  Har- 
lan is  as  follows :  For  the  acute  form,  the  pockets  formed  by  the  sepa- 
ration of  the  gum  should  be  first  filled  with  iodoform  and  eucalyptus, 
iodoform  and  oil  of  cinnamon,  or  be  thoroughly  syringed  with  a  one 
to  three-grain  solution  to  the  ounce  of  water  of  chlorid  of  alumina, 
which  is  a  good  disinfectant  and  astringent.     In  three  or  four  days  the 

sanguinary  deposits  may  be  re- 
'I  r  moved,  as  well  as  the  edges  of 
the  alveoli.  The  pockets  should 
then  be  syringed  with  peroxid 
of  hydrogen,  for  the  purpose  of 
thoroughly  cleansing  them  and 
also  to  destroy  the  micro-organ- 
isms present.  After  drying  the 
gums  the  pockets  should  be  in- 
jected with  a  solution  of  iodid  of 
zinc,  grs.  xij  to  grs.  xiv  to  the 
ounce  of  water,  two  or  three 
drops  or  more  to  each  pocket.  After  several  days  have  elapsed  the  gums 
should  be  carefully  dried,  and  a  fine  cone  of  cotton  or  bibulous  paper 
moistened  with  peroxid  of  hydrogen  gently  pressed  into  each  pocket ; 
if  any  pus  is  present  effervescence  will  take  place,  when  each  pocket 
must  be  again  injected  with  the  iodid  of  zinc  solution.  In  chronic  cases, 
after  the  removal  of  the  diseased  bone  and  the  careful  cleansing  of  the 
roots,  the  pockets  should  be  syringed  with  peroxid  of  hydrogen,  fol- 
lowed by  the  injection  of  a  xxiv  gr.  solution  of  the  iodid  of  zinc,  in 
the  same  manner  as  before  described.  In  very  bad  cases  a  stronger 
solution  of  the  iodid  of  zinc  is  recommended,  xxviij  grs.  to  the  ounce 
of  water ;  and  when  the  margins  of  the  gums  present  a  ragged  border 
or  cone-shaped  slit,  pure  granular  iodid  of  zinc  is  applied  to  the  edges 
of  the  slit  once  in  three  days,  the  injection  into  the  pockets  being  re- 
peated every  fourth  day.  Combinations  of  iodoform  and  eucalyptus, 
iodoform  and  oil  of  cinnamon,  iodoform  and  eugenol,  chlorid  of 
aluminum  in  the  form  of  a  solution  composed  of  one  to  three  grains 
to  the  ounce  of  water,  sanitas,  three  parts  to  one  part  of  eugenol, 
peroxid  of  sodium,  have  also  been  employed  with  benefit,  in  the  form 
of  paste  and  injections. 

A  strong  solution  of  chlorid  of  zinc,  20  to  30  per  cent.,  applied 
with  care  about  the  teeth  by  means  of  an  abscess-syringe,  will  prove 
beneficial  by  relieving  the  congestion  and  constringing  the  soft 
tissues.  The  after-treatment  consists  in  the  use  of  stimulating  appli- 
cations, such  as  cinnamon-water,  or  carbolic  acid  combined  with  oil 
of  cinnamon  and  oil  of  gaultheria,  in  the  proportion  of    one  dram 


DISEASES    OF    THE    DENTAL    PULP.  23! 

of  the  former  and  four  to  five  drams  each  of  the  latter.  Cleanli- 
ness should  also  be  observed,  and  in  the  use  of  the  tooth-brush  the 
motion  should  always  be  lengthwise  instead  of  across  the  teeth — a 
soft  brush  being  preferable  to  a  stiff  one.  It  is  advisable,  in  cases 
where  the  destruction  of  the  alveolar  process  has  not  been  great,  to 
preserve  the  gingival  margin,  in  order  that  a  perfect  restoration  of 
the  peridental  membrane  may  take  place.  Such  an  operation  may 
be  performed  by  introducing  through  the  gingival  aperture  a  bent 
chisel,  or  a  hoe-shaped  excavator,  and  the  diseased  structure  removed 
as  high  up  as  it  may  extend  toward  the  apex  of  the  root.  In  cases 
where  the  cutting  instrument  cannot  be  introduced  in  such  a  manner 
without  injury  to  the  gingival  margin,  a  flap  of  the  soft  tissue  over 
the  diseased  bone  may  be  raised,  and  all  carious  structure  removed, 
as  well  as  calcic  depos'its  from  the  denuded  root,  through  such  an 
opening,  without  destroying  the  gingival  margin.  After  the  parts 
are  thoroughly  cleansed  by  injections  of  tepid  water,  stimulating 
applications  may  be  made  of  carbolic  acid  (in  crystals)  one  part, 
oil  of  cinnamon  two  parts,  and  oil  of  gaultheria  three  parts.  Dr. 
Gilmer  recommends  for  obstinate  cases  the  use  of  carbolic  acid  and 
camphor,  in  the  form  of  "phenol  camphor,"  which  consists  of 
equal  parts  of  carbolic  acid  and  gum  camphor,  prepared  by  melting 
such  a  mixture  on  a  sand  bath  until  an  oily  liquid  is  obtained  ;  it 
is  applied  by  means  of  a  syringe  to  the  pus-pockets.  Before  the 
application  of  disinfectants  and  antiseptics,  the  parts  should  be  cleansed 
with  the  peroxid  of  hydrogen,  either  alone  or  combined  with  the 
bichlorid  of  mercury,  pyrozone  5  per  cent,  solution,  or  solution  of 
peroxid  of  sodium. 


CHAPTER  VI. 

DISEASES  OF  THE  DENTAL  PULP. 

The  pulp  of  a  tooth,  from  the  high  degree  of  vitality  with  which 
it  is  endowed,  is  one  of  the  most  sensitive  structures  of  the  body,  and, 
like  other  parts,  is  liable  to  become  the  seat  of  various  morbid  phe- 
nomena. Its  susceptibility  to  morbid  impressions  is  influenced  by  a 
variety  of  circumstances,  such  as  temperament,  habit  of  body,  the 
state  of  the  constitutional  health,  the  condition  of  the  hard  structures 
of  the  tooth,  etc.  A  cause,  which  under  some  circumstances  would 
not  be  productive  of  the  slighest  disturbance,  might  under  others 
give  rise  to  acute  inflammation,  with  all  its  painful  and  disagreeable 


232  DENTAL    PATHOLOGY,    THERAPEUTICS. 

concomitants.  Increased  irritability  (hyperesthesia)  may  exist  inde- 
pendently of  any  organic  change,  either  in  the  pulp,  dentine,  or 
enamel.  Examples  are  often  met  with  in  females  during  gestation  ; 
but  it  arises  more  frequently  as  a  consequence  of  caries  than  from  any 
other  cause  connected  with  the  teeth.  Even  before  the  disease  has 
penetrated  to  the  central  chamber  of  the  organ  the  pulp  often  assumes 
a  most  wonderful  and  marked  increase  of  irritability,  either  from 
functional  disturbance  arising  from  decomposition  of  the  dentine,  im- 
paired relationship  between  the  two,  or  from  being  more  exposed  to 
the  action  of  external  deleterious  agents.  Impaired  digestion,  as  well 
as  a  disordered  state  of  other  functions  of  the  body,  frequently  pro- 
duces the  same  effect. 

The  susceptibility  of  the  pulp  to  impressions  of  heat  and  cold  and 
of  acids  is  always  increased  by  heightened  irritability.  When  this 
exists  to  any  considerable  degree  the  mere  contact  of  these  agents 
with  the  tooth  is  often  productive  of  severe  pain,  which  on  their  re- 
moval very  soon  subsides.  The  pulp,  however,  may  remain  in  this 
condition  for  months,  and  even  years,  without  becoming  the  seat  of 
inflammatory  action. 

Preternatural  sensibility  of  the  dentine,  whether  in  a  sound  or  par- 
tially decomposed  state,  augments  very  appreciably  the  irritability  of 
the  pulp.  The  sensibility  of  dentine  is  sometimes  so  much  increased 
that  the  mere  contact  of  any  hard  substance  with  a  part  which  has 
become  exposed  by  the  destruction  of  a  portion  of  the  enamel  is 
often  productive  of  severe  pain.  Impressions  of  heat  and  cold  con- 
veyed through  the  conducting  medium  of  a  metallic  filling,  or  through 
a  thin  covering  of  dentine,  as  sometimes  happens  when  a  considerable 
portion  of  the  tooth  has  been  worn  away,  is  a  very  frequent  cause  of 
heightened  irritability  of  the  pulp.  With  its  susceptibility  thus  in- 
creased, the  impressions  produced  by  these  agents  are  often  a  source 
of  irritation  and  even  of  inflammation  and  suppuration,  causing  the 
death  of  the  entire  crown  and  inner  walls  of  the  root  of  the  tooth. 
At  other  times  the  irritation  is  only  followed  by  slight  increase  of 
vascular  action  and  an  effusion  of  plastic  lymph  over  the  affected  part 
of  the  pulp,  which  is  gradually  converted  into  osteo-dcntifie  ;  and  thus 
a  barrier  is  interposed  between  it  and  the  irritating  agents. 

Hyperemia  and  Irritation. — The  pulp  of  a  tooth  may  become  the 
seat  of  severe  pain  even  when  there  is  no  inflammation.  The  slightest 
increase  of  vascular  action,  a  condition  known  as  hyperemia,  when 
this  organ  is  in  a  preternaturally  irritable  condition,  is  productive  of 
more  or  less  irritation.  The  pressure  of  even  slightly  distended  ves- 
sels upon  the  nervous  filaments  distributed  upon  it,  at  such  times,  is 
sufficient  to  cause  pain. 


DISEASES   OF   THE    DENTAL   PULP.  233 

Hyperemia  of  the  dental  pulp  may  exist  in  any  degree,  according 
to  the  increased  amount  of  blood  which  expands  its  vessels.  The 
coronal  portion  of  the  pulp,  what  is  generally  known  as  its  *'  bulb," 
exhibits  the  greatest  distention  under  such  conditions,  and  the  pain 
resulting  is  often  sharp  and  lancinating,  and  even  paroxysmal  in  char- 
acter. The  pain  from  hyperemia  is  often  referred  to  other  organs, 
such  as  the  ear,  face,  and  in  fact  to  any  part  of  the  distribution  of 
the  fifth  pair  of  nerves.  Hyperemia  may  result  in  diffuse  inflammation 
of  the  pulp  when  the  red  blood-globules  escape  through  the  pulp-tissue, 
which  generally  occurs  at  the  point  where  the  distention  is  greatest. 
This  condition  is  liable  to  occur  in  sound  teeth  as  well  as  in  carious 
ones,  although  the  approach  of  caries  to  the  pulp-chamber  is  perhaps, 
the  most  frequent  cause  of  irritation  of  the  pulp.  Within  certain 
limits  hyperemia  is  a  physiological  condition,  an  impression  induced 
by  a  temporary  excitant,  which  soon  passes  away  without  injury  to  the 
parts  involved.  But  when  the  cause  is  sufficient  to  bring  about  re- 
peated attacks,  the  vessels  of  the  pulp  fail  to  contract,  and  remain 
distended  with  blood,  and  the  affected  organs  become  very  suscepti- 
ble to  even  slight  thermal  changes,  and  the  hyperemia  becomes 
pathological  instead  of  physiological.  The  treatment  for  hyperemia 
or  irritation  of  the  dental  pulp  consists  in  the  removal  of  the  cause  of 
irritation  and  the  protection  of  the  tooth  from  all  thermal  and  other 
influences  which  may  cause  irritation,  by  disinfecting  and  filling  the 
cavity.  In  the  case  of  very  sensitive  teeth  the  use  of  non-conducting 
filling  materials,  such  as  gutta  percha,  or  the  oxyphosphate  or  oxychlo- 
rid  of  zinc  preparations  is  indicated  ;  in  cases  of  otherwise  healthy  and 
sound  teeth  they  should  be  protected  from  thermal  changes  until  the 
susceptibility  to  such  influences  has  passed  away.  Dr.  G.  V.  Black 
recommends  for  the  latter  case  a  closely-fitting  gutta-percha  cap  as  a 
protection. 

Impressions  of  heat  and  cold  are  conveyed  more  readily  to  the  pulp 
when  the  dentine  is  in  a  morbidly  sensitive  condition,  and  when  this 
is  the  case  they  produce  a  more  powerful  effect. 

The  remedial  indications  of  pain  in  a  tooth  arising  simply  from 
irritation  of  the  pulp,  consist  in  the  removal  of  the  primary  and  ex- 
citing causes.  When  produced  by  impressions  of  heat  and  cold  con- 
veyed to  it  through  the  conducting  medium  of  a  metallic  filling  and 
intervening  super-sensitive  dentine,  if  the  severity  and  continuance  of 
pain  is  such  as  to  warrant  the  belief  that  it  will  give  rise  to  inflamma- 
tion, the  filling  should  be  removed  and  some  non-conducting  substance 
placed  in  the  bottom  of  the  cavity  before  replacing  it.  If  this  is  done 
before  inflammation  actually  takes  place  it  will  prevent  subsequent 
irritation  from  these  causes.     It  is  worthy  of  remark,  however,  that  the 


234  DENTAL   PATHOLOGY,    THERAPEUTICS. 

pain  thus  produced  is  in  proportion  to  the  sensibility  of  the  subjacent 
dentine.  If  this  is  destroyed  previously  to  filling  the  tooth,  irritation 
of  the  pulp  will  be  as  effectually  prevented  as  by  the  interposition  of 
a  non-conducting  substance.  But  in  the  application  of  agents  for  this 
purpose  there  is  danger  of  destroying  the  vitality  of  the  pulp.  The 
employment  of  them,  however,  is  resorted  to  more  frequently  to  pre- 
vent pain  during  the  removal  of  caries  than  to  relieve  any  subsequent 
irritation  from  impressions  of  heat  and  cold.  (See  Hypersensitive 
Dentine.) 

Although  a  frequent  cause,  yet  a  metallic  filling  is  not  the  only 
medium  through  which  impressions  of  heat  and  cold  are  conveyed  to 
the  dental  pulp.  When  the  dentine  on  the  coronal  extremity  or  side 
of  a  tooth  becomes  very  thin  from  loss  of  substance  occasioned  by 
mechanical  abrasion  or  erosion,  by  the  use  of  a  cutting  instrument, 
or  other  cause,  the  pulp  sometimes  becomes  painfully  susceptible 
to  the  action  of  these  agents.  Loss  of  substance  from  any  of  these 
causes  is  also  often  attended  by  exalted  sensibility  of  the  exposed 
dentine  ;  and  when  this  is  the  case  the  contact  of  acids  with  it  is  pro- 
ductive of  more  or  less  pain.  Nature,  however,  usually  prevents  the 
painful  consequences  that  would  naturally  arise  from  continued  abra- 
sion of  the  coronal  ends  of  the  teeth,  and  the  consequent  exposure  of 
their  nervous  pulp,  by  the  gradual  ossification  of  this  organ  ;  so  that 
by  the  time  it  would  become  exposed  it  is  converted  into  osteo-den- 
tine.  But  this  does  not  always  take  place  in  time  to  prevent  irritation 
and  pain. 

When  irritation  of  the  pulp  occurs  in  a  tooth  that  has  been  so  much 
cut  away  as  to  leave  only  a  thin  covering  of  dentine  over  the  pulp,  the 
best  known  means  of  preventing  morbid  sensibility  is  to  keep  the  cut 
surface  constantly  clean  by  frequent  friction  with  a  brush  and  waxed 
floss  silk,  or  with  some  other  suitable  substance.  This  operation  should 
be  repeated  after  each  meal,  and  in  the  morning  immediately  after  ris- 
ing, and  at  night  before  going  to  bed.  The  application  of  nitrate  of 
silver  for  sensitiveness  arising  from  loss  of  substance  or  from  exalted 
sensibility  of  exposed  dentine,  has  proved  successful.  The  nitrate  in  the 
solid  form  may  be  applied  by  enveloping  a  portion  of  the  stick  with 
wax,  which  will  enable  the  operator  to  handle  it  with  impunity.  Or  the 
end  of  a  silver  wire  may  be  dipped  in  nitric  acid  and  the  application 
be  thus  made  to  the  sensitive  surface,  taking  care  to  protect  the  adja- 
cent parts.  Some  are  in  the  habit  of  applying  salt  as  soon  as  the 
sensitive  surface  has  been  touched  with  the  nitrate,  to  neutralize  its 
effects.  To  prevent  contact  with  the  gum,  when  it  is  necessary  to 
apply  the  nitrate  to  the  necks  of  the  teeth,  a  coating  of  collodion  may 
be  painted  on  them  with  a  camel's-hair  brush.     But  discoloration  may 


INFLAMMATION    OF    THE    PULP — PULPITIS.  235 

result  from  such  an  application.  Chromic  acid  has  also  been  used  in 
these  cases  with  success. 

The  careless  use  of  the  burr,  and  also  of  sand-paper  discs,  in  the 
dental  engine,  may  also  induce  irritation  of  the  dental  pulp  on  account 
of  the  heat  generated  by  such  agents. 

When  caries  has  extended  to  the  central  cavity,  irritation  is  often 
produced  by  contact  of  partially  decomposed  portions  of  dentine  or 
other  foreign  matter  with  the  pulp.  The  proper  remedial  indication 
in  such  cases,  it  is  scarcely  necessary  to  say,  consists  in  the  removal  of 
all  matter  from  the  teeth  that  can  either  act  as  a  mechanical  or  chemi- 
cal irritant.  This  done,  the  cavity  in  the  crown  of  the  tooth,  suppos- 
ing the  pulp  to  be  in  a  healthy  condition,  should  be  properly  filled. 

But  when  the  irritation  arises  as  a  consequence  of  exalted  irritability 
and  increased  vascular  action  of  the  pulp,  dependent  upon  disease  or 
altered  function  of  some  other  part  or  parts  of  the  body,  the  remedial 
indications  are  different.  Tlie  treatment  then  should  be  addressed  to 
the  primary  affection.  Examples  of  this  sort  are  of  frequent  occur- 
rence. They  are  met  with  almost  daily,  particularly  in  females  during 
gestation,  in  dyspeptic  individuals,  and  in  persons  affected  with  gout 
and  chronic  rheumatism.  They  are  also  sometimes  met  with  in  indi- 
viduals who  have  been  exposed  to  miasmatic  emanations  of  marshy 
districts,  when  the  irritation  assumes  an  intermittent  form,  occurring 
at  stated  intervals  of  twenty-four,  forty-eight,  or  seventy-two  hours, 
and  continuing  from  one  to  three  hours.  Some  of  the  worst  forms  of 
toothache  are  produced  by  one  or  other  of  these  causes. 

The  local  disturbance,  when  it  occurs  in  females  during  pregnancy, 
may  generally  be  removed  by  mild  aperients,  warm  foot-bath,  and 
anodynes  at  night  on  going  to  bed.  When  it  depends  upon  other 
kinds  of  derangement  of  the  uterine  organs,  treatment  suited  to  the 
peculiar  indications  of  the  case  should  be  instituted.  When  it  occurs 
in  a  person  affected  with  dyspepsia,  rheumatism,  or  gout,  the  constitu- 
tional treatment  required  by  the  particular  disease  constitutes  the 
proper  remedy.  When  the  irritation  assumes  an  intermittent  form,  an 
emetic  or  cathartic,  followed  by  quinine,  will  generally  put  a  stop  to 
the  local  disturbance,  provided  it  has  no  connection  with  caries  of  the 
crown  of  the  tooth. 

INFLAMMATION    OF    THE    PULP — PULPITIS. 

The  pulp  of  a  tooth,  when  healthy,  has  a  grayish-white  appearance, 
and  its  capillaries  are  invisible  to  the  naked  eye,  but  when  it  becomes 
the  seat  of  acute  or  active  inflammation,  they  may  be  distinctly  seen, 
as  the  organ  then  assumes  a  bright  red  color.  Inflammation,  having 
established  itself,  soon  extends  to  every  part  of  the  pulp,  and  even  to 


236  DENTAL    PATHOLOGY,    THERAPEUTICS. 

the  peridental  membrane.  When  permitted  to  run  its  course  uninter- 
ruptedly, it  usually  terminates  in  suppuration  in  from  three  to  eight  or 
ten  days. 

The  unyielding  nature  of  the  walls  of  the  cavity  in  which  it  is  on  all 
sides  inclosed  renders  expansion  of  the  pulp  impossible,  and  as  its 
capillaries  become  distended  with  blood,  they  press  on  the  nervous 
filaments  which  are  everywhere  distributed  upon  it,  causing  at  first 
constant  gnawing  pain,  which  afterward,  as  the  distention  of  the 
vessels  increases,  becomes  severe,  deep-seated,  throbbing,  and  some- 
times almost  insupportable. 

Inflammation  may  attack  the  pulps  of  sound  teeth  as  well  as  those 
affected  with  caries ;  but  it  occurs  more  frequently  in  the  latter  than 
in  the  former,  and  it  is  oftener  met  with  before  than  after  the  pulp 
has  become  actually  exposed.  The  severity  of  the  pain,  however,  is 
determined  by  the  condition  of  the  tooth,  the  state  of  the  general 
health,  and  the  causes  concerned  in  its  production.  The  pulp,  when 
in  an  irritable  condition,  is  more  liable  to  become  the  seat  of  acute  in- 
flammation than  when  in  a  perfectly  healthy  state,  and  the  occurrence 
of  suppuration  is  soon  followed  by  alveolar  abscess,  unless  an  opening 
is  made  immediately  through  the  crown,  neck,  or  root  of  the  tooth, 
for  the  escape  of  the  matter. 

The  effusion  of  lymph,  which  takes  place  during  the  inflammatory 
stage,  and  which,  under  other  circumstances,  and  when  the  inflamma- 
tion is  less  severe,  is  made  to  play  an  important  part  in  the  reparation 
of  the  injury,  compresses  the  pulp  into  still  narrower  limits  as  it  accu- 
mulates in  quantity,  and  thus  becomes  an  additional  source  of  irrita- 
tion, adding  fuel  to  the  flame  already  lighted  up. 

Inflammation  of  the  pulp  may  be  caused  by  a  blow  on  the  tooth  ;  by 
impressions  of  heat  and  cold  conveyed  to  it  through  the  enamel  and 
dentine,  or  through  a  metallic  filling;  or  by  the  pressure  of  a  filling, 
or  the  direct  contact  of  external  irritating  agents,  such  as  disorganized 
portions  of  the  tooth,  particles  of  alimentary  substances,  acrid  humors, 
etc.  But,  as  we  have  stated  in  another  place,  inflammation  of  the  den- 
tal pulp  is  not  always  a  necessary  consequence  of  impressions  of  heat 
and  cold  ;  pain  may  be  produced  by  them  when  jmlpitis  does  not  exist ; 
but  in  this  case  it  usually  subsides  soon  after  the  removal  of  the  irri- 
tant. The  exposure  of  the  pulp  by  decay  is  a  common  cause  of  inflam- 
mation of  the  organ,  also  abrasion  and  the  careless  preparation  of  a 
cavity  for  the  insertion  of  a  filling,  although  in  rare  cases  the  pulp  ofa 
tooth  may  be  exposed  for  months,  and  subjected  several  times  a  day  to 
the  actual  contact  of  foreign  bodies,  without  becoming  the  seat  of  acute 
inflammation.  The  irritation  and  increased  vascular  action  thus  occa- 
sioned are,  no  doubt,  removed  by  the  effusion  of  lymph  to  which  they 


INFLAMMATION   OF   THE    PULP — PULPITIS.  237 

give  rise,  and  the  pulp,  after  it  has  become  exposed,  having  room  to 
expand  as  its  vessels  become  distended,  does  not  suffer  irritation  from 
the  pressure  to  which  it  would  otherwise  be  subjected. 

Where  suppuration  takes  place,  the  pain  very  nearly  ceases,  but 
the  tooth  for  a  time  remains  sore  to  the  touch,  and  its  appearance  is 
changed.  It  has  no  longer  the  peculiar  animated  translucency  of  a 
living  tooth,  but  has  assumed  an  opaque,  muddy  or  brownish  aspect. 
With  the  disorganization  of  the  pulp,  the  entire  crown  and  inner 
walls  of  the  root  lose  their  vitality ;  still,  if  the  peridental  mem- 
brane has  not  become  seriously  involved  in  disease,  the  vascular 
and  nervous  supply  furnished  to  the  cementum  is  often  sufficient  to 
prevent  the  tooth  from  exerting  any  injurious  influence  upon  the  sur- 
rounding and  more  highly  vitalized  parts.  The  cementum,  being 
more  analogous  in  structure  to  true  osseous  tissue  than  dentine,  now 
plays  an  important  part  in  the  animal  economy.  It  being  more 
liberally  supplied  with  vitality  and  with  nutritive  fluids,  and  not 
being  sensibly  affected  by  the  death  of  the  other  parts  of  the  organ, 
it  keeps  up  the  living  relationship  of  the  tooth  with  the  peridental 
membrane,  at  least  sufficiently  to  prevent  it  from  acting  perceptibly 
as  a  morbid  irritant. 

Inflammation  of  the  pulp  of  a  tooth,  besides  the  local  pain  with 
which  it  is  attended,  often  gives  rise  to  a  train  of  constitutional  morbid 
phenomena,  usually  of  a  mild,  but  sometimes  of  an  aggravated  and 
even  threatening  character.  Among  these  are  headache,  constipation 
of  the  bowels,  furred  tongue,  dry>iess  of  the  skin,  quick,  full  and  hard 
pulse,  earache,  ophthalmia,  disease  of  the  maxillary  sinus,  etc. 

The  amount  of  constitutional  disturbance  arising  from  inflammation 
of  the  pulp  of  a  tooth  depends  on  the  state  of  the  general  health,  and 
the  nervous  irritability  of  the  system  at  the  time.  In  the  majority  of 
cases  it  may  occasion  but  little  inconvenience,  and  disappear  as  soon 
as  the  inflammation  ceases,  but  sometimes  it  assumes  a  very  alarming 
character.  A  fatal  case  of  tetanus,  produced  by  inflammation  of  the 
pulp  of  a  lower  molar,  occurred  a  number  of  years  ago  in  Baltimore. 
The  subject  was  a  young  lady  about  eighteen  years  of  age.  The 
system  at  the  time,  from  great  bodily  fatigue  and  mental  excitement, 
was  in  an  exceedingly  irritable  condition,  but  in  other  respects, 
though  constitutionally  rather  delicate,  she  was  in  the  enjoyment  of 
good  health. 

There  is  not  an  organ  or  tissue  of  the  body  in  which  acute  inflam- 
mation is  more  intractable  in  its  nature  and  rapid  in  its  progress, 
than  in  the  pulp  of  a  tooth ;  and  when  we  take  into  consideration 
its  situation,  and  its  physical  and  vital  peculiarities,  it  is  not  to  be 
wondered  that  it  should,  in  so  large  a  majority  of  the  cases,  termi- 


238 


DENTAL    PATHOLOGY,    THERAPEUTICS. 


nate  in  the  disorganization  of  the  part.  Still,  it  may  sometimes  be 
arrested,  and  the  remedial  indications  here,  though  they  cannot  be 
as  readily  and  fully  carried  out,  are  the  same  as  for  inflammation 
in  any  other  part  of  the  body.  The  first  and  most  important  one 
consists  in  the  removal  of  all  local  and  exciting  causes.  For  simple 
exposure  of  the  pulp,  without  sloughing,  the  first  step,  after  removal 


Fig.  124  RepresiiNTs  an  Area  of  Pulp  Akfecteu  with  Acute  Pulpitis.  (After Bodecker.) 
L  Intensely-inflamed  portion.      M.  MoHerately-inflamed  portion.     S.  Slightly-inflamed  por- 
tion.    N,  N.  Small  bundles  of  inedullated  nerves,  slii;htly  inflamed.     T.  Nerve-bundle  in 
transverse  section.     V.  Vein,  engorged  with  red  and  coiorless  blood-corpuscles.     C.  Ca- 
pillary, engorged  and  widened.     Magnified  500  diameters. 


of  all  irritants  from  the  carious  cavity,  is  to  attempt  the  reduction  of 
inflammation  and  the  prevention  of  the  effusion  of  serum  or  lymph, 
by  cleansing  the  exposed  surface  with  tepid  water,  and,  after  careful 
drying,  to  bathe   it  with  dilute  tincture  of  aconite,  when  it  may  be 


INFLAMMATION    OF    THE    PULP — PULPITIS.  239 

covered  with  a  thin  coating  of  a  solution  of  gutta-percha  in  chloro- 
form, or  glycerin,  or  collodion  carefully  applied,  and  the  tooth 
protected  from  irritation.  Some  prefer  the  use  of  a  preparation 
composed  of  crystallized  carbolic  acid  rendered  fluid  by  a  small 
quantity  of  chloroform.  This  preparatory  treatment,  if  successful, 
is  to  be  followed  by  the  process  of  "  capping  the  pulp,"  as  described 
in  another  place.  If  it  be  the  result  of  irritation  produced  by  the 
pressure  of  a  filling,  the  plug  should  be  immediately  removed,  leeches 
applied  to  the  gum  of  the  affected  tooth,  and,  if  the  patient  be  of  a 
full  habit,  blood  may  be  taken  from  the  arm,  and  a  brisk  saline 
purgative  prescribed.  The  removal  of  the  filling,  however,  when 
the  inflammation  has  previously  made  much  progress,  will  not  pre- 
vent suppuration,  but  it  may  keep  it  from  extending  to  every  part 
of  the  pulp.  When  an  external  opening  is  made  for  the  escape  of 
the  matter,  the  moment  suppuration  takes  place  the  remaining  por- 
tion of  the  pulp  will  be  relieved  from  the  pressure  which  caused  the 
irritation,  and  then  the  inflammatory  action  may  cease.  But  if 
the  matter  remains  in  the  central  cavity  of  the  tooth,  the  part  of  the 
pulp  which  has  not  suppurated  will  still  be  subjected  to  pressure,  and 
the  inflammation  and  suppuration  will  go  on  until  the  entire  organ 
perishes.  Nor  will  the  disorganizing  process  stop  here.  The  peri- 
dental membrane  at  the  extremity  of  the  root  will  soon  become  impli- 
cated, and  in  a  short  time  alveolar  abscess  will  form',  thus  terminating 
the  acute  stage  of  the  disease. 

There  may  be  no  indication  of  irritation  or  inflammation  for  several 
weeks,  or  even  months,  after  a  tooth  has  been  filled  ;  but  at  the  ex- 
piration of  this  time  the  pulp,  from  increased  irritability,  caused 
perhaps  by  some  change  in  the  state  of  the  patient's  general  health, 
may  be  attacked  by  inflammation.  Although  this  very  seldom  happens, 
it  does,  nevertheless,  sometimes  occur.  When  there  is  reason  to  appre- 
hend that  it  is  about  to  take  place — and  it  may  be  suspected  if  pain  is 
felt  in  the  tooth  when  anything  hot  or  cold  is  taken  into  the  mouth, 
or  if  it  becomes  the  seat  of  gnawing  or  gradually  increasing  pain — the 
filling  should  be  removed.  If  the  pain  now  ceases,  a  thick  layer  of 
gutta-percha  dissolved  in  chloroform,  or  Hill's  stopping,  or  oxychlo- 
rid  or  oxyphosphate  of  zinc  preparation,  may  be  placed  in  the  bottom 
of  the  cavity  and  the  filling  replaced  ;  using  the  precaution,  as  before 
directed,  to  introduce  the  gold  in  such  a  way  as  to  prevent  the  liability 
of  depressing  the  floor  of  the  cavity ;  or  a  temporary  filling  of  some 
plastic,  non-irritating  substance,  such  as  Hill's  stopping  or  chloro- 
percha,  may  be  inserted  and  permitted  to  remain  for  some  time,  when 
a  more  durable  filling  may  be  introduced.  But  if  the  pain  and  inflam- 
mation continue  unabated,  and  the  application  of  such  escharotics  as 


240  DENTAL   PATHOLOGY,    THERAPEUTICS. 

carbolic  acid,  chlorid  of  zinc,  nitrate  of  silver,  and  chromic  acid, 
fails  to  reduce  the  congestion,  it  may  be  necessary  to  expose  the  puip 
and  destroy  its  vitality.  When  this  is  done  it  is  usually  with  the  view 
of  securing  the  retention  and  preservation  of  the  tooth  by  filling  the 
pulp-cavity  and  root. 

It  is  not  advisable  to  attempt  to  preserve  the  vitality  of  the  pulp 
when  it  is  affected  with  the  diffuse  form  of  pulpitis.  The  pulp  in 
such  cases  should  be  completely  extirpated  and  the  pulp-canal  be 
thoroughly  disinfected  and  filled.  A  purulent  condition  of  the  pulp 
is  evident  when  pus  oozes  from  the  pulp-chamber  as  soon  as  it  is 
opened,  and  relief  from  pain  ensues  almost  instantly.  The  treatment 
of  such  cases  consists  in  removing  the  putrescent  pulp  and  disinfect- 
ing and  filling  the  pulp-canal. 

Chronic  inflammation  of  the  dental  pulp  often  occurs  where  the 
pulp-chamber  of  a  tooth  has  become  gradually  exposed  by  caries  of  the 
dentine  ;  and  when  this  happens  the  action  of  the  fluids  of  the  mouth, 
and  of  other  foreign  substances  which  obtain  access  to  the  cavity,  as 
well  as  of  the  decomposed  portions  of  the  tooth-substance,  causes  an 
increase  of  vascular  action  in  the  exposed  part,  followed  very  often  by 
a  slight  discharge ;  but  the  morbid  action  thus  induced  is  compara- 
tively seldom  accompanied  by  pain.  The  pulp  may  remain  thus  par- 
tially exposed  for  months,  and  even  years,  without  causing  any  other 
inconvenience  than  a  momentary  twinge  of  pain  when  some  hard  sub- 
stance is  accidentally  introduced  into  the  cavity  of  the  tooth,  which 
subsides  immediately  after  its  removal.  Sooner  or  later,  however,  the 
pain  thus  excited  will  become  more  permanent,  continuing  each  time 
it  occurs  from  five  to  ten  minutes  to  one  or  more  hours  after  the  cause 
of  the  irritation  has  been  removed.  If  a  tooth  be  filled  under  such 
circumstances,  the  pressure  of  the  fluid  upon  the  pulp,  which  is  poured 
out  from  its  exposed  surface  beneath  the  filling,  will  give  rise  to  a  more 
general  and  active  form  of  inflammatory  action.  Pain,  too,  is  often 
experienced  before  actual  exposure  of  the  pulp  occurs. 

The  liability  of  the  tooth  to  ache  increases  as  the  pulp  becomes  more 
and  more  exposed  by  the  gradual  decomposition  of  the  dentine  ;  and 
the  inflammation  may  ultimately  assume  a  more  active  form,  when  the 
pain  becomes  very  acute,  owing  to  the  consequent  effusion  into  tissue 
surrounded  by  unyielding  walls,  or  the  pulp  may  become  the  seat  of 
fungous  growth,  or  it  may  be  absorbed  or  destroyed  by  ulceration,  or 
by  gangrene  and  mortification.  Cases  sometimes  occur  in  which  the 
disease  is  attended  with  severe  darting  pains,  often  occurring  several 
times  in  the  space  of  two  or  three  minutes,  succeeded  by  intervals  of 
perfect  ease  for  many  hours.  At  other  times  it  is  attended  by  dull, 
aching  pains,  aggravated  by  taking  sweet  or  acid  substances  into  the 


INFLAMMATION    OF   THE   PULP — PULPITIS.  241 

mouth.  In  cases  of  this  sort  the  application  of  heating  or  stimulating 
substances  to  the  exposed  surface  of  the  pulp  will  usually  procure  relief. 
Permanent  exemption  from  pain,  however,  is  not  always  obtained,  and 
sooner  or  later  it  may  become  necessary  either  to  destroy  the  pulp  or 
to  extract  the  tooth.  In  some  cases,  however,  where  the  pulp  becomes 
exposed  by  the  action  of  caries,  no  pain  is  experienced  except  by  con- 
tact of  foreign  substances  with  the  exposed  surface. 

The  body  of  the  pulp,  when  the  organ  becomes  exposed  from  a 
decayed  opening  in  the  grinding  surface  of  a  molar,  is  sometimes 
absorbed,  while  its  prolongations  in  the  roots  often  remain  unchanged 
for  two  or  more  years. 

Long  exposure  of  the  pulp  is  usually  attended  with  ulceration — a  dis- 
organizing process,  which  often  causes  the  destruction  of  a  large  por- 
tion of  the  part  occupying  the  central  chamber  of  the  crown  of  the 
tooth,  making  in  it  numerous  little  excavations.  The  ulcerated  surface 
usually  presents  a  yellowish  appearance,  that  of  an  irritable  ulcer,  with 
the  exudation  of  a  serous  or  sanguino-serous  fluid,  a  condition,  how- 
ever, which  must  not  be  confounded  with  a  state  of  suppuration. 
The  exuded  fluid  is  very  offensive,  as  it  rapidly  decomposes,  and  its 
reaction  is  alkaline  ;  when  the  disorganizing  process  is  arrested  before 
it  has  effected  the  destruction  of  any  very  large  portion  of  the  pulp, 
the  remaining  portion  usually  becomes  covered  with  healthy  granula- 
tions. 

When  the  inflammation  occurs  in  cachectic  individuals  it  often 
assumes  an  acute  form,  and  sometimes  terminates  in  gangrene  and 
mortification.  The  loss  of  vitality  may  be  confined  to  the  body  of 
the  pulp,  or  it  may  extend  to  every  part  of  the  organ.  In  the  former 
case  the  pain  continues,  but  in  the  latter  it  ceases  as  soon  as  mortifica- 
tion takes  place.  When  this  happens,  the  entire  pulp,  which  has  now 
a  dark-brown  or  black  color,  may  be  removed.  But  this  is  not  a  very 
common  termination. 

The  symptoms  of  chronic  as  well  as  acute  inflammation  are  always 
modified  by  the  state  of  the  general  health,  habit  of  body,  and  the 
temperament  of  the  individual.  The  pain  attending  the  former,  how- 
ever, is  periodical,  occurring  at  irregular  and  uncertain  intervals,  and 
constitutes  that  variety  of  toothache  so  often  relieved  by  local  applica- 
tions ;  whereas,  in  the  latter,  it  is  constant. 

In  chronic  inflammation,  which  implies  a  state  of  ulceration,  the 
pulp  is  either  actually  exposed  or  only  covered  by  decomposed  or 
partially  decomposed  dentine,  and  the  diseased  surface  rarely  embraces 
a  larger  circumference  than  that  described  by  the  bottom  of  the  de- 
cayed cavity.  The  inflammation,  therefore,  is  local  as  well  as  chronic, 
but,  nevertheless,  it  is  often  of  so  persistent  a  character  as  to  render 
16 


242  DENTAL    PATHOLOGY,    THERAPEUTICS. 

its  removal  exceedingly  difficult.  The  dentist,  however,  is  not  so 
much  restricted  in  the  application  of  remedies  as  in  the  treatment  of 
acute  inflammation,  and  to  the  action  of  which  it  yields  more  readily. 
But  notwithstanding  all  this,  he  will  necessarily  encounter  difficulties 
in  his  efforts  to  subdue  it.  A  greater  length  of  time  is  sometimes  re- 
quired than  the  patient  is  willing  to  give  ;  and  the  opening  through 
the  crown  to  the  central  cavity  is  frequently  too  small,  previously  to 
the  removal  of  the  partially  decomposed  dentine,  to  admit  of  the  direct 
application  of  the  necessary  remedial  agent  to  the  inflamed  surface  of 
the  pulp.  Again,  it  often  happens  that  the  situation  of  the  tooth  and 
cavity  are  such  as  to  prevent  a  complete  view  of  the  diseased  part.  It 
is  important  that  the  operator  should  get  such  a  view  to  enable  him  to 
determine  whether  the  inflamed  surface  is  ulcerated,  or  pours  out  a 
serous  fluid  ;  or  whether  the  morbid  condition  is  simply  one  of  irrita- 
tion, produced  by  the  presence  of  acrid  matter,  or  of  partially  or 
wholly  decomposed  dentine.  Unless  his  diagnosis  is  correct,  his  pre- 
scription will  be  as  likely  to  do  harm  as  good  ;  but,  having  ascertained 
the  exact  character  of  the  disease,  he  may  often  be  able  to  institute 
treatment  that  will  result  in  the  restoration  of  the  pulp  and  the  preser- 
vation of  the  tooth. 

It  is  important,  too,  to  understand  the  part  which  nature  plays  in 
the  curative  process ;  for  cure  here,  as  in  other  parts  of  the  body,  is 
effected  by  that  internal  force  which,  as  Chomel  says,  "  presides  over 
all  the  phenomena  of  life,  contends  unremittingly  with  physical  and 
chemical  laws,  receives  the  impressions  of  deleterious  agents,  reacts 
against  them,  and  effects  the  resolution  of  disease."  This  vital  force 
is  sometimes  exercised  in  the  cure  of  disease  in  the  pulp  of  a  tooth, 
but  more  frequently  in  its  prevention  ;  as  is  shown  by  the  gradual  ossi- 
fication of  the  organ  in  those  cases  where  it  would  otherwise  become 
exposed  by  mechanical  or  spontaneous  abrasion  of  the  solid  structures 
which  enclose  it ;  and  occasionally  by  the  formation  of  secondary 
dentine  upon  the  surface  of  the  original  or  primary  dentine  at  a  point 
toward  which  the  caries  is  advancing.  Nature,  no  doubt,  would 
always  provide  in  this  way  against  the  exposure  of  the  pulp,  if  the 
■jccurrence  were  always  long  enough  preceded  by  sufficient  irritation 
r  increase  of  vascular  action  in  it  to  call  her  energies  into  operation. 
ilut  the  formation  of  osteo-dentine,  which  constitutes  the  protective 
wall  of  defense,  is  a  tardy  process,  and,  as  a  general  rule,  proceeds 
more  slowly  than  the  caries  in  the  tooth,  which  causes  the  exposure  of 
the  pulp.  Besides,  it  often  happens  that  the  approach  of  the  caries  is 
not  announced  by  the  slightest  irritation,  a  condition  necessary  to  the 
new  formation  of  dentine,  until  it  reaches  the  central  cavity.  At 
other  times  the  approach  of  the  disease  gives  rise  to  too  much  irritation. 


INFLAMMATION    OF    THE    PULP PULPITIS.  243 

a  condition  equally  unfavorable  to  the  dentinification  of  the  pulp. 
Thus,  no  protective  covering  being  formed,  it  soon  becomes  exposed, 
when  it  is  subjected  to  the  action  of  such  irritating  agents  as  may 
chance  to  be  brought  into  contact  with  it.  Hence  its  liability  to 
become  the  seat  of  chronic  inflammation  as  well  as  other  forms  of 
diseased  action. 

If  the  disease  is  attended  with  pain,  the  removal  of  this  must  first 
claim  attention,  and  should  be  effected  with  as  little  delay  as  possi- 
ble ;  otherwise  the  morbid  action  may  extend  to  every  part  of  the 
pulp  and  peridental  membrane  and  assume  a  more  active  and  unman- 
ageable form.  If  the  pain  is  the  result  of  irritation  produced  by 
the  direct  action  of  mechanical  or  chemical  agents,  the  cavity  in  the 
tooth  should  at  once  be  carefully  freed  from  all  extraneous  substances 
and  decomposed  portions  of  dentine.  This  done,  a  dossil  of  raw 
cotton  or  lint — saturated  with  spirits  of  camphor,  laudanum,  sul- 
phuric ether,  chloroform,  creasote,  or  some  one  of  the  essential  oils — 
may  be  applied.  The  following  anodyne  application  has  bee« 
employed  with  advantage  to  relieve  the  pain  arising  from  congestion 
of  the  pulp  :  Cotton  saturated  with  a  solution  composed  of  alcohol. 
I  ounce ;  chloroform,  2  ounces ;  ether,  ^  ounce ;  gum  camphor,  ^ 
ounce  ;  tincture  of  opium,  j^  ounce ;  and  oil  of  cloves,  i  dram. 
When  the  pain  is  relieved  another  application,  consisting  of  carbolic 
acid  and  oil  of  cloves,  is  made  and  permitted  to  remain  for  some 
fifteen  minutes.  A  paste  composed  of  iodoform  and  glycerin  is 
also  employed  after  the  active  symptoms  of  congestion  have  subsided. 

For  the  treatment  of  wounded  and  irritated  pulps  the  tincture  of 
calendula  proves  a  very  useful  remedy.  Such  agents  as  glycerole 
of  thymol,  carvacrol,  oil  of  eucalyptus,  tannic  acid,  lead  water,  mor- 
phine, creasote,  chloral,  and  tincture  of  aconite  have  also  been  found 
serviceable  in  the  treatment  of  inflamed  conditions  of  the  pulp. 

When  the  irritation  is  produced  by  acidulated  buccal  fluids,  the 
application  of  carbonate  of  soda,  or  some  other  alkali — tepid  water 
containing  sufficient  carbonate  of  soda  to  make  it  slightly  alkaline 
— will  often  give  immediate  temporary  relief;  but  as  the  condition 
of  the  secretions  of  the  mouth,  especially  the  salivary,  is  usually  acid, 
owing  to  gastric  derangement,  the  correction  of  this  constitutes  the 
first  and  most  important  remedial  indication.  When  any  application 
is  made  to  the  pulp  for  the  purpose  of  removing  irritation  and  pain,, 
its  full  effect  will  not  be  obtained  unless  the  fluids  of  the  mouth  are 
excluded  from  the  cavity  of  the  tooth;  this  may  be  done  by  closing 
the  orifice  with  softened  wax,  or  cotton  saturated  with  the  sandarach 
solution,  using  the  precaution  not  to  force  it  so  far  as  to  press  the 
application  previously  made  upon  the  exposed  pulp. 


244  DENTAL    PATHOLOGY,    THERAPEUTICS. 

Suppuration  of  the  Pulp. — Independent  of  the  condition  known  as 
alveolar  abscess,  the  pulp  of  a  tooth  is  liable  to  suppuration  when 
exposed  for  a  considerable  time,  by  the  formation  of  either  an  abscess 
within  its  substance,  or,  more  frequently,  by  a  superficial  suppression 
on  its  surface. 

In  such  cases,  layer  after  layer  of  the  substance  of  the  organ  is 
destroyed  at  the  point  of  exposure,  and  inflammatory  elements  or 
products  take  their  places.  The  layer  of  odontoblasts  is  disorgan- 
ized as  a  result  of  superficial  inflammation,  and  becomes  a  mass  of 
sanious  pus  filled  with  micro-organisms.  Deep  pockets  are  formed 
in  the  substance  of  the  pulp  by  the  suppurative  process,  and  a  sec- 
tion of  the  organ  is  progressively  destroyed  from  the  exposed  sur- 
face in  the  direction  of  the  root.  This  progressive  suppuration  and 
destruction  may  continue  until  a  small  portion  only  remains  in  the 
apical  portion  of  the  root-canal,  or  the  entire  organ  is  destroyed. 
Many  histologists  are  disposed  to  question  the  theory  that  the  dental 
pulp  ever  recovers  after  suppuration  is  once  established  in  it,  while 
some  contend  that  cicatrization  and  ability  to  perform  its  functions 
are  possible  after  such  attacks. 

Suppuration  of  the  pulp  generally  commences  in  the  form  of 
small  collections  of  pus  within  the  layer  of  odontoblasts  which  may 
retain  their  distinct  forms  for  some  time,  when  they  may  coalesce. 
Deeper  in  the  structure  of  the  pulp  a  large  abscess  may  undermine 
the  layer  of  odontoblasts,  and  if  the  pus  generated  under  such  cir- 
cumstances is  greater  in  quantity  than  the  cavity  for  its  retention, 
compression  and  strangulation  of  the  pulp  result,  causing  the  de- 
struction of  the  organ.  The  pain  accompanying  abscess  of  the  pulp 
generally  commences  with  a  slight  gnawing  sensation,  which  per- 
sistently increases  in  severity  until  it  becomes  very  excruciating. 
When  decomposition  of  the  entire  pulp  occurs,  gas  is  generated, 
which,  by  its  pressure,  gives  rise  to  severe  pain,  and  the  trouble  is 
only  relieved  by  a  vent  being  made  for  the  escape  of  the  gas  and 
secretion.  It  is  seldom,  however,  that  gas  is  formed  within  the  liv- 
ing pulp,  although  there  are  cases  sometimes  met  with  where  gas  is 
generated  in  a  closed  jnilp-cavity  during  the  progress  of  the  suppu- 
ration in  the  pulp.  A  small  amount  of  pus  in  a  pulp-chamber  may 
undergo  absorption,  for  even  fatty  degeneration,  but  such  cases  are 
rare. 

The  causes  of  putrescent  pulps  may  be  enumerated  as  follows : 
Mechanical  violence,  such  as  blows;  the  careless  regulating  of  teeth  ; 
the  rapid  separation  of  teeth  by  wedges,  screws,  etc.,  or  separation  by 
any  method  when  the  condition  of  the  system  contraindicates  such  an 
operation  ;  thermal  influence  through  a  metallic  filling,  and  especially 


INFLAMMATION    OF   THE    PULP — PULPITIS.  245 

in  the  case  of  young  teeth  ;  exposure  of  the  pulp  to  irritating  agents. 
A  dead  pulp  may  remain  quiet  for  months,  or  even  years,  and  if  not 
exposed  by  caries,  even  for  many  years,  but  the  action  of  the  atmos- 
phere may  in  a  very  short  time  cause  inflammation  of  the  peridental 
membrane  ;  hence  it  is  often  a  question  whether  teeth  in  which  dead 
pulps  are  quiescent  should  be  interfered  with.  But  as  all  such  teeth 
are  liable  to  cause  periodontitis  and  alveolar  abscess,  the  treatment  of 
such  cases,  where  no  exposure  exists,  is  to  make  an  opening  wqth  a  drill 
into  the  pulp-chamber,  the  entrance  of  the  instrument  being  easily 
recognized  by  its  sudden  opening  into  such  a  space. 

When  this  is  effected,  an  antiseptic  agent,  such  as  oil  of  eucalyptus, 
iodoform  in  the  form  of  an  ethereal  saturated  solution,  or  permangan- 
ate of  potash,  etc.,  etc.,  should  be  introduced  into  the  pulp-cavity, 
taking  care  to  leave  a  vent  through  the  temporary  filling  which  is  to 
confine  the  antiseptic  agent.  The  remains  of  the  devitalized  pulp 
should  be  removed  at  a  second  sitting  by  means  of  a  barbed  broach, 
and  the  pulp-canal  thoroughly  disinfected.  Such  treatment  should  be 
continued  until  all  odor  of  decomposition  has  disappeared,  and  the 
cavity  will  permit  of  being  closed  tightly  without  trouble  ensuing. 
The  antiseptic  agent  must  be  thoroughly  applied,  so  that  it  may  pass 
into  every  part  of  the  pulp-cavity  and  the  dentinal  tubes.  It  should 
be  remembered  that  the  product  of  decomposition,  which  is  princi- 
pally sulphuretted  hydrogen  exhibited  in  the  form  of  gas,  is  not  only 
rapidly  developed,  but  exerts  great  pressure  in  the  apical  space  ;  hence 
the  roots  of  a  tooth  thus  affected  should  not  be  filled  until  there  is 
every  reason  for  believing  that  the  decomposition  has  been  overcome. 
It  may  be  necessary  in  these  cases  to  continue  the  disinfectant  and 
antiseptic  treatment  for  several  weeks  before  filling  the  pulp-cavity, 
although  immediate  root-filling,  even  in  such  cases,  has  its  advocates. 

Atrophy,  or  Degeneration  of  Structure. — This  condition  may  result 
from  a  low  degree  of  inflammation  of  the  pulp  when  long  continued, 
which  has  the  effect  of  so  reducing  its  volume  that  it  presents  a 
shriveled  appearance,  and  to  which  the  term  "mummified  "  has  been 
applied. 

The  pulp-cavity  in  such  cases  is  entirely  free  from  any  products  of 
decomposition,  and  the  tooth  retains  its  natural  color.  This  affection 
appears  to  be  more  common  to  teeth  of  a  dense  structure,  and  has 
been  ascribed  by  writers  on  this  subject  to  a  gradual  obliteration  of 
the  tubuli  by  a  deposit  of  secondary  dentine,  which  interferes  with 
nutrition  to  such  a  degree  as  to  produce  attenuation.  The  original 
cells  of  the  tissue  disappear  and  are  changed  into  fine  fibres,  and 
areolae  are  developed  in  the  matrix,  and  the  sensibility  of  the  pulp  is 
either  greatly  diminished,  appearing  like  a  thin,  flattened  thread,  or 


«46  DENTAL   PATHOLOGY,    THERAPEUTICS. 

altogether  destroyed,  the  latter  being  the  condition  of  completely 
mummified  pulps.  Wedl  attributes  this  atrophy  to  a  withering  of  the 
reticulated  connective-tissue  cells,  together  with  the  peripheral  blood- 
vessels and  nerves.  Dental  pulps  in  such  a  condition  may  never 
become  a  source  of  irritation,  if  atmospheric  germs  are  not  admitted 
by  the  opening  of  the  root-canals,  and  the  only  treatment  required  is 
the  removal  of  the  remains  of  the  attenuated  organ  and  the  disinfec- 
tion and  filling  of  the  root-canals. 

Disorganization,  or  Gangrene. — The  disorganization  of  the  pulp  of 
a  tooth  is  generally  the  result  of  acute  pulpitis  where  micro-organisms 
gain  access  to  the  inflamed  pulp,  which  is  transformed  into  a  dark- 
brown  or  grayish  fetid  mass,  the  odor  being  due  to  the  generation  of 
putrefactive  gases.  The  accumulation  of  these  gases  in  the  pulp- 
chamber,  it  is  claimed,  has  caused  the  bursting  of  the  crown  of  the 
teeth  with  a  loud  sound.  Dry  gangrene  of  the  pulp  is  a  condition  due 
to  the  obstruction  of  the  afferent  artery,  as  by  an  embolus  or  blood- 
clot.  The  pulp  when  in  this  condition  presents  the  appearance  of  a 
grayish-white  dry  substance,  without  odor.  In  all  of  the  cases  which 
have  attracted  the  attention  of  the  author,  the  disorganization  has 
been  carried  on  so  insidiously  that  neither  the  presence  of  disease  nor 
structural  alteration  was  suspected  until  the  teeth  assumed  a  dull 
brownish  or  bluish-brown  appearance.  The  death  of  the  pulp  had  not 
been  preceded  in  any  of  these  cases  by  the  slightest  indication  of 
inflammatory  action.  It  had  apparently  resulted  from  want  of  suffi- 
cient vital  energy  to  sustain  the  nutritive  function. 

The  alveolar  cavities  of  the  affected  teeth  in  these  cases  were,  seem- 
ingly, in  a  healthy  condition — a  circumstance  which,  when  we  take 
into  consideration  that  the  parts  of  the  extremity  of  the  roots  were 
exposed  to  the  action  of  the  disorganized  remains  of  the  dental  pulps, 
may  appear  somewhat  strange.  But  this  may  have  been  owing, 
partly,  to  diminished  excitability  in  the  peridental  membrane,  and 
partly  to  the  smallness  of  the  quantity,  and  the  innocuous  character 
of  the  matter  contained  in  the  central  cavities  of  the  teeth.  The 
gums  of  that  portion  of  the  alveolar  border  occupied  by  the  affected 
teeth  had  a  pale,  grayish-purple  appearance,  but  exhibited  no  indica- 
tions of  actual  disease.  They  were  as  thin  and  their  margins  as  dis- 
tinctly festooned  here  as  in  any  other  part  of  the  mouth.  In  some 
instances,  the  teeth  had  been  in  this  condition  for  seven  or  eight 
years. 

The  remedial  indications  in  cases  of  this  kind  are  the  removal  of 
the  pulp  and  the  disinfection  and  filling  of  the  root  canals. 

Fatty  Degeneration. — This  affection  of  the  pulp,  according  to  Wedl, 
is  of  frequent  occurrence.     The  fatty  pulp  presents  a  cloudy  appear- 


INFLAMMATION    OF    THE    PULP PULPITIS.  247 

ance,  and  under  the  microscope  appears  to  be  full  of  fat-granules  in 
all  of  its  constituent  elements. 

This  condition  is  also  observed  in  deciduous  teeth  when  their  roots 
are  undergoing  the  process  of  absorption. 

Fungous  Growth. — The  pulp  of  a  tooth,  when  exposed  by  decay  of 
the  crown,  sometimes  becomes  the  seat  of  a  fungous  growth,  in  the 
form  of  a  small  vascular  tumor,  the  formation  of  which  is  caused  by 
constant  irritation.  These  morbid  growths  sometimes  attain  the  size 
of  a  large  pea,  completely  filling  the  cavity  made  in  the  crown  of  the 
tooth  by  caries ;  at  other  times  they  do  not  exceed  that  of  a  small 
elderberry.  The  former  have  little  sensibility,  and  bleed  freely  from 
the  slightest  injury;  the  latter  are  less  vascular,  but  are  nearly  as 
sensitive  as  the  pulp  in  a  healthy  state. 

It  often  happens  that  a  fungous  growth  of  the  gum  or  peridental 
membrane,  finding  its  way  through  an  opening  in  the  side  of  the  neck 
or  root  of  a  decayed  tooth,  appears  in  the  central  cavity,  and  is  some- 
times mistaken  for  a  morbid  growth  of  the  pulp.  But  the  character 
of  a  fungous  growth  or  polypus  of  the  pulp  can  be  readily  determined 
by  its  attachment  to  the  portion  of  the  organ  occupying  the  pulp- 
chamber  by  a  constricted  neck.  Such  fungous  growths  have  a  dark- 
red  color  and  a  fleshy  or  spongy  consistence.  Such  fungous  growths 
are  more  common  to  the  pulps  of  the  inferior  molar  teeth  when  caries 
has  hollowed  out  the  crowns  to  a  considerable  degree.  Such  tumors 
usually  grow  very  fast,  and  sometimes  attain  the  size  of  a  hickory  nut. 
They  are  exceedingly  vascular,  bleeding  profusely  when  wounded,  and 
are  soon  reproduced  after  removal.  The  author  has  met  with  tumors 
of  this  kind  which  had  originated  in  the  peridental  membrane  of  the 
extremity  of  the  alveolar  cavity. 

Where  there  is  a  tendency  to  fungous  growth  of  the  pulp,  the  appli- 
cation of  an  escharotic  has  proved  serviceable.  Of  these  agents 
chromic  acid  appears  to  be  very  effective. 

Another  method  is  to  apply  carbolic  acid  freely  to  the  fungous 
growth,  to  obtund  its  sensitiveness,  excise  it,  and  then  make  an  appli- 
cation of  nitric  acid  on  a  disc  of  card-board.  A  method  of  treating 
such  a  fungous  growth  is  described  by  Dr.  Maercklein  as  follows  : 
After  carefully  removing  all  foreign  substances  and  carefully  drying 
the  cavity,  apply  the  tincture  of  iodin  with  a  pledget  of  absorbent 
cotton  or  bibulous  paper  until  the  entire  growth  is  covered  with  tne 
iodin  ;  after  which  seal  the  cavity  in  the  usual  manner.  This  should 
be  repeated  every  twenty-four  hours  until  it  has  been  completely  de- 
stroyed. If  the  fungous  growth  should  fill  the  entire  cavity,  take 
small  pledgets  of  the  paper  or  cotton  saturated  with  the  iodin  and 


248 


DENTAL    PATHOLOGY,    THERAPEUTICS. 


place  them  between  the  fungoid  and  the  walls  of  the  cavity  until  as 
much  pressure  has  been  made  as  is  consistent  with  the  comfort  of  the 
patient,  but  in  no  case  giving  pain.  This  dressing  is  repeated  daily 
until  sufficient  room  has  been  obtained  to  proceed  as  in  the  first  case. 


Fig.  125.— Pulp  with  Pulp  Stones.    C.  C.  Calcareous  globules.    L.  Lymph  vessel.    N.  N. 
Bundles  of  medullated  nerves  magnified  10  diameters. 


It  frequently  happens,  however,  that  teeth  with  pulps  in  this  condition 
are  too  far  gone  to  justify  their  retention. 

Calcareous  Concretions. — Calcareous  depositions  in  the  shape  of  nod- 
ules and  irregular  needles  or  spiculae  are  often  found  in  the  pulp,  and 


INFLAMMATION    OF    THE    PULP — PULPITIS. 


249 


are  ascribed  to  a  calcification  of  the  cells  or  to  a  direct  impregnation 
of  the  organic  substance  with  lime  salts.  Fig.  125  (after  Bodecker) 
represents  a  pulp  with  the  so-called  pulp-stones  imbedded  in  its  sub- 
stance. 

The  age  of  the  person  does  not  appear  to  influence  the  formation 
of  these  calcic  deposits,  as  the  teeth  of  both  young  and  old  are  sub- 
ject to  calcification.  Calcified  pulps  contain  more  fibrous  connective 
tissue  than  myxomatous  tissue,  and  Bodecker  states  that  "invariably 
around  the  calcified  masses  a  dense  layer  of  fibrous  connective  tissue 
has  formed,  ensheathing  the  calcified  masses."  "  Where  these  masses  " 
(or  pulp-stones)  "  have  fallen  out  an  empty  fibrous  sac  is  left  behind,  in 
which  there  are  neither  endothelia,  so  characteristic  of  blood-vessels,  nor 
oblong  nuclei,  which  we  see  in  the  external  perineurium  of  the 
bundles  of  medullated  nerve- 
fibres.  The  presence  of  this 
envelope  may  convey  the  idea 
(especially  if  the  calcified 
masses  are  elongated  and  ap- 
pear like  small,  lobulated  sau- 
sages) that  an  obliteration 
has  first  occurred  in  the 
blood-vessels  by  a  process 
which  in  other  vascular  sys- 
tems, mainly  that  of  the 
lungs,  is  known  as  '  fatty 
embolism.'  "  Dr.  Bodecker 
also  ascribes  the  primary 
cause  of  calcification  in  an 
unerupted  wisdom  tooth  to 
be  embolism  of  micrococci 
of  an  unknown  nature  in  the 
arteries  and  capillaries  which 
did  not  cause  pulpitis. 
Others  ascribe  the  deposit  of 
lime-salts  to  the  plasma  of  the  blood  laden  with  such  salts  accumu- 
lating in  the  capillaries  of  the  pulp  and  unable  to  escape.  Fig.  126 
represents  calcification  in  the  pulp  of  a  first  lower  molar  of  a  healthy 
young  man  eighteen  years  of  age. 

Ossification. — Allusion  has  been  made  several  times,  in  the  course 
of  this  work,  to  the  ossification  of  the  dental  pulp  as  a  means  em- 
ployed by  nature  to  prevent  the  exposure  of  this  most  delicate  and 
exquisitely  sensitive  structure.  But  examples  of  it  are  occasionally 
met  with  in   teeth  which  have  suffered  no  loss  of  substance,  either 


Fig.  126.— Calcification. 
C.  Calcified  masses  of  irregular  lumps,  probably 
former  medullary  corpuscles.  M.  Medullary 
corpuscles  unchanged.  P.  Central  plastid,  free 
from  infiltration.  F.  Capsule  of  fibrous  con- 
nective tissue.     Magnified  300  diameters. 


250  DENTAL    PATHOLOGY,    THERAPEUTICS. 

from  mechanical  abrasion  or  from  the  decay  of  the  dentine.  The 
occurrence,  whatever  may  be  the  circumstances  under  which  it  takes 
place,  is  evidently  the  result  of  the  operation  of  an  established  law  of 
the  economy,  dependent  upon  moderate  irritation  and  a  slight  in- 
crease of  vascular  action ;  ossification  having  commenced,  it  usually 
goes  on  until  every  part  of  the  pulp  is  converted  into  a  substance 
analogous  to  cementum.  We  infer,  then,  that  when  the  pulp  of  a 
tooth  becomes  the  seat  of  a  sufficient  amount  of  irritation,  ossifica- 
tion must  follow  as  a  necessary  consequence;  but  if  the  irritation  be 
succeeded  by  active  inflammation,  a  different  result  may  be  expected. 

The  irritation  necessary  for  the  ossification  of  the  pulp  of  a  tooth 
sometimes  arises  from  constitutional  causes  ;  but  in  the  majority  of 
cases  it  results  from  the  action  of  local  irritants,  and  most  frequently 
from  impressions  of  heat  and  cold,  communicated  through  the  me- 
dium of  a  metallic  filling  or  a  thin  layer  of  dentine. 

During  the  ossification,  a  sensation  is  occasionally  experienced  in 
the  tooth  somewhat  similar,  though  altogether  less  in  degree,  to  that 
which  attends  the  knitting  of  the  fractured  extremities  of  a  broken 
bone.  A  numb,  vibratory  pain",  barely  perceptible,  is  first  felt  pass- 
ing through  the  tooth  several  times  a  day,  but  only  lasting  a  second 
or  two  at  a  time.  It  is  often  scarcely  sufficient  to  occasion  any  an- 
noyance, or  to  attract  anything  more  than  momentary  attention. 

As  the  ossified  deposit  increases  in  size,  pain  of  a  neuralgic  char- 
acter may  ensue,  and  similar  to  the  sensation  which  results  from  the 
knitting  together  of  the  fractured  extremities  of  a  bone,  but  not  con- 
stantly severe.  At  times,  however,  the  pain  becomes  sharp  and 
darting,  affecting  the  side  of  the  face  and  head.  The  treatment 
consists  in  the  application  of  an  anodyne,  such  as  lead  water,  about 
the  affected  root  and  the  opening  of  the  pulp-chamber,  in  order  to 
remove  the  affected  pulp,  which  should  be  completely  extirpated  and 
the  root-canals  filled. 

With  the  ossification  of  the  pulp,  the  crown  and  inner  walls  of  the 
root  lose  their  vitality,  but  the  appearance  of  the  tooth  is  not,  as 
in  the  case  of  necrosis  arising  from  the  disorganization  of  the  pulp, 
materially  affected.  The  central  cavity  being  filled  with  semi-trans- 
lucent osteo-dentine,  the  crown  retains  its  natural  color.  The  dis- 
coloration and  opacity  attending  necrosis  produced  by  other  causes 
result  partly  from  the  presence  of  putrid  matter  in  the  pulp-cavity, 
and  partly  from  its  absorption  by  the  surrounding  dentinal  wall. 

Odotitalgia. — Pain   in  a  tooth,  toothache,  or  odontalgia,'^  as  it   is 


*  So  much  has  been  said  upon  this  subject  in  the  consideration  of  the  different 
forms  of  inflammation  of  the  pulp  in  the  preceding  pages,  that  but  Httle  remains  to 
be  noticed. 


INFLAMMATION    OF    THE    PULP — PULPITIS.  25  I 

technically  termed,  is  a  symptom  of  some  functional  or  structural  dis- 
turbance, either  of  the  organ  in  which  the  pain  is  seated,  or  of  some 
other  part  or  parts  of  the  body,  but  more  frequently  of  the  former 
than  of  the  latter.  So  variable  is  the  character  of  the  sensation,  that 
any  description  would  fail  to  convey  to  one  who  has  never  experienced 
it  a  correct  idea  of  its  nature.  The  pain  sometimes  amounts  only  to 
slight  uneasiness  ;  at  other  times  the  agony  is  almost  insupportable. 
It  may  be  dull,  deep-seated,  boring,  throbbing,  or  lancinating.  It 
may  be  slight  at  first,  gradually  increasing  in  severity  until  it  amounts 
to  the  most  excruciating  torture,  or  it  may  come  on  without  any  pre- 
monition whatever.  It  may  be  confined  to  a  single  tooth,  or  it  may 
affect  several  at  the  same  time.  It  may  commence  in  one  tooth  and 
pass  from  thence  to  another,  and  continue  until  every  one  in  turn  has 
been  attacked.  It  may  continue  for  hours  and  days  with  scarcely  any 
cessation  ;  or  it  may  be  intermittent,  the  paroxysms  recurring  at  stated 
or  irregular  intervals,  and  each  lasting  from  thirty  minutes  to  one, 
two,  or  more  hours. 

The  causes  of  odontalgia  are  almost  as  numerous  as  are  the  varieties 
of  character  which  it  exhibits.  Irritation  and  inflammation  of  the 
pulp,  and  inflammation  of  the  investing  membrane,  are  among  the 
most  frequent ;  but  it  is  sometimes  referable  to  a  morbid  condition  of 
the  nerve  or  nerves  going  to  a  single  tooth,  or  of  the  trunk  from 
which  several  teeth  are  supplied  ;  also  to  derangement  of  the  digestive 
organs,  to  increased  nervous  susceptibility  of  the  uterus  resulting  from 
pregnancy,  amenorrhea,  etc.,  and  to  certain  diatheses  of  the  general 
system. 

Inflammation  of  the  peridental  membrane  and  pulp  may  be  pro- 
duced by  a  blow  upon  a  tooth,  or  by  powerful  impressions  of  heat  and 
cold  communicated  through  the  enamel  and  dentine,  or  through  a 
metallic  filling ;  but  it  is  more  frequently  occasioned  by  pressure,  or 
by  the  direct  contact  of  irritating  agents,  such  as  carious  portions  of 
the  tooth,  particles  of  food,  acrid  humors,  and  other  irritating  external 
substances.  But  inflammation  is  not  always  a  necessary  consequence 
of  such  impressions.  Pain  may  be  produced  by  them  when  inflam- 
mation does  not  exist ;  in  this  case  it  usually  subsides  soon  after  the 
removal  of  the  irritant.  Indeed,  the  pulp  of  a  tooth  may  be  exposed 
for  months,  and  subjected  .several  times  every  day  to  the  contact  of 
foreign  substances,  without  becoming  the  seat  of  inflammatory  action  ; 
and  in  the  absence  of  this,  the  pain,  though  coming  on  with  the  sud- 
denness of  an  electric  flash,  and  often  of  the  most  excruciating  kind, 
is  seldom  of  long  duration. 

But  when  inflammation  exists,  the  pain,  which  at  first  amounts  only 
to  a  slight  gnawing  sensation,   is  more  constant ;  after   a   while   it 


252  DENTAL    PATHOLOGY,    THERAPEUTICS. 

assumes  a  throbbing  character,  and  if  not  promptly  arrested  it  in- 
creases in  severity  and  continues  until  suppuration  of  the  lining  mem- 
brane and  pulp  takes  place.  So  long  as  it  is  confined  to  the  parts 
within  the  pulp-cavity  the  pain  is  not  increased  by  pressure  on  the 
tooth,  nor  is  the  tooth  started  from  the  socket,  as  in  periodontitis. 
The  locality  of  the  inflammation  may  also  be  distinguished  by  the 
fact  that  cold  water  or  ice  applied  to  the  tooth  generally  gives  relief. 
But  the  inflammation  rarely  confines  itself  long  to  the  interior  of  the 
tooth  ;  it  usually  soon  extends  to  the  peridental  membrane  of  the  root 
and  its  cavity,  when  a  somewhat  different  train  of  phenomena  are 
developed.  Suppuration,  however,  having  taken  place,  an  abscess 
soon  forms  at  the  extremity  of  the  root. 

The  severity  of  the  pain  attending /^/^///j  is  doubtless  owing  to  the 
fact  that  this  exceedingly  sensitive  structure,  as  its  vessels  become  in- 
jected, is  prevented  from  expanding  by  the  unyielding  nature  of  the 
walls  of  the  cavity  in  which  it  is  situated.  Its  capillaries  being  thus 
distended,  must,  as  a  necessary  consequence,  press  upon  the  nerves 
which  are  everywhere  distributed  through  it,  and  the  excruciating 
painful,  throbbing  sensation,  by  which  this  variety  of  odontalgia  is 
characterized,  is  produced  by  the  pulsation  of  these  vessels.  Hence, 
increased  action  of  the  heart  and  arteries,  from  whatever  cause  pro- 
duced, augments  the  pain  ;  it  is  also  more  severe  at  night,  while  the 
body  is  in  a  recumbent  posture,  than  during  the  day,  because  this 
position  gives  an  increased  fullness  to  the  arteries  of  the  head.  The 
phenomena  attending  the  inflammation,  however,  are  influenced  very 
much  by  the  condition  of  the  tooth  and  the  habit  of  body  of  the 
patient. 

When  the  inflammation  is  acute  it  extends  to  every  part  of  the  pulp 
and  lining  membrane.  It  also  occurs  more  frequently  before  than 
after  these  tissues  have  become  exposed,  and  generally  terminates  in 
suppuration.  Chronic  inflammation  usually  arises  from  partial  expos- 
ure of  the  pulp,  and  may  exist  for  months  without  being  attended 
with  pain  ;  but  the  pulp,  when  thus  aff"ected,  is  more  susceptible  to 
injury  by  heat  or  cold  and  by  irritating  substances ;  and  the  liability 
of  the  tooth  to  ache,  especially  at  night,  is  greatly  increased. 

Odontalgia,  caused  by  acute  inflammation  of  the  investing  mem- 
brane, is  characterized  by  pain,  at  first  dull,  afterward  acute  and 
throbbing,  soreness  and  elongation  of  the  tooth,  redness  and  tumefac- 
tion of  the  gums,  and  sometimes  by  swelling  of  the  cheek  ;  indicating 
the  formation  of  alveolar  abscess.  In  this  variety  of  odontalgia  the 
tooth  is  often  so  much  raised  in  its  socket  as  to  interfere  more  or  less 
with  mastication. 

The  pain  attending  the  foregoing  pathological   conditions,  when 


INFLAMMATION    OF   THE    PULP — PULPITIS.  253 

severe  and  protracted,  is  often  accompanied  by  constipation,  headache, 
dryness  of  the  skin,  flushed  cheeks,  fullness  and  increased  rapidity  of 
pulse,  and  other  constitutional  symptoms. 

The  nervous  susceptibility  of  the  teeth  is  sometimes  so  much  in- 
creased by  organic  and  even  functional  disturbances  of  other  and 
often  remote  parts,  that  the  mere  contact  of  the  minute  nerves  of  the 
pulp  and  the  lining  membrane  against  the  wall  of  dentine  which 
encases  them  is  attended  with  severe  pain.  This  variety  of  odontalgia 
is  termed  syftipathetic,  and  is  supposed  to  be  the  result  of  the  transfer 
of  nervous  irritation,  or,  more  properly,  of  exalted  sensibility  of  the 
dental  nerves,  arising  from  a  morbid  condition  or  functional  disturb- 
ance of  some  other  part.  If  this  hypothesis  be  true,  it  is  probable 
that  with  this  heightened  nervous  excitability  there  is  a  slight  increase 
of  vascular  action  in  the  pulp,  with  a  corresponding  increase  of  size  in 
its  capillaries  ;  in  consequence  of  which,  it  is  fair  to  presume  the 
nervous  filaments  supplying  these  tissues  would  be  apt  to  respond 
painfully  to  the  undue  pressure.  Though  pain  arising  from  this  cause 
may  have  its  seat  in  sound  as  well  as  in  decayed  teeth,  it  occurs  more 
frequently  in  the  latter  than  the  former,  owing  to  the  fact  that  any 
structural  alteration  in  the  dentine  adds  to  their  already  increased 
nervous  excitability. 

Persons  of  highly  excitable  nervous  temperaments,  pregnant  females, 
and  individuals  laboring  under  derangement  of  the  digestive  organs, 
are  particularly  subject  to  this  variety  of  odontalgia.  Odontalgia 
arising  from  pathological  conditions  or  functional  disturbances  of 
other  parts  assumes  a  great  variety  of  forms.  The  pain  may  be  con- 
tinued, but  more  frequently  it  is  periodical ;  it  may  be  confined  to  a 
single  tooth,  or  it  may  attack  half  a  dozen  or  more  at  the  same  time. 
It  sometimes  also  alternates  with  the  paroxysms  of  rheumatism  or 
gout,  the  pain  in  such  cases  assuming  the  specific  character  of  these 
diseases. 

In  what  is  termed  neuralgic  odontalgia,  "  the  pain,"  says  Dr. 
Wood,  "  is  usually  of  the  acute  character;  sometimes  mild  in  the 
beginning,  gradually  increasing  in  intensity,  and  as  gradually 
declining,  but  usually  very  irregular ;  at  one  time  moderate,  at 
another  severe,  and  occasionally  darting  with  excruciating  violence 
through  the  dental  arches.  Not  unfrequently  it  assumes  a  regular 
intermittent  form.  Instead  of  pain,  strictly  speaking,  the  sensation 
is  sometimes  of  that  kind  which  is  indicated  when  we  say  that  the 
teeth  are  on  edge,  and  is  apt  to  be  excited  by  certain  harsh  sounds, 
such  as  that  produced  in  the  filing  of  a  saw,  or  by  mental  inquietude, 
and  by  the  contact  of  acids  or  other  irritant  substances.  Neuralgic 
toothache   sometimes   persists,   with   intervals   of   exemption,    for    a 


254  DENTAL    PATHOLOGY,    THERAPEUTICS. 

great  length  of  time.  The  diagnosis  is  occasionally  difficult.  When, 
however,  it  occurs  in  sound  teeth,  is  paroxysmal  in  its  character,  is 
attended  with  little  or  no  swelling  of  the  external  parts,  occupies  a 
considerable  portion  of  the  jaw,  and  especially  when  it  alternates 
or  is  associated  with  pain  of  the  same  character  in  other  parts  of 
the  face,  there  can  be  little  doubt  as  to  its  real  nature."  This  variety 
of  sympathetic  toothache  is  perhaps  induced  by  caries,  or  by  the 
manner  in  which  the  teeth  are  arranged  in  the  alveolar  arch,  or  by 
some  peculiar  susceptibility  of  the  parts;  as  is  shown  by  the  fact 
that  the  pain  usually  ceases  on  the  removal  of  all  such  causes  of 
irritation. 

But  while,  on  the  one  hand,  pain  in  the  teeth  may  be  caused  by 
a  morbid  condition  of  other  organs,  these  organs,  on  the  other  hand, 
frequently  sympathize  with  the  diseased  condition  of  the  teeth,  and 
become,  to  quote  the  language  of  Mr.  Bell,  "  the  apparent  seat  of 
pain.  I  have  seen  this  occur  not  only  in  the  face,  over  the  scalp,  in 
the  ear,  and  underneath  the  lower  jaw,  but  down  the  neck,  over  the 
shoulder,  and  along  the  whole  length  of  the  arm."  Cases  of  this 
sort  are  frequently  met  with. 

Mr.  Fox  gives  a  striking  example  in  a  person  from  whom  he 
extracted  a  tooth,  which  afforded  little  or  no  relief;  in  consequence 
of  which  his  patient  applied  to  him  only  two  days  afterward  and 
requested  the  removal  of  several  adjoining  teeth,  which  were  perfectly 
sound.  This  he  objected  to,  and,  suspecting  the  real  nature  of  the 
disease,  he  immediately  took  him  to  Sir  Astley  Cooper,  who,  by 
dividing  the  affected  nerve,  produced  a  radical  cure  in  a  few  days. 
The  author  is  acquainted  with  a  gentleman  similarly  affected.  He 
has  had  all  his  teeth  on  the  right  side  of  both  jaws  extracted  without 
obtaining  any  relief. 

There  is  still  another  cause  of  odontalgia  which  we  should  not  omit 
to  mention — hypercementosis  ;  but  from  the  obscurity  of  the  diag- 
nosis, the  existence  of  the  affection  can  seldom  be  determined  with 
positive  certainty,  except  by  the  removal  of  the  tooth.  In  the  early 
stage  of  hypercementosis,  when  the  trouble  is  thought  to  be  in  a 
tooth,  the  only  method  of  relief  is  to  open  the  pulp-chamber,  devitalize 
and  remove  the  pulp,  and  fill  the  root-canals. 

Finally,  some  teeth,  from  peculiar  constitutional  idiosyncrasy,  are 
more  liable  to  odontalgia  than  others.  It  sometimes  happens  that 
every  tooth  in  the  mouth  is  destroyed  by  caries  without  being  affected 
with  pain,  while  at  other  times  teeth  apparently  sound  become  the 
seat  of  the  most  agonizing  torture. 

The  first  thing  to  be  attended  to  in  the  treatment  of  odontalgia  is 
the  removal  of  the  causes  which  have  given  rise  to  it  ;    this  can  only 


INFLAMMATION    OF    THE    PULP — PULPITIS.  255 

bt  done  by  carrying  out  the  curative  and  remedial  indications  of 
the  morbid  conditions  and  functional  disturbances  with  which  it  is 
connected.  While  these  continue,  it  will  be  impossible  to  obtain 
permanent  relief.  The  sensibility  of  the  nerves  supplying  a  tooth 
may  often  be  obtunded  and  the  pain  palliated  by  the  application 
of  stimulating  and  anodyne  agents  to  the  exposed  pulp,  but  the  relief 
thus  procured  is  seldom  of  long  duration.  When  their  effects  subside, 
the  pain  usually  returns  with  increased  severity.  When  the  pain 
arises  from  chronic  inflammation  and  irritation,  produced  by  external 
agents  on  an  exposed  portion  of  the  lining  membrane,  such  applica- 
tions may  often  be  employed  with  great  advantage ;  and  among  those 
which  have  been  used  for  this  purpose  are  creasote,  the  oil  of  cloves, 
cinnamon,  laudanum,  spirits  of  camphor,  tannin,  ether,  chloroform, 
etc.  But  of  all  the  remedies  prescribed  by  the  author  he  has  found 
none  more  useful  in  allaying  the  pain  than  the  following  :  — 

R.   Sulphuric  ether,    ....  Jj, 

Creasote,        3  ss. 

•   Ext.  of  nutgalls,  .    .    .    .  3J. 

Powdered  camph.,   .    .    .  ^ss. 


B .   Sulphuric  ether,   .    .    . 

•  .5J- 

Powdered  camphor, 

■  3iJ- 

Powdered  alum,    .    .    . 

•  3iJ- 

Sulphate  of  morphine, 

■  gr-  ij- 

The  alum  should  be  very 

finely  pc 

fore  use. 

R .  Chloroform, 

Tinct.  opii,    .    .  aa  .    . 

•  3'J- 

Tinct.  benzoin,     .    .    . 

•  S^iij- 

R.  Chloral, 

Camphor,  .    .    .  aa  .    .    .  3J. 

M.  Morphine, gi".  ij- 

Oil  of  peppermint,    .    .    .  3  ij.     M. 

After  removing  all  foreign  matter  and  carefully  drying  the  cavity 
of  the  tooth,  a  small  bit  of  cotton  or  lint  dipped  in  either  of  the  above 
mixtures  may  be  applied,  and  renewed  several  times  a  day,  if  neces- 
sary. The  relief  obtained  is,  in  the  majority  of  cases,  almost  instanta- 
neous ;  but  as  the  effect  is  only  temporary,  the  pain  is  apt  to  recur. 
The  author  has  sometimes  used  a  solution  of  gutta-percha  in  chloro- 
form (chloro-percha).  The  application  of  a  drop  or  two  of  this  to  the 
exposed  pulp  is  usually  followed  by  the  immediate  cessation  of  pain, 
and  as  the  chloroform  evaporates,  a  thin  layer  of  gutta-percha  remains, 
and  serves  for  a  time  as  a  sort  of  protection  to  the  pulp. 

It  often  becomes  necessary  to  have  recourse  to  the  destruction  of 
the  pulp,  in  order  to  preserve  the  tooth  and  restore  its  usefulness. 
This  may  be  effected  either  by  immediate  extirpation  with  a  small, 
sharp-pointed  elastic  stilet  or  probe,  by  the  actual  cautery,  arsenious 
acid,  carbolic  acid,  cobalt,  or  chlorid  of  zinc.  Immediate  extirpation, 
or  the  application  of  devitalizing  agents,  are  the  means  usually  env 
ployed  for  the  purpose. 


256  DENTAL    PATHOLOGY,    THERAPEUTICS. 

Pain  in  a  tooth  arising  from  acute  inflammation  of  the  pulp  and 
lining  membrane  can  only  be  relieved  by  the  extraction  of  the  tooth, 
the  destruction  of  the  pulp,  or  by  subduing  the  inflammatory  action ; 
the  last  can  seldom  be  done  except  by  the  most  energetic  treatment  in 
the  very  beginning,  in  cases  where  the  decay  has  not  penetrated  to  the 
pulp  cavity.  The  propriety  or  impropriety  of  extraction  will  be  deter- 
mined by  the  amount  of  pain,  the  degree  of  the  inflammation,  the 
condition  of  the  parts  with  which  the  tooth  is  immediately  con- 
nected, the  effect  of  local  disturbance  upon  the  general  system,  the 
situation  and  importance  of  the  tooth,  and  the  extent  of  structural 
alteration  which  has  taken  place  in  the  crown.  If  the  retention  of  the 
tooth,  on  account  of  its  location,  or  the  loss  of  several  other  teeth,  is 
of  great  importance  to  the  patient,  and  the  circumstances  of  the  case 
justify  a  well-grounded  belief  that  it  can  be  preserved  and  rendered 
useful  without  acting  as  a  morbid  irritant,  extraction  should  be 
avoided.  In  this  case,  supposing  the  inflammation  to  have  proceeded 
too  far  to  be  arrested,  the  pulp  may  be  destroyed  and  the  tooth  treated 
in  the  manner  described  in  another  chapter. 

When  the  inflammation  is  produced  by  other  causes  than  exposure 
of  the  pulp  and  the  contact  of  external  irritants,  it  may  perhaps  be 
successfully  combated.  The  treatment  is  similar  to  that  for  local  in- 
flammation in  other  parts  of  the  body ;  the  administration  of  saline 
cathartics,  the  application  of  leeches  to  the  gum  of  the  affected  tooth, 
abstinence  from  animal  food  and  stimulating  drinks.  If  the  pulse  is 
full  and  hard,  blood  may  be  taken  from  the  arm  with  advantage.  Dia- 
phoretics are  often  beneficial,  such  as  Dover's  Powder  or  Spirit  of 
Mindererus.  Bromid  of  potassium,  in  doses  of  gr.  v  to  gr.  xl,  with  a 
mustard  plaster  to  the  back  of  the  neck  and  a  hot  foot-bath,  together 
with  the  local  treatment  for  pulpitis,  before  described,  will  often  be 
found  efficacious.  Should  these  means  fail  to  arrest  the  inflammation, 
and  suppuration  take  place,  the  formation  of  alveolar  abscess  may 
be  prevented  by  promptly  perforating  the  crown  of  the  tooth  for  the 
escape  of  the  matter  ;  but  such  cases  usually  terminate  in  periodontitis, 
which  perhaps  arises  as  frequently  from  this  as  from  any  other  cause. 

As  the  treatment  of  periodontitis  or  inflammation  of  the  investing 
membrane  is  described  in  another  chapter,  it  is  unnecessary  to  repeat  it. 

Odontalgia  assuming  a  rheumatic  or  gouty  character,  calls  for  a 
somewhat  different  plan  of  treatment.  In  addition  to  the  local  means 
already  described,  it  may  be  necessary  to  adopt  the  constitutional 
treatment  applicable  to  rheumatism  and  gout.  When  the  pain  arises 
irom  increased  vascular  action  and  nervous  irritation  of  the  pulp, 
occasioned  by  a  disordered  condition  of  the  digestive  organs,  and 
assumes  an  intermittent  form,  an  emetic  or  cathartic,  followed  by  the 


DEVITALIZATION    AND    REMOVAL    OF    THE    PULP.  257 

use  of  quinin,  will  generally  afford  relief,  provided  caries  has  not  pene- 
trated to  the  pulp  cavity.  If  dependent  on  general  nervous  irritability 
of  the  system,  tonics,  exercise,  change  of  air,  or  such  other  constitu- 
tional measures  as  the  peculiarities  of  the  case  may  indicate,  should  be 
recommended. 

The  extraction  of  the  tooth  is  the  only  remedy  that  can  be  relied 
upon  for  relief  of  pain  arising  from  hypercementosis  when  the  formation 
of  cementum  has  attained  considerable  size.  The  internal  use  of  iodid 
of  potassium  in  the  early  stage  of  the  growth  has  been  suggested. 

DEVITALIZATION   AND    REMOVAL    OF    THE    PULP. 

With  regard  to  the  best  means  of  destroying  the  pulp  of  the  tooth, 
when  it  is  impossible  to  preserve  it,  there  exists  much  diversity  of 
opinion.  There  are  two  methods  by  which  this  may  be  accomplished, 
one  by  immediate  extirpation  yv\t\\  an  instrument  and  by  actual  cautery, 
the  other  by  the  application  of  some  devitalizing  agent,  such  as  arsenic. 

For  the  removal  of  the  pulp  by  extirpation  there  are  different  forms 
of  instruments  employed,  such  as  a  three-  or  four-sided  broach,  barbed 
for  some  distance  from  the  point,  which  is  thrust  as  far  up  the  pulp 
canal  as  is  possible,  then  rotated  and  withdrawn,  bringing  the  pulp  with 
it.  Fig.  127  represents  a  broach  of  this  kind,  which  may  be  used  with 
or  without  a  holder.  Another  form  of  broach  is  used  for  this  operation 
which  is  not  barbed,  but  thrust  into  the  pulp  for  the  purpose  of  so  lac- 
erating it  that  it  may  afterward  be  removed  with  nerve  instruments 
without  much  pain.  A  fine,  round,  steel  wire,  from  which  the  temper 
has  been  drawn,  and  having  a  flat  point  bent  on  an  angle  of  about 
forty  degrees,  is  also  used  for  extirpating  the  pulp. 

The  edge  of  the  point,  in  introducing  this  instrument,  is  pressed 
against  one  wall  of  the  canal  and  gradually  forced  up  as  far  as  it  will 
enter,  when  it  is  suddenly  turned  so  as  to  excise  the  pulp  and  on  with- 
drawing the  instrument  bring  the  severed  organ  with  it. 

Figs.  128  and  129  represent  excellent  forms  of  instruments  devised 
by  Dr.  R.  B,  Donaldson  for  cleansing  pulp-canals  and  removing  pulp. 

For  extirpating  the  pulps  of  the  molar  teeth  a  larger  instrument  is 
required,  which  is  thrust  into  the  pulp-chamber,  and  rotated  so  as  to 
sever  the  body  of  the  pulp  from  the  branches  filling  the  root  canals. 
The  small  nerve  instruments  are  then  employed  for  removing  these 
branches. 

The  operation  of  extirpation  should  depend  upon  the  temperament 
of  the  patient  and  the  condition  and  class  of  the  tooth.  Where  such 
an  operation  would  cause  a  severe  shock,  owing  to  a  nervous,  irritable 
temperament,  it  is  best  to  employ  the  therapeutical  method ;  on  the 
other  hand,  where  there  is  great  power  of  endurance,  and  the  tooth  is 
*7 


258 


DENTAL    PATHOLOGY,    THERAPEUTICS. 


of  a  frail,  chalky  consistence,  or  threatened  with  periosteal  inflamma- 
tion, it  is  preferable  to  remove  the  pulp  by  an  operation.  The  pain, 
boHrever,  can  be  greatly  mitigated  by  the  previous  application  of  some 


I^'IG.  127. 


Fig.  128. 


Fig.  129. 


Ill 


DEVITALIZATION    AND    REMOVAL   OF    THE    PULP.  259 

obtunding  agent,  such  as  sulphate  of  atropin,  aconite,  cocain,  chloro- 
form, or  other  local  anesthetics. 

In  all  cases,  and  by  whatever  method,  the  orifice  of  exposure  should 
be  large  and  nearly  on  a  line  with  the  axis  of  the  tooth,  so  as  to  admit 
of  easy  manipulation,  especially  if  the  barbed  broach  or  bent  wire  are 
employed  ;  and  when  a  pulp  is  removed  by  such  an  operation  the  wound 
usually  heals  by  first  intention,  and  no  peridental  irritation  results. 

The  late  Dr.  Harwood,  of  Boston,  who  was  strongly  opposed  to  the 
use  of  arsenious  acid  as  a  devitalizing  agent,  described  his  plan  of 
accomplishing  this  object  by  the  surgical  method,  as  follows  : — 

"I  first  effect  such  an  opening  as  will  enable  me  to  approach  the 
exposed  pulp  in  the  line  of  its  axis,  or  as  nearly  so  as  circumstances 
will  permit.  Then,  having  carefully  but  sufficiently  exposed  the  sur- 
face of  the  pulp,  I  pass  down  to  the  apex  of  the  root,  through  the 
pulp,  a  small  untempered  steel  instrument,  with  a  trocar-shaped  point, 
and  revolving  it  once  or  twice  sever  the  vessels  and  nerve.  This,  as 
any  one  knows  who  is  accustomed  to  inserting  artificial  teeth,  pro- 
duces but  a  slight  and  momentary  pain.  I  then,  by  means  of  minute 
instruments  adapted  to  the  purpose,  endeavor  to  remove  every  portion 
of  the  severed  pulp  and  lining  membrane,  and,  as  soon  as  the  hemor- 
rhage ceases,  dry  and  fill  the  cavity. 

"It  should  be  borne  in  mind  that  at  the  point  where  the  vessels  and 
nerve  in  question  enter  the  root  the  passage  is  much  smaller  than  it  is 
immediately  within.  This  strait  will  be  easily  recognized,  when 
reached,  by  the  touch,  the  instrument  appearing  to  be  arrested  by  an 
obstacle,  and  not  by  being  wedged  in  a  narrow  passage.  Care  should 
be  taken,  I  think,  that  the  instrument  is  not  allowed  to  pass  through 
the  strait,  either  by  being  too  small,  or  by  being  revolved  there  till  it 
cuts  its  way  through.  For  by  wounding  the  parts  without  the  tooth 
and  forcing  particles  of  bone  out  upon  the  parts  external  to  the  root 
the  danger  of  an  unfavorable  result  would  be  greatly  increased." 

The  actual  cautery  consists  in  thrusting  a  wire,  heated  to  a  white 
heat,  up  the  canal ;  but  as  this  is  considered  a  barbarous  method,  it  is 
not  resorted  to  by  practitioners  in  this  country.  Besides,  peridental 
inflammation  is  often  a  result  of  its  use,  and  the  pain  following  its 
application  is  sometimes  very  severe.  The  galvanic  cautery  is  prefer- 
able to  the  actual  cautery  for  the  destruction  of  pulps,  and  is  applied 
by  means  of  a  bent  platinum  wire  maintained  at  a  white  heat. 

Arsenious  acid*  has  long  been  used  in  connection  with  acetate  of 

*  The  employment  of  arsenious  acid  for  the  destruction  of  an  exposed  dental  pulp 
and  the  relief  of  the  pain  arising  therefrom  originated  with  the  late  Dr.  Spooner,  of 
Montreal  ;  and  in  1835  it  was  recommended  to  the  profession  by  his  brother,  Dr.  S. 
Spooner,  of  New  Vork,  in  an  excellent  popular  treatise  upon  the  teeth. 


26o  DENTAL   PATHOLOGY,    THERAPEUTICS. 

morphin  and  creasote,  or  carbolic  acid,  to  devitalize  the  pulp  ;  the 
arsenic  and  morphin  being  mixed  in  equal  parts  and  taken  up  on  a 
small  pellet  of  cotton  saturated  with  creasote,  which  is  introduced 
directly  upon  the  exposed  portion  of  the  pulp,  and  the  cavity  filled 
with  wax  or  cotton  saturated  with  a  solution  of  gum  sandarach  and 
alcohol.  The  morphin  was  formerly  supposed  to  modify  the  irritat- 
ing action  of  the  arsenious  acid ;  but  since  this  has  been  discovered 
not  to  be  the  case,  its  use  has  been  dispensed  with  by  many  who  prefer 
no  other  combination  than  creasote  or  carbolic  acid.  Water,  alcohol, 
and  ether  have  also  been  employed  as  substitutes  for  the  creasote. 
The  arsenious  acid  is  at  times  combined  with  an  equal  part  by  weight 
of  pulverized  charcoal,  on  account  of  the  antiseptic  properties  of  this 
latter  agent  and  also  on  account  of  its  mechanical  action  in  preventing 
the  dentine  from  absorbing  what  is  intended  for  the  pulp  alone.  A 
favorite  mixture  is  known  as  "nerve  paste;"  but  when  a  definite 
quantity  of  the  arsenious  acid  is  desired  for  application  to  a  pulp  it  is 
better  to  employ  the  dry  form.  Various  formulae  are  in  use  for  the 
preparation  of  devitalizing  mixtures,  such  as  equal  parts  by  weight  of 
arsenious  acid  and  acetate  of  morphin  ;  three  parts  by  weight  of 
arsenious  acid  to  two  parts  of  morphin  ;  two  parts  of  arsenious  acid 
and  one  part  of  morphin.  Creasote  or  carbolic  acid  is  generally 
employed  to  combine  the  ingredients  and  also  to  act  as  a  sedative. 
Although  the  thirtieth  part  of  a  grain  of  arsenious  acid  is  the  average 
quantity  generally  employed  to  devitalize  the  pulp,  yet  the  amount 
may  be  reduced  to  the  -j-J^  of  a  grain  in  many  cases  wheri  judiciously 
used.  The  length  of  time  the  preparation  should  be  allowed  to  remain 
varies  from  six  to  twenty-four  hours.  Dr.  J.  F.  Flagg  recommends  the 
following  formula :  — 

R .     Arsenious  acid, gj-  j- 

Acetate  of  morphin,       gr-  ij- 

Carbolic  acid, gtt.  iij. 

A  very  convenient  form  of  devitalizing  mixture  is  that  known  as 
"  nerve  fibres,"  which  consists  of  a  combination  of  arsenic,  creasote, 
tannin,  and  opium  incorporated  in  the  fibres  of  cotton  or  lint,  which 
is  afterward  dried  and  cut  up  into  shreds.  Dr.  James  Gordon  has 
suggested  the  following  method  of  devitalizing  pulps,  which  is  claimed 
to  be  less  painful  than  that  heretofore  employed  :  After  carefully 
cleansing  the  cavity  saturate  a  very  small  pledget  of  cotton,  held  by 
a  foil  carrier,  with  benzol,  and  then  apply  to  the  cotton  a  little  nerve 
paste,  and  place  the  whole  directly  upon  the  exposed  pulp  and  cover 
it  by  loosely  filling  the  cavity  with  cotton  saturated  with  sandarach 
varnish.     If  a  solution  of  caoutchouc  in  benzol   is  employed  to  satu- 


DEVITALIZATION    AND    REMOVAL    OF    THE    PULP.  261 

rate  the  first  pledget  of  cotton  to  which  the  nerve  paste  is  applied,  the 
preparation  will  better  retain  its  place  in  the  cavity  and  is  less  liable 
to  be  displaced  when  the  retaining  pledget  of  cotton  saturated  with 
sandarach  is  introduced. 

When  arsenious  acid  is  applied  to  temporary  teeth  the  quantity 
employed  should  be  very  minute,  and  many  are  disposed  to  question 
the  safety  of  its  application  to  such  teeth,  as  the  agent  may  be  absorbed 
by  the  very  vascular  structure  and  injure  the  surrounding  membranes. 
Not  unfrequently  cases  are  met  with  where  repeated  applications  of  the 
preparation  fail  to  destroy  the  vitality  of  the  pulp,  which  is  doubtless 
owing,  in  cases  where  the  organ  is  fairly  exposed,  to  its  inflamed  con- 
dition at  the  time  the  application  is  made,  which  enables  it  to  resist  the 
absorbent  action  of  the  arsenic.  In  such  cases  a  preparation  composed 
of  tannin  and  creasote  has  proved  serviceable. 

Arsenic  when  applied  to  a  pulp  excites  inflammation,  and  as  this 
condition  passes  off  the  agent  is  absorbed  and  devitalization  follows. 
Too  great  a  quantity  of  arsenic  will  defeat  the  object,  and  in  many 
cases  its  devitalizing  action  is  prevented  by  the  high  degree  of  inflam- 
mation present,  so  that  it  is  necessary  to  reduce  the  inflammatory  con- 
dition before  a  successful  application  of  the  devitalizing  agent  can  be 
made. 

The  time  the  arsenious  acid  is  permitted  to  remain  in  the  tooth  is 
important,  and  should  be  determined  by  the  condition  of  the  pulp, 
the  class  of  tooth,  the  structure  of  the  tooth,  the  age  of  the  patient, 
and  the  susceptibility  to  the  influence  of  the  agent.  The  time  neces- 
sary for  the  action  of  arsenious  acid  varies  from  six  to  twelve  and  in 
some  cases  twenty-four  hours,  when  minute  quantities  are  employed. 

As  the  degree  of  inflammation  excited  by  the  arsenic  depends  upon 
the  quantity  of  the  agent  employed,  it  is  much  the  safer  and  better 
plan  to  apply  small  quantities  than  an  amount  which  will  devitalize 
the  pulp  by  one  application  ;  for  in  the  latter  case  there  is  danger 
of  the  effects  being  carried  to  the  peridental  membrane  through  the 
apical  foramen. 

It  is  often  very  difficult  to  retain  the  devitalizing  agent  on  frac- 
tured teeth  when  it  becomes  necessary  to  destroy  their  pulps.  A 
method  pursued  by  some  is  to  apply  a  minute  quantity  and  cover  it 
with  gutta-percha,  which  is  held  in  position  by  ligatures.  Another 
method  suggested  by  Dr.  Rich  is  to  secure  the  arsenical  preparation 
by  surgeon's  rubber  plaster,  passing  it  around  any  portion  of  the 
crown  which  remains. 

Dr.  E.  C.  Kirk,  whose  experiments  with  coagulants  in  pulp-canals 
demonstrate  very  clearly  that  notwithstanding  the  care  we  may  take  in 
sealing  drugs  in  the  cavity  of  a  tooth,  we  cannot  prevent  their  exerting 


262  DENTAL    PATHOLOGY,    THERAPEUTICS. 

more  or  less  influence  on  the  peridental  membrane,  suggests  the  follow- 
ing devitalizing  mixture,  Avhich  he  states  has  given  uniform  satisfaction 
as  a  prompt  obtunder  and  immediate  relief  from  pain  : — 

I  R.     Acid,  arsenic  pulv.,  cocain  hydrochloiat,       aa  .  gr.   xx. 

'  Menthol  cryst. , gr-  v. 

Glycerin, q.   s.  M. 

To  make  a  stiff  paste. 

Dr.  A.  G.  Johnson  claims  that  the  following  formula  has  proven  the 
best  of  a  number  experimented  with  :  — 

R.     Arsenious  acid, gr.  xx. 

Hydrochlorate  of  cocain, gr.  xxx. 

Lanolin  q.  s.  ft.  paste. 

Dr.  James  Truman  recommends  the  following  devitalizing  mixture 
as  prompt  and  painless  :  Take  the  amount  of  arsenic  it  is  proposed  to 
employ  and  add  an  equal  quantity  of  iodoform,  and  on  a  glass  slide, 
by  means  of  a  5  per  cent,  solution  of  carbolic  acid,  make  a  paste. 
The  whole  is  carried  to  the  pulp  on  a  piece  of  cotton  the  size  of  a  pin- 
head,  in  which  it  is  incorporated,  and  covered  with  a  cap  of  platinum 
or  of  red  gutta-percha,  and  over  this  a  temporary  filling  of  wax  or 
cotton  saturated  with  sandarach. 

Another  method  is  to  saturate  a  piece  of  blotting  paper  with  creasote, 
and  on  this  place  the  least  possible  amount  of  arsenic,  then  a  little 
powdered  cocain,  all  of  which  is  covered  with  wax  or  cotton  saturated 
with  sandarach  varnish,  avoiding  any  pressure  on  the  pulp.  This  is 
permitted  to  remain  in  the  tooth  for  two  or  three  days. 

Dr.  George  A.  Mayfield's  method  of  devitalizing  pulp  is  as  follows  : 
Apply  the  rubber-dam,  if  possible,  dry  out  the  cavity,  uncover  the 
pulp  by  first  blowing  on  warm  air,  then  an  application  of  a  saturated 
solution  of  cocain  in  alcohol  and  ether  or  chloroform,  equal  parts, 
allowing  this  to  remain  about  thirty  seconds,  then  another  application 
of  warm  air,  continuing  in  this  way  till  sensitiveness  is  wholly 
obtunded.  As  soon  as  the  pulp  is  exposed,  apply  crystals  of  cocain 
and  moisten  with  campho-phenique.  After  waiting  thirty  seconds, 
apply  warm  air,  and  work  the  crystals  of  cocain  into  the  pulp,  and  in 
from  two  to  ten  minutes  introduce  the  needle  of  the  hypodermic  syr- 
inge, and  inject  a  4  per  cent,  solution  of  hydrochlorate  of  cocain  into 
the  pulp,  which  can  be  done  without  pain.  The  piston  of  the  syringe 
is  forced  down  with  a  quick  push,  thus  forcing  the  needle  into  the 
benumbed  pulp.  The  pulp-chamber  is  then  opened  with  burs,  and  the 
body  of  the  pulp  removed. 

Such  agents  as  nitric  acid  and  carbolic  acid  are  also  employed  to 


SENSITIVENESS    OF    DENTINE.  263 

destroy  pulps  ;  the  method  being  first  to  apply  the  carbolic  acid  to  the 
exposed  surface  of  the  pulp,  and  then  the  nitric  acid  on  a  small  disc 
of  card-board  cut  a  little  larger  than  the  orifice  of  exposure  and  re- 
tained for  half  a  minute.  After  this  is  removed  a  second  application 
of  the  carbolic  acid  is  made,  and  the  pulp  removed  from  the  cavity  by 
means  of  a  barbed  broach.  Some  employ  a  fine  splinter  of  wood 
dipped  in  nitric  acid,  which  is  thrust  into  the  previously  obtunded 
pulp.  Repeated  applications  of  carbolic  acid,  chlorid  of  zinc,  nitrate 
of  silver,  or  caustic  potash  are  also  preferred  by  some  to  arsenious  acid 
for  devitalizing  agents.  A  piece  of  hard  elastic  wood,  shaped  to  con- 
form to  the  pulp-canal,  which  is  freely  opened,  and  suddenly  forced 
up  on  the  pulp  by  the  blow  of  a  condensing  hand-mallet,  is  recom- 
mended as  being  almost  painless. 


CHAPTER   VII. 
SENSITIVENESS   OF   DENTINE. 

While  inflammation  of  the  soft  tissues  exhibits  such  symptoms  as 
pain,  redness,  heat,  and  swelling,  the  dentine  of  a  tooth  in  a  similar 
pathological  condition  does  not  indicate  all  such  manifestations;  for, 
owing  to  its  peculiar  structure,  there  is  no  redness,  on  account  of  a 
want  of  red  globules,  nor  swelling,  on  account  of  the  density.  There 
is,  however,  exalted  sensibility,  and  to  such  a  condition  the  term 
inflammation  has  been  applied.  Inflammation  of  the  dentine  is  due 
to  exposure  of  this  structure  consequent  upon  the  breaking  down  of 
the  enamel  or  protective  covering,  and  its  degree  will  depend  upon 
the  organic  structure  of  the  teeth,  susceptibility  to  irritation,  and  the 
nature  of  the  irritating  agents.  Teeth  that  are  very  vascular  and 
highly  organized  are  often  extremely  susceptible  to  the  action  of  irri- 
tating substances,  and  such  a  state  of  exalted  sensibility  may  at  times 
be  occasioned  by  disturbance  of  other  and  remote  organs,  such  as  the 
uterus,  for  example. 

The  direct  cause  of  inflammation  of  the  dentine  is  irritation  of  the 
fibrillse,  which  occupy  the  dentinal  tubuli  and  are  processes  from  the 
odontoblasts,  and  proceed  through  these  tubules  to  the  periphery  of 
the  dentine,  and,  in  some  cases,  even  beyond  this  structure.  The 
odontoblasts  are  arranged  in  a  layer  on  the  outer  surface  of  the  pulp, 
and  slight  irritation  of  the  ends  of  the  fibrillae,  which  proceed  from 
these  cells,  results  in  the  formation  of  secondary  deposits  of  dentine. 


264  DENTAL    PATHOLOGY,    THERAPEUTICS. 

The  greatest  sensitiveness  is  generally  found  where  the  union  of  the 
dentine  with  the  enamel  occurs,  for  the  reason  that  at  this  point  the 
f.brillae  on  terminating  bifurcate  on  the  periphery  of  the  dentine,  and 
are  more  closely  arranged,  which  accounts  for  the  greater  sensitiveness 
of  dental  caries  in  its  incipient  stage,  and  also  for  the  increased  sensi- 
tiveness of  the  dentine  at  its  periphery. 

Dr.  Bodecker  and  others  claim  to  have  proved  that  the  fibrillae  and 
their  coarse  offshoots  are  formations  of  living  matter,  and  that  the 
basic  substance,  which  is  so  rich  in  lime  salts,  is  traversed  by  an 
extremely  delicate  filigree  of  living  matter.  Dr.  Herbst  has  also 
shown  that  only  a  portion  of  the  pulp  tissue  left  alive  in  the  pulp- 
canals  is  capable  of  preserving  the  life  of  the  dentine  and  enamel. 

Dr.  Bodecker,*  in  accounting  for  the  ^transmission  of  pain  through 
the  dentine,  says:  "  Nerves  are  made  up  of  living  matter,  and  owing 
to  their  reticulated  or  beaded  structure,  are  fittest  for  that  transmission 
of  contractions  "  (living  matter  being  contractile  tissue,  according  to 
Heitzman)  "  from  the  periphery  to  the  nervous  centers  which  we  call 
sensation.  Contraction  of  the  dentinal  fibres  transmitted  into  the 
reticulum  of  the  protoplasm  at  the  periphery  of  the  pulp,  and  thence 
into  the  ultimate  nerve  fibrillae, — all  of  which  formations  are  proven  to 
be  continuous, — are  sufificient  to  explain  the  transmission  of  sensation 
— pain." 

A  tooth  is  sometimes  exceedingly  sensitive  when  the  pulp  is  not 
exposed  ;  but,  in  the  majority  of  cases,  this  need  not  deter  the  oper- 
ator from  removing  the  decayed  part  and  filling  the  cavity,  for  the 
inflammation  of  the  dentine  may  be  confined  to  a  thin  lamina  directly 
beneath  the  carious  matter,  and  the  only  inconvenience  it  will  occa- 
sion the  patient  will  be  a  little  suffering  during  the  operation,  and 
slight  momentary  pain  for  a  few  days,  whenever  anything  hot  or  cold 
is  taken  into  the  mouth.  A  sharp,  thin  instrument  rapidly  used  with 
skillful  touches  will  often  prove  effective.  But  when  the  sensibility  is 
so  great  that  the  patient  cannot  bear  the  removal  of  the  diseased  part, 
as  occasionally  occurs,  it  may  be  allayed  by  the  application  of  chlorid 
of  zinc  to  the  cavity  of  the  tooth  for  from  three  to  six  minutes.  When 
this  is  done,  care  should  be  taken  to  prevent  it  from  coming  in  con- 
tact with  any  of  the  soft  parts  of  the  mouth,  on  account  of  its  active 
escharotic  properties. 

For  the  destruction  merely  of  morbid  sensibility  in  the  solid  struct- 
ures of  a  tooth,  chlorid  of  zinc  is  one  of  the  oldest  agents  employed 
for  such  a  purpose.  Although  a  powerful  escharotic,  it  does  not,  as  all 
arsenical  preparations  are  liable  to  do,  produce  any  deleterious  effect 


Anatomy  and  Pathology  of  the  Teeth." 


SENSITIVENESS    OF    DENTINE.  265 

on  the  pulp  of  the  tooth.  It  is  thought,  however,  in  some  cases  to 
modify  the  texture  of  the  dentine ;  and,  in  the  opinion  of  some  prac- 
titioners, so  much  so  as  to  render  it  more  easily  acted  upon  by  decay- 
ing agencies.  When  first  applied  it  excites  a  sensation  of  heat,  fol- 
lowed by  burning  pain ;  but  these  soon  subside,  and  on  removing  it 
from  the  tooth  the  parts  of  the  cavity  with  which  it  was  in  contact 
will,  in  a  large  majority  of  the  cases,  be  found  totally  insensible  to  the 
touch  of  an  instrument. 

The  chlorid  may  be  applied  directly  to  the  cavity  of  a  sensitive 
tooth,  without  being  combined  with  any  other  substance,  on  a  little 
raw  cotton  or  lint ;  or  it  may  be  made  into  a  paste  by  mixing  it  with 
an  equal  quantity  of  flour,  the  moisture  which  it  absorbs  from  the 
atmosphere  being  sufficient  for  the  formation  of  the  paste ;  or  it  may 
be  mixed  with  a  little  pure  anhydrous  sulphate  of  lime  in  an  impalpable 
powder  and  then  applied  to  the  tooth.  But  before  this  is  done  as 
much  of  the  decomposed  dentine  as  possible  should  be  removed,  and 
the  application  should  be  held  firmly  in  contact  with  the  part  of  the 
cavity  on  which  it  is  intended  to  act.  A  single  application  will  gen- 
erally suffice  to  destroy  the  sensibility  to  a  sufficient  depth  as  will 
enable  the  operator  to  remove  any  remaining  portions  of  decayed  den- 
tine without  pain  ;  but  repeated  applications  are  sometimes  necessary. 

Tannin  or  tannic  acid  in  alcoholic  solution,  or  in  creasote  and 
glycerin,  are  valuable  applications  for  this  pathological  condition  of 
the  dentine.  Nitrate  of  silver,  chromic  acid,  and  the  terchlorid  of 
gold  are  also  used  for  the  same  purpose — the  nitrate  being  applied 
in  either  a  solid  form  or  in  a  concentrated  solution ;  and  while  it 
affects  the  dentine  to  a  greater  depth  than  either  the  tannic  acid  or 
chlorid  of  zinc,  yet  its  action  is  not  so  painful  as  the  latter. 

Creasote  and  carbolic  acid,  either  alone  or  combined  with  acetate 
of  morphin  or  tannic  acid,  are  extensively  used  for  this  condition  of 
dentine,  and  are  among  the  safest  of  these  agents. 

Chloroform  applied  to  the  cavity  on  a  small  piece  of  cotton  will 
often  give  a  temporary  insensibility,  and  has  the  merit  of  being  quite 
harmless;  which  cannot  be  said  of  chlorid  of  zinc,  arsenic,  or  cobalt 
— the  first  sometimes  acting  injuriously  upon  the  dentine,  the  two 
latter  upon  the  dental  pulp. 

A  mixture  of  chloroform  and  aconite,  equal  parts,  is  also  recom- 
mended ;  also,  carvacrol,  oil  of  cloves,  oil  of  cedar,  oil  of  eucalyptus, 
glycerin  and  tannin,  creasote  and  tannin,  camphor  and  chloral  solu- 
tion, camphorized  ether,  oxid  of  calcium  (this  latter,  however,  causes 
considerable  pain  when,  first  applied),  carbonate  of  sodium,  menthol, 
thymol,  the  sesquichlorid  of  chromium,  a  mixture  of  equal  parts  of 
tincture  of  aconite  and  a  saturated  solution  of  iodin,  carbonate  of 


266 


DENTAL    PATHOLOGY,    THERAPEUTICS. 


potash,  equal  parts  of  sulphate  of  morphin  and  gum  cam- 
phor, ethylate  of  sodium,  carbonate  of  potash  and  glycerin, 
equal  parts  of  crystallized  carbolic  acid  and  caustic  potash, 
made  by  mixing  into  a  crystalline  paste  and  known  as  the 
"  Robinson  Remedy,"  and  the  insertion  of  temporary  fill- 
ings composed  of  oxychlorid  of  zinc  or  oxyphosphate  of 
zinc,  or  Hill's  stopping. 

The  desiccation  of  the  sensitive  surface  by  heated  air  is 
also  of  great  benefit.  When  this  method  is  employed  all 
moisture  is  excluded  and  the  air  injected  by  a  hot-air 
syringe,  gently  at  first,  at  intervals  of  a  few  seconds,  and 
as  the  pain  diminishes  the  force  is  increased  at  shorter 
intervals  until  the  pain  ceases,  when  the  operation  can  be 
proceeded  with. 

An  efficient  means  for  the  application  of  heat  as  an 
Id  obtunder  of  sensitive  dentine  is  the  "  Dento-Electric 
Cautery,"  represented  in  Fig.  130.  The  looped-wire  of 
this  instrument  is  rapidly  passed  across  the  sensitive  sur- 
face, and  obtunds  it  to  such  a  degree  as  to  produce  an 
immunity  from  suffering  of  considerable  duration. 

In  the  instrument  a  platinum  loop,  A,  is  held  by  set- 
screws,  B,  in  contact  with  metal  conductors  which  pass 
through  a  hard-rubber  handle.  The  battery  wires  are 
coupled  to  the  two  terminals,  C.  The  appliance  is  held  in 
the  hand  somewhat  in  the  same  manner  as  a  pen  or  pen- 
cil in  writing,  and  the  circuit  is  closed  by  pressing  upon 
the  button,  D,  with  the  forefinger,  when  the  resistance  of 
the  loop  causes  it  to  become  heated.  The  platinum  loop 
when  destroyed  is  readily  and  inexpensively  replaced. 

A  safe  way  of  meeting  th.e  difficulty  in  slight  cases  is 
to  have  the  excavators  and  burs  very  sharp  and  well  tem- 
pered, and  to  cut  firmly  and  decidedly  (for  the  scraping 
of  a  dull  instrument  is  quite  as  painful  as  the  cut  of  a  sharp 
one),  making  cuts  "which  sweep  the  circumference  of  the 
cavity,"  or  in  a  direction  from  the  pulp  chamber. 

Friction,  by  means  of  a  burnisher,  is  also  recommended 
as  being  effectual  where  the  position  of  the  sensitive  sur- 
face will  permit  of  its  use. 

When  painful  escharotics  are  employed,  the  sensitive- 
ness of  the  dentinal  surface  should  first  be  obtunded  by 
a  solution  of  sulphate  of  atropin,  or  other  local  anesthetic. 
If  these  are  inefficient,   or  from  the  nature  of  the  case 


SENSITIVENESS    OF    DENTINE.  267 

cannot  be  applied,  the  inhalation  of  sulphuric  ether  has  been  resorted 
to  with  beneficial  results. 

Having  noticed  the  agents  usually  employed  for  destroying  morbid 
or  hyper-sensibility  in  dentine,  we  will  proceed  to  notice  a  few  of  the 
non-conductors  against  thermal  influences  that  have  been  used  for  the 
accomplishment  of  the  same  object.  Among  the  substances  which 
have  been  employed  for  this  purpose  are  asbestos,  gutta  percha,  cork, 
oiled  silk  ;  also  such  filling  materials  as  Hill's  stopping,  chloro-percha, 
the  oxychlorid  and  oxyphosphate  of  zinc. 

Asbestos,  as  a  non-conductor  of  caloric,  certainly  possesses  every 
desirable  property,  and  is  as  indestructible  in  a  tooth  as  gold.  When 
used  for  this  purpose  the  purest  variety  should  be  selected.  A  small 
pellet  made  from  the  filaments  of  this  mineral,  placed  in  the  bottom 
of  a  cavity  previously  to  filling,  will  effectually  prevent  irritation  of 
the  pulp  from  impressions  of  heat  and  cold.  The  cavity,  however, 
should  be  first  properly  prepared,  washed  with  tepid  water,  and  made 
perfectly  dry.  The  asbestos  may  occupy  from  one-fourth  to  one-sixth 
of  the  depth  of  the  cavity  after  the  filling  has  been  introduced  and 
consolidated. 

A  thin  layer  of  gutta  percha  placed  in  the  bottom  of  the  cavity, 
previously  to  introducing  the  gold,  is  as  effectual  in  preventing  the 
transmission  of  impressions  of  heat  and  cold  as  asbestos,  and  can  be 
more  conveniently  applied.  There  is,  however,  a  preparation  of  it, 
known  as  "Hill's  stopping,"  which  is  better  than  the  simple  article 
for  a  temporary  filling. 

Cork  is  an  equally  good  non-conductor  of  caloric,  but  some  object 
to  its  use  on  account  of  its  being  more  destructible  than  asbestos  or 
gutta  percha ;  but  cut  off,  as  it  necessarily  would  be  in  the  bottom  of 
the  cavity  beneath  the  filling,  its  liability  to  undergo  any  change 
would  seem  to  be  rendered  wholly  impossible.  But  it  is  of  a  more 
porous  nature  than  gutta  percha,  and  cannot  be  adapted  as  perfectly 
to  the  inequalities  of  the  floor  of  the  cavity.  There  is  also  danger, 
in  introducing  the  filling,  of  forcing  some  portions  of  the  gold  through 
it,  unless  a  very  thick  piece  be  used.  Oiled  silk  has  also  been  used  in 
some  cases  very  successfully,  but  it  is  not  as  good  a  non-conductor  as 
either  of  the  afore-mentioned  agents.  Mastic,  copal  and  other  var- 
nishes are  also  used  as  non-conductors  in  sensitive  cavities  prior  to  the 
introduction  of  the  metallic  filling. 

The  filling  materials  known  as  oxychlorid  of  zinc  and  oxyphosphate 
of  zinc  often  prove  effectual  in  preparing  a  sensitive  cavity  for  a  more 
durable  metallic  filling.  For  the  method  of  applying  these  agents, 
and  also  Hill's  stopping,  the  reader  is  referred  to  the  chapter  on 
"  Materials  Employed  for  Filling  Teeth." 


268  DENTAL    PATHOLOGY,    THERAPEUTICS. 

Should  it,  however,  be  necessary  to  fill  the  cavity  with  a  more  per- 
manent material,  such  as  metal,  and  the  inflammation  is  confined  to  a 
portion  of  the  dentine,  this  may  be  protected  by  a  layer  of  the  non- 
conducting material  and  the  metal  introduced  over  it. 


CHAPTER  VIII. 
TUMORS  OF  THE  MOUTH  AND  JAWS. 

Tumors  of  the  gums  are  of  various  kinds;  some  interesting  cases  of 
simple  hypertrophy  are  reported  by  Dr.  Gross  and  Mr.  Salter  and  Mr. 
Erichsen  which  are  reproduced  by  Mr.  Heath  in  his  admirable 
"  Essay."  Mr.  Salter's  case  was  found  to  consist  of  a  pinkish,  corru- 
gated, and  lobed  mass,  composed  of  an  expansion  of  the  alveolus,  with 
"  immense  hypertrophy  of  the  fibrous  gum,  and  an  exuberant  growth 
of  the  papillae  of  the  mucous  membrane."  Dr.  Gross's  case  was  some- 
what similar.  Mr.  Erichsen's  was  found,  "  on  section,  to  consist  of 
firm,  fibrous  stroma,  containing  much  glandular  tissue  in  its  interstices, 
and  covered  on  its  surface  by  very  large  and  vascular  papillae.  The 
epithelial  layer  was  of  unusual  thickness,  but  no  abnormal  epithelial 
structures  were  found  in  the  growth,  which  was  an  example  of  true 
hypertrophy."     (Heath's  "  Jacksonian  Essay,"  190.) 

A  peculiarity  of  this  case  was  that  the  teeth  were  also  hypertrophied. 
In  each  of  these  cases  the  diseased  tissue  was  removed  and  the  exposed 
surface  cauterized. 

Polypus  is  a  simple  hypertrophy  of  the  interdental  gum,  or  dental 
pulp,  and  is  generally  occasioned  by  the  irritation  of  a  worn-out  or 
broken  tooth  with  a  ragged  edge.  In  structure  these  growths  are  like 
the  gum  from  which  they  arise.  They  seldom  give  much  pain,  except 
ulceration  should  take  place.  If  simply  cut  away  they  are  very  likely 
to  return,  but  if  the  tooth  is  removed  and  astringent  or  cauterant 
applications  be  made  they  give  but  little  trouble. 

Continuous  pressure  by  gutta  percha  or  other  means  will  also  con- 
trol them. 

Mr.  Salter  reports  two  cases  of  "  Papillary  Tumors  of  the  Gums," 
consisting  almost  entirely  of  epithelium,  arranged  in  filiform  papillae 
resembling  those  of  the  tongue.  It  is  described  as  "a  curious  white 
mass,  consisting  of  coarse,  detached  fibres,  pointed  and  free  at  one 
extremity  and  attached  at  the  other  ;  in  fact,  it  was  amass  of  papillae, 
many  of  them  nearly  an  inch  long,  and  similar  in  shape  to   the  '  fili- 


TUMORS    OF   THE    MOUTH    AND   JAWS. 


269 


form  '  papillae  of  the  tongue  ;  their  surface  was  shreddy  and  broken  ; 
among  the  elongated  processes  were  a  few  rounded  eminences  like 
'  fungiform  '  papillae,  and  these  had  a  smooth  and  broken  surface." 

The  term  Epulis  is  usually  applied  to  tumors  springing  from  the 
margin  of  the  gums,  whatever  their  structural  character.  They  most 
commonly  spring  from  the  gum  between  two  teeth  ;  as  they  continue 
to  grow  the  base  may  increase  also  in  size  till  it  covers  the  alveolar 
bone,  or  it  may  undergo  superficial  development,  the  point  of  attach- 
ment undergoing  but  little  change;  in  other  words,  it  may  possess  a 
broad,  flattened  base  or  a  narrow  pedicle.  In  structure  it  bears  a  close 
resemblance  to  the  gum,  and  sometimes  has  imbedded  in  it  spiculae  of 
bone,  which  may  have  been  detached  from  the  alveolar  bone,  consti- 
tuting the  source  of  irritation  which  gave  rise  to  the  morbid  growth  ; 
or  it  may  have  been  a  true  osseous  development ;  a  portion  of  germi- 
nal matter,  having  escaped  from  its  true  osseous  relation,  has  been  here 
arrested,  established  a  false  center  of  growth,  and  undergone  develop- 
ment, in  obedience  to  the  primitive  impulse  of  the  parent  cell  from 
which  it  was  derived. 

Fig.  131,  from  Mr.  Heath,  is  a  typical  epulis  of  the  most  common 
variety.  It  is  seen  to  be  a  "firm 
fibrous  tumor,"  with  "some  fibro- 
plastic cells  intermingled."  This 
variety  of  epulis  is  not  unusually  at- 
tached to  the  periosteum  of  the  alveo- 
lus, with  projecting  spiculae  of  bone 
entering  it  from  the  maxilla. 

Left  to  themselves,  these  tumors  will 
often  continue  to  grow,  encroaching 
upon  the  tongue,  hard  palate,  and 
teeth.  They  are  thus  made  liable  to 
injury  by  the  teeth,  and  an  ulcerated  surface  is  in  this  way  established, 
which  discharges  freely,  occasions  considerable  pain,  and  may  become 
the  seat  of  hemorrhage. 

A  softer  and  more  vascular 'variety  is  described  by  Mr.  Hutchinson 
as  consisting  of  fibrous  tissue,  in  which  are  imbedded  a  large  number 
of  polynucleated  cells  of  the  myeloid  variety.  In  the  "  Transactions 
of  the  Pathological  Society  "  he  thus  describes  them:  "  The  epulis 
presented  all  the  characters  of  myeloid  growth  in  a  most  remarkable 
degree.  Its  section  was  very  vascular,  and  showed  hues  varying  from 
a  deep  red  to  buff,  and  a  peculiar  light-greenish  tint  of  yellow  (.xan- 
thoid  of  Lebert).  Scattered  in  its  structures  were  some  detached 
masses  of  soft,  spongy  bone.  Under  the  microscope  were  seen  an 
abundance  of  the  large  polynucleated   bodies  characteristic   of  these 


Fig.  131. — (Fig.  90  of"  Heath  on  the 
Jaws.") 


270  DENTAL    PATHOLOGY,    THERAPEUTICS. 

growths,  many  of  them  being  very  irregular  in  shape  and  much 
branched."  This  form  of  epulis  is  most  frequently  connected  with 
the  interior  of  the  alveolus,  and  hence  more  closely  resembles  the 
endosteal  structures.  When  presenting  an  ill-conditioned  and  ulcer- 
ated surface,  it  closely  resembles  a  malignant  growth,  but  does  not,  as 
has  been  thought  by  some  writers,  pass  into  cancer. 

Mr.  Heath  also  describes  a  variety  which  he  calls  "  giant-celled 
epulis,"  consisting  of  "large,  irregular,  disc-like  cells  containing 
numerous  beard-like  nuclei  interspersed  among  the  fibrous  tissue." 
It  presents  a  surface  of  uniform  smoothness,  of  a  dark-gray  color, 
with  numerous  purple  spots  upon  it.  He  considers  it  as  holding  a 
position  intermediate  between  "  fibro-cellular  and  myeloid  tumors," 
and  of  a  similar  nature  to  the  growths  described  by  Otto  Weber  as 
"giant-celled  sarcoma,"  and  as  a  "fibrous  form  of  cancer  arising 
from  bone  "  by  Wedl. 

Another  form  of  epulis,  resembling  epithelioma,  and  of  interest  as 
showing  that  epithelioma  may  be  developed  in  the  gum  as  elsewhere, 
is  thus  described  in  a  report  by  Mr.  Bruce  to  Mr.  Heath  : — 

"  The  surface  of  the  tumor  is  covered  with  healthy  mucous  mem- 
brane. The  interior  of  the  tumor  is  whiter,  firmer,  and  more  com- 
pact than  the  surface,  but  there  is  no  line  of  demarcation  between  the 
tumor  and  its  mucous  covering.  The  structure  of  the  growth  is  dis- 
tinctly glandular,  very  much  resembling  some  form  of  compact  adenoid 
tumor  of  the  breast. 

"At  the  point  of  attachment  of  the  tumor  to  the  parts  beneath  a 
remarkable  transformation  of  the  glandular  into  the  epitheliomatous 
structure  is  seen.  In  one  part  of  the  section  may  be  seen  the  cut  ends 
of  gland  tubules,  whilst  in  their  immediate  neighborhood  are  most 
distinct  nests  of  true  epithelioma,  consisting  evidently  of  concentrically 
arranged  cells  compressed  from  the  center  upward." 

Mr.  Adams  reports  a  similar  case  which  resulted  in  death,  the 
disease  having  reappeared  in  the  skin  after  its  removal. 

It  is  often  difficult  to  determine  the  causation  of  epulis,  but  they 
may  often  be  referred  to  the  irritation  of  broken  or  unsound  teeth,  or 
to  fragments  of  the  alveolar  bone  which  become  detached,  or  to 
outgrowths  from  the  alveolus ;  most  .frequently,  however,  to  roots  of 
decayed  teeth  ;  hence,  Mr.  Heath  thinks,  the  greater  frequency  of 
these  tumors  in  women — five  to  three — they,  having  a  greater  dread  of 
all  surgical  operations,  are  more  likely  to  permit  useless  roots  to  re- 
main in  their  mouths. 

It  is  rarely  fatal,  but  sometimes  attains  such  size  as  to  produce  great 
deformity,  pain,  and  embarrassment  of  the  functions  of  mastication 
and  deglutition. 


TUMORS  OF  THE  MOUTH  AND  JAWS.  271 

For  the  treatment  of  epulis,  nothing  short  of  the  entire  removal  of 
the  tumor  with  its  periosteal  attachments,  together  with  all  decayed 
teeth,  or  even  sound  ones — when  the  disease  seems  inclined  to  repro- 
duce itself — promises  any  good  result.  After  excision,  the  actual 
cautery  should  be  freely  applied,  for  the  double  purpose  of  destroying 
all  trace  of  the  disease  and  of  arresting  hemorrhage. 

Tumors  of  the  hard  palate  are  closely  related  to  epulis,  and  papil- 
lary and  epithelial  forms  are  reported — the  former  presenting  but 
little  difference  from  tumors  of  the  same  character  arising  on  the  gum. 

An  epithelial  tumor  occurring  on  the  hard  palate  is  reported  by 
Dr.  Andrew  Clark,  which  was  described  as  "soft,  elastic,  and  vas- 
cular. The  cut  surface  is  of  a  dead-white  color,  distinctly  granular, 
like  rough  honey,  crumbly-looking,  and  studded  with  red  or  pink 
blotched  parts  sunk  below  the  general  level.  On  further  examina- 
tion it  appears  to  be  permeated  by  a  kind  of  glairy  substance  (col- 
loid matter),  which  helps,  seemingly,  to  give  coherence  to  the  tumor. 
To  the  naked  eye  the  tumor  resembles  in  some  respects  a  cephaloid 
or  myeloid  mass.  To  the  latter  it  bears  the  greatest  resemblance  in 
general  character,  seat,  and  structure.  The  microscopic  characters 
are  those  of  epithelial  cancer,  epithelial  cells  in  all  stages  of  devel- 
opment and  of  the  most  various  forms,  together  with  a  few  nest-cells 
and  fat.  The  mucous  membrane  over  the  tumor,  though  not  con- 
tinuous with  it,  presents  the  same  structural  characters.  This  decides 
the  doubt  between  the  epithelioma  and  myeloma."  (Heath's  "  Jack- 
sonian  Essay,"  p.  208.) 

Encysted  tumors  of  the  hard  palate  are  also  sometimes  found,  but 
they  are  rare,  and  require  no  special  description  in  a  work  of  this 
character. 

These  tumors,  when  epuloid  in  character,  are  to  be  treated  in  the 
manner  already  described.  When  the  bone  becomes  affected,  it  also 
must  be  removed  to  such  an  extent  as  will  leave  an  entirely  healthy 
surface. 

Unerupted  teeth  may  also  give  rise  to  osseous  tumors,  requiring 
surgical  interference.  This  is  more  peculiarly  the  case  with  the  wisdom 
tooth,  for  a  reason  easily  understood  :  the  space  nominally  allotted 
it,  between  the  second  molar  and  the  terminal  point  of  the  alveolar 
ridge,  is  often  too  limited  for  its  eruption  ;  endeavoring  to  make  its 
way  through  the  bone  under  such  circumstances,  the  opposition  it 
encounters  is  often  sufficient  to  occasion  great  irritation  and  pain, 
and  occasionally  to  entirely  prevent  its  eruption.  The  retained  tooth 
thus  becomes  a  center  of  irritative  action,  and  may  serve  not  only  to 
determine  the  site,  but  the  fact  of  such  tumors.  Mr.  Tomes  also 
relates  a  case  in  which  the  wisdom  tooth  was  bound  down  by  a  "  mass 


272  DENTAL    PATHOLOGY,    THERAPEUTICS. 

of  enamel,  dentine,  and  cementum,  thrown  together  without  any 
definite  arrangement,"  which  occupied  the  place  of  the  second  molar. 
Mr.  Heath  also  records  a  case,  reported  by  Dr.  Forget,  in  which  a 
tumor  about  the  "  consistence  of  ivory,"  covered  everywhere  with 
enamel,  and  about  the  size  of  an  egg,  occupied  that  portion  of  the 
jaw  between  the  ramus  and  the  first  bicuspid.  It  was  composed 
chiefly  of  enamel  and  dentine,  with  portions  of  cementum  "  dipping 
into  the  crevices  "  here  and  there,  and  was  regarded  by  Dr.  Forget  as 
a  "fusion  and  hypertrophy  of  the  last  two  molars." 

Again,  one  of  the  anatomical  elements  of  the  tooth  may  become 
so  hypertrophied  as  to  constitute  a  troublesome  disease  and  call  for 
surgical  interference.  The  cementum  is  most  likely  to  undergo  such 
change.  M.  Maisonneuve  reports  a  case  cited  by  Mr.  Heath,  in 
which  the  hypertrophied  cementum  attained  the  size  of  a  pigeon's 

egg- 
It  is  desirable,  if  possible,  to  remove  all  such  morbid  growths  with- 
out injury  to  the  bone  in  which  they  are  implanted ;  but  it  may 
become  necessary  to  excise  that  part  of  the  jaw  in  which  it  is.  All 
neighboring  teeth  which  may  possibly  be  associated  with  it  should  be 
removed. 

Tumors  of  the  antrum  and  upper  jaw  may  be  appropriately  described 
together,  the  distinguishing  characteristics  being  pointed  out. 

Polypus. — Growths  of  this  character  occasionally  occur  in  the  an- 
trum, and  are  closely  allied  to  the  small  cysts  occurring  in  its  mucous 
membrane;  both  are  essentially  a  "  hypertrophy  of  some  element  of 
the  mucous  or  sub-mucous  tissue.  When  the  connective  or  areolar 
tissue  predominates,  the  fleshy  polypus  is  produced  ;  when  the  glandu- 
lar element  is  especially  affected,  we  have  the  cystic  form  produced. 
Intermediately,  when  the  fibrous  element  is  very  loose  and  we  have 
some  glandular  hypertrophy,  the  semi-gelatinous  polypus  is  produced, 
which  closely  resembles  the  nasal  polypus."  ("  Jacksonian  Essay," 
p.  210.) 

Antral  polyps  are  very  vascular,  and  are  sometimes  the  ushers  of 
malignant  disease.  The  diagnosis  is  exceedingly  difficult  until  they 
have  advanced  sufficiently  to  break  down  the  osseous  wall  somewhere ; 
this  most  frequently  takes  place  into  the  nose,  through  the  thin  nasal 
wall. 

They  should  be  removed  as  soon  as  ascertained  to  exist,  and  the 
troublesome  hemorrhage  which  is  likely  to  occur  should  be  arrested  by 
injections  of  a  reliable  styptic,  in  any  strength  which  is  not  likely  to 
give  rise  to  trouble,  if  the  opening  is  sufficiently  large  to  permit  its 
ready  escape. 

A  single  instance  of  a  peculiar  form  of  fibroid  growth  of  the  antrum 


TUrORS    OF    THE    MOUTH    AND    JAWS.  273 

IS  recorded  by  Mr.  Heath,  from  whose  work  we  take  the  following 
description  by  Mr.   Bruce  : — 

"  It  appears  to  consist  of  a  fine,  soft,  fibrous  stroma,  in  which  very 
numerous  nuclear  bodies  and  a  few  elongated  fibre-cells  are  distributed. 
Its  structure  resembles  that  of  the  upper  strata  of  a  mucous  membrane, 
from  which  it  is  probably  an  outgrowth.  It  consists  of  newly-formed 
fibrous  tissue,  and  of  the  elements  from  which  fibrous  tissue  is  devel- 
oped, and  may,  therefore,  be  classed  among  the  simple  fibro-plastic 
growths  as  distinguished  from  the  true  myeloid  tumors." 

Fibrous  tumors  of  the  upper  jaw  are  not  unlike  fibrous  tumors  found 
elsewhere.  They  are  slow  of  growth,  dense  in  structure,  with  interlac- 
ing, slender  bundles  of  fibres,  and  are  frequently  lobulated.  They 
commonly  spring  from  the  interior  of  the  antrum  or  from  the  alveolus, 
and  sometimes  attain  to  an  enormous  size,  crushing  in  the  antrum  or 
obliterating  its  walls  by  absorption,  encroaching  upon  the  orbit, 
destroying  its  floor,  penetrating  the  nasal  cavity,  and,  extending  out- 
ward, conceal  the  teeth  on  the  same  side  from  view.  Mr.  Liston 
removed  a  tumor  of  this  kind  from  the  face  of  a  lady,  where  it  had 
arisen  six  years  before,  apparently  from  a  blow  received  on  the  face, 
and  had  attained  to  an  enormous  size,  covering  the  whole  of  that  side 
of  the  face.  Its  smallest  diameter  was  six  inches.  This  tumor  became 
of  increased  vascularity  after  the  cessation  of  the  catemenia  at  the 
regular  monthly  period,  and  bled  slightly  at  these  times  from  the  adja- 
cent parts  of  the  gum.  They  are  usually  of  an  oval  or  rounded  form, 
freely  movable,  and  painless.  When  laid  open  they  present  a  white, 
shining,  ligamentous  structure,  and  are  composed  of  nucleated  fibres. 
If  left  to  themselves  they  may  become  softened  in  the  center  and 
undergo  disintegration,  though  Mr.  Heath  thinks  they  never  suppurate 
except  where  they  have  been  punctured  in  establishing  a  diagnosis. 
They  may  also  undergo  calcareous  degeneration,  but  are  never  ossified. 

Mr.  Paget  reports  a  case  in  which  distinct  pulsation,  synchronous 
with  the  radial  pulse,  was  felt.  They  rarely  recur  after  removal, 
perhaps  never  when  entirely  removed.  Mr.  Weber  thinks  "  they  are 
usually  connected  with  the  lining  of  the  Haversian  canals,"  and 
advises  that  a  portion  of  the  bone  be  removed  in  all  operations. 
Their  origin  is  usually  referred  to  the  irritation  of  decayed  teeth  or  to 
direct  violence. 

Fibro-cellular  tumor,  or  osteo-sarcoma,  is  of  softer  consistence  than 
the  simple  fibrous  tumor  ;  they  are  smooth,  round,  elastic  tumors,  of  a 
yellowish  color,  and  are  infiltrated  with  a  serous  fluid.  Unlike  the 
simple  fibrous  tumor,  they  exhibit  a  strong  tendency  to  ulceration, 
which  sometimes  serves  to  confound  them  with  malignant  growths, 
from  which  they  are  to  be  distinguished  by  the  history  of  the  case  and 
18 


2  74  DENTAL    PATHOLOGY,    THERAPEUTICS. 

the  non-implication  of  the  lymphatic  glands.  They  are  thus  described 
by  Sir  Philip  Crampton  :  "  In  the  earlier  stages  of  the  disease  the 
tumor  consists  of  a  dense,  elastic  substance  resembling  fibro-cartilagi- 
nous  structure,  but  the  resemblance  is  more  in  color  than  consistency, 
for  it  is  not  nearly  so  hard,  and  is  granular  rather  than  fibrous,  so  that 
it  '  breaks  short.'  On  cutting  into  the  tumor  the  edge  of  the  knife 
grates  against  spicula,  or  small  grains  of  earthy  matter,  with  which  its 
substance  is  beset."  Fibro-cellular  tumors  may  undergo  fatty  or  cal- 
careous degeneration. 

Recurring  fibroid  tumors  occur,  if  at  all,  so  rarely  in  the  upper  jaw, 
that  any  description  is  unnecessary  in  a  work  of  this  kind.  The  same 
may  be  said  of  vascular  tumors. 

Myeloid  tumors  are  described  by  Mr.  Paget  as  occupying  an  inter- 
mediate position  between  fibrous  and  fibro-cellular  tumors.  They  are 
composed  of  parallel  fibres,  with  fibro-plastic  cells,  and  bear  a  close 
resemblance  to  "  granulation  cells  in  process  of  development  into  fibro- 
cellular  tissue."  On  section  they  present  a  smooth,  shiny,  semi-trans- 
parent appearance;  are  of  a  pinkish  or  bluish  color  and  of  brittle 
texture.  They  usually  occur  in  the  young,  are  painless,  and  seldom 
recur.  Externally  they  present  a  dark  maroon  color,  quite  character- 
istic. An  excellent  description  of  a  tumor  of  this  class  is  furnished 
Mr.  Heath  by  Dr.  Tonge,  from  which  we  make  the  following  extract : 
"  It  was  of  firm  consistence  throughout,  and  on  section  presented  a 
whitish  appearance,  with  a  small  pink  patch  or  two,  and  a  whitish, 
creamy-looking  juice  could  be  scraped  from  the  cut  surface.  .  .  . 
The  fibrous  element  was  much  less  abundant  than  the  cellular,  and 
consisted  of  white  fibrous  tissue,  with  numerous  fine,  curling  fibres  of 
yellow  elastic  tissue,  and  many  small  oval  and  rounded  nuclei  were 
imbedded  in  the  fibrous  structure.  The  greater  portion  of  the  tumor 
seemed  to  be  composed  of  cells.  These  were  mostly  of  an  irregularly 
rounded  form,  often  with  pointed  processes ;  and  some  shuttle-shaped 
and  spindle-shaped,  of  a  somewhat  trapezoidal  form,  were  not  uncom- 
mon, while  a  few  cells  presented  the  character  of  those  distinctive  of 
myeloid  tumors.  All  the  cells  contained  one,  and  often  two,  very 
large  and  generally  oval  nuclei,  with  one,  two,  or  three  nucleoli,  and 
a  variable  number  of  oil  globules.  The  myeloid  cells  observed  were 
of  irregular  outline  and  contained  from  three  to  five  nuclei,  with 
single  or  double  nucleoli ;  one  very  large  cell  contained  six 
nuclei." 

Their  formation  takes  place  slowly,  after  the  manner  of  cyst  forma- 
tion or  other  simple  tumors.  When  the  bone  has  been  removed  by 
absorption  or  otherwise  they  may  be  recognized  by  their  characteristic 
color,  and  when  a  cyst  forms  within   them,  as  sometimes  happens, 


TUMORS  OF  THE  MOUTH  AND  JAWS.  275 

myeloid  cells  may  be  found  in  the  fluid  that  escapes  when  it  has  been 
punctured,  thus  distinguishing  it  from  cystic  formations. 

Cartilaginous  tumors  are  of  two  kinds  :  simple,  innocent,  or  benig- 
nant tumors,  and  tumors  presenting  a  malignant  appearance.  Those 
of  the  first  class  present  a  round  or  ovoidal  form,  are  smooth,  hard, 
of  slow  growth,  and  painless.  Those  of  the  second  class  grow  with 
great  rapidity,  to  a  large  size,  and  are  of  a  malignant  appearance. 

Cartilaginous  tumors  occur  on  the  upper  jaw,  but  may  affect  it 
secondarily  by  extension  from  other  parts. 

Mr.  Heath  describes  specimens  taken  from  St.  George's  and  St. 
Bartholomew's  Hospitals,  in  one  of  which  the  disease  occurred  on  the 
inner  side  of  the  orbit,  and  two  years  later  had  pressed  the  superior 
maxillae  forward  nearly  an  inch  beyond  the  inferior,  while  the  "  bones 
of  the  face  and  orbit  were  extensively  absorbed."  In  the  other  the 
superior  maxillary  bones  were  entirely  absorbed,  the  cavity  of  the  skull 
was  invaded,  and  the  brain  pressed  aside;  it  is  attached  to  the  soft 
palate  below,  and  presses  forward  the  walls  of  the  nose  in  front.  Mr. 
Paget  relates  a  case  in  which  the  disease  had  existed  nine  years,  was 
removed,  but  returned,  and  the  patient  died  seven  years  after.  "A 
section  of  the  tumor  showed  that  it  was  composed  of  an  outer,  hard, 
thin  shell  of  bone,  completely  enclosing  a  morbid  growth  of  spongy, 
cancellated  structure,  devoid  of  all  appearance  of  carcinomatous  or 
spongy  disease."  These  growths  are  usually  very  slow,  and  when  re- 
moved exhibit  but  a  slight  tendency  to  recur.  Cases  are  reported  in 
which  the  free  local  use  of  iodin  has  effected  the  absorption  of  tumors 
of  this  kind  that  had  not  yet  attained  a  large  size.  They  sometimes 
soften,  disintegrate,  slough,  and  establish  fistulous  openings,  through 
which  a  jelly-like  mass  escapes. 

Osseous  tumors  in  their  simplest  form  are  but  a  hypertrophy  of 
previously  existing  bone  tissue.  They  are  predisposed  to  by  syphilitic 
and  scrofulous  affections,  and  sometimes  their  immediate  origin  may 
be  traced  to  the  irritation  of  imperfect  teeth  ;  in  general,  however,  it 
is  difficult  to  refer  them  to  a  determinate  cause.  They  are  of  slow 
growth,  painless,  and  closely  resemble  true  bone  in  structure.  Their 
slowness  of  growth,  hardness,  painlessness,  and  fixity  are  the  charac- 
teristics on  which  a  diagnosis  may  be  based,  though  they  are  occasion- 
ally movable.  Occasionally  they  ulcerate,  and  troublesome  fistulous 
openings  are  established.  When  of  a  large  size  they  may  invade 
important  organs,  occasioning  great  trouble,  as  in  the  case  reported  by 
Mr.  Hilton,  where  it  invaded  the  orbit  and  by  its  pressure  burst  the 
ball  of  the  eye. 

Cancerous  tumors  of  the  upper  jaw  are,  in  Mr.  Heath's  experience, 
limited  to  the  medullary  form ;  other  observers  have,  however,  occa- 


276  DENTAL    PATHOLOGY,    THERAPEUTICS. 

sionally  met  with  schirrhus.  Mr.  Hancock  advanced  the  view  that 
medullary  disease  does  not  begin  in  the  antrum,  but  in  the  bones  at 
the  base  of  the  skull.  This  view  is  refuted  by  the  observation  of  Mr. 
Liston  and  others,  who  have  shown  that  it  unquestionably  begins  in 
the  antrum  very  often.  They  are  characterized  by  rapid  development, 
softness  to  the  touch,  and,  when  fully  established,  by  a  peculiar  ex- 
pression and  sallow,  putty-like  appearance  of  the  skin.  In  this  situation 
it  is  seldom  accompanied  by  glandular  enlargement.  By  pressing 
upon  the  nasal  duct  it  may  occasion  considerable  edema  of  the  lower 
eyelid,  with  enlargement  of  the  facial  veins,  from  obstructed  circu- 
lation. 

For  the  cure  of  all  solid  tumors  of  the  upper  jaw  there  is  but  one 
remedy  on  which  we  can  rely — the  knife.  All  operative  procedures 
should  be  resorted  to  at  the  earliest  practicable  moment,  before  the 
facial  structures  have  been  extensively  invaded  by  the  disease.  When 
the  disease  is  entirely  removed,  in  even  malignant  growths,  we  may 
sometimes  entertain  a  hope  of  permanent  relief.  To  effect  the  re- 
moval of  tumors  in  this  situation  various  methods  have  been  devised. 
Until  1826  surgeons  usually  contented  themselves  with  the  removal  of 
so  much  of  the  disease  as  could  be  effected  with  the  gouge  and 
chisel ;  but  about  this  time  Mr.  Lizars,  of  Edinburgh,  proposed  the 
removal  of  the  entire  superior  maxilla,  having  previously  secured  the 
carotid  artery.  An  opportunity  to  carry  out  his  suggestion  did  not 
offer  until  December  of  the  following  year,  when,  in  attempting  this 
operation,  the  hemorrhage,  notwithstanding  the  ligation  of  the  caro- 
tid, was  so  great  as  to  necessitate  the  discontinuance  of  the  operation. 
In  the  meantime,  without  any  knowledge  of  Mr.  Lizars'  suggestion, 
Mr.  Gensoul  successfully  removed  the  upper  jaw  without  securing  the 
artery  and  with  but  little  hemorrhage.  Mr.  Lizars  afterward  operated 
successfully,  and  the  operation  is  now  an  established  one.  His  inci- 
sion was  carried  from  the  angle  of  the  mouth  to  the  malar  bone, 
where,  when  more  space  was  required,  it  was  met  by  a  short,  vertical 
incision,  and  an  incision  was  also  made  from  the  middle  line  of  the 
lip  to  the  nostril.  Mr.  Gensoul  employed  a  vertical  incision  from  the 
inner  canthus  to  the  angle  of  the  mouth,  which  was  met  midway  by 
another  at  right  angles  to  it,  letting  fall  on  its  outer  extremity  another 
vertical  incision.  The  bone  was  then  removed  with  the  mallet  and 
chisel.  An  obvious  objection  to  these  operations  was  the  great  de- 
formity occasioned  and  the  division  of  the  facial  nerve.  To  obviate 
these  difificulties  Sir  William  Fergusson  suggested  a  plan,  which  has 
since  been  very  generally  adopted.  It  consisted  solely  in  an  incision 
from  the  middle  line  of  the  lip  to  the  nostril,  when,  by  stretching  the 
integument,  sufficient  space  was  usually  gained.     If  more,  however, 


TUMORS    OF    THE    MOUTH    AND    JAWS. 


277 


was  required,  the  incision  was  carried  up  alongside  of  the  nose  to  the 
inner  canthus,  and  below  the  eye  to  the  outer  canthus ;  thus  the  facial 
nerve  and  artery  were  divided  so  high  up  as  to  give  but  little  trouble, 
while  the  scars  are  most  favorably  situated  (see  Fig.  132). 

After  deflecting  the  skin,  a  small  saw  is  passed  into  the  nostril,  with 
which  the  hard  palate  and  alveolus  are  divided.  The  nasal  and  malar 
processes  of  the  superior 
maxilla  are  next  sawed 
nearly  through,  and  the  di- 
vision completed  with  bone 
forceps.  The  bone  is  then 
grasped  by  the  powerful  for- 
ceps devised  by  Sir  William 
Fergusson,  and  forcibly 
wrenched  from  its  attach- 
ments to  the  pterygoid  pro- 
cess and  palate  bones.  The 
infra-orbital  nerve  is  then 
divided,  the  soft  palate  care- 
fully dissected  from  the  de- 
tached bone,  which  is  ready 
for  removal,  after  which 
hemorrhage  is  arrested  by 
ligatures  and  the  actual  cau- 
tery, and  the  wound  closed 
with  silver  sutures.      When 

the  palate  bone  and  orbital  palate  are  not  involved  they  may  be 
spared  by  sawing  horizontally  above  and  below  them  respectively. 
Sir  William  Fergusson  now  prefers  to  avoid  the  removal  of  all  healthy 
tissue  by  attacking  the  disease  from  center  to  circumference  with  strong 
curved  and  angular  bone  forceps.  Both  superior  maxillas  have  occa- 
sionally been  removed  ;  but  it  is  an  operation  so  seldom  required  that 
a  description  of  it  is  not  called  for  in  a  work  of  this  kind. 

Tumors  of  the  lower  jaw  do  not  differ  in  essential  particulars  from 
those  already  described.  They  are  more  readily  diagnosed  and  safely 
removed  than  those  of  the  upper  jaw.  Deaths  are  comparatively  rare 
from  operative  procedures  here.  When  the  tumors  are  small  they  may 
be  removed  without  incision  of  the  lip  by  simply  dissecting  them  from 
their  attachment  to  the  bone,  turning  them  down,  and  removing  the 
diseased  portion  with  bone  forceps.  When  a  large  body  is  to  be  re- 
moved the  incision  should  be  carried  beneath  the  margin  of  the  jaw, 
where  the  scar  shall  afterward  be  concealed  from  view.  When  the  bone 
IS  exposed  we  should  endeavor  carefully  to  ascertain  if  the  disease  may 


Fig.  132. 


278  DENTAL    PATHOLOGY,    THERAPEUTICS. 

not  be  removed  with  the  external  plate  of  bone  alone  ;  if  this  may  not 
be  done,  the  saw  should  be  brought  into  requisition  and  the  diseased 
structure  removed.  Amputation  of  the  lower  jaw  is  far  more  readily 
effected  than  of  the  upper.  For  a  detailed  account  of  this  operation 
the  student  is  referred  to  more  exclusively  surgical  works. 

CYSTIC    TUMORS,    DENTIGEROUS    CYSTS. 

It  must  be  remembered,  in  connection  with  diseases  of  the  antrum, 
that  it  is  of  variable  size,  with  walls  of  variable  thickness.  In  youth 
the  walls  are  thick  and  the  cavity  small.  After  attaining  its  maximum 
size  in  the  adult  it  is  found  again  to  diminish  with  old  age  ;  it  is  larger 
in  males  than  in  females.  But  in  adult  life  its  capacity  varies  in 
different  subjects,  from  one  dram  to  eight  drams,  the  average  ca- 
pacity being  about  two  and  a  half  drams. 

Suppurative  inflammation,  or  abscess  of  the  antrum,  is  commonly 
due  to  extension  of  inflammation  from  the  teeth  to  the  lining  mem- 
brane of  its  cavity.  The  roots  of  the  first  and  second  molars  not 
infrequently  present  prominences  at  the  antrum,  and  sometimes  the 
first  molar  roots  are  found  extending  into  this  cavity  entirely  uncovered 
by  bone.  It  will,  therefore,  be  readily  seen  how  disease  of  the  roots 
may  prove  a  source  of  irritation  and  inflammation  to  the  lining  mem- 
brane of  this  cavity;  but  such  direct  communication  is  not  necessary ; 
and  disease  beginning  in  alveoli  not  in  immediate  relation  with  the 
antrum  may  extend  through  intervening  bone  and  establish  communi- 
cation. Direct  blows  upon  the  face  may  also  induce  suppurative  in- 
flammation of  its  membrane,  and  it  may  also  arise  from  "pressure 
during  birth." 

The  symptoms  are,  pain  of  a  dull  character,  shooting  up  the  side  of 
the  face  and  head,  rigors  succeeded  by  irritative  fever,  with  tenderness 
and  swelling  of  the  cheek.  As  the  pus  accumulates,  the  pressure  to 
which  it  subjects  the  walls  of  the  cavity,  together  with  the  vitiated 
nutrition  occasioned  by  its  presence,  determines  absorption  of  the 
bone  and  the  discharge  of  the  contained  fluid  through  the  opening 
thus  established  either  into  the  orbit  or  by  the  side  of  the  teeth.  Before 
an  opening  is  established,  however,  the  orbital  wall  may  become  so 
dilated  as  to  occasion  partial  blindness  by  displacement  of  the  eye,  or 
it  may  even  induce  an  amaurosis  which  shall  result  in  permanent  blind- 
ness. Sometimes  extensive  necrosis  is  occasioned,  affecting  all  the 
adjacent  bones,  as  in  the  case  reported  by  Mr.  Salter,  in  which  the 
"  floor  of  the  orbit,  the  upper  cheek  portion  of  the  superior  maxilla, 
and  the  infraorbital,  and  a  large  plate  of  bone  from  the  inner  (nasal) 
wall  of  the  antrum,  were  involved."  Dr.  Mair,  of  Madras,  reports  a 
case  in  which  death  resulted  in  sixteen  days,  though  apparently  begin- 


TUMORS  OF  THE  MOUTH  AND  JAWS.  279 

ning  as  a  simple  ozena.  The  post-mortem  examination  in  this  case 
revealed  a  condition  of  things  that  led  Dr.  Mair  to  conclude  that  it 
began  as  a  "disease  of  the  antrum,  originating  in  degeneration  of  the 
mucous  membrane  lining  its  cavity,  or,  perhaps,  connected  with  the 
soft  tumors  which  grow  from  the  apex  of  the  tooth  and  from  the  lining 
membrane  of  the  root ;  secondarily,  involving  the  ethmoid,  lachrymal, 
palatine,  and  inferior  turbinated  bones  of  the  left  side,  causing  sup- 
puration and  disintegration,  the  purulent  matter  filling  the  cavity  of 
the  antrum  extending  toward  the  left  nostril,  causing  ozena,  and 
upward  into  the  orbit,  behind  the  globe  of  the  eye,  pushing  the  eye 
outward  and  forward,  the  matter  finding  its  way  through  the  optic 
foramen  to  the  anterior  surface  of  the  left  hemisphere  of  the  brain, 
there  acting  as  a  foreign  body,  exciting  inflammatory  action,  termi- 
nating in  cerebral  abscess,  causing  convulsions,  coma,  and  death." 
(^Edinburgh  Medical  Journal,  May,  1806.)  Cases  of  such  severity  are, 
fortunately,  rare;  but  they  indicate  the  possibilities  of  the  apparently 
most  simple  cases,  as  well  as  the  line  of  treatment  most  likely  to  obviate 
such  conditions  and  result. 

Treatment. — In  the  simplest  cases  in  which  suppuration  of  the 
antrum  is  strongly  suspected,  we  should  at  once  remove  all  decayed 
teeth  or  roots,  and  even  sound  teeth,  when  found  to  be  tender.  If 
matter  has  not  yet  formed,  the  disease  may  then  subside  under  the  use 
of  simple  fomentations.  It  is  safer,  however,  in  most  cases,  to  pene- 
trate the  antrum,  preferably  through  the  socket  of  the  first  molar, 
because  of  the  greater  depth  of  the  socket ;  and  this,  too,  without 
delay,  care  being  taken  to  regulate  the  force  so  as  not,  by  too  great 
violence,  to  injure  the  floor  of  the  orbit.  Should  the  teeth  be  sound 
and  it  be  desired  to  save  them,  an  opening  may  be  made  through  the 
alveolus  above  the  gum.  The  cavity  should  be  freely  injected  with 
tepid  water,  and  subsequently  with  some  slightly  stimulating  and  anti- 
septic lotion  ;  and  care  must  afterward  be  taken  to  prevent  the  admis- 
sion of  foreign  substances  into  the  cavity. 

In  the  more  chronic  forms  of  this  disease  the  purulent  accumulation 
takes  place  so  slowly,  and  the  consequent  expansion  is  so  gradual, 
that  it  is  often  mistaken  for  solid  growths;  and  in  many  cases  the 
diagnosis  is  of  extreme  difficulty ;  surgeons  of  distinction,  having 
begun  an  operation  for  the  removal  of  a  solid  growth,  have  been  sur- 
prised to  find  their  hands  bathed  in  pus,  whilst  the  supposed  tumor 
disappeared  from  beneath  them.  In  all  cases  in  which  the  diagnosis 
is  not  perfectly  clear  an  exploratory  puncture  should  be  made,  and 
thus  the  difficulty  is  at  once  resolved. 

Sometimes  the  pus  is  enclosed  in  a  second  bony  investment,  due 
to   the  ossification  of  the  antral  periosteum.     When  this  occurs,  it 


28o  DENTAL    PATHOLOGY,    THERAPEUTICS. 

occasionally  happens  that  the  bone  remains  thickened  long  after 
the  evacuation  of  the  pus  and  the  entire  cure  of  the  abscess,  the 
deformity,  of  course,  remaining  unaltered.  It  then  becomes  neces- 
sary to  open  the  antrum  and  remove  this  ossified  periosteum. 

A  clear  or  yellowish  serous  fluid  is  not  un frequently  found  in  the 
antrum,  which  the  older  writers  took  to  be  a  secretion  of  mucus, 
which,  having  failed  to  make  its  escape  by  the  aperture  between  the 
antrum  and  the  nostril,  accumulated  in  such  quantity  as  to  occasion 
wasting  of  antral  walls  to  such  an  extent  as  to  permit  the  fluctuating 
mass  to  be  felt  at  certain  points.  This  fluid  was  found  on  examination 
to  contain  numerous  flakes  of  cholesterin,  as  is  the  case  in  well-defined 
cystic  growths,  and,  as  it  in  no  respect  resembled  mucus,  recent  writers 
have  referred  this  form  of  disease  to  cystic  formations. 

The  most  recent  and  able  writer  on  this  subject,  Mr.  Heath,  thus 
describes  their  mode  of  origin:  "It  is  certain,  however,  that  some 
of  these  cases,  and  very  probably  all  of  them,  originate  in  the  growth 
of  a  cyst,  or  cysts,  within  the  antrum  or  in  connection  with  the  fangs 
of  the  teeth,  which  either  grow  to  such  a  size  as  to  be  mistaken  for  the 
cavity  of  the  antrum  when  opened,  or  break  into  the  antrum  by  absorp- 
tion of  the  cyst-wall,  so  that  on  subsequent  examination  no  evidence 
of  the  cyst  formation  can  be  discovered." 

These  cyst  formations  are  also  occasionally  mistaken  for  solid  growths, 
and  Mr.  Heath  relates  an  instance  in  which  "  a  very  able  surgeon 
removed  the  upper  jaw  before  the  mistake  was  discovered."  And  Sir 
William  Fergusson  relates  a  case  in  which  a  similar  error  was  avoided 
by  an  exploratory  puncture,  which  should  in  no  case  be  omitted. 

They  may  be  single  or  multiple  ;  sometimes  there  appears  to  be  a 
"cystic  regeneration  of  the  entire  mucous  membrane."  Mr.  Giraldds, 
who  was  the  first  writer  on  this  subject,  thinks  they  are  due  to  "  dila- 
tion of  the  glandular  follicles  of  the  mucous  membrane,  and  that  in 
such  cases  it  will  be  necessary  to  open  the  antrum,  so  as  to  remove  the 
entire  mass,  it  being  useless  in  such  cases  to  pursue  the  customary  plan 
of  tapping  the  antrum." 

Cysts  of  teeth  are  divided  by  Mr.  Heath  into  two  classes:  "First, 
cysts  connected  with  the  roots  of  fully  developed  teeth  ;  and,  secondly, 
cysts  connected  with  imperfectly  developed  teeth — to  which  the  term 
'  Dentigerous  Cysts'  has  been  applied  in  modern  times."  They  occur 
indifferently  in  either  jaw ;  in  the  upper,  however,  are  sometimes  com- 
plicated with  collections  of  fluid  in  the  antrum,  which  they  have  sec- 
ondarily affected.  When  of  very  small  size  they  give  but  little  trouble, 
and  are  frequently  found  attached  to  the  roots  of  teeth  after  extrac- 
tion, where  their  existence  had  not  before  been  suspected.  They  seem 
to  occur   most  frequently  in  connection  with   the  incisor  teeth,  and 


TUMORS  OF  THE  MOUTH  AND  JAWS.  2S1 

sometimes  attain  a  very  large  size,  even  when  not  communicating  with 
the  antrum.  They  are  commonly  associated  with  the  disease  of  the 
root  about  which  they  are  formed,  whether  as  cause  or  effect  it  is  diffi- 
cult to  determine,  the  majority  of  observers  holding  the  latter  opinion. 
Mr.  Paget  relates  a  case  in  which  the  cyst  contained  as  much  as  an 
ounce  of  fluid,  and  was  re- 
ceived in  a  deep  depression 
in  the  alveolar  border  of  the 
jaw.  And  Delpech  reports 
one  containing  so  much  as 
three  ounces,  without  connec- 
tion with  the  antrum.  They 
consist  essentially  of  a  serous 
bag  growing  from  the  dental 

periosteum    at    the    extremity      Fig.  133. -Cysts    Connected    with    Roots    of 

of  the  root,  filled  with  a  clear  '^^''^"• 

or  yellowish  fluid  with  bright  shining  particles  of  cholesterin  floating 
about  in  it.  According  to  Mr.  Tomes  the  morbid  process  is  prob- 
ably identical  with  that  resulting  in  the  formation  of  alveolar 
abscess,  but,  being  less  acute,  a  serous  cyst  is  formed  instead  of  a  sup- 
purating one. 

Mr.  Heath  remarks  that  "large  cysts  produce  more  or  less  absorp- 
tion of  the  outer  wall  of  the  maxilla,  and  are  very  common  conse- 
quences of  diseased  teeth,  but  seem  to  give  surprisingly  little  incon- 
venience to  the  patients,  even  when  of  large  size  and  producing 
considerable  deformity  of  the  face.  They  are  commonly  confounded 
with  cystic  distention  of  the  antrum." 

Mr.  Heath  says  "  the  clinical  history  of  cysts  connected  with  the 
teeth  is  that  of  painless  expansion  of  the  alveolus,  more  frequently  of 
the  upper  jaw,  with  crackling  of  the  bone  on  pressure  and  ultimate 
absorption  of  the  bony  wall.  The  cyst  then  presents  a  bluish  appear- 
ance through  the  distended  mucous  membrane,  and  if  large,  gives  dis- 
tinct evidence  of  fluctuation."  When  an  incision  is  made  into  the 
cyst  a  dark-colored,  clear  fluid  escapes,  but  when  inflammation  is 
present  the  contents  become  purulent. 

The  treatment  of  such  cysts  consists  in  cutting  away  the  thin  outer 
wall,  so  that  the  cavity  may  granulate  up. 

Dentigerous  cysts  occur  in  connection  with  teeth,  most  commonly 
permanent  teeth,  in  which  the  process  of  evolution  has  been  arrested, 
and  is  due,  Mr.  Tomes  thinks,  to  the  accumulation  of  fluid  between 
the  enamel  and  soft  outer  tissue  at  the  time  when  the  enamel  is  com- 
pleted, which  fluid  is  usually  discharged  when  the  tooth  is  erupted ; 
but  when  the  tooth  remains  within  the  jaw  this  discharge  cannot  take 


282 


DENTAL    PATHOLOGY,    THERAPEUTICS. 


place,  and  it  continues  to  increase  in  quantity  until  a  cyst  is  estab- 
lished. We  are  thus  enabled  to  account  for  the  presence  of  cysts  in 
those  cases  in  which  neither  the  tooth  nor  adjacent  bone  presents  any 
appearance  of  disease.  In  illustration  of  this  theory,  Mr.  Tomes 
relates  a  case  in  which,  "  instead  of  having  the  two  fangs  common  to 
second  molars  of  the  lower  jaw,  the  implanted  portion  of  the  tooth 
was  dilated  into  one  large  concavity,  in  which  was  placed  the  crown 
of  a  second  tooth,  perfectly  invested  with  well-developed  enamel,  and 
with  the  masticating  surface  directed  toward  the  jaw.  The  two  teeth 
appear  to  be  united  by  dentine  at  one  point,  and  to  have  one  common 

pulp-cavity I  consider  that  in  the  case  cited  fluid  collected 

between  the  enamel  of  the  inverted  tooth  and  the  remains  of  the 


Fig.  134.— Dentigerous  Cyst  of  Lower  Jaw.    b.  Showing  position  of  tooth. 


enamel  organ,  situated  within  the  socket  of  the  second  molar.  As  the 
cyst  enlarged,  the  contiguous  bone  was  absorbed  to  make  room  for  it, 
and  new  tissue  was  concurrently  developed  on  the  outer  walls  of  the 
socket  till  at  last  a  large  cup  of  bone  was  formed."  ("Dental 
Surgery.") 

When  cysts  of  this  kind  occur  in  the  lower  jaw  they  present  more 
obvious  deformity.  Sometimes  the  cyst  undergoes  calcification,  and 
is  exceedingly  difficult  to  diagnose  from  a  solid  tumor. 

Mr.  Heath  remarks  that  "  the  diagnosis  of  dentigerous  cysts  from 
other  cysts  is  exceedingly  difficult  until  they  are  opened,  as,  indeed,  is 
the  recognition  of  any  form  of  cyst.  A  careful  examination  of  the 
mouth  may  reveal  the  absence  of  a  permanent  tooth,  or  may  show  a 
temporary  tooth  occupying  a  permanent  position.     On  the  other  hand, 


TUMORS  OF  THE  MOUTH  AND  JAWS.  283 

however,  it  must  be  remembered  that  teeth  may  be  wanting  without 
being  connected  with  any  disease." 

Many  errors  of  diagnosis,  leading  to  operations  for  the  removal  of 
supposed  tumors,  have  been  made  by  able  and  distinguished  surgeons, 
who  have  had  the  courage  and  candor  to  confess  their  mistakes, 
among  whom  may  be  mentioned  Gensoul,  Syme,  Feavu,  and  Lisfranc. 
The  two  latter  gentlemen  each  removed  half  the  jaw.  It  is  only 
when  the  osseous  walls  have  become  so  wasted  as  to  give  under  pres 
sure  a  parchment-like  crackling  that  the  diagnosis  may  be  made  with 
any  approach  to  certainty.  In  every  case  an  exploratory  puncture 
should  be  insisted  on  before  proceeding  to  operate.  The  existence  of 
a  cyst  determined,  and  communication  with  the  antrum  suspected, 
the  first  molar  tooth  should  be  removed  and  the  wall  of  the  antrum 
be  perforated  through  the  socket,  and  if  a  supernumerary  tooth  is 
found  in  the  cavity  it  should,  of  course,  be  removed.  In  many 
cases  it  is  necessary  to  remove  the  front  wall  of  the  antrum  and 
stuff  the  cavity  with  lint,   thus  inducing  granulations,  before  a  cure 


Fig.  135.— Inverted  Crowns  of  Teeth   between  Expanded  Roots  ok  other  Tep;th, 
Causing  Dentigerous  Cysts. 

can  be  effected.  This  can  generally  be  effected  without  incision  of 
the  integument.  When  feasible,  the  plate  of  bone  removed  should 
be  left  attached  to  the  periosteum  and  be  replaced  after  removal  of 
the  cyst. 

Cysts  in  the  lower  jaw  present  some  peculiarities  which  make  a 
second  description  necessary.  They  may  occur  in  connection  with 
fully  developed  teeth,  or  without  any  direct  connection  with  the  teeth. 
They  may  be  multilocular,  and  in  rare  instances  may  contain  one 
within  another.  Mr.  Coote  reports  a  case  in  an  infant  of  six  months 
— which  resulted  in  death  from  exhaustion  occasioned  by  continued 
discharge  after  an  operation — in  which,  covered  by  a  thin  shell  of 
bone,  a  perfect  nest  of  cysts  connected  with  the  antrum  have  been 
shown  to  arise  in  the  glandular  structure  of  its  lining  membrane,  but 
in  the  lower  jaw  we  have  no  such  membrane.  Instead  thereof  we 
have  two  layers  of  laminated  bone  enclosing  a  cancellated  structure 
lined  by  the  endosteum  alone.  Mr.  Heath  is  of  opinion  that  it 
is  in  these  calculi  the  disease  is  developed,  "A  cancellus  expanding 
and  producing  gradual  absorption  and  obliteration  of  its  neighbors 


284 


DENTAL    PATHOLOGY,    THERAPEUTICS. 


until  a  cyst  of  considerable  size  is  produced."  The  causation  of 
cystic  formations  in  the  lower  jaw  is  very  obscure,  though  they  are 
probably  associated  in  some  way  with  the  irritation  from  adjacent  roots. 
They  may  continue  to  reproduce  themselves  from  time  to  time,  until 
the  cancellated  tissue  is  entirely  destroyed. 

Cysts  in  connection  with  undeveloped  teeth — dentigerous  cysts — 
which  are  common  to  both  jaws,  may  suppurate  and  form  abscesses. 
They  generally  occur,  in  the  caseof  unerupted  teeth,  from  some  irrita- 
tion, and  are  more  common  to  permanent  than  to  deciduous  teeth. 
Inversion  of  the  tooth  also  appears  to  be  a  cause  of  these  cysts. 

Mr.  Heath  remarks  that  "when  dentigerous 
cysts  occur  in  the  lower  jaw  they  form  more 
isolated  and  prominent  tumors  than  in  the  case 
of  the  upper  jaw,  and  in  some  cases  the  pro- 
jecting bony  wall  has  been  removed." 


Fig.  136.  Fig.  137. 

Dentigerous  Cyst  due  to  Non-development  of  Canine  Tooth. 


The  treatment  of  dentigerous  cysts  consists  in  a  free  incision  and 
the  removal  of  the  unerupted  tooth,  as  a  simple  puncture  will  not 
answer.  The  front  wall  of  the  cyst  should  be  removed,  and  the  cavity 
filled  with  lint,  '^  so  as  to  induce  granulation  and  gradual  obliteration." 
This  may  be  accomplished  in  the  majority  of  cases  without  any  in- 
cision of  the  integuments.  After  the  removal  of  a  portion  of  the  cyst 
wall,  in  the  case  of  dentigerous  cysts  of  the  lower  jaw,  the  plates 
should  be  pressed  together  as  much  as  possible ;  and  the  same  may  be 
accomplished  in  the  case  of  the  upper  jaw  by  the  pressure  of  pads  and 
bandages.  Mr.  Heath  directs  that  the  cyst  should  always  be  reached 
by  dividing  the  mucous  membrane  within  the  mouth,  and  without  in- 
cising the  cheek  ;  but,  if  necessary,  a  single  line  of  incision  only  should 
be  made,  so  that  as  little  after-deformity  as  possible  may  be  produced. 


SALIVARY    CALCULUS.  285 

Unilocular  cysts  are  to  be  treated  simply  by  extracting  adjacent 
teeth,  and,  after  evacuating  the  contents,  when  the  walls  are  thin, 
crushing  them  in  so  as  to  diminish  the  size  of  the  cavity.  Accord- 
ing to  Mr.  Eve  multilocular  cysts,  so  far  from  having  a  dental  origin, 
are  produced  by  an  ingrowth  of  the  epithelium  of  the  gum.  They 
may  result  from  injury,  the  irritation  of  decayed  teeth,  or  long-con- 
tinued inflammation.  They  are  of  slow  growth,  and  present  very 
little  tendency  to  implicate  surrounding  parts.  Multilocular  cysts 
are  found  in  the  lower  jaw,  consisting  of  cells  varying  in  size  from 
that  of  a  pea  to  others  occupying  the  entire  thickness  of  the  bone. 

Multilocular  cysts  may  be  treated  according  to  the  plan  of  Mr. 
Butcher,  which  consists  in  dividing  the  mucous  membrane  over  the 
cyst  freely,  and  then  with  a  gouge  and  the  bone-forceps  removing  the 
expanded  external  plate  of  the  bone,  with  the  contents  and  lining 
membrane  of  the  cyst,  interfering  with  the  teeth  as  little  as  possible 
and  avoiding  the  facial  artery.  Dr.  Mason  Warren  recommends  a 
more  conservative  practice  than  that  of  Mr.  Butcher.  His  treatment 
consists  in  the  puncture  of  the  sac  within  the  mouth,  and  at  the  same 
time  obliterating  its  cavity  by  crushing ;  then  to  keep  up,  by  injections, 
etc.,  a  sufficient  degree  of  irritation  to  favor  the  deposition  of  new 
bone. 


CHAPTER  IX. 

CALCIC  DEPOSITS  ON  THE  TEETH. 

SALIVARY    CALCULUS. 

The  color,  consistence,  and  quantity  of  salivary  calculus,  or  tartar, 
as  it  is  most  commonly  called,  vary  in  different  temperaments,  and  upon 
all  of  them  the  state  of  the  general  health  exercises  considerable  influ- 
ence. The  characteristics  of  this  substance,  therefore,  furnish  diagno- 
ses important  both  to  the  physician  and  dentist.  Their  indications  are, 
in  many  cases,  less  equivocal  than  the  appearances  of  any  other  part  of 
the  mouth  ;  but,  like  those  of  the  gums,  should  not,  perhaps,  be  alone 
relied  upon.  It  is  necessary  to  interrogate  every  part  from  which  in- 
formation can  be  derived  concerning  the  pathological  condition  of 
the  several  organs  of  the  body. 

Salivary  calculus  is  composed  of  earthy  salts  and  animal  matter. 
Phosphate  of  lime  and  fibrin,  or  cartilage,  are  its  principal  ingredi- 
ents ;  a  small  quantity  of  animal  fat,  however,  enters  into  its  compo- 
sition, and  the  relative  proportions  of  its  constituents  vary  accordingly 


286  DENTAL    PATHOLOGY,    THERAPEUTICS. 

as  it  is  hard  or  soft,  or  as  the  temperament  of  the  individual  from 
whose  mouth  it  is  taken  is  favorable  or  unfavorable  to  health.  Hence 
it  is  that  the  analyses  that  have  been  made  of  it  by  different  chemists 
differ.     No  two  give  the  same  result. 

The  black,  dry  calculus  deposited  around  the  necks  of  the  teeth  of 
such  only  as  have  good  constitutions  is  never  in  large  quantities  ;  it  is 
dissolved  in  muriatic  acid  with  difificulty,  while  the  dry,  light-brown 
calculus  found  upon  the  teeth  of  bilious  persons  dissolves  more  readily 
in  it ;  but  the  soft,  white  calculus  found  upon  the  teeth  of  individuals 
of  neuro-lymphatic  temperaments  is  scarcely  at  all  soluble  in  the  acids, 
but  is  readily  dissolved  in  the  alkalies. 

All  persons  are  subject  to  deposits  of  salivary  calculus,  but  not 
alike  ;  it  collects  on  the  teeth  of  some  in  larger  quantities  than  on 
those  of  others,  and  its  chemical  and  physical  characteristics  are 
exceedingly  variable.  It  is  sometimes  almost  wholly  composed  of 
calcareous  ingredients  ;  at  other  times  these  constitute  but  about  one- 
half,  or  little  more  than  one-half,  of  its  substance,  the  remainder  being 
made  up  of  animal  matter.  Nor  is  its  color  more  uniform.  Some- 
times it  is  black,  at  other  times  it  is  of  a  dark,  pale,  or  yellowish 
brown,  and  in  some  instances  it  is  nearly  white.  It  also  differs  in  den- 
sity. In  the  mouths  of  some  it  has  a  solidity  of  texture  nearly  equal 
to  that  of  the  teeth  themselves  ;  in  others  it  is  so  soft  that  it  can  be 
scraped  from  the  teeth  with  the  thumb-  or  finger-nail.  The  black 
kind  is  the  hardest,  the  white  the  softest,  and  its  density  is  increased 
or  diminished  as  it  approaches  the  one  or  the  other  of  these  colors. 

Salivary  calculus  collects  in  very  small  quantities  on  the  teeth  of 
persons  possessed  of  the  most  perfect  constitutions,  and  even  on 
these  it  is  seldom  found  except  on  the  inner  surfaces  of  the  lower 
incisors  next  the  gums.  It  is  then  black,  or  of  a  dark  brown,  very  dry, 
and  almost  as  hard  as  the  teeth,  to  which  it  adheres  with  great  tenacity. 

It  rarely  happens  that  any  unpleasant  effects  are  produced  by  the 
presence  of  this  form  of  calculus  upon  the  teeth.  The  general  health 
is  never  affected  by  it,  and  the  only  local  injury  that  results  from  it  is 
slight  turgidity  of  the  edge  of  the  gums  in  immediate  contact  with  it. 

The  indications,  therefore,  of  this  description  of  calculus  are  favor- 
able, both  with  regard  to  the  teeth,  gums,  and  organism  generally. 
The  teeth  upon  which  it  is  found  are  of  an  excellent  quality  and 
rarely  affected  by  caries.  They  have  the  characteristics  represented 
as  belonging  to  the  best  kind,  and  teeth  of  this  description  are  only 
found  among  persons  having  good  innate  constitutions. 

There  is  another  form  of  black  calculus  differing  from  this  in  many 
particulars.  It  is  found  in  the  mouths  of  those  having  good  constitu- 
tions, but  whose  physical  powers  have  been  enervated  by  privation  or 


SALIVARY    CALCULUS.  287 

disease,  or  intemperance  and  debauchery,  and  most  frequently  by  the 
last  named.  It  is  found  in  large  quantities  on  the  teeth  opposite 
the  mouths  of  the  salivary  ducts;  it  is  exceedingly  hard,  and  agglu- 
tinated so  firmly  to  the  organs  that  it  is  removed  with  great  difficulty  ; 
it  is  very  black,  has  a  rough  and  uneven  surface,  and  is  covered  with  a 
glairy,  viscid,  and  almost  insufferably  offensive  mucus. 

The  presence  of  this  kind  of  salivary  calculus  is  attended  with  very 
hurtful  consequences,  not  only  to  the  gums,  alveolar  processes,  and 
teeth,  but  also  to  the  general  health.  It  causes  the  gums  to  inflame, 
swell,  suppurate,  and  recede  from  the  teeth,  the  alveoli  to  waste,  and 
the  teeth  to  loosen  and  frequently  to  drop  out.  The  secretions  of  the 
mouth  are  also  vitiated  by  it  and  rendered  unfit  to  be  taken  into  the 
stomach.  Hence,  as  long  as  it  is  permitted  to  remain  on  the  teeth, 
neither  the  skill  of  the  physician  nor  the  best  regulated  regimen, 
though  they  may  afford  partial  and  temporary  relief,  will  fully  restore 
to  the  system  its  healthy  functions. 

As  this  form  of  calculus  is  seldom  if  ever  met  with  except  in  con- 
stitutions fairly  excellent,  the  teeth  on  which  it  is  deposited  are 
generally  sound,  but  they  are  often  caused,  by  the  disease  which  is 
produced  in  the  gums  and  alveoli,  to  loosen  and  drop  out. 

The  dark-brown  calculus  is  not  so  hard  as  either  of  the  descriptions 
of  black.  It  sometimes  collects  in  tolerably  large  quantities  on  the 
lower  front  teeth  and  on  the  first  and  second  superior  molars ;  it  is 
also  often  found  on  all  the  teeth,  though  not  in  as  great  abundance  as 
on  these.  It  does  not  adhere  with  as  much  tenacity  as  either  of  the 
preceding  kinds,  and  can  be  more  easily  detached  from  them.  It  ex- 
hales a  more  fetid  odor  than  the  first  variety,  but  is  less  offensive  than 
the  second. 

The  persons  most  subject  to  this  kind  of  calculus  are  of  mixed 
temperaments,  the  sanguineous,  however,  always  predominating.  They 
may  be  denominated  sanguineo-serous  and  bilious.  Their  physical 
organization,  though  not  the  strongest  and  most  perfect,  may,  never- 
theless, be  considered  very  good.  But,  being  more  susceptible  to 
morbid  impressions,  their  general  health  is  less  uniform  and  more  liable 
to  impairment  than  those  possessed  of  the  most  perfect  constitutions. 

The  effects  arising  from  the  accumulations  of  this  description  of 
salivary  calculus,  both  local  and  constitutional,  are  less  hurtful  than 
the  variety  last  noticed;  but,  like  that,  it  causes  the  gums  to  inflame, 
swell,  suppurate,  and  to  retire  from  and  expose  the  necks  of  the  teeth, 
the  alveoli  to  waste,  the  teeth  to  loosen  and  sometimes  to  drop  out. 
It  also  gives  rise  to  a  vitiated  condition  of  the  fluids  of  the  mouth. 

Salivary  calculus  of  a  light  or  pale  yellowish-brown  color  is  of  a 
much  softer  consistence  than  the  darker  varieties,  and  is  seldom  found 


288  DENTAL    PATHOLOGY,    THERAPEUTICS. 

upon  the  teeth,  except  of  persons  of  bilious  temperament,  or  those  in 
whom  this  predominates.  It  has  a  rough  and,  for  the  most  part,  a  dry 
surface ;  it  is  found  in  large  quantities  opposite  the  mouths  of  the  sali. 
/ary  ducts,  and  sometimes  every  tooth  in  the  mouth  is  completely  im- 
bedded in  it.  It  contains  less  of  the  earthy  salts  and  more  of  the 
animal  matter  than  any  of  the  foregoing  descriptions,  and,  from  the 
quantity  of  vitiated  mucus  in  and  adhering  to  it,  has  an  exceedingly 
offensive  smell.  It  is  sometimes,  though  not  always,  so  soft  that  it 
may  be  crumbled  between  the  thumb  and  finger. 

Inflammation,  turgescence,  and  suppuration  of  the  gums,  inflam- 
mation of  the  alveolo-dental  periosteum,  the  destruction  of  the  sock- 
ets and  loss  of  the  teeth,  and  an  altered  condition  of  the  fluids  of  the 
mouth  are  among  the  local  effects  produced  by  the  long-continued 
presence  of  large  collections  of  this  variety  of  tartar.  The  constitu- 
tional effects  are  not  much  less  pernicious.  Indigestion  and  general 
derangement  of  all  the  assimilative  functions  are  among  the  most  com- 
mon. When  the  deposit  is  not  large,  inflammation  and  sponginess  of 
such  parts  of  the  gums  as  are  in  immediate  contact  with  it,  and  fetid 
breath,  are  the  principal  of  the  unpleasant  effects  produced  by  it. 

White  calculus  rarely  collects  in  very  large  quantities,  and  though 
most  abundant  on  the  outer  surfaces  of  the  first  and  second  superior 
molars  and  the  inner  surfaces  of  the  lower  incisors,  it  is  nevertheless 
frequently  found  on  all  the  teeth.  Its  calcareous  ingredients  are  less 
abundant  than  those  of  any  of  the  preceding  descriptions.  Fibrin, 
animal  fat,  and  mucus  constitute  by  far  the  larger  portion  of  its  sub- 
stance. It  is  very  soft,  seldom  exceeding  in  consistence  common 
cheese-curd,  to  which  in  appearance  it  bears  considerable  resemblance. 
Although  it  exerts  but  little  mechanical  irritation  upon  the  gums,  it 
keeps  up  a  constant  morbid  action  in  them.  Its  effects,  however, 
upon  the  teeth  are  far  more  deleterious  than  any  other  description  of 
calculus.  It  causes  rapid  decay  of  the  organs,  and  the  fluids  of  the 
mouth  are  also  vitiated  by  it. 

It  is  only  upon  the  teeth  of  persons  of  mucous  habit,  or  those  who 
have  suffered  from  diseases  of  the  mucous  membranes,  or  those  in 
whom  these  tissues  have  been  more  or  less  involved,  that  this  kind  of 
calculus  accumulates. 

Salivary  calculus  sometimes  accumulates  in  very  large  quantities, 
giving  to  the  mouth  a  most  disagreeable  and  repulsive  aspect,  and  im- 
parting to  the  breath,  not  unfrequently,  an  almost  insufferably  offen- 
sive odor.  Fig.  138  represents  a  set  of  teeth  incrusted  with  it,  and 
Fig.  139  a  single  tooth,  presented  to  the  author  by  Dr.  W.  Allen,  of 
Massachusetts,  with  the  largest  accumulation  of  this  substance  he  has 
ever  seen  in  one  mass.     Its  longest  diameter  is  an  inch  and  an  eighth. 


SALIVARY   CALCULUS.  289 

its  shortest  seven-eighths,  and  its  thickest  five-eighths  of  an  inch. 
Imbedded  in  its  substance  is  the  entire  crown  and  neck  of  a  lower  dens 
sapientiae,  which  was  removed  with  it.  It  is  of  a  light-brown  color, 
and  weighs  two  drams  and  seventeen  grains. 

The  late  Prof.  Austen  described  an  interesting  case  where  every 
tooth,  above  and  below,  had  been  loosened  by  alveolar  absorption 
caused  by  this  deposit ;  no  tooth  having  more  than  an  eighth  of  an 
inch  depth  of  socket,  and  some  of  them  held  only  by  an  exceedingly 
tough  attachment  to  the  gum  and  periosteum.  The  calculus  upon  the 
lower  incisors  was  equal  to  five  times  the  size  of  the  teeth,  most  of  it 
being  on  the  inside,  and  three-quarters  of  an  inch  thick  at  the  base. 


■  kiiiHl  'lii'  W\  Iml  Wi-nmWm 


Fig.  138. 


Fig.  139. 


A  singular  peculiarity  in  this  case  was  the  excessive  pain  of  extraction. 
Small  as  was  the  attachment,  it  was  uncommonly  firm,  and  the  patient, 
a  working-man,  was  laid  up  with  nervous  prostration  for  two  weeks 
after  the  operation. 


CHEMICAL   CONSTITUENTS    OF   SALIVARY   CALCULUS. 

Salivary  calculus  is  composed  of  phosphate  of  lime  and  animal  mat- 
ter, combined  in  various  proportions,  accordingly  as  it  is  hard  or  soft ; 
consequently  no  two  analyses  will  yield  the  same  result. 

Schehevetskey  gives  the  following  analysis.  He  found  one  hundred 
parts  to  contain  : — 

Water  and  organic  matter, 22.07 

Magnesium  phosphate, 1.07 

Calcium  phosphate, 67.18 

Calcium  carbonate, 8. 1 3 

Calcium  fluorid, 1. 55 

100.00 
Dr.  Stevenson  furnishes  the  following: — 

Friable  soft  calculus  Hard  calculus  from 
from  molars.  lower  incisors. 

Water  and  organic  matter, 21.48  "7-51 

Phosphate  of  magnesia, 1. 31  I.31 

Phosphate  of  calcium,  with  a  little  carbonate 

and  a  trace  of  fluorid, 77-21  81.18 

100.00  100.00 

19 


290  DENTAL    PATHOLOGY,    THERAPEUTICS. 

Hard,  dry  salivary  calculus  contains  more  earthy  and  less  animal 
matter  than  the  soft,  humid  calculus. 

Chemical  analysis  reveals  a  large  proportion  of  mucus,  aS  is  shown 
by  the  following  table  of  Vaquelin  and  Langier  : — 

Phosphate  of  lime  and  a  little  magnesia, 66 

Carbonate  of  lime, 9 

Salivary  mucus  (including  ptyalin), 13 

Animal  matter  soluble  in  hydrochloric  acid, 5 

Water  and  loss, „ .  7 

100 

An  analysis  of  saliva  reveals  water,  ptyalin,  fat,  chlorid  of  sodium, 
£hlorid  of  potassium,  phosphate  of  lime,  and  sulphocyanid  of  po- 
tassium. 

The  infusoria  of  salivary  calculus,  according  to  M.  Mandl,  have 
their  origin  in  the  vitiated  mucus  which  is  always  mixed  with  it. 

Scherer  detected  with  a  microscope  infusoria  in  large  numbers  in 
the  saliva  of  a  girl  laboring  under  a  scorbutic  affection  of  the  mouth  ; 
but  the  author  is  inclined  to  believe  that  they  had  their  origin  in  the 
mucous  secretions  of  this  cavity,  which  are  always  mixed  with  the 
former  fluid.  They  are  more  or  less  numerous,  as  the  calculus  is  hard 
or  soft,  or  in  proportion  to  the  quantity  of  mucus  that  enters  into  its 
composition.* 

ORIGIN   AND    DEPOSITION    OF   SALIVARY   CALCULUS. 

There  formerly  existed  much  diversity  of  opinion  as  to  the  source 
whence  salivary  calculus  is  derived,  but  it  is  now  generally  conceded 
that  this  deleterious  concretion  is  a  deposit  chiefly  from  the  saliva, 
with  an  admixture  of  mucus,  as  the  analyses  of  both  these  secretions 
reveal  the  necessary  materials  in  sufficient  quantity  to  form  it.  Bid- 
der and  Schmidt  make  the  phosphates  and  carbonates  amount  to  very 
nearly  one  per  cent,  in  the  saliva.  All  that  is  necessary,  therefore,  is 
that  the  surfaces  of  the  teeth  should  have  a  sufficient  affinity  for  the 
substance  in  question  to  cause  a  nucleus,  which,  when  once  formed,  the 
secretion  continues  until  serious  secondary  effects  are  liable  to  result. 

In  most  varieties  of  salivary  calculus  there  is  a  notable  superabun- 
dance of  the  phosphates  and  carbonates,  while  in  others  there  is  nearly 
forty  per  cent,  of  purely  animal  matter.  Hence  the  difference  in 
action  upon  them  by  acids  and  alkalies.  Of  the  animal  matter  enter- 
ing into  the  composition  of  salivary  calculus,  fibrin,  animal  fat,  and 
mucus  are  in  the  largest  proportion. 

*  Dr.  Dwindle  gives  a  minute  description  of  their  appearance  in  the  first  number 
of  the  tifth  volume  of  the  American  Journal  of  Dental  Science. 


SALIVARY    CALCULUS.  29 1 

Of  the  existence  of  the  elements  of  the  composition  of  calculus  in 
the  saliva  there  can  be  no  question.  Chemical  analyses  of  this  fluid, 
direct  from  the  glands,  place  all  doubt  upon  the  subject  at  rest.  Thus 
it  is  seen  that  the  chief  earthy  constituents  which  enter  into  the  for- 
mation of  this  substance  are  contained  in  the  saliva.  It  may  also  exist 
in  solution  in  the  mucous  fluid  of  the  mouth. 

That  the  deposition  of  calculus  may  take  place  on  one  side  of  the 
mouth  without  a  similar  deposit  on  the  opposite  side  furnishes  no  evi- 
dence in  support  of  the  doctrine  which  has  been  advanced,  that  it  is 
an  exhalation  from  the  capillaries  of  the  mucous  membrane  of  the 
gums.  The  mastication  of  food  is,  with  most  persons,  performed  more 
on  one  side  of  the  mouth  than  on  the  other ;  that  this  function  pre- 
vents, in  a  great  degree,  the  accumulation  of  calculus  on  the  organs  im- 
mediately concerned  is  a  fact  with  which  every  dentist  must  be  famil- 
iar. Hence  its  frequent  collection  on  the  teeth  of  one  side  and  not 
on  those  of  the  other.  And  that  it  is  ascribable  to  this  circumstance 
is  susceptible  of  positive  proof.  If,  on  the  removal  of  the  calculus  from 
the  teeth  of  a  person  in  whose  mouth  it  has  collected  only  on  those 
of  one  side,  mastication  be  afterward  altogether  performed  on  this 
side,  it  will  not  reaccumulate  on  them ;  and  if  requisite  attention  to 
the  cleanliness  of  the  teeth  on  the  other  side  be  not  observed,  it  will 
soon  collect  there,  although  these  teeth  had  before  remained  free  from  it. 

Again,  it  often  happens  that  disease  of  a  severe  character  is  excited 
in  the  gums  by  the  use  of  mercurial  medicines  and  other  causes,  and 
yet  but  a  small  quantity  of  calculus  collects  on  the  teeth ;  but  that  any 
condition  of  the  general  system,  or  of  the  mouth,  tending  to  make 
the  fluids  of  this  cavity  more  viscid,  promotes  its  formation  is  undeni- 
able. There  are,  however,  some  temperaments  much  more  favorable 
to  its  production  than  others  ;  and  it  is  a  well-established  fact  that  the 
mucous  membrane  of  those  in  whose  mouths  it  accumulates  in  largest 
quantity  is  the  most  irritable,  and  the  buccal  most  viscid.  Again,  if 
it  were  deposited  by  the  mucous  fluids  of  the  mouth,  it  would  collect 
in  largest  quantities  on  those  teeth. which  are  less  abundantly  bathed  in 
the  saliva ;  as,  for  example,  the  anterior  surfaces  of  the  upper  incisors 
and  cuspids,  while  those  opposite  to  the  mouths  of  the  ducts  which 
discharge  this  fluid  into  the  mouth  would  be  less  liable  to  deposits  of 
calculus  than  any  of  the  other  teeth  ;  whereas  the  contrary  is  found  to 
be  the  case. 

The  conclusion,  therefore,  is,  that  this  earthy  matter  is  chiefly 
a  salivary  deposit  and  takes  place  in  the  following  manner :  It  is 
precipitated  from  the  saliva,  as  this  fluid  enters  the  mouth— especially 
when  the  secretion  is  sluggish — upon  the  surfaces  of  the  teeth  opposite 
the  openings  into  the  ducts  from  which  it  is  poured.     To  these  its 


292  DENTAL    PATHOLOGY,    THERAPEUTICS. 

particles  become  agglutinated  by  the  mucus  always  found,  in  greater 
or  less  quantity,  upon  them.  Particle  after  particle  is  deposited,  until 
it  sometimes  accumulates  in  such  quantities  that  nearly  all  the  teeth 
are  almost  entirely  incrusted  with  it. 

As  regards  the  points  of  deposit  of  salivary  calculus,  the  greatest 
quantities  are  found  opposite  the  mouths  of  the  ducts  of  the  salivary 
glands,  upon  the  lingual  surfaces  of  the  inferior  incisors,  cuspidati  and 
bicuspids,  and  the  buccal  surfaces  of  the  superior  molars.  The  necks 
of  the  teeth,  about  the  free  margins  of  the  gums,  afford  favorable 
points  for  its  collection,  as  here  the  saliva  is  longer  retained  and  its 
calcareous  ingredients  precipitated  than  upon  more  exposed  parts.  It 
first  collects  about  the  necks  of  the  teeth  in  semicircular  or  crescent- 
like lines  close  to  the  enamel,  under  the  edge  of  the  gums,  and  a 
nucleus  being  once  formed  it  rapidly  encroaches  upon  the  crown, 
where  it  is  deposited  more  abundantly.  Certain  varieties  of  salivary 
calculus  adhere  to  the  necks  of  the  teeth  with  great  tenacity,  and  often 
progress  as  far  as  the  apex  of  the  root,  until  the  teeth  are  deprived 
of  their  support  and  their  roots  left  denuded  and  exposed.  Salivary 
calculus  is  never  deposited  on  the  flesh,  but  only  upon  such  substances 
as  represent  the  teeth  or  form  nuclei,  as  artificial  teeth,  for  example.  It 
is  sometimes  deposited  in  the  ducts,  which  may  be  owing  to  a  sluggish 
condition  of  the  saliva,  in  a  form  known  as  ranula,  and  has  been  re- 
moved in  a  mass  as  large  as  a  hazelnut. 

M.  Robert  presented  to  the  Anatomical  Society  of  Paris  a  hog's 
bristle,  which  had  been  forced  into  the  duct  of  Wharton,  densely  cov- 
ered with  a  thick  salivary  concretion. 

From  the  fact  that  salivary  calculus  is  often  found  upon  parts  where 
the  saliva  cannot  be  retained  for  any  length  of  time,  it  is  evident  that 
it  is  sometimes  precipitated  as  soon  as  this  fluid  enters  the  mouth. 

EFFECTS    OF    SALIVARY    CALCULUS    UPON    THE   TEETH,    GUMS,    AND 
ALVEOLAR    PROCESSES. 

Although  salivary  calculus  does  not  directly  act  injuriously  upon  the 
substance  of  the  teeth,  but,  on  the  contrary,  preserves  the  part  it 
covers  from  the  action  of  chemical  agents,  yet  the  effects  of  the  pres- 
ence of  this  substance  are  always  pernicious,  though  sometimes  more 
so  than  at  others.  An  altered  condition  of  the  fluids  of  the  mouth, 
diseased  gums,  and  not  unfrequently  the  gradual  destruction  of  the  al- 
veolar processes,  and  the  loosening  and  loss  of  the  teeth,  are  among 
the  consequences  that  result  from  it.  But  besides  these,  other  effects 
are  occasionally  produced,  among  which  may  be  enumerated  tumors 
and  spongy  excrescences  of  the  gums  of  various  kinds,  necrosis  and 
exfoliation  of  the  alveolar  processes  and  of  portions  of  the  maxillary 


SALIVARY    CALCULUS.  293 

bones,  hemorrhage  of  the  gums,  anorexia,  derangement  of  the  whole 
digestive  apparatus,  and  foul  breath,  catarrh,  cough,  diarrhea,  diseases 
of  various  kinds  in  the  maxillary  antra  and  nose,  pain  in  the  ear, 
headache,  melancholy,  hypochondriasis,  etc.  So  irritating  is  its  pres- 
ence that  wherever  it  comes  in  contact  with  the  gums  and  alveoli  it 
causes  their  absorption,  which  in  some  cases  may,  at  first,  be  attended 
with  little  or  no  inconvenience ;  while  in  others  considerable  inflam- 
mation, ending  in  suppuration  of  the  gums,  may  result,  extending  to 
the  mucous  membrane  of  the  mouth.  Periostitis  and  necrosis  of  the 
alveolar  processes  are  also  results  of  the  irritating  action  of  this 
substance.  The  character  of  the  effects,  however,  both  local  and 
constitutional,  depends  upon  the  quantity  and  consistence  of  the 
calculus,  and  upon  the  temperament  of  the  individual  as  well  as 
the  state  of  the  general  health  ;  the  two  former  of  these  are  deter- 
mined by  the  two  latter  and  by  the  attention  paid  to  the  cleanliness 
of  the  teeth.  If  this  last  be  properly  attended  to,  salivary  calculus, 
no  matter  how  great  the  constitutional  tendency  to  its  formation,  will 
not  collect  in  large  quantity  upon  the  teeth.  The  importance,  there- 
fore, of  its  constant  observance  cannot  be  too  strongly  impressed  upon 
the  patient,  especially  in  those  in  whom  there  exists  a  great  tendenc]' 
to  its  deposition. 

The  teeth  and  their  contiguous  parts  suffer  more  from  accumulations 
of  this  substance  than  from  almost  any  other  cause.  Caries  is  not 
much  more  destructive  to  them.  When  permitted  to  accumulate  for 
any  great  length  of  time  the  gums  become  so  morbidly  sensitive  that 
a  tooth-brush  cannot  be  used  without  causing  pain  ;  consequently,  the 
cleanliness  of  the  mouth  is  not  attempted,  and  thus,  no  means  being 
taken  to  prevent  its  formation,  it  accumulates  with  increased  rapidity, 
until  the  teeth,  one  after  another,  fall  in  quick  succession  victims  to 
its  desolating  ravages. 

It  sometimes  not  only  undermines  the  constitution  by  occasioning 
discharges  of  fetid  matter  from  the  gums  and  corrupting  the  fluids  of 
the  mouth,  but  it  also  renders  the  breath  exceedingly  unpleasant  and 
offensive.  So  nauseating  and  disagreeable  is  the  odor  which  some 
descriptions  of  calculus  exhale  that  the  atmosphere  of  a  whole  room 
is  contaminated  by  it  in  a  few  minutes. 

MANNER    OF    REMOVING    SALIVARY    CALCULUS. 

This  is  an  operation  of  great  importance  to  the  health  of  the  gums, 
alveolar  processes,  and  teeth.  But  from  a  misconception  of  its  nature, 
rather  than  from  fear  of  pain,  many  are  much  opposed  to  it;  and,  not- 
withstanding the  universal  admiration  in  which  clean  and  white  teeth 
are  held,  they  will  suffer  the  beauty  of  these  organs  to  be  destroyed 


294 


DENTAL    PATHOLOGY,    THERAPEUTICS. 


rather  than  submit  to  its  perforniance.  There  are  some,  indeed,  whc, 
though  scrupulously  particular  in  everything  that  regards  dress,  seem, 
nevertheless,  to  consider  cleanliness  of  the  mouth  as  unworthy  of  notice. 
,  For  the  removal  of  calculus  from  the  teeth  a  variety  of  instruments 
are  necessary,  which  should  be  so  constructed  that  they  may  be  easily 
applied  to  every  part  of  every  tooth.  Those  in  common  use  among 
dental  practitioners  are  so  very  similar  in  their  shape  and  so  well 
known  that  we  do  not  deem  it  necessary *to  point  out  the  minute  dif- 
ferences of  construction,  or  even  to  give  a  general  description  of  the 
instruments  themselves.  The  instruments  should  be  light,  made  with 
ivory,  ebony,  or  cocoa  handles,  and  tapering  from  a  little  above  the 
ferule  both  ways  ;  and  the  points  of  the  instruments  should  be  deli- 
cately shaped,  so  as  readily  to  pass  below  the  free  edge  of  the  gum. 
The  success  of  the  operation  depends  much  upon  the  careful  removal 
of  every  particle  of  deposit,  for  which  a  heavy,  clumsy,  or  large- 
bladed  instrument  is  wholly  unsuited.  If  any  particles  of  calculus  be 
suffered  to  remain,  they  will  irritate  the  gums  and  serve  as  nuclei  for 
immediate  re-accumulations. 

Drs.  F.  Abbott's  and  How's  sets  of  scalers,  represented  in  the  fol- 
lowing figures,  are  well  adapted  for  removing  salivary  calculus  from 
all  parts  of  the  teeth. 


678 


Fig.  140. 


SALIVARY    CALCULUS. 


^95 


The  adhesion  of  salivary  calculus  to  the  teeth  is  sometimes  so  great 
that  considerable  force  is  required  for  its  removal,  even  when  the 
sharpest  and  best-tempered  instruments  are  employed,  but  ordinarily 
it  may  be  removed  with  ease.  Considerable  tact,  however,  is  neces- 
sary to  perform  the  operation  in  a  skillful  manner;  more  than  most 
persons,  from  its  apparent  simplicity,  imagine.      This  skill  can  only 


Fig.  141. 

be  acquired  by  practice.  Calculus  may  be  taken  from  the  outer  and 
inner  surfaces  of  the  teeth  without  much  difficulty,  but  the  removal  of 
it  from  between  them  is  more  troublesome,  and  can  only  be  effected 
by  means  of  very  thin,  sharp-pointed  instruments.  Many,  however, 
prefer  scaling  instruments  with  slender  points,  such  as  are  represented 
by  Fig.  141,  which  are  used  with  a  pushing  motion  in  a  direction  from 


r 


Fig.  142. 


the  hand,  instead  of  toward  the  hand.     Fig.  142  represents  a  set  of 
five  scalers  suggested  by  Dr.  How. 

In  removing  this  substance  from  the  teeth  the  point  or  edge  of  the 
scaling  instrument  should  be  applied  below  the  deposit,  between  it 
and  the  gum,  and  passed  well  under,  until  it  comes  in  contact  with 
the  surface  of  the  tooth,  and  the  mass  scaled  off  in  the  direction  of 
the  cutting  edge  or  grinding  surface. 


2g6 


DENTAL   PATHOLOGY,    THERAPEUTICS. 


Fig.  143. 


Care  is  necessary  that  the  edge  of  the  instrument  does  not  roughen 
the  tooth  substance,  especially  the  dentine,  beyond  the  enamel.  After 
the  removal  of  the  greater  part  of  the  deposit,  the  instrument  should 
be  lightly  passed  over  the  surface,  to  detach  any  particles  which  may 
remain,  especially  upon  the  approximal  surfaces.  After  the  use  of  the 
scaling  instruments  finely  pulverized  pumice  or  silex  should  be  applied 
on  a  piece  of  orange  wood  so  shaped  as  to  reach  all  parts  on  which  the 
deposit  has  collected. 

The  wood-points  of  various  forms,  charged  with  finely-powdered 
pumice  or  silex  and  rotated  by  means  of  the  dental  engine,  are  very 

useful  for  removing  the  discoloration 
caused  by  salivary  calculus  and  the 
dark  mucous  deposit,  which  often 
cause  the  teeth  to  present  quite  an 
unsightly  appearance. 

The  small  tooth-polishing  brushes 
represented  by  Fig.  143,  and  the 
soft-rubber  polishing  cups  suggested 
by  Dr.  J.  B.  Wood,  Fig.  144,  both 
operated  by  the  dental  engine,  will  cleanse  teeth  from  remains  of  cal- 
culus after  use  of  scalers  and  from  discoloration,  even  under  the  free 
borders    of     the     gums. 


The  cervical  margins  of 
fillings  may  also  be  pol- 
ished by  the  small  brushes 
and  cups. 

Where  the  surface  of 
the  enamel  or  dentine  is 
found  to  be  rough  and 
without  the  natural  pol- 
ish, after  the  use  of  the 
pumice  or  silex,  Arkan- 
sas stone  and  the  bur- 
nisher may  be  applied 
vith  advantage,  and  a 
finely  polished  surface 
obtained. 

Several  sittings  are 
sometimes  necessary  for 
the  completion  of  the 
operation,  especially  when  the  calculus  has  accumulated  in  very  large 
quantities.  In  all  cases  of  this  sort  it  should  be  first  removed  from 
between  the  edges  of  the  gums  and  the  necks   of  the  teeth.     During 


Fig.  144. 


SANGUINARY  OR  SERUMAL  CALCULUS.  297 

the  intervals  between  the  several  operations  the  mouth  should  be 
gargled  several  times  a  day  with  some  cooling  and  astringent  wash ; 
but  on  this  subject  more  particular  directions  will  be  given  in  another 
chapter. 

During  the  removal  of  calculus  from  the  teeth  the  gums  often  bleed 
very  freely ;  and  when  much  swollen  and  spongy  it  may  be  well  to 
promote  it  by  holding  tepid  water  in  the  mouth.  When  the  lower 
incisors  are  loose,  as  is  often  the  case,  the  operation  should  be  pro- 
ceeded with  very  cautiously,  and  the  teeth  supported  by  the  fingers  of 
the  left  hand  holding  the  jaw,  especially  when  the  calculus  is  very 
hard  and  adheres  with  great  tenacity. 

Chemical  agents  are  sometimes  employed  for  the  removal  of  sali- 
vary calculus,  especially  such  of  the  vegetable  and  mineral  acids  as 
are  supposed  to  have  less  affinity  for  the  lime  of  the  teeth  than  the 
phosphoric  acid  with  which  it  is  combined  ;  but  it  is  scarcely  neces- 
sary to  say  that  any  acid  capable  of  dissolving  tartar  will  act  upon 
these  organs.  The  use  of  all  such  agents  should  be  most  scrupulously 
avoided.  Nearly  all  acids,  both  mineral  and  vegetable,  as  has  been 
shown  in  another  part  of  this  work,  are  prejudicial  to  the  teeth. 
Their  careless  administration  by  physicians  is  a  fruitful  source  of  in- 
jury to  the  teeth.  And  they  certainly  should  form  no  part  of  any 
dentifrice,  or  be  in  any  way  used  for  the  removal  of  stains  of  any 
kind  from  the  teeth. 

Pyrozone,  in  three  or  five  per  cent,  solutions,  is  recommended  for 
its  softening  action  upon  any  incrustations  about  the  teeth,  thus  ren- 
dering their  removal  easy,  and  causing  no  injury  to  the  tooth  structure 
or  on  myxomatous  tissues.  Care  should  be  taken,  however,  that  the 
five  per  cent,  solution  does  not  come  in  contact  with  the  gum,  as  its 
effect  is  more  or  less  painful  for  a  short  time. 

SANGUINARY    OR   SERUMAL   CALCULUS. 

By  this  title  Dr.  L.  C.  Ingersoll  designates  a  structureless  calcare- 
ous deposit  found  at  the  apex  of  the  root  of  a  tooth,  or  sometimes 
extending  in  a  line  of  granules  along  the  root  from  the  apex  to  the 
neck  of  the  tooth,  or  again  encircling  the  root  immediately  beneath 
the  free  margin  of  the  gum.  Being  of  sanguinary  origin,  it  is  found 
only  where  the  serum  of  the  blood  is  present,  which,  being  decom- 
posed, gives  up  its  lime  salts  and  affords  material  for  the  deposit, 
which  is  stained  with  the  hematin  of  the  blood.  This  form  of  calcu- 
lus is  derived  from  the  serum  that  exudes  from  the  diseased  tissue, 
and  its  superior  hardness  is  due  to  its  being  more  purely  mineral 
than  salivary  calculus,  and  it  is  generally  of  a  black  or  dark-green 
color.     Sanguinary  calculus  is  deposited  upon  the  roots  of  the  teeth, 


298  DENTAL    PATHOLOGY,    THERAPEUTICS. 

and  not  upon  their  crowns,  as  is  the  case  with  salivary  calculus,  being 
often  found  upon  the  very  apex  of  the  roots.  It  also  differs  in  another 
respect  from  salivary  calculus  ;  the  sanguinary,  resulting  from  the 
disorganization  of  blood  and  ulceration  of  tissues,  is  in  the  form  of 
dark,  hard  granulations  approaching  crystallization.  The  root  of  the 
affected  tooth  is  denuded  of  its  cementum,  and  the  granular  de- 
posit so  closely  adheres  that  its  removal  is  quite  difficult.  Sometimes 
it  is  found  immediately  beneath  the  margin  of  the  gum,  in  the  form 
of  a  dark,  hard,  rough  ring,  which  may  occasionally  be  visible  through 
the  gum  in  the  form  of  a  dark  circle.  A  viscid,  serous  fluid  may 
exude  from  about  the  neck  of  the  tooth  under  slight  pressure,  the 
result  of  the  ulceration  which  gives  rise  to  the  deposit.  This  fluid  is 
not  of  the  same  nature  as  the  pus  from  an  abscess,  being  watery  and 
nearly  odorless,  and  composed,  in  a  great  part,  of  the  serum  of  the 
blood.  While  salivary  calculus  causes  inflammation,  sanguinary  cal- 
culus is  a  result  of  inflammatory  action,  and  is  found  upon  teeth 
affected  with  ulceration.  The  method  of  removing  sanguinary  calcu- 
lus is  referred  to  in  the  treatment  of  alveolar  pyorrhea. 

MUCOUS    DEPOSIT    ON    THE    TEETH. 

While  persons  of  all  ages  are  subject  to  deposits  of  salivary  cal- 
culus, there  is  a  mucous  deposit  to  which  the  teeth  of  children  are 
especially  liable,  in  the  form  of  a  brown  or  a  green  stain,  which  has 
been  erroneously  called  green  tartar.  This  deposit  is  generally 
found  upon  the  labial  surfaces  of  the  front  teeth,  more  especially  upon 
those  of  the  upper  jaw,  and  varies  in  color  from  a  light  brown  to  a 
dark  green.  From  its  not  collecting  upon  the  posterior  teeth  and 
upon  the  lingual  surfaces  of  the  inferior  front  teeth  opposite  the 
mouths  of  the  ducts  leading  from  the  salivary  glands,  there  is  every 
reason  to  conclude  that  this  deposit  is  not  precipitated  by  the  saliva, 
and  hence  is  altogether  different  in  its  origin  from  salivary  calculus. 
It  is  generally  considered  to  be  a  deposit  from  the  mucus,  when  this 
secretion  is  in  a  more  acid  condition  than  is  natural.  From  its  effects 
upon  the  teeth  when  it  is  allowed  to  remain  on  them  for  a  considera- 
ble time,  and  also  from  the  fact  that  it  is  most  abundant  when  the 
mucus  is  secreted  in  large  quantities  and  of  a  decidedly  acid  reaction, 
there  is  little  doubt  as  to  its  origin  from  this  secretion. 

That  it  is  not  deposited  on  all  parts  of  the  teeth  is  no  reason  for 
doubting  the  correctness  of  this  theory,  when  we  consider  that  the 
parts  upon  which  it  is  found  are  those  protected  from  the  friction  of 
food  and  the  movements  of  the  tongue  and  the  flow  of  the  saliva. 

This  form  of  discoloration  of  the  enamel  is  indicative  of  an  irrita- 
ble condition  of  the  mucous  membranes  and  viscidity  of  the  fluids 


MUCOUS    DEPOSIT    ON    THE    TEETH.  299 

of  the  mouth.  Sour  eructations,  vomitings,  diarrhea,  and  dysentery- 
are  not  infrequent  with  those  whose  teeth  are  thus  affected.  While 
the  presence  of  this  green  stain  on  lately  erupted  teeth  is  almost  a 
certain  indication  of  softened  enamel,  this  is  not  the  case  when  it  is 
deposited  on  adult  and  very  dense  teeth.  In  the  latter  case  it  does 
not  appear  to  be  a  precipitate  from  the  mucus,  as  salivary  calculus 
is  from  the  saliva,  but  is  rather  a  growth  of  fungi  upon  the  surface, 
and  it  is  yet  an  open  question  whether  it  develops  its  own  acid,  as  in 
the  case  of  the  "  sprosspilz  "  lately  described  by  Dr.  Miller,  or  whether 
it  retains  the  neutral  secretions  to  the  acidulated  stage. 

According  to  Wedl,  it  may  "readily  be  demonstrated  that  the  de- 
posit is  a  green,  greenish-yellow,  uniformly  minutely  granular  mass 
which  is  morphologically  identical  with  the  matrix  of  the  leptothrix." 

In  regard  to  the  effects  of  this  mucous  deposit  upon  the  teeth,  while 
salivary  calculus  tends  to  preserve  the  portion  of  tooth-substance  on 
which  it  is  precipitated,  this  green  stain  so  erodes  the  enamel  that  de- 
cay advances  in  the  part  which  it  covers,  more  or  less  rapidly,  accord- 
ing to  the  quality  of  the  teeth  and  the  length  of  time  it  is  allowed  to 
remain.  The  removal  of  this  mucous  deposit  requires  more  skillful 
manipulation  than  that  of  salivary  calculus,  on  account  of  its  being  a 
thin  film  entering  into  the  substance  of  the  enamel,  rendering  it  diffi- 
cult to  detach  without  injury  to  the  tooth  substance  ;  whereas  salivary 
calculus  is  deposited  in  such  quantities  as  to  leave  thick  incrustations, 
which  are  readily  scaled  off  from  an  uninjured  surface.  Where  the 
erosion  caused  by  this  mucous  deposit  is  but  slight,  it  may  be  removed 
by  Arkansas  or  Superior  stones,  or  by  finely  powdered  silex  or  pumice 
stone  and  water  applied  on  a  stick  of  hard,  fine-grained  wood,  such  as 
orange  wood  or  hickory ;  the  point  of  the  piece  of  wood  being  so  formed 
as  to  adapt  it  well  to  the  surface  on  which  it  is  to  be  used.  The  wood- 
points  or  small  brushes,  or  soft  rubber  cups,  charged  with  either  of  the 
powders  referred  to,  and  rotated  by  means  of  the  dental  engine,  will 
prove  very  serviceable  for  such  an  operation.  After  all  the  discolora- 
tion is  removed  by  the  means  just  referred  to,  the  surface  should  be 
well  burnished  with  a  steel  burnisher  and  a  solution  of  pure  Castile  or 
white  Windsor  soap.  Pyrozone  in  five  per  cent,  solution  is  also  useful 
in  removing  this  green  stain,  care  being  taken  that  it  does  not  come 
in  contact  with  the  gum  tissue.  When,  however,  the  effects  of  this 
mucous  deposit  are  more  serious,  the  enamel  not  only  being  discolored 
but  deeply  eroded,  it  is  necessary  to  make  use  of  the  corundum  point, 
rotated  by  means  of  the  dental  engine,  the  enamel  chisel,  or  file,  to  re- 
move the  injured  surface.  The  enamel  chisel  is  to  be  preferred  to  the 
file  in  all  cases  where  it  is  applicable ;  and  the  plain  surface  thus  ob- 
tained should  be  polished  with  fine  silex  or  pumice  stone,  Arkansas  or 


300  DENTAL    PATHOLOGY,    THERAPEUTICS. 

Superior  stones,  and  the  burnisher.  Care  is  necessary  in  the  use  of 
the  enamel  chisel,  to  avoid  wounding  the  neighboring  soft  tissues.  To 
prevent  the  possibility  of  such  an  accident  and  to  enable  the  operator 
to  have  control  over  his  instrument,  the  chisel  should  be  held  firmly 
with  the  hand  in  such  a  manner  as  to  allow  the  thumb  to  rest  on  an 
adjoining  tooth.  When  the  dentine  is  very  sensitive,  as  is  frequently 
the  case,  a  proper  agent  for  allaying  the  sensitiveness  may  be  applied 
from  time  to  time  to  the  surface,  as  the  operation  of  cutting  it  away 
proceeds.     (See  ''Treatment  of  Sensitive  Dentine.") 


CHAPTER  X. 

NECROSIS    AND    EXFOLIATION    OF   THE   ALVEOLAR   PROCESSES. 

The  alveolar  processes,  as  well  as  other  osseous  structures,  are  liable 
to  necrosis  or  loss  of  vitality.  When  their  connection  with  the  peri- 
osteum— the  source  from  whence  they  derive  their  nourishment  and 
vitality — is  destroyed,  death  follows  as  a  necessary  consequence.  The 
loss  of  vitality  may  be  confined  to  the  socket  of  a  single  tooth,  but 
more  frequently  it  extends  to  several,  and  sometimes  to  the  alveolar 
border,  occasionally  including  a  part  or  the  whole  of  the  jaw.  It  may 
occur  in  either  jaw,  but  it  is  more  liable  to  take  place  in  the  lower 
than  in  the  upper.  When  confined  to  the  alveoli  the  dead  part  is  never 
wholly  replaced  with  new  bone,  but  examples  are  on  record  of  the  re- 
generation of  a  large  portion  of 
the  lower  jaw. 

When   one    or   more   of    the 

cavities  of  the  teeth  lose   their 

vitality,    nature   exerts     all  her 

energies   to   separate    the   dead 

^5''-^'--^*'^ '^'•X'-'t'^^^i^^^^w  from  the  living  bone;  this  pro- 

^'-.  ..xj^-,    '  ,:.  ce?,?,,  technically  termed  exfolia- 

tion, is  supposed  by  some  to  con- 

FiG.  145. — Section  of  Necrosed  Lower  Jaw.      •   .    •  .       r  .  •        • 

sist  in  a  sort  of  suppurative  in- 
flammation, but  there  is  reason  to  believe  it  is  effected  by  the  action 
of  a  corrosive  fluid  poured  out  from  the  fungous  granulations  of  the 
living  bone  in  immediate  contact  with  the  necrosed  part.  During  the 
process  of  exfoliation  a  thin,  acrid  matter  is  discharged  from  one  01 
more  fistulous  openings  through  the  gums  or  from  between  them  and 
the  necks  of  the  teeth  ;  the  gums,  having  lost  their  connection  with 


NECROSIS   AND    EXFOLIATION    OF   ALVEOLAR   PROCESSES.  30I 

the  necrosed  bone,  become  soft  and  spongy,  and  assume  a  dark  purple 
appearance,  are  preternaturally  sensitive  to  the  touch,  and  bleed  from 
the  most  trifling  injury. 

The  subject  of  a  case  worthy  of  notice  was  a  lady  of  a  cachectic 
habit,  about  thirty-five  years  of  age.  The  necrosis  resulted  from 
inflammation  of  the  peridental  membrane,  oc- 
casioned by  irritation  produced  by  the  roots  of 
four  incisors  upon  which  pivot  teeth  had  been 
placed,  which,  however,  had  been  removed  some 
two  or  three  weeks  before  the  author  saw  the  pa- 
tient. At  this  time  necrosis  had  extended  not 
only  to  the  sockets  of  these  teeth,  but  also  up  to 
the  nasal  crest  of  the  maxillary  bone,  and  the  process  of  exfoliation 
had  already  proceeded  so  far  that  he  was  enabled  to  remove  the  entire 
piece,  the  appearance  of  which  is  represented  in  Fig.  146.  A  few 
weeks  after  the  removal  of  this  piece  he  again  saw  the  patient,  and, 
on  examination,  found  a  large  portion  of  the  palatine  plate  of  the 
bone  in  a  necrosed  state ;  but  the  process  of  separation  had  not  yet 
proceeded  far  enough  to  enable  him  to  remove  it. 

The  accompanying  engraving,  made  from  a  drawing  furnished  the 
author  by  Dr.   Maynard,  represents  a  case  of  necrosis  and  exfoliation 

of  a  portion  of  the  outer  wall  of 
the  alveolar  ridge,  and  the  conse- 
quent protrusion  of  the  roots  of  the 
teeth  on  one  side  of  the  mouth. 

The  alveolar  process  in  relation 
with  the  superior  central  incisors 
appears  to  be  more  susceptible  to 
necrosis  than  other  portions,  and  this  may  be  ascribed  to  such  causes 
as  diminished  vitality  occurring  during  conditions  of  depression  and 
debility,  the  liability  of  such  a  prominent  part  to  mechanical  injury, 
and  the  effect  of  suppurative  inflammation  upon  a  portion  of  the  process 
which  possesses  a  less  degree  of  restorative  power  than  other  portions 
better  protected  by  muscular  tissue. 

Phosphor-Necrosis. — Necrosis  of  the  bones  of  the  jaws  may  also 
result  from  exposure  to  the  fumes  of  phosphorus,  as  in  the  manufac- 
ture of  matches,  for  example. 

The  disease,  when  due  to  such  a  cause,  usually  commences  about  a 
carious  tooth,  or  in  an  alveolar  cavity  opened  by  the  extraction  of  a 
tooth,  and  is  sometimes  complicated  with  affections  of  the  lungs  and 
air-passages. 

In  phosphor-necrosis  there  is  a  peculiar  pasty  appearance  of  the 
face,  puffiness  of  the  cheeks,  and  considerable  pain  and  swelling  in  the 


302  DENTAL    PATHOLOGY,    THERAPEUTICS. 

affected  jaw.  Instead  of  the  separation  of  a  sequestrum,  the  dead 
bone  becomes  incrusted  with  a  pumice-stone-like  material,  which 
adheres  very  firmly  to  it.  Abscesses  form  and  discharge  externally 
through  the  skin  of  the  cheek,  and  leave  fistulous  openings  for  the 
escape  of  the  matter. 

Causes. — The  immediate  cause  of  necrosis  is  the  death  of  the  peri- 
osteum, occasioned  by  inflammation.  The  cause  of  this,  as  has 
already  been  shown,  is,  in  a  large  majority  of  the  cases,  dental  irrita- 
tion. Necrosis  of  the  alveolar  process  occurs  very  frequently  while 
the  system  is  under  the  influence  of  mercurial  medicines,  and  during 
bilious  and  inflammatory  fevers,  and  certain  other  constitutional  dis- 
eases, as  syphilis,  smallpox,  etc.  It  may  also  result  from  mechanical 
injuries  and  the  devitalizing  effect  of  such  agents  as  arsenious  acid 
and  chlorid  of  zinc,  when  applied  to  destroy  pulps  of  teeth,  and  so 
obtund  the  sensibility  of  dentine,  etc.,  etc. 

Treatment. — The  treatment  of  cases  of  this  kind  consists  in  the  re- 
moval of  the  sequestra,  strict  attention  to  cleanliness,  and  the  free  use 
of  chlorinated  washes.  As  soon  as  the  dead  portions  of  bone  become 
separated  from  the  living,  and  can  be  easily  removed,  they  should  be 
taken  away  with  a  pair  of  forceps.  Should  the  removal  of  a  consid- 
erable portion  of  the  bone  of  the  jaw  be  requisite,  it  is  seldom  neces- 
sary to  interfere  with  the  skin  or  make  an  external  incision.  The 
wliole  of  the  lower  jaw  can  be  removed  in  this  manner  by  dividing  it 
at  the  chin,  and  after  separating  all  the  attachments  of  the  soft  parts 
with  the  knife,  drawing  out  each  half  at  a  time. 

To  correct  the  offensive  odor  and  disagreeable  taste  occasioned  by 
the  constant  discharge  of  fetid  matter,  washes  of  chlorid  of  sodium 
may  be  employed. 

There  is  no  remedy,  perhaps,  that  gives  more  satisfaction  in  the 
treatment  of  necrosed  alveolar  process  and  carious  bone,  than  dilute 
aromatic  sulphuric  acid,  combined  with  a  small  quantity  of  tincture  of 
capsicum,  using  alternately  the  antiseptic  known  as  "listerine." 
Prior  to  the  application  of  such  agents,  the  diseased  parts  should  be 
syringed  with  tepid  water,  and  this  cleansing  process  continued 
throughout  the  entire  course  of  treatment.  While  cold  water  will 
coagulate  pus  and  unhealthy  secretions,  which  are  irritating  by  their 
j;ressure,  warm  water  will  produce  the  opposite  effect,  and  is  a  useful 
adjunct  to  the  antiseptic  remedies.  The  removal  of  teeth,  in  cases  of 
necrosis  of  the  alveolar  process,  should  only  be  resorted  to  after  mature 
consideration,  for  it  frequently  happens  that  the  affection  is  confined 
to  the  labial  walls,  and  if  it  is  arrested  new  bone  may  be  formed  to 
such  a  degree  as  to  give  stability  to  the  teeth  in  relation  with  the 
affected  part. 


ABSORPTION    OF    THE    ALVEOLAR    PROCESSES.  303 

Condy's  fluid,  or  a  solution  of  permanganate  of  potash,  a  weak 
solution  of  carbolic  acid,  or  a  solution  of  chlorinated  soda,  will 
answer  as  disinfectants  and  correct  the  fetor.  The  strength  of  the 
patient  should  be  supported  by  stimulants  and  tonics,  and  good 
nourishment. 


ABSORPTION    OR    GRADUAL    DESTRUCTION    OF     THE    ALVEOLAR 
PROCESSES. 

This  disease,  to  which  the  term  "  phagedenic  pericementitis  "  has 
been  applied,  is  a  destruction  of  the  walls  of  the  alveolar  cavities  of 
the  teeth,  by  a  process  of  absorption  which  is  always  preceded  by  a 
corresponding  loss  of  the  peridental  membrane,  and  which  is  usually 
the  result  of  a  chronic  form  of  inflammation. 

It  is  always  accompanied  by  a  slight  increase  of  redness,  tumefac- 
tion, and  a  shrinkage  of  the  edges  of  the  gums  (ulatrophia) ;  but  the 
diseased  action  here  is  so  inconsiderable  as  often  to  attract  little  atten- 
tion. It  is  also  attended  by  a  slight  discharge  of  purulent  matter  from 
between  the  margin  of  the  gum  and  tooth ;  but  the  quantity  is  so 
small  that  it  usually  escapes  observation.  The  peridental  membrane 
participates  also  in  the  diseased  action,  but  this  is  so  often  confined  to 
the  corresponding  wall  of  the  process  which  is  absorbed  away,  that 
the  tooth  often  remains  quite  firmly  articulated,  after  the  wasting  of 
its  socket  has  proceeded  even  so  far  as  to  expose  more  than  half  of  the 
root.  Indeed,  the  affection  appears  to  be  closely  allied  to  chronic  in- 
flammation and  tumefaction  of  the  gums. 

The  progress  of  the  disease  is  often  so  slow  that  ten,  fifteen,  or 
twenty  years  are  required  to  affect  very  per- 
ceptibly the  stability  of  the  teeth  in  their 
cavities.  The  commencement  of  this  de- 
structive process  is  usually  first  observed 
around  the  cuspid  teeth  ;  sometimes  it  makes 
its  appearance  on  the  alveoli  of  the  palatine 
roots  of  the  first  and  second  upper  molars,  and 
occasionally  it  goes  on  here  for  years  before  it 
affects  the  cavities  of  any  of  the  other  teeth. 

The  teeth,  after  their  roots  have  been  partially  exposed,  become, 
as  might  naturally  be  supposed,  more  susceptible  to  impression  from 
heat  and  cold,  and  more  easily  affected  by  acids  or  saccharine  matters  ; 
but  this  is  about  the  only  manifest  inconvenience  experienced  from  the 
disease  until  the  teeth  begin  to  loosen  in  their  cavities  and  are  gradu- 
ally displaced. 

In  Fig.  148  is  represented  a  case  in  which  the  roots  of  the  teeth 
have  become  considerably  exposed  by  the  gradual  wasting  of  their 


304  DENTAL    PATHOLOGY,    THERAPEUTICS. 

sockets — the  destruction  being,  as  is  usual,  greatest  toward  the  median 
line. 

Apparently  the  absorption  of  the  bone  occurs  as  a  consequence  of 
the  inflammation  of  the  peridental  membrane. 

Causes. — The  cause  of  this  peculiar  affection  has  never  been  very 
satisfactorily  explained.  Some  have  supposed  that,  inasmuch  as  it 
occurs  most  frequently  in  persons  of  advanced  age,  it  results  from  a 
decline  of  the  vital  powers  of  the  body,  independently  of  local  causes ; 
but,  as  it  is  often  met  with  in  middle-aged  persons  whose  constitutional 
health  is  unimpaired,  we  doubt  the  correctness  of  the  opinion.  In 
all  cases  which  have  come  under  our  observation,  whether  in  middle- 
aged  or  very  old  persons,  the  teeth  indicated  an  excellent  innate  con- 
stitution, whatever  may  have  been  the  state  of  the  general  health  at 
the  time.  In  every  instance  these  organs  were  possessed  of  great 
density,  and  it  is  evident  that  teeth  endowed  with  the  power  of  resist- 
ing to  so  late  a  period  of  life  the  action  of  the  causes  of  decay,  to 
which  all  teeth  are  more  or  less  exposed,  must  be  possessed  of  extreme 
hardness,  and,  necessarily,  a  corresponding  low  degree  of  vitality.  In 
view  of  this  fact  we  have  been  led  to  the  opinion  that  the  teeth  them- 
selves may  act  to  some  extent  as  the  mechanical  irritants  to  the  more 
highly  vitalized  parts  with  which  they  are  immediately  connected, 
causing  an  increase  of  vascular  action  in  the  periosteum  of  the  thin 
edges  of  the  alveoli  and  margin  of  the  gums.  This  abnormal  condition 
is  attended  by  a  slight  secretion  of  purulent  matter  observed  between 
the  edges  of  the  gums  and  teeth.  It  is  to  the  corrosive  action  of  this 
purulent  matter  that  the  gradual  destruction  of  the  alveoli  has  by  some 
been  attributed  ;  but  it  is  more  probably  a  result  of  the  obscure  dis- 
ease than  its  cause. 

This  affection  has  been  ascribed  to  the  presence  of  salivary  and  san- 
guinary calculus,  the  use  of  charcoal  powder  as  a  dentifrice,  and  the 
application  of  a  very  stiff  brush  for  cleaning  the  teeth;  but  when 
caused  by  these  two  latter  agents  the  absorption  does  not  progress  to 
such  a  degree  as  when  it  is  owing  to  a  want  of  congeniality  between 
the  tooth  and  the  more  highly  vitalized  structure  surrounding  its  root, 
or  the  other  causes  before  referred  to. 

A  later  theory  as  to  the  cause  of  this  affection  has  been  advanced 
by  Dr.  Arkoevy,  who  believes  that  it  is  caused  by  a  certain  fungous 
formation  found  in  close  connection  with  the  wasting  of  the  alveoli 
and  the  gingival  margin,  as  well  as  the  subsequent  loosening  of  the 
teeth  ;  and  that  it  is  quite  different  from  leptothrix  buccalis,  although 
it  is  in  developmental  relation  with  it. 

Dr.  G.  V,  Black  also  states  that  it  is  probable  that  the  disease  is 
caused  and  maintained  by  the  presence  of  some  peculiar  fungus  or 


ABSORPTION    OF   THE   ALVEOLAR    PROCESSES.  3©^ 

form  of  microorganism,  and  that  it  is  infectious,  this  tendency  being 
shown  by  the  loss  of  the  neighboring  teeth.  Others  have  ascribed 
this  affection  to  a  peridental  inflammation  arising  from  a  gouty  or 
rheumatic  diathesis. 

Treatment. — From  what  has  been  said  concerning  the  cause  of  this 
affection,  it  is  obvious  that  a  cure  cannot  always  be  effected  ;  its 
progress,  however,  may  sometimes  be  arrested.  The  first  step  in  the 
treatment  is  to  remove  all  irritants,  such  as  deposits  of  calculus,  from 
the  necks  and  roots  of  the  teeth,  and  correct  the  nature  of  the  fluids 
of  the  mouth  abnormal  in  character  by  constitutional  treatment,  the 
use  of  lime-water,  and  a  detergent  dentifrice.  Should  such  means 
prove  ineffectual,  the  application  of  a  solution  of  iodin  and  creosote  or 
carbolic  acid,  or  chlorid  of  zinc  to  the  margins  of  the  gums  will  often 
be  of  benefit  in  retarding  the  absorption  and  inducing  a  more  healthy 
action.  The  secretion  of  the  purulent  matter,  to  the  action  of  which 
some  attribute  the  destruction  of  the  alveoli,  is  the  result  of  a  disease 
in  the  peridental  membrane  and  the  edges  of  the  gums,  arising  from 
some  peculiar  physical  condition  of  the  teeth,  the  progress  of  which 
may  be  retarded  by  cleaning  the  teeth  frequently  and  thoroughly, 
using  the  precaution  each  time  to  remove  the  purulent  matter  from 
between  the  edges  of  the  gums  and  teeth,  lest,  if  allowed  to  remain,  it 
should  become  putrescent,  and  in  this  condition  act  as  an  irritant  to 
the  gum.  For  this  purpose  the  parts  should  be  washed  with  a  solution 
of  peroxid  of  hydrogen  and  bichlorid  of  mercury  (one  grain  of  the 
latter  to  the  ounce  of  the  former),  after  which  much  benefit  will  be 
derived  by  applying  a  30  per  cent,  solution  of  chlorid  of  zinc,  by 
means  of  a  camel's-hair  brush,  to  the  margins  of  the  gums.  As  the 
margin  of  the  gum  is  inflamed,  and  a  sulcus  or  pocket  formed  between 
it  and  the  tooth,  the  use  of  the  agents  above  referred  to  will  promote 
healthy  granulations. 

The  judicious  application  of  pressure  upon  the  gum  has,  in  some 
cases,  restored  the  receded  portion,  to  a  degree,  at  least. 

Dr.  G.  V.  Black  suggests  that  when  there  is  rapid  destruction  of  the 
tissue  and  a  considerable  portion  of  the  alveolar  wall  has  been  de- 
stroyed, and  much  of  the  peridental  membrane  detached  from  the 
root  of  the  tooth,  it  is  better  to  cut  away  some  parts  of  this  with  instru- 
ments until  firm  bone  is  felt,  but  that  care  should  be  taken  not  to  in- 
jure the  gingival  margin  in  any  manner.  The  soft  tissue  farther  up, 
however,  may  be  lacerated  without  evil  result,  but  the  margin  of  the 
gum  should  be  preserved  so  that  it  may  close  around  the  neck  of  the 
affected  tooth. 

Where  it  is  desirable  to  preserve  a  valuable  tooth,  one  of  the  roots 
of  which  has  been  denuded  of  gum   and  process,  such  root  may  be 


3o6  DENTAL    PATHOLOGY,    THERAPEUTICS. 

amputated  by  the  use  of  a  fissure-burr  operated  by  the  dental  engine. 
The  root  should  be  cut  off  as  close  to  its  union  with  the  crown  as  pos- 
sible and  the  surface  made  smooth.  It  is  advisable  to  fill  all  the  roots 
with  gold  before  amputating. 

HYPERTROPHY    OF   THE   WALLS    OF    THE   ALVEOLAR   CAVITIES. 

A  tooth  is  sometimes  slowly  forced  from  its  place  by  a  deposit  of 
bony  matter  in  the  bottom  or  on  the  side  of  the  socket.  Two,  or  even 
three,  teeth  may  be  gradually  displaced  at  the  same  time,  by  exostosis 
of  the  alveoli.  The  deposition  usually  proceeds  so  slowly  that  one  or 
two  years  are  required  to  effect  a  very  perceptible  change  in  the  situation 
of  a  tooth.  The  upper  central  incisors  are  more  frequently  affected 
than  any  of  the  other  teeth,  and  the  deposit  occurs  oftener  at  the  bot- 
tom than  on  the  sides  of  the  alveoli.  In  the  first  case,  the  tooth  is 
gradually  protruded  from  the  socket ;  in  the  other,  it  is  either  pressed 
out  of  the  arch  or  against  one  of  the  adjoining  teeth.  Irregularity  in 
the  arrangement  of  the  teeth  is,  in  this  manner,  sometimes  produced, 
especially  when  more  than  one  socket  is  affected  at  the  same  time. 
The  central  incisors  are  sometimes  forced  apart ;  at  other  times  they 
are  forced  against  each  other  and  caused  to  overlap.  The  deposition 
of  bone,  however,  being  generally  confined  to  the  bottom  of  the 
sockets,  the  teeth  are  more  generally  thrust  from  their  alveolar  cavi- 
ties. When  this  occurs  with  a  person  whose  upper  and  lower  teeth 
strike  directly  upon  each  other,  it  occasions  much  inconvenience,  for 
the  elongated  tooth  must  either  be  thrown  from  the  circle  of  the  other 
teeth,  or,  by  striking  its  antagonist,  prevent  the  jaws  from  coming 
together. 

Causes  — Whereas  excessive  iritation  causes  absorption  or  destructive 
pathologic  conditions,  slight  irritation  may  cause  new  formations ; 
hence,  slight,  but  long-continued  irritation  of  the  peridental  mem- 
brane may  produce  exostosis  of  the  alveolar  cavities  ;  it  may  also  be 
caused  by  the  gradual  elongation  of  a  tooth  which  has  lost  its  antago- 
nistic teeth,  and  the  consequent  filling  up  of  the  alveolar  cavity.  A 
diseased  state  of  the  gums  can  have  no  agency  in  the  production  of 
the  exostosis,  for  it  most  frequently  occurs  in  individuals  whose  gums 
are  perfectly  healthy ;  and  if  it  were  the  result  of  any  constitutional 
tendency,  all  the  teeth  would  be  likely  to  be  affected  by  it. 

Treatment. — When  the  exostosis  is  on  the  side  of  the  alveolar  cavity, 
the  tooth  cannot  be  restored  to  its  natural  position;  but  when  it  is  in 
the  bottom  of  the  cavity  the  elongated  organ  may,  from  time  to  time, 
as  it  is  forced  from  the  alveolus,  be  filed  or  ground  off  even  with  the 
other  teeth  ;  but  in  doing  this  care  should  be  taken  to  avoid  as  much 
as  possible  the  unpleasant  jar  which  the  file  or  corundum  disc  is   so 


NECROSIS  OF  THE  TEETH.  307 

tpt  to  cause,  and  which  might,  in  such  cases,  excite  the  peridental 
membrane  to  increased  activity  and  a  more  rapid  deposit.  This  will 
remove  the  deformity  and  prevent  its  displacement  by  the  antagoniz- 
ing tooth.  By  this  simple  operation,  repeated  as  occasion  may  require, 
it  is  preserved  for  years,  and  rendered  almost  as  useful  as  any  of  the 
other  teeth.  Steady  pressure  in  the  proper  direction,  applied  to  the 
crown  of  a  tooth  so  affected,  may  also  prove  serviceable  at  an  early 
stage. 


CHAPTER  XL 

DISEASES  OF  THE  TEETH. 

NECROSIS    OF   THE    TEETH. 

The  term  necrosis  implies  death,  but  when  this  term  is  applied  to  a 
tooth,  it  usually  signifies  loss  of  vitality  of  the  pulp ;  for  it  often 
happens  that  a  degree  of  vitality  is  kept  up  in  the  outer  portion  of  the 
dentine  and  the  investing  cementum  by  the  peridental  membrane 
long  after  the  devitalization  of  the  pulp.  When  other  bones  are 
affected  with  necrosis,  the  dead  part  is  thrown  off  and  the  loss 
supplied  by  the  formation  of  new  bone.  But  the  teeth  are  not 
endowed  with  the  recuperative  power  which  the  process  of  exfolia- 
tion calls  for. 

The  density  of  a  tooth  may  not  be  sensibly  affected  by  the  mere 
loss  of  vitality ;  but  so  great  a  change  takes  place  in  the  appearance 
of  the  organ,  that  it  may  readily  be  detected  by  the  most  careless 
observer.  After  the  destruction  of  the  lining  membrane,  the  tooth  grad- 
ually loses  its  peculiar  semi-translucent  and  animated  appearance,  assum- 
ing a  dingy  or  muddy-brown  color  ;  and  this  change  is  more  striking  in 
teeth  of  a  soft,  than  in  those  of  a  hard  texture.  The  discoloration, 
too,  is  always  more  marked  when  the  loss  of  vitality  has  resulted  from 
a  blow,  than  when  produced  in  a  more  gradual  manner.  The  discol- 
•  oration  is  partly  owing  to  the  presence  of  disorganized  matter  in  the 
pulp-cavity,  and  partly  to  the  absorption  of  this  matter  by  the  sur- 
rounding walls  of  dentine. 

After  the  destruction  of  the  lining  membrane,  the  tooth  may  receive 
a  sufficient  amount  of  vitality  from  the  peridental  membrane  to 
prevent  it  from  exerting  a  manifest  morbid  influence  upon  the  parts 
with  which  it  is  immediately  connected.  Teeth  have  been  retained 
under  such  circumstances  with  apparent  impunity  for  many  years. 
But  when   every  part  of  a  tooth  has  lost  its  vitality,  it  becomes  an 


308  DENTAL    PATHOLOGY,    THERAPEUTICS. 

extraneous  body.  When  this  happens,  inflammation  of  the  cavity 
ensues,  the  gum  around  it  becomes  turgid  and  spongy,  and  bleeds  from 
the  slightest  injury,  and  the  organ  gradually  loosens  and  ultimately 
drops  out.  In  the  meantime  the  diseased  action  frequently  extends 
to  the  cavities  and  gums  of  the  adjoining  teeth. 

The  front  teeth,  being  more  exposed  to  injuries  from  violence,  are 
imore  liable  to  necrosis  than  the  molars. 

Causes. — Necrosis  of  the  teeth  may  be  produced  by  a  variety  of 
causes,  such  as  protracted  fevers,  the  long-continued  use  of  mercurial 
medicines,  by  caries,  and  by  external  violence.  The  immediate  cause, 
however,  when  not  occasioned  by  a  blow  sufficient  to  destroy  the  vas- 
cular connection  of  the  tooth  with  the  rest  of  the  system,  is  inflam- 
mation and  suppuration  of  the  lining  membrane ;  but  it  may  result 
from  deficiency  of  vital  energy  and  from  impaired  nutrition  ;  for  the 
author  has  met  with  several  cases  in  which  the  loss  of  vitality  could 
not  be  accounted  for  in  any  other  way. 

Treatment. — When  a  tooth  deprived  of  vitality  is  productive  of 
injury  to  the  gums  and  to  the  adjacent  teeth,  it  should  be  immediately 
removed;  for,  however  important  or  valuable  it  maybe,  the  health 
and  durability  of  the  others  should  not  be  jeopardized  by  its  retention. 
When  necrosis  of  a  tooth  is  apprehended,  we  should  endeavor  to 
prevent  its  occurrence  by  the  application  of  leeches  to  the  gums,  and 
by  gargling  the  mouth  with  suitable  astringent  washes,  and  the  em- 
ployment of  such  remedies  as  are  useful  in  the  treatment  of  perio- 
dontitis. If  this  plan  of  treatment  is  adopted  at  an  early  period,  it 
will  sometimes  prevent  the  loss  of  vitality  ;  but  if  long  neglected,  a 
favorable  result  need  not  be  anticipated. 

When  the  loss  of  vitality  is  confined  to  the  crown  and  inner  walls  of 
the  root,  if  the  former  is  not  seriously  impaired  by  caries,  it  may  be  per- 
forated, and  the  pulp-cavity  and  root  cleansed,  disinfected  and  filled  in 
the  manner  as  directed  in  another  part  of  this  work.  If  the  necrosed 
tooth  is  an  incisor,  the  perforation  should  be  made  from  the  palatal 
surface,  provided  the  proximate  surfaces  are  sound.  But  previously 
to  the  introduction  of  a  filling,  the  decomposed  surface  of  the  walls 
of  the  pulp-cavity  should  be  completely  removed,  and  if  this  does  not 
restore  the  tooth  to  its  natural  color,  the  process  of  bleaching  should 
be  resorted  to. 

Bleaching  Necf'osed  Teeth. — To  improve  the  appearance  of  a  necrosed 
tooth  which  has  become  discolored  from  the  dentinal  tubuli  absorb- 
ing the  coloring  matter  from  the  blood,  the  following  method  may 
be  pursued  :  First,  remove  all  decayed  matter  from  the  crown-oavity, 
where  such  a  cavity  exists,  taking  care,  however,  to  leave  the  enamel 
uninjured,  and  also  as  much  of  the  dentine  as  is  necessary  for  the 


NECROSIS  OF  THE  TEETH.  309 

Strength  of  the  tooth.  Pursue  the  same  course  with  regard  to  the 
canal  in  the  root,  cleansing  this  carefully  by  means  of  a  syringe  and 
tepid  water  after  the  removal  of  decomposed  matter  with  the  nerve 
canal  instruments.  When  the  discoloration  is  recent  and  not  more 
than  a  red  tinge  in  degree,  such  treatment  as  has  been  described  may 
prove  sufficient ;  should  it  not  be,  however,  owing  to  the  length  of 
time  the  discoloration  has  existed,  and  the  hue  is  a  brown,  dark 
brown,  or  black,  it  is  then  necessary  to  resort  to  such  agents  as  contain 
chlorin.  Solutions  of  chlorid  of  soda,  chlorid  of  lime,  chlorate  of 
potash,  decompose  organic  substances  by  removing  the  hydrogen  of 
their  coloring  matter.  One  of  the  most  reliable  of  these  preparations 
is  the  solution  of  chlorid  of  soda,  known  as  "  Labarraque's  Disinfect- 
ing Fluid,"  which  may  be  introduced  on  a  pellet  of  cotton  and 
allowed  to  remain  in  the  tooth  from  thirty  to  sixtv  minutes,  according 
to  the  degree  of  discoloration  present.  Repeated  applications  maybe 
necessary  in  some  cases  before  the  object  desired  is  accomplished.  To 
prevent  the  caustic  action  of  these  agents  on  the  soft  parts,  the  canal 
in  the  root  should  be  partly  filled  prior  to  their  introduction,  and  care 
taken  to  prevent  their  coming  in  contact  with  the  mucous  membrane 
of  the  mouth  by  the  application  of  the  rubber-dam.  The  chlorid  of 
lime  is  introduced  in  the  same  manner  as  the  chlorid  of  soda,  and  is 
allowed  to  remain  for  five,  ten,  or  fifteen  minutes  at  a  time,  and  its 
application  repeated  if  necessary,  the  crown-cavity  during  the  interval 
being  protected  by  a  temporary  filling  of  Hill's  stopping. 

Dry,  fresh  chlorid  of  lime  made  into  a  paste  with  dilute  tartaric 
acid  has  given  satisfaction  in  many  cases  as  a  bleaching  preparation ; 
and  in  recent^  cases  or  in  slightly  discolored  teeth,  the  plastic  filling 
material  known  as  oxychlorid  of  zinc,  introduced  into  the  crown 
cavity  and  worn  as  a  temporary  filling,  has  been  effective  in  improv- 
ing the  appearance  of  a  discolored  crown.  Oxalic  acid,  carefully 
protected,  is  also  effective  as  a  bleaching  agent,  applied  in  the 
form  of  a  crystal  introduced  into  the  carious  cavity  and  dissolved 
by  applying  to  it  a  drop  of  water.  Cyanid  of  potassium  in  solution 
will  remove  the  stains  caused  by  old  amalgam  fillings,  but  must  be  em- 
ployed with  great  care,  as  it  is  a  very  active  and  deadly  poison.  In 
the  use  of  all  these  agents  it  must  be  remembered  that  upon  the  cause 
of  the  discoloration  will  depend  the  efficacy  of  the  chemical  agent, 
and  that  chlorin  will  answer  in  some  cases,  owing  to  the  nature  of 
the  agents  instrumental  in  producing  the  discoloration,  while  cases  of 
discoloration  arising  from  the  action  of  other  agents  will  require  such 
preparations  as  oxalic  acid,  etc. 

After  the  action  of  the  bleaching  agent  is  no  longer  required  a  good 
practice  is  to  fill  the  crown  cavity  of  the  tooth  with  either  prepared 


3IO  DENTAL    PATHOLOGY,    THERAPEUTICS. 

chalk  or  carbonate  of  magnesia,  which  may  be  secured  by  a  temporary 
filling,  and  permitted  to  remain  for  several  days;  or  a  filling  of  the 
oxychlorid  of  zinc  may  be  temporarily  used,  and  a  more  permanent 
filling  be  subsequently  introduced.  Chlorid  of  zinc  in  the  form  of 
crystals  may  also  be  employed  as  a  bleaching  agent ;  also  chlorin 
water  injected  repeatedly  by  means  of  a  syringe  ;  also  chlorate  of  pot- 
ash and  chlorid  of  alumina.  The  peroxid  of  hydrogen  has  also  been 
used  successfully  for  bleaching  discolored  teeth,  and  its  disinfectant 
properties  add  to  its  value.  The  following  directions  are  given  by 
Dr.  A.  W.  Harlan  :  — 

"After  the  root  has  been  filled  and  the  tooth  is  free  from  tender- 
ness, apply  the  dam,  dry  the  cavity,  and  remove  all  discolored  den- 
tine. Wash  the  cavity  several  times  with  fresh  peroxid  of  hydrogen 
and  place  a  few  crystals  of  chlorid  of  alumina  in  the  cavity,  moisten 
with  the  peroxid  of  hydrogen,  and  wait  from  three  to  five  minutes  ; 
wash  the  cavity  thoroughly  with  distilled  water,  then  apply  a  solution 
of  30  grains  of  borax  to  the  ounce  of  water  until  the  acid  is  entirely 
neutralized.  Dry  the  cavity  with  hot  air,  and  paint  the  interior  with 
copal-ether  varnish.  When  it  is  dry  mix  oxychlorid  of  zinc  of  the 
desired  color  and  fill  the  cavity  full ;  allow  it  to  harden,  then  prepare 
the  cavity  for  the  gold  filling  and  fill  at  once." 

The  active  agent  is  oxygen,  and  even  when  chlorin  is  used  to  bleach 
discolored  teeth  the  cavity  should  be  moistened  with  water,  as  the 
latter  is  essential,  for  the  chlorin,  having  a  great  affinity  for  the  hydro- 
gen of  the  water,  unites  with  it  and  liberates  the  nascent  oxygen, 
which  is  the  active  agent. 

Peroxid  of  hydrogen,  peroxid  of  sodium,  and  pyrozone  in  five  and 
twenty-five  per  cent,  solutions  are  effective  bleaching  agents,  especially 
the  latter,  which  attack  the  hydrogen  in  the  color  compound,  and  when 
this  is  given  off  only  water  remains.  Dr.  Meeker's  method  is  as  fol- 
lows: Apply  the  rubber-dam,  and  wipe  out  the  prepared  cavity  with 
ammonia  to  neutralize  possible  acidity;  then  with  a  gold  probe  armed 
with  a  pellet  of  bibulous  paper  saturated  with  the  twenty-five  per  cent, 
solution  of  pyrozone,  liberally  moisten  the  interior  of  cavity  and 
outer  surface  of  tooth,  evaporating  the  solution  with  repeated  blasts  of 
cold  air.  Repeat  this  treatment,  although  thirty  minutes  will  often 
suffice. 

Electrolysis  is  also  applied  to  the  bleaching  of  discolored  teeth  by 
placing  nascent  oxygen  in  contact  with  the  discolored  surface.  It  is 
applied,  according  to  Dr.  W.  B.  Ames,  as  follows:  First  fill  the  root 
and  moisten  the  cavity  with  acidulated  water  (one  drop  to  the  ounce 
of  water,  in  order  to  render  it  a  more  effectual  electrolyte),  then  apply 
a  metal  electrode  connected  with  the  negative  pole  of  the  battery  in 


HYPERCEMENTOSIS. 


311 


contact  with  the  moistened  surface  of  the  margin  of  the  cavity,  and 
pass  a  platinum  needle,  connected  with  the  positive  pole  of  the  bat- 
tery, over  the  surface  to  be  bleached.  Upon  closing  the  circuit  the 
oxygen  of  the  water  is  liberated  at  the  positive  pole  near  the  surface 
to  be  bleached,  and  the  hydrogen  is  liberated  at  the  negative  electrode 
outside  the  cavity.  Electrolysis  is  also  recommended  for  the  treat- 
ment of  alveolar  pyorrhea. 

It  should  be  remembered  that  the  effect  of  these  agents  is  to  remove 
the  organic  or  animal  matter  from  the  tooth-structure,  and  that  their 
repeated  application  may  cause  the  crown  of  the  tooth  to  become  frail 
and  brittle. 

HYPERCEMENTOSIS. 

This  disease,  formerly  designated  ''exostosis  of  the  teeth,"  but 
now  designated  hypercementosis,  and  also  hyperostosis,  attacks  no  other 
part  of  a  fully  formed  tooth  than  the  root ;  for  in  the  cementum  alone, 
of  the  three  osseous  dental  tissues,  do  we  find  that  degree  of  vascu- 
larity which  is  a  necessary  condition  of  growth — normal  or  abnormal. 
It  usually  commences  at  or  near  the  extremity,  then  extends  upward, 
covering  a  greater  or  less  portion  of  the  external  surface.  It  some- 
times, however,  commences  upon  the  side  of  the  root  and  forms  a 
large  tubercle ;  at  other  times  the  deposit  of  the  new  bony  matter  is 
spread  over  the  surface  of  the  root,  often  uniformly,  but  more  fre- 
quently unequally.  When  it  exists  in  a  nodular  form  upon  the  roots, 
this  deposit  offers  a  very  serious  obstacle  in  the  extraction  of  such 
teeth.  The  osseous  matter  thus  deposited  has  usually  the  color,  con- 
sistence, and  structure  of  the  cementum,  though  sometimes  it  is  a  little 
harder  and  assumes  a  yellower  tinge.  The  enlargement  is  in  fact  an 
hypertrophied  condition  of  this  substance.  Mr. 
Tomes,  alluding  to  normal  cementum,  remarks : 
"  When  it  is  limited  to  a  thin  layer  the  lacunae  are 
altogether  absent,  and  even  canaliculi  do  not  ap- 
pear until  a  certain  thickness  is  attained.  In  a 
longitudinal  section  of  a  front  tooth  the  cementum 
near  the  neck  will  present  a  thin  layer  of  transpar- 
ent tissue,  marked  with  faint  indications  of  granu- 
larity, accompanied  in  some  cases  with  an  obscure 
linear  appearance,  suggestive  of  the  idea  that  the 
calcification  of  parallel  fibres  had  contributed  to  its 
production.  Proceeding  in  the  direction  of  the  root, 
the  cement  thickens  and  is  traversed  here  and  there 
by  canaliculi  ;  and  still  farther  down  lacunae  make 
their  appearance,  first  as  a  single  series,  then,  with  an  increased  thick- 
ness of  the  cementum,  in  numbers,  the  number  generally  depending 


Fig.  149. 


312 


DENTAL    PATHOLOGY,    THERAPEUTICS. 


upon  the  thickness  of  the  tissue."  Those  singular  anomalies  occa- 
sionally met  with,  where  enamel,  dentine,  and  cementum  are  mixed  up 
in  a  shapeless  confusion,  are  no  exceptions  to  the  rule  that  hyper- 
cementosis  is  confined  to  the  cementum ;  for  though  classed  under  this 
head,  these  cases  arise  from  the  disruption  of  the  formative  membranes 
(possibly  the  result  of  violence),  each  secreting  its  peculiar  tissue. 

The  deposit  of  osseous  matter  is  sometimes  so  considerable  that  the 
roots  of  two  or  more  teeth  are  firmly  united  by  it.  Fig.  149  repre- 
sents some  common  examples  of  hypercementosis. 

Fig.  150  a  represents  the  circumscribed  variety,  and  Fig.  150  b  the 
diffused  variety. 

Hypercement  is  a  product  of  the  peridental  membrane,  and  is 
formed  in  layers,  the  first  of  which  is  attached  to  the  primary  cemen- 
tum in  the  same  manner  as  the  first  layer  of  this  latter  substance  is  at- 
tached to   the  peripheral  surface  of  the  dentine.     When  the  normal 


Fig.  150. 


cementum  is  fully  formed  the  peridental  membrane  becomes  inactive 
as  a  hard  tissue  producer,  until  some  pathological  condition  causes  it 
to  again  assume  such  a  function. 

In  one  instance  the  author  was  compelled  to  extract  four  sound 
teeth  and  nine  roots ;  yet  the  pain  was  not  at  any  time  severe,  but  it 
was  constant  and  a  source  of  great  annoyance  to  the  patient. 

Several  years  ago  Prof.  Gorgas,  while  demonstrating  practical 
anatomy,  discovered  all  the  teeth  in  the  mouth  of  one  of  the  subjects 
(a  negro  girl  about  twenty-five  years  of  age)  to  be  in  an  exostosed  con- 
dition. On  the  roots  of  one  of  the  superior  molar  teeth  the  deposit 
of  osseous  matter  measured  three-fourths  of  an  inch  in  diameter. 

Teeth  affected  with  hypertrophy  of  the  cementum  may  be  free  from 
tenderness  even  under  pressure  or  percussion,  although  the  gum  may,  in 
some  cases,  be  slightly  congested  ;  but  the  diagnosis  of  this  affection 
is  extremely  difficult  unless  the  enlargement  of  the  root  causes  a  prom- 
inence on  the  alveolar  ridge,  which  is  not  often  the  case. 

In  many  but  not  in  all  cases  of  this  affection  more  or  less  discom- 
fort and  pain  attend   this  deposit,  owing  to  the  enlargement  of  the 


EROSION  OF  THE  TEETH.  313 

cementum  with  consequent  pressure  upon  the  nerves.  When  such  an 
enlargement  is  in  proportion  to  that  of  the  alveolus,  little  or  no  pain 
may  be  experienced.  The  pain  arising  from  the  enlargement  of  the 
cementum  is  at  times  moderate  though  persistent,  but  in  some  cases  it 
may  be  excruciating,  and  may  be  referred  to  distant  parts  of  the  face 
and  head  or  ear  and  about  the  terminal  branches  of  the  fifth  pair  of 
nerves,  thus  resembling  neuralgia. 

Causes. — Most  writers  concur  in  attributing  the  proximate  cause  of 
hypertrophy  of  the  cementum  to  irritation  of  the  peridental  mem- 
brane ;  but  this  is  not,  as  some  suppose,  necessarily  dependent  upon 
any  morbid  condition  of  the  crown  itself,  for  it  often  attacks  teeth 
that  are  perfectly  sound.  It  seems  rather  to  be  attributable  to  some 
peculiar  constitutional  diathesis.  Dr.  Bodecker  believes  that  a  congen- 
ital surplus  of  pericementum  in  the  patient  is  productive  of  the  enlarge- 
ment of  the  cementum,  and  that  in  this  case  the  movement  of  the 
tooth  in  mastication  would  slightly  exceed  the  normal  degree,  and 
that  the  constant  irritation  of  the  pericementum  under  such  condi- 
tions might  cause  an  increase  in  the  amount  of  the  cementum. 

It  never  makes  its  appearance  on  the  roots  of  temporary  teeth,  nor 
upon  permanent  teeth  until  the  sixteenth  or  twentieth  year,  when  the 
dental  tissues  are  completely  calcified. 

Treatment. — When  it  is  possible  to  discover  the  existence  of  hyper- 
cementosis  at  an  early  stage,  iodid  of  potassium  in  large  doses,  and 
painting  tl^e  gum  over  the  affected  root  with  such  counter-irritants  as 
a  saturated  tincture  of  iodin,  or  cantharidal  collodion  to  produce  a 
blister. 

The  disease  having  established  itself  does  not  admit  of  cure,  and 
when  it  has  progressed  so  far  as  to  be  productive  of  pain  and  incon- 
venience to  the  patient  the  loss  of  the  affected  teeth  becomes  inevi- 
table. When  the  enlargement  is  very  considerable  and  confined  to 
the  extremity  of  the  root,  and  has  not  induced  a  corresponding  en- 
largement of  the  alveolus  around  the  neck  of  the  tooth,  the  extraction 
of  the  affected  organ  is  often  attended  with  difficulty,  and  can  only 
be  accomplished  by  removing  a  portion  of  the  alveolar  wall  of  the 
cavity  or  fracturing  it. 

Some  are  of  the  opinion,  however,  that  the  deposit  of  osseous 
matter  may  be  arrested  and  absorption  excited,  so  as  to  make  room  for 
that  already  deposited,  by  the  administration  of  iodid  of  potassium,  as 
referred  to  above. 

EROSION    OF    THE    TEETH. 

Erosion  of  the  teeth,  to  which  the  name  "denudation  "  was  formerly 
applied,  is  a  process  in  which  the  enamel  and  dentine  of  the  teeth  are 
dissolved  or  wasted  away,  the  location  of  the  affection  being  princi- 


314  DENTAL    PATHOLOGY,    THERAPEUTICS. 

pally  on  the  labial  surfaces  near  the  cervical  margins.  The  approxi- 
mal  surfaces  of  the  teeth  are  sometimes  the  seat  of  this  affection,  and  in 
very  rare  cases  it  has  appeared  upon  the  lingual  surfaces.  It  attacks 
the  incisors  more  frequently  than  the  canines,  and  sometimes  extends 
to  the  bicuspids  and  first  and  second  molars.  It  first  appears  as  a 
slight  cup-shaped  depression  and  increases  over  a  limited  space  until  it 
forms  a  continuous  horizontal  groove,  as  regularly  and  smoothly  con- 
structed as  if  it  had  been  made  vi'ith  a  file,  about  one  line  or  less  from 
the  free  margin  of  the  gum,  the  eroded  surface  being  generally  verv 
sensitive,  having  a  polished  appearance  and  being  sharply  defined. 
(See  Fig.  151.)  After  it  has  removed  the  enamel  it  commits  its 
ravages  upon  the  subjacent  dentine,  sometimes  penetrating  to  the  pulp- 
cavity.  It  rarely  changes  the  color  of  the  enamel,  but  the  dentine, 
after  it  becomes  exposed,  assumes  first  a  light,  and  afterward  a  dark 
brown  color,  retaining,  however,  a  smooth  and  polished  surface.  This 
destructive  process  does  not  always  commence  at  merely  one  point  on 
the  labial  surface  of  the  central  incisors,  as  just   described  ;  it  some- 


FiG.  151.  Fig.  152. 

times  attacks  several  points  simultaneously.  (See  Fig.  1^2.)  As  it 
spreads  these  unite,  and  ultimately  a  deep  excavation  is  formed  with 
walls  so  smooth  and  highly  polished  that  the  tooth  presents  the  appear- 
ance of  having  been  scooped  out  with  a  broad,  square,  or  round- 
pointed  instrument.  It  is  often  confined  to  the  incisor  and  canine 
teeth,  and  in  some  cases  to  the  teeth  on  one  side  of  the  mouth  only. 
This  affection  generally  appears  after  the  thirtieth  year  of  age,  and 
when  the  eroded  surfaces  become  rough  the  change  is  generally  due  to 
the  action  of  caries. 

The  i)rogress  of  the  affection  is  exceedingly  variable.  It  is  some- 
times so  rapid  that  the  dentine  becomes  exposed  within  two  or  three 
years  from  the  commencement  of  the  disease  ;  at  other  times  its  effect 
upon  the  enamel  is  scarcely  perceptible  for  the  first  six  or  eight  years 
after  it  makes  its  appearance.  In  the  case  of  a  lady  whose  teeth  were 
thus  affected  the  denuding  process  did  not  perforate  the  enamel  for 
nearly  twenty  years.  The  dentine,  after  it  is  denuded  of  enamel,  is 
generally  quite  sensitive  and  very  susceptible  to  heat  and  cold  ;  this  is 
especially  the  case  with  the  superior  canines. 

Causes. — Some  writers  suppose  it  is  occasioned  by  chemical  action, 
to  which,  however,  there  appears  to  be  many  valid  objections.     Mr. 


NECROSIS  OF  THE  TEETH.  315 

John  Tomes  and  also  Mr.  Salter  ascribe  it  to  the  vigorous  use  of  the 
tooth-brush  or  other  friction,  but  such  a  cause  is  improbable.  That 
this  may  increase  the  size  of  the  horizontal  groove  is  more  than  prob- 
able;  that  it  may  even  in  some  cases  determine  the  commencement 
of  the  groove  is  just  possible.  But  no  conceivable  action  of  the 
brush  could  be  an  inciting  cause  of  that  form  of  the  disease  shown  in 
Fig.  152.  There  is  better  reason  for  believing  that  this  affection  is  due 
to  a  condition  of  enamel  deficient  in  vital  resistance,  owing  to  some 
modification  at  the  period  of  its  formation,  thus  rendering  it  suscepti- 
ble to  the  action  of  agents  which  it  might,  under  more  favorable  cir- 
cumstances, successfully  resist ;  but  microscopical  examinations  have 
failed  to  establish  such  a  theory,  as,  according  to  Dr.  Black,  the  ero- 
.sion  does  not  follow  the  developmental  lines,  which  would  be  the  case 
if  portions  of  the  teeth  could  be  worn  away  on  account  of  any  soft- 
ness from  faulty  development.  The  generally  accepted  theory  is  that 
this  affection  is  caused  by  the  action  of  an  acid  secretion,  abnormal  in 
character,  or  such  constitutional  acidity  as  may  be  present  in  a  gouty 
diathesis,  the  movements  of  the  lip  assisting  in  the  solution  of  the 
tooth-substance.  Dr.  W.  D.  Miller  records  the  following  experiment, 
which  he  regards  as  definitely  settling  the  question  as  to  whether  or 
not  erosion  occurs  in  pulpless  teeth  :  "  We  have  all  seen  pulpless  teeth 
which  presented  extensive  erosions,  but  we  have  not  been  able  to  say 
that  these  erosions  were  not  produced  while  the  pulp  of  the  tooth  was 
still  alive,  and,  as  far  as  I  am  aware,  no  one  has  succeeded  in  refut- 
ing beyond  all  doubt  the  assertion  that  erosion  attacks  only  teeth 
with  living  pulps.  On  the  7th  of  April,  1886,  a  piece  of  ivory 
was  set,  by  means  of  cement,  in  the  cavity  of  a  right  inferior  bicus- 
pid, where  the  loss  of  substance  by  erosion  was  so  extensive  that  it 
would  have  exposed  the  pulp  if  the  latter  had  not  been  protected  by 
secondary  dentine.  On  the  23d  of  April,  1888,  the  piece  was  removed 
for  examination,  and  showed  two  very  distinct  parallel  horizontal  fur- 
rows. The  surface  had  a  very  fine  polish,  characteristic  of  abraded 
dentine.  No  one  examining  the  piece  of  ivory  would  hesitate  for  a 
moment  to  pronounce  it  a  typical  case  of  erosion." 

Treatment. — In  advanced  stages  of  the  affection  its  progress  may  be 
arrested  by  properly  preparing  the  cavities  and  afterward  filling  them 
with  gold  ;  or,  if  the  defective  spaces  will  permit,  porcelain  sections 
or  facings  may  be  inserted.  This,  in  the  majority  of  cases,  will  prove 
successful.  Should  the  grooves  or  pits  when  superficial  become  dis- 
colored it  will  be  proper  to  use  occasionally  pumice  or  silex  applied  on 
a  point  of  wood. 

Erosion  Associated  with  Abrasion. — This  process  was  formerly 
treated  under  the  title  of  ■'  Chemical  Abrasion,"  but  as  it  appears  to 


3i6 


DENTAL    PATHOLOGY,    THERAPEUTICS. 


be  an  affection  of  the  teeth  in  which  the  effects  of  both  erosion  and 
abrasion  from  mechanical  causes  are  combined  it  is  considered  under 
the  head  of  erosion.  It  is  of  comparatively  rare  occurrence  and  com- 
mences on  the  central  incisors,  proceeding  thence  to  the  laterals,  the 
cuspids,  and  sometimes,  though  very  rarely,  to  the  first  bicuspids. 
Teeth  thus  affected  have,  when  the  jaws  are  closed,  a  truncated  appear- 
ance; the  upper  and  lower  teeth  do  not  come  together,  and  they  are 
rather  more  than  ordinarily  susceptible  to  the  action  of  acids  or  of 
heat  and  cold.  In  other  respects  little  or  no  inconvenience  is  experi- 
enced until  the  crowns  of  the  affected  teeth  are  nearly  destroyed. 

Its  progress,  as  in  the  case  of  simple  abrasion  of  the  labial  surfaces, 
is  exceedingly  variable.  It  sometimes  destroys  half  or  two-thirds  of 
the  crowns  of  the  central  incisors  in  two  or  three  years  ;  at  other 
times  seven  or  eight  years  are  required  to  produce  the  same  effect.  In 
one  case  which  came  under  our  own  observation  the  abrasion  had 
extended  to  the  bicuspids,  and  the  central  incisors  of  both  jaws  were 
so  much  wasted  that  on  closing  the  mouth  they  did  not  come  together 
by  nearly  three-eighths  of  an  inch ;  yet  two  years  only  had  elapsed 
since  its  commencement.  In  another  case,  where  it  had  been  going 
on  for  seven  years,  it  had  not  extended  to  the  cuspids,  and  the  space 
between  the  upper  and  lower  incisors  did  not  exceed  an  eighth  of  an' 
inch.     The  subjects  of  these  two  were  gentlemen — the  first  aged  about 

twenty-eight  and  the  other  twenty- 
one. 

Mr,  Bell  gives  an  interesting  case 
(Fig.  153)  of  a  gentleman  whose 
teeth  were  thus  affected  :  ' '  About 
fourteen  months  since  (1831)  this 
gentleman  perceived  that  the  edges 
of  the  incisors,  both  above  and  below,  had  become  slightly  worn  down, 
and,  as  it  were,  truncated,  so  that  they  could  no  longer  be  placed  in 
contact  with  each  other.  This  continued  to  increase  and  extend  to 
the  lateral  incisors,  and,  afterward,  successively  to  the  cuspids  and 
bicuspids.  There  has  been  no  pain,  and  only  a  trifling  degree  of 
uneasiness,  on  taking  acids  or  any  very  hot  or  cold  fluids  into  the 
mouth.  When  I  first  saw  these  teeth  they  had  exactly  the  appearance 
of  having  been  most  accurately  filed  down  at  the  edges  and  then  per- 
fectly and  beautifully  polished  ;  and  it  has  now  extended  so  far  that 
when  the  mouth  is  closed  the  anterior  edges  of  the  incisors  of  the 
upper  and  lower  jaws  are  nearly  a  quarter  of  an  inch  asunder.  The 
cavities  of  those  of  the  upper  jaw  must  have  been  exposed  but  for  a 
very  curious  and  beautiful  provision;  they  have  become  gradually  filled 
by  a  deposit  of  new  bony  matter,  perfectly  solid  and  hard,  but  so 


Fig.  153. 


MECHANICAL    ABRASION    OF    THE    TEETH.  317 

transparent  that  nothing  but  examinatiqn  by  actual  contact  could 
convince  an  observer  that  they  were  actually  closed.  This  appearance 
is  exceedingly  remarkable,  and  exactly  resembles  the  transparent  layers 
which  are  seen  in  agatose  pebbles,  surrounded  by  a  more  opaque  mass. 
The  surface  is  uniform,  even,  and  highly  polished,  and  continues, 
without  the  least  break,  from  one  tooth  to  another.  It  extends  at 
present  to  the  bicuspids,  is  perfectly  equal  on  both  sides,  and  when  the 
molars  are  closed  the  opening,  by  this  loss  of  substance  in  front,  is 
observed  to  be  widest  in  the  center,  diminishing  gradually  and  equally 
on  both  sides  to  the  last  bicuspids." 

The  same  causes  may  be  ascribed  for  this  affection  as  for  those  of 
erosion  and  abrasion.  There  is  apparently  some  constitutional  acidity 
due  to  a  gouty  diathesis,  the  effect  of  which  upon  defective  tooth- 
structures  renders  the  central  portions  of  the  tooth-surface  susceptible 
to  both  erosion  and  mechanical  abrasion,  and  the  latter  process  may 
account  for  the  smooth  and  polished  surfaces  which  are  invariably 
present. 

From  the  fact  that  teeth  thus  affected  continue  to  lose  structure 
much  more  rapidly  than  the  unaffected  teeth  of  the  same  mouth  do 
from  mastication,  and  this,  too,  even  after  they  cannot  be  brought  in 
contact  with  each  other,  we  cannot  ascribe  the  affection  to  mechanical 
abrasion  alone. 

Dr.  Black  remarks  that  "the  effect  is  certainly  that  of  erosion,  and 
is  identical  with  that  process  as  seen  on  the  labial  surfaces  of  the  teeth 
and  occurring  independently  of  mechanical  abrasion." 

The  only  treatment  for  such  cases  is  that  of  restoration,  either  by 
means  of  capping  with  gold  or  the  attachment  of  sections  of  porcelain 
crowns,  as  no  local  therapeutic  treatment  will  control  or  arrest  this 
singular  disease. 

MECHANICAL   ABRASION    OF   THE   TEETH. 

Mechanical  abrasion  of  the  teeth  is  a  process  of  attrition  which  re- 
sults in  a  loss  of  substance,  the  progress  of  which  depends  upon  the 
consistence  of  the  tooth  structures  and  the  amount  of  friction  to 
which  the  abraded  tooth  is  subjected.  Such  a  loss  of  substance  is  the 
result  of  imperfect  articulation,  the  loss  of  masticating  teeth,  the  na- 
ture of  the  food  used,  the  action  of  hard  substances  upon  natural 
teeth,  such  as  porcelain  teeth,  the  stems  of  clay  pipes,  the  chewing  of 
tobacco,  etc.,  etc.  Enamel  and  dentine,  once  formed,  pass  beyond 
the  sphere  of  that  reparative  power  found  in  other  bony  tissues  where 
red  blood  circulates  freely.  New  enamel  is  therefore  never  formed 
after  the  eruption  of  the  tooth  ;  and  new  dentine  only  within  the  pulp- 
cavity  by  the  action  of  the  odontoblasts. 


31 8  DENTAL    PATHOLOGY,    THERAPEUTICS. 

The  teeth  rarely  suffer  much  loss  of  substance  from  friction  when 
the  incisors  of  the  upper  jaw  shut  in  front  of  those  of  the  lower.  It 
is  only  when  the  former  fall  directly  upon  the  latter  that  mechanical 
abrasion  of  the  cutting  edges  of  the  front  teeth  can  take  place,  and 
when  this  happens,  they  sometimes  suffer  great  loss  of  substance.  The 
crowns  of  these  teeth  are  occasionally  worn  entirely  off,  while  those 
of  the  molars  and  bicuspids  are,  comparatively,  little  affected.  The 
lateral  motions  of  the  jaw,  being  in  these  cases  unrestricted — and  this 
motion  being,  of  course,  greater  at  the  anterior  than  at  the  posterior 
part  of  the  mouth — it  necessarily  happens  that  the  front  teeth  suffer 
the  most  abrasion.  Sometimes  all  the  teeth  are  worn  off  alike  ;  at 
other  times,  owing  to  the  peculiar  manner  in  which  the  jaws  come  to- 
gether, the  abrasion  is  confined  to  a  few. 

Abraded  surfaces  of  teeth  often  become  very  sensitive,  and  the 
irritation  affects  the  dental  pulp  in  such  a  manner  as  to  often  favor  the 
deposit  of  secondary  dentine,  the  site  of  the  deposit  corresponding  to 
the  abraded  surface. 

The  rapidity  of  the  abrasion  depends  greatly  upon  the  manner  in 
which  the  teeth  antagonize,  as  sliding  movements  when  the  jaws  are 
closed  cause  abnormal  wear  of  the  two  surfaces.  No  doubt  the  grind- 
ing together  of  the  teeth  during  sleep,  the  effect  of  nervousness,  also 
facilitates  the  abrasion. 

Abrasion  is  frequently  caused  by  the  loss  of  a  number  of  teeth, 
which  necessarily  brings  the  entire  work  of  mastication  upon  the  re- 
maining ones  to  such  a  degree  as  to  rapidly  wear  them  away,  espe- 
cially when  the  latter  are  few  in  number. 

Mr.  Bell  believed  that  certain  kinds  of  diet  tend,  more  than  others, 
to  produce  abrasion  of  teeth ;  in  proof  of  which  he  referred  to  sailors 
who,  the  greater  portion  of  their  lives,  live  on  hard  biscuits,  and  have 
only  a  small  part  of  the  crowns  of  their  teeth  remaining.  But  the  an- 
tagonism of  the  teeth  has  much  more  to  do  with  it  than  the  nature  of 
the  food  ;  though,  of  course,  when  they  do  strike  in  such  a  way  as  to 
wear  the  cutting  surfaces,  very  hard  or  gritty  articles  of  food  would 
make  the  abrasion  more  rapid. 

When  the  front  teeth  of  the  lower  jaw  strike  against  the  palatine 
surface  of  those  of  the  upper,  the  latter  are  sometimes  worn  away 
more  than  three-fourths,  and  in  some  instances  entirely  upon  the  gums. 
We  have  seen  the  teeth  of  some  individuals  so  much  abraded  in  this 
way,  that  little  of  the  crown  remained,  except  the  enamel  on  the  ante- 
rior surface. 

The  wearing  away  of  the  crowns  of  the  teeth  would  sooner  or  later 
expose  the  pulp,  were  it  not  that  nature,  in  anticipation  of  the  event, 
sets  up  an  action  by  which  layers  of  odontoblasts  of  the  pulp  resume 


INJURIES    OF    THE    TEETH    FROM    MECHANICAL    VIOLENCE.  319 

their  functional  activity,  and  a  portion  of  the  organ,  or  the  entire 
mass  of  it,  at  times  is  transformed  into  secondary  dentine.  By  this 
beautiful  operation  of  the  economy,  the  painful  consequences  that 
would  otherwise  result  from  the  exposure  of  the  pulp  are  wholly 
prevented. 

Treatment. — The  early  correction  of  irregularities  in  the  arrange- 
ment of  the  teeth,  so  that  a  proper  antagonism  of  the  teeth  is  secured, 
by  which  the  cusps  will  fit  into  sulci  of  the  opposing  teeth,  may  be 
suggested  as  preventive  treatment  in  many  cases. 

After  the  abrasion  has  occurred,  the  adaptation  of  caps  of  gold  or 
other  metal,  or  gold  in  the  form  of  contour  fillings,  or  enamel  sections, 
to  the  cutting  edges  and  grinding  surfaces  thus  worn  away,  or  the  inser- 
tion of  artificial  masticating  teeth,  will  often  preserve  and  render  use- 
ful teeth  in  such  a  condition,  and  prevent  further  abrasion. 

FRACTURES    AND    OTHER     INJURIES     OF     THE    TEETH     FROM    MECHANICAL 

VIOLENCE. 

The  injuries  to  which  teeth  are  subject  from  mechanical  violence  are 
so  variable  in  their  character  and  results  as  to  render  a  detailed  de- 
scription impossible.  The  same  amount  of  violence  inflicted  upon  a 
tooth  does  not  always  produce  the  same  effect.  The  nature  and  ex- 
tent of  the  injury  will  depend  as  much  upon  the  physical  condition 
of  the  teeth,  the  state  of  the  constitutional  health,  and  the  suscepti- 
bility of  the  body  to  morbid  impressions,  as  upon  the  violence  of  the 
blow.  Thus,  a  blow  sufficiently  severe  to  loosen  a  tooth  might  not,  in 
one  case,  be  productive  of  any  permanent  bad  consequences ;  while 
in  another  it  might  cause  the  death  of  the  organ  and  inflammation  of 
the  adjacent  parts,  as  well  as  necrosis  of  the  alveolus. 

A  tooth  of  compact  texture,  and  in  a  healthy  mouth,  may  be  de- 
prived of  a  portion  of  its  substance  without  any  serious  injury;  but 
a  similar  loss  of  substance  in  a  tooth  not  so  dense  in  structure  would 
be  likely  to  produce  inflammation  and  suppuration  of  the  pulp,  and 
possibly  of  the  peridental  membrane.  Hence,  in  order  to  form  a 
correct  opinion  of  the  result  of  injuries  of  this  sort,  we  must  take  into 
consideration  not  only  the  character  of  the  tooth  upon  which  the  blow 
has  been  inflicted  but  also  the  state  of  the  mouth  and  the  health  of  the 
individual. 

If  the  tooth  is  not  loosened  in  its  cavity  any  injury  resulting  from 
a  loss  of  a  small  portion  of  the  enamel,  or  even  of  the  dentine,  may 
be  prevented  by  smoothing  the  fractured  surface  with  a  file  or  corun- 
dum disc  or  point,  that  the  fluids  of  the  mouth  and  particles  of  extra- 
neous matter  may  not  be  retained  in  contact  with  it.  But  if  the  tooth 
is  loosened  and  pulpitis  or  periodontitis  has  supervened,  leeches  should 


320  DENTAL    PATHOLOGY,    THERAPEUTICS. 

be  applied  to  the  gums,  and  the  mouth  washed  several  times  a  day  with 
some  anodyne  and  refrigerant  lotion,  until  the  inflammation  subsides. 
For  more  detailed  treatment  the  reader  is  referred  to  the  chapters  on 
periodontitis  and  pulpitis. 

When  a  tooth  has  been  displaced  from  its  cavity  by  a  blow,  and  its 
vascular  connection  with  the  general  system  destroyed,  necrosis  is  very 
prone  to  occur.  An  imperfect  union  between  the  tooth  and  alveolus 
may  sometimes  be  re-established  by  the  effusion  of  a  coagulable  lymph 
and  the  formation  of  an  imperfectly  organized  membrane;  but  the 
tooth  may  after,  from  the  slightest  cold  or  derangement  of  the  digestive 
organs,  be  liable  to  become  sore  to  the  touch,  and  in  most  cases  will 
ultimately  assume  a  discolored  appearance. 

The  author  has,  on  several  occasions,  replaced  teeth  that  had  been 
knocked  from  their  cavities;  and  in  some  instances  the  operation  was 
attended  with  success.  The  subject  in  one  case  was  a  healthy  boy  of 
about  thirteen  years  of  age,  who,  while  playing  bandy,  received  a  blow 
from  the  club  of  one  of  his  playmates,  which  knocked  the  left  central 
incisor  of  the  upper  jaw  entirely  out  of  its  cavity.  He  saw  the  boy 
about  fifteen  minutes  after  the  accident.  The  alveolus  was  filled  with 
coagulated  blood.  This  he  sponged  out,  and  after  having  bathed  the 
tooth  in  tepid  water,  carefully  and  accurately  replaced  it  in  its  socket, 
and  secured  it  there  by  silk  ligatures  attached  to  the  adjacent  teeth. 
On  the  following  day  the  gums  around  the  tooth  were  considerably 
inflamed,  to  reduce  which  inflammation  he  directed  an  application  of 
three  leeches  and  the  frequent  use  of  an  anodyne  and  refrigerant  lotion 
(solution  of  acetate  of  lead  combined  with  tincture  of  opium).  At 
the  expiration  of  four  weeks  the  tooth  became  firmly  fixed  in  its 
cavity,  but  the  tooth  protruded  somewhat,  and  slight  soreness  is  ex- 
perienced on  taking  cold  (the  result,  no  doubt,  of  the  retention  of  a 
dead  pulp.) 

Numerous  cases  have  occurred  of  replanted  teeth  which  were  prop- 
erly prepared  before  re-insertion,  by  filling  of  pulp-canals  after  the 
removal  of  the  dead  pulp,  becoming  firmly  fixed. 

The  alveolar  processes  and  jaw-bones  are  sometimes  seriously  injured 
by  mechanical  violence.  The  author  was  requested  by  the  late  Dr. 
Baker,  of  Baltimore,  to  visit  with  him  a  lady  who,  by  the  upsetting  of 
a  stage,  had  her  face  severely  bruised  and  lacerated.  All  that  portion 
of  the  lower  jaw  which  contained  the  six  anterior  teeth  was  splintered 
off,  and  was  only  retained  in  the  mouth  by  the  gums  and  integuments 
with  which  it  was  connected.  The  wounds  of  her  face  having  been 
properly  dressed,  the  detached  portion  of  the  jaw  was  carefully  ad- 
justed and  secured  by  a  ligature  passed  around  the  front  teeth  and  first 
molars,  and  by  a  bandage  on  the  outside,  around  the  chin  and  back 


CARIES    OF   THE    TEETH.  32! 

part  of  the  head.  Her  mouth  was  washed  five  or  six  times  a  day  with 
diluted  tincture  of  myrrh.  The  third  day  after  the  accident  Dr. 
Baker  directed  the  loss  of  twelve  ounces  of  blood  ;  and  in  five  or  six 
weeks,  with  no  other  treatment  than  the  dressing  of  the  wounds,  she 
perfectly  recovered. 

It  often  happens  that  the  crown  of  a  tooth  is  broken  off  at  the  neck. 
We  have  known  the  crowns  of  four,  and  in  some  cases  of  thirteen, 
teeth  to  be  fractured  by  a  single  blow.  The  subject  of  the  last  case 
was  a  fireman,  who  received  an  accidental  blow  on  his  mouth  from  the 
head  of  an  axe,  which  broke  off  the  crowns  of  all  the  upper  and  lower 
incisors,  two  cuspids,  and  three  of  the  bicuspids  of  the  inferior  maxilla. 
The  subject  in  the  other  case  was  a  boy  about  twelve  years  of  age, 
who,  from  a  similar  accident,  occasioned  by  running  up  suddenly  be- 
hind a  man  who  was  chopping  wood,  had  the  crowns  of  his  upper 
incisors  broken  off.  In  both  of  these  cases  the  inflammation  which 
supervened  was  so  great  as  to  render  the  removal  of  the  roots  neces- 
sary. The  crowns,  roots,  and  alveolar  processes  are  sometimes  ground 
to  pieces,  or  the  teeth  driven  into  the  very  substance  of  the  jaw.  Mr. 
Bell  says  he  once  found  a  central  incisor  so  completely  forced  into  the 
bone  that  he  thought  it  to  be  the  remains  of  a  root ;  but,  on  removing 
it,  found  it  to  be  an  entire  tooth. 

When  the  crown  of  a  tooth  has  been  broken  off  by  a  blow,  and 
destructive  inflammation  results,  the  root  should  be  extracted.  When, 
however,  the  injury  has  not  been  sufficient  to  cause  such  a  degree  of 
inflammation,  an  artificial  crown  may  be  engrafted  on  the  root ;  but  it 
is  very  necessary  that  the  inflammation  should  be  entirely  subdued 
previous  to  the  operation  of  crowning.  If  the  tooth  is  to  be  replaced 
with  an  artificial  substitute  attached  to  a  plate,  the  root  should  be  first 
extracted,  unless  it  is  adapted  to  serve  as  a  support  for  a  section  of 
bridge-work.  In  some  cases,  however,  the  root  may  be  filled  and  be 
permitted  to  remain,  but  the  practice  is  usually  a  bad  one.  The  pos- 
sibility of  a  fractured  tooth  reuniting  was  formerly  doubted,  but 
Wedl,  in  his  "  Pathology  of  the  Teeth,"  refers  to  some  fifteen  cases  in 
which  union  took  place,  some  of  which  he  ascribed  to  the  formation 
of  secondary  dentine  and  others  to  that  of  cementum. 

CARIES    OF    THE    TEETH. 

There  is  no  affection  to  which  the  teeth  are  liable  more  frequent  in 
its  occurrence  or  fatal  in  its  tendency  than  caries.  It  is  often  so  insidi- 
ous in  its  attacks  and  rapid  in  its  progress  that  every  tooth  in  the  mouth 
may  be  more  or  less  involved  before  even  its  existence  is  suspected. 

Its  presence  is  usually  first  indicated  by  an  opaque  or  dark  spot  on 
the  enamel,  and  if  this  be  removed  the  subjacent  dentine  will  exhibit 
21 


322 


DENTAL    PATHOLOGY,    THERAPEUTICS. 


a  black,  dark-brown,  or  whitish  appearance.  It  usually  commences  on 
the  outer  surface  of  the  crown,  at  some  point  where  the  enamel  is  im- 
perfect or  has  been  fractured  or  otherwise  injured,  or  on  the  surface 
of  the  dentine  when  this  structure  becomes  exposed ;  from  thence  it 
proceeds  toward  the  centre  of  the  tooth,  increasing  in  circumference 
until  it  reaches  the  pulp-cavity. 

If  the  diseased  part  is  of  a  soft  and  humid  character  the  enamel, 
after  a  time,  usually  breaks  in,  disclosing  the  ravages  the  disease  has 
made  on  the  subjacent  dentine.  But  this  does  not  always  happen  ;  the 
form  of  the  tooth  sometimes  remains  nearly  perfect  until  its  whole 
interior  structure  is  destroyed. 

No  portion  of  the  crown  or  neck  of  a  tooth  is  exempt  from  this 
disease  ;  yet  some  parts  are  more  liable  to  be  first  attacked  than  others ; 
as,  for  example,  the  depressions  in  the  grinding  surfaces  of  the  molars 
and  bicuspids,  the  approximal  surfaces  of  all  the  teeth,  the  posterior  or 
palatine  surfaces  of  the  lateral  incisors,  and,  in  short,  wherever  an  im- 
perfection of  the  enamel  exists. 

The  enamel  is  much  harder  than  the  dentine,  and  is  by  far  less  easily 
acted  on  by  the  causes  that  produce  caries.  It  is  sometimes,  however, 
the  first  to  be  attacked,  and  when  this  happens  the  disease  develops 
itself  more  frequently  on  the  labial  or  buccal  surface,  near  the  gum, 
than  in  any  other  locality,  often  commencing  at  a  single  point,  and  at 

other  times  at  a  number  of  points.  When 
the  enamel  is  first  attacked  it  is  usually 
called  erosion  ;  but  as  this  tissue  does  not 
contain  so  much  animal  matter  as  the 
subjacent  dentine,  the  diseased  part  is 
often  washed  away  by  the  saliva  of  the 
mouth,  while  in  the  dentinal  part  of  the 
tooth  it,  in  most  instances,  remains,  and 
may  be  removed  in  distinct  laminae,  after 
the  earthy  salts  have  been  decomposed. 

In  very  hard  teeth  the  decayed  part  is 
of  a  firmer  consistence  and  of  a  darker 
color  than  in  soft  teeth.  Sometimes  it  is 
black,  at  other  times  of  a  dark  or  light 
brown,  and  at  other  times  again  it  is 
nearly  white.  As  a  general  rule,  the 
softer  the  tooth,  the  lighter,  softer,  and  more  humid  the  caries.  The 
color  of  the  decayed  part,  however,  may  be,  and  doubtless  is  in  some 
cases,  influenced  by  other  circumstances ;  perhaps  by  some  peculiar 
modification  of  the  agents  concerned  in  the  production  of  the  disease. 
Commencing  externally  beneath  the  enamel,  the  disease  proceeds. 


Fig.  154. 
*  A  transparent  zone  of  dentine 
removed  a  short  distance  from  and 
surrounding  that  which  is  under- 
going decomposition  consequent 
upon  caries. 


CARIES    OF    THE    TEETH.  323 

as  before  stated,  toward  the  center  of  the  tooth,  destroying  layer  after 
layer,  until  it  reaches  the  pulp,  leaving  each  outer  stratum  softer  and 
of  darker  color  than  the  subjacent  one. 

The  dentinal  tubuli  become  less  distinct  near  the  margin  of  the 
carious  structure  than  is  the  case  in  the  perfectly  normal  tissue  in 
proximity  with  the  pulp-chamber,  and,  according  to  Mr.  John  Tomes, 
has  a  zone-like  form  (the  zone  of  Tomes,  Fig.  154),  which  he  regards  as 
a  consolidation  of  the  dentinal  tubuli,  an  effort  on  the  part  of  nature  to 
place  a  line  of  demarcation  between  the  healthy  and  carious  structure. 

Other  writers,  however,  consider  this  zone  of  transparency  to  be  the 
result  of  diseased  action  causing  a  complete  exclusion  of  air  from  the 
tubuli,  thus  rendering  them  invisible  when  viewed  by  transmitted 
light. 

The  terms  deep-seated,  superficial  external  and  internal,  simple  and 
complicated,  have  been  applied  to  the  disease.  These  distinctions  only 
designate  different  stages  of  the  same  affection.  By  complicated  de- 
cay is  meant  caries  which  has  penetrated  to  the  pulp-cavity  of  the 
tooth,  accompanied  by  inflammation  and  suppuration  of  the  pulp. 

The  roots  of  the  teeth  frequently  remain  firm  in  their  cavities  for 
years  after  the  crowns  and  necks  have  been  destroyed  ;  but  nature, 
after  the  destruction  of  the  crowns,  as  if  conscious  that  the  roots  are 
of  no  further  use,  exerts  herself  to  expel  them  from  the  system,  which 
is  effected  by  the  gradual  wasting  and  filling  up  of  their  cavities.  After 
this  operation  of  the  economy  has  been  accomplished  they  are  fre- 
quently retained  in  the  mouth  for  months,  and  even  for  years,  by  their 
membranous  connection  with  the  gums. 

Differences  in  the  Liability  of  Different  Teeth  to  Decay. — Having  ex- 
plained at  some  length,  in  a  preceding  part  of  this  work,  the  manner 
in  which  the  physical  condition  of  the  teeth  is  influenced,  it  will  not 
now  be  necessary  to  dwell  upon  this  portion  of  the  subject.  It  will 
only  be  requisite  to  state,  therefore,  that  teeth  which  are  well  formed, 
well  arranged,  and  of  a  firm  texture,  seldom  decay,  and  when  they  are 
attacked  the  progress  of  the  disease  is  not  rapid ;  whereas  those  that 
are  imperfect  in  their  formation  and  of  a  soft  texture  are  more  suscep- 
tible to  the  action  of  the  causes  which  produce  it ;  and  when  assailed, 
if  the  progress  of  the  affection  is  not  arrested  by  art,  they  usually  fall 
speedy  victims  to  its  ravages.  Just  in  proportion  as  the  dentinal  struc- 
ture of  the  teeth  is  hard  or  soft,  the  shape  of  the  organs  perfect  or  im- 
perfect, their  arrangement  regular  or  irregular,  is  their  liability  to 
caries  diminished  or  increased. 

The  density,  shape,  and  arrangement  of  the  teeth  are  influenced  by 
the  state  of  the  general  health,  and  that  of  the  mouth  at  the  time  of 
their  dentinification  and  amelification.      If  at  this  period  all  the  func- 


324  DENTAL    PATHOLOGY,    THERAPEUTICS. 

tions  of  the  body  are  healthily  performed  these  organs  will  be  com- 
pact in  their  structure,  perfect  in  their  shape,  and  usually  regular  in 
their  arrangement.  That  the  teeth  should  be  thus  influenced  will  not 
appear  strange  when  we  consider,  as  Richerand  remarks,  "  that  there 
exist  amongst  all  the  parts  of  the  living  body  intimate  relations,  all 
of  which  correspond  to  each  other  and  carry  on  a  reciprocal  inter- 
course of  sensations  and  affections.  Hence,  if  there  is  a  morbid 
action  in  one  part,  other  parts  sympathize  with  it,  rallying,  as  if  sensi- 
ble of  the  mutual  dependence  existing  between  them,  all  their  energies 
to  rescue  their  neighbor  from  the  power  of  disease." 

Increased  action  in  one  portion  of  the  system  is  generally  followed 
by  diminished  action  in  some  other  part ;  thus,  for  example,  gastritis 
may  be  produced  by  constipation  of  the  bowels ;  puerperal  fever  by 
diminished  action  in  the  heart,  with  an  increased  action  in  the  uterus, 
etc.  Hence,  we  may  conclude  that  if  the  body  at  an  early  age  be 
morbidly  excited,  its  functions  will  be  languidly  performed,  the  process 
of  assimilation  checked,  the  regular  and  healthy  supply  of  earthy 
matter  in  the  bones  interrupted,  and,  consequently,  that  the  teeth 
which  are  then  formed  will  be  defective.  Other  parts  of  the  body,  in 
which  constant  changes  are  going  on,  if  thus  affected  at  these  early 
periods,  may  afterward  recover  their  healthful  vigor ;  but  if  the  teeth 
are  badly  formed  they  must  ever,  because  of  their  low  degree  of  vas- 
cularity, continue  so ;  hence  they  will  be  more  liable  to  decay  than 
when  dentinified  under  other  and  more  favorable  circumstances. 

Capillary  blood-vessels  form  a  large  part  of  every  organ,  the  char- 
acteristic tissue  of  each  being  strictly  extra-vascular  (literally,  outside 
of  the  vessels).  Where  the  blood-vessels  are  most  abundant,  as  in  the 
nervous  and  muscular  structures,  growth  and  change  take  place  rapidly 
and  constantly,  since  almost  every  particle  of  the  extra-vascular  or 
interstitial  tissue  is  in  contact  with  the  circulating  fluid,  the  function 
of  which  is  to  supply  material  for  growth  and  carry  off  waste  matter. 
Hence  such  organs  have  great  recuperative  power  and  are  modified  by 
the  varying  conditions  of  the  body.  But  the  dentine  and  enamel  of  the 
teeth,  when  once  formed,  do  not  possess  such  a  degree  of  vascularity 
as  will  restore  carious  tissues,  although  the  pulp  may  deposit  new 
structure  in  the  form  of  secondary  dentine  as  a  barrier  against  its 
exposure. 

Most  writers  are  of  opinion  that  the  power  of  the  teeth  to  resist  the 
various  causes  of  decay  is  sometimes  weakened  by  a  change  brought 
about  in  their  physical  condition  through  the  agency  of  certain  remote 
causes,  such  as  the  profuse  administration  of  mercury,  the  existence  of 
fevers,  and  all  severe  constitutional  disorders. 

Severe  constitutional  disorders,  and   the  administration  of  certain 


CARIES    OF   THE    TEETH.  325 

kinds  of  medicine,  may  not  act  directly  on  the  teeth  by  altering  their 
physical  condition,  and  thus  rendering  them  more  susceptible  to  the 
action  of  corrosive  agents  ;  but  they  are  indirectly  affected  in  propor- 
tion as  the  secretions  of  the  mouth  are  vitiated  and  their  corrosive 
properties  increased. 

The' formation,  arrangement,  and  physical  condition  of  the  teeth  are 
sometimes  influenced  by  hereditary  diathesis,  affecting  the  parts  con- 
cerned in  their  production  or  the  general  system.  That  a  morbid 
condition  of  the  system  on  the  part  of  either  parent  often  predisposes 
their  progeny  to  like  affections  is  an  axiom  fully  recognized  in  path- 
ology, and  a  fact  of  which  we  have  many  fearful  proofs. 

That  there  is  an  hereditary  tendency  in  the  teeth  to  decay  cannot 
be  denied.  But  we  believe  it  to  be  the  result  of  the  transmission  of  a 
similarity  of  action  in  the  parts  concerned  in  the  production  of  these 
organs;  so  that  the  teeth  of  the  child  are,  in  form  and  structure,  like 
those  of  the  parent  whom  it  most  resembles,  and  from  whom  it  has 
inherited  the  diathesis.  The  teeth  of  the  child,  if  shaped  like  those 
of  the  parent,  possessing  a  like  degree  of  density,  and  similarly  ar- 
ranged, are  equally  liable  to  disease ;  when  exposed  to  the  action  of 
the  same  causes  they  are  affected  in  like  manner  and  usually  at  about 
the  same  period  of  life.  Such  being  the  fact,  is  it  unreasonable  to 
conclude  that  judicious  early  attention  may  so  influence  the  formation 
and  arrangement  of  the  teeth  that  their  liability  to  disease  maybe 
diminished?  Medicinal  remedies  and  sickness  have  a  powerful  influ- 
ence upon  the  dental  tissues;  first,  through  hereditary  transmission  of 
an  impaired  constitution  ;  secondly,  by  their  action  upon  the  process 
of  development,  if  given  while  the  teeth  are  being  formed.  It  is, 
then,  to  the  differences  in  the  physical  condition  and  manner  of  ar- 
rangement of  these  organs — whether  in  different  individuals  or  in  the 
same  mouth — that  the  difference  in  their  liability  to  decay  is  attribu- 
table. 

Dr.  John  Allen  years  ago  remarked  :  "  The  nutritious  substances  in 
the  food  that  we  take  are  intended  to  build  up  all  parts  of  the  system — 
the  hard  tissues  as  well  as  the  soft  tissues.  Of  the  food  intended  to 
build  up  these  organisms,  certain  portions  make  bone  and  teeth.  Now 
the  particles  of  matter  are  deposited  atom  by  atom,  and  the  system  is 
gradually  built  up.  When  we  take  food  into  the  system  it  is  converted 
into  blood.  This  blood  is  conveyed  through  all  parts  in  little  cor- 
puscles, which  are  freighted  with  the  proper  constituents  to  sustain  and 
build  up  these  organisms.  These  little  corpuscles  convey  such  con- 
stituents as  are  necessary  for  the  production  of  bone,  teeth,  flesh,  and 
the  fat,  and  these  various  substances  are  deposited  just  where  they 
should  be.     Now  it  is  essentially  necessary  that  we  have  these  little 


326  DENTAL    PATHOLOGY,    THERAPEUTICS. 

vesicles  freighted  with  the  proper  constituents,  and  duly  freighted. 
How  shall  we  know  this?  By  taking  the  food  just  in  the  proportion 
that  it  is  provided  for  us  by  our  Creator  and  as  it  comes  from  nature's 
laboratory. 

"Now  we  take  this  ground  from  the  fact  that,  as  a  nation,  we  have 
worse  teeth  than  any  other  on  the  earth.  Now  why  is  this?  Simply 
because  we  change  the  proportions  of  these  various  constituents  that 
our  Creator  has  provided  for  us,  by  separating  away  what  has  been  put 
there  for  the  building  up  of  the  hard  tissues. 

"To  prove  this,  let  us  look  to  other  nations.  They  that  do  not 
change  the  proportions  of  the  various  constituents  that  enter  into  their 
bodies  do  not  have  decayed  teeth. 

"There  is  a  constant  change  going  on,  and  particles  of  matter  are 
deposited  atom  by  atom,  and  the  system  kept  fully  charged  with  the 
mineral  elements  of  which  the^e  structures  are  built  up.  When  you 
look  at  nations  that  do  not  change  the  proportions,  you  see  no  decayed 
teeth,  and  the  history  of  these  nations  proves  that  their  teeth  are 
sound  and  beautiful  to  old  age.  What  is  the  condition  in  our  country  ? 
We  do  change  these  proportions.  We  do  ignore  the  mineral  elements 
provided  for  us,  and  we  do  have  decayed  teeth.  We  find  that  there  are 
over  twenty  millions  of  teeth  swept  from  our  population  every  year. 
We  do  not  take  the  material  into  our  system  that  carries  back,  atom  by 
atom,  and  keeps  the  hard  tissues  built  up  until  the  old  particles  pass 
away.  The  old  particles  pass  away  after  they  have  served  their  purpose, 
and  new  ones  then  take  their  places. 

"  It  is  estimated  that  every  child  uses  half  a  barrel  of  flour  every  year ; 
and  it  is  estimated  that  there  are  forty  pounds  of  the  bone-forming 
material  thrown  out  from  every  barrel  that  we  use.  The  child  takes 
its  food  on  fine  flour,  and  is  deprived  of  twenty  pounds  in  a  year  of 
this  mineral  element,  which  should  be  taken  into  the  system  in  order  to 
make  those  hard,  flinty  substances  that  our  Creator  intended.  Now, 
by  the  time  that  child  is  twenty  years  of  age  it  has  been  deprived  of 
four  hundred  pounds  of  the  elements  which  should  have  been  taken  into 
the  system,  and  would  have  kept  it  charged  sufficiently  to  have  preserved 
these  substances  hard  and  flinty,  as  they  should  be. 

"  We  sweep  from  our  American  population  over  twenty  millions  of 
teeth  every  year,  and  this  should  prove  the  theory  that  our  tissues  do 
undergo  a  change,  and  that,  particle  by  particle,  they  pass  away.  As 
it  is  now,  the  teeth  are  becoming  worse  and  worse  every  year  ;  and  not 
only  this,  but  it  becomes  hereditary,  and  is  transmitted  from  parent  to 
child." 

Predisposing  Causes  of  Dental  Caries. — The  causes  of  dental  caries 
are  divided  into  predisposing  and  exciting  ;  among  the  former  may  be 


CARIES    OF    THE    TEETH.  327 

enumerated  a  defective  constitution,  either  innate  in  the  child  as  de- 
rived from  the  parent,  or  acquired  from  accidental  influences  to  which 
the  child  has  been  exposed.  Any  condition  of  the  system  that  will 
interfere  with  the  proper  elimination  and  application  of  the  materials 
necessary  for  the  formation  of  perfect  structures  may  have  a  deleterious 
influence  upon  the  teeth.  Hereditary  defects  are  quite  common,  the 
teeth  of  the  child  exhibiting  the  peculiarities  of  those  of  the  parents. 
Impaired  or  diminished  vitality  from  constitutional  or  local  causes  is 
also  a  predisposing  cause  of  dental  caries.  Febrile  conditions  not  only 
impair  or  diminish  vitality,  but  change  the  nature  of  the  fluids  of  the 
oral  cavity  to  such  a  degree  as  to  cause  them  to  act  upon  the  teeth  very 
injuriously.  Dr.  George  Watt  remarked  that  "all  diseases  tend  to 
weaken  the  dental  organs,  and  thus  are  predisposing  causes  of  decay. 
The  most  virulent  are  the  eruptive  fevets,  such  as  typhus,  typhoid,  and 
scarlet  fevers,  measles,  smallpox,  erysipelas,  etc.  These  fevers,  and 
perhaps  all  diseases,  predispose  to  decay  in  two  ways.  Weakening  the 
entire  constitution,  they  correspondingly  impair  the  vitality  of  the 
teeth,  and  thus  they  have  less  power  to  resist  the  encroachments  of  the 
exciting  causes  of  decay.  And  further,  they  deprave  the  secretions  of 
the  salivary  glands  and  the  oral  cavity,  rendering  them  liable  to  such 
decomposition  as  will  result  in  the  formation  of  exciting  causes.  That 
the  condition  of  the  teeth  is  influenced  by  heredity,  no  observing  den- 
tist can  doubt.  We  have  seen  a  family  in  which  its  female  members, 
for  four  generations,  lacked  the  left  upper  lateral  incisor.  Sometimes 
one  parent  has  good  teeth,  and  good  dental  organs  pertain  to  the 
family  history,  and  the  case  with  the  other  parent  is  just  the  reverse; 
we  see  children  not  usually  having  dental  organs  of  an  average  between 
the  two  parents,  but  some  of  them  copying  one  parent  and  some  the 
other.  The  constitution  of  the  parents,  and  especially  that  of  the 
mother,  may  be  unable  to  impart  due  vigor  or  proper  materials  in  requi- 
site quantities  to  the  process  of  developing  the  teeth.  From  some 
cause,  hereditary  or  otherwise,  there  may  be  a  lack  of  lime  salts  in  the 
system,  or  a  lack  of  physiological  ability  to  appropriate  them  and 
build  them  in  properly  with  the  organic  matter  of  the  teeth.  Another 
condition  may  show  the  very  best  formed  teeth  while  the  alveolar  pro- 
cesses, periosteum,  and  mucous  membrane  may  be  defective.  A  defec- 
tive periosteum  cannot  give  efficient  nutrition  ;  deficient  develop- 
ment of  the  alveoli  results  in  ineffectual  support ;  while  if  anything  is 
wrong  with  the  mucous  membrane  we  may  have  to  contend  with  defec- 
tive or  depraved  secretions."  Dyspepsia  affords  an  example  of  both  a 
predisposing  and  an  exciting  cause  of  caries,  as  its  effect  is  to  generate 
an  acid  in  the  stomach  which,  by  eructation,  is  brought  into  direct 
contact  with  the  teeth.     Malaria  is  a  predisposing  cause  of  dental  caries, 


328  DENTAL    PATHOLOGY,    THERAPEUTICS. 

on  account  of  the  unfavorable  conditions  it  induces ;  also  such 
medicinal  agents  as  vitiate  the  oral  fluids  and  irritate  the  mucous  mem- 
brane and  periosteum,  and  interfere  with  the  functions  of  the  mucous 
follicles  and  salivary  glands — mercury,  for  example  ;  also  salivary  cal- 
culus, by  its  irritating  effects  upon  the  soft  tissues  in  connection  with 
the  teeth  and  its  influence  upon  the  oral  secretions;  also  want  of  exer- 
cise, which  affects  the  stability  of  the  teeth  and  causes  absorption  of  the 
alveoli ;  also  want  of  cleanliness,  which  maybe  regarded  as  one  of  the 
most  common  of  the  predisposing  causes  of  dental  caries ;  also  arti- 
ficial teeth  improperly  inserted  or  composed  of  bad  materials  ;  also 
improper  dental  operations,  both  as  regards  manner  and  time  ;  also 
diseased  teeth  and  roots,  which  are  productive  of  irritation  to  the 
peridental  membrane  and  gums ;  also  sudden  changes  of  temperature, 
which  may  cause  an  exalted  sensibility  of  the  dentine,  diminish  the 
vitality  of  the  teeth,  or  produce  checks  in  the  enamel  of  frail  teeth. 

The  fissures  and  grooves  on  the  crowns  of  the  molars  and  bicuspids 
are  ascribed  by  some  to  an  arrest  of  development,  a  failure  of  the 
enamel  covering  in  its  formation  from  the  cusps  toward  the  center  of 
the  crown  to  come  together  and  coalesce.  Others,  however,  ascribe 
these  defective  places  to  be  due  to  a  rupture  of  the  enamel  organ  at 
these  points — a  separation  of  the  ameloblastic  layer,  thus  separating 
the  enamel  rods  and  forming  a  fissure  ;  such  fissures  being  more  com- 
mon in  teeth  with  prominent  cusps. 

Exciting  or  Immediate  Causes. — The  exciting  or  immediate  cause  of 
dental  caries  is  conceded  to  be  the  action  of  agents  chemically  disin- 
tegrating the  hard  structures  of  the  teeth,  and  which  have  their  source 
in  the  vitiated  secretions  of  the  mouth,  abnormal  secretions  from  the 
stomach,  the  saliva,  the  mucus,  and  the  decomposition  of  animal  and 
vegetable  substances.  The  theory  that  the  decay  of  the  teeth  is  the 
result  of  the  action  of  external  agents  was  first  distinctly  suggested  to 
the  dental  profession  of  the  United  States  about  the  year  1821,  by  Drs. 
L.  S.  and  Eleazer  Parmly.  The  late  Professor  Westcott,  by  a  series 
of  experiments  made  in  1843,  found  that  "acetic  and  citric  acids 
so  corroded  the  enamel  in  forty-eight  hours  that  much  of  it  was  easily 
removed  with  the  finger-nail,  and  malic  acid  or  the  acid  of  apples,  in 
its  concentrated  state,  also  acts  promptly  upon  the  teeth.  Dr.  W.  D. 
Miller,  an  American  dentist  practicing  in  Berlin,  deserves  great  credit 
for  many  careful  investigations  made  to  determine  the  cause  of  dental 
caries.  He  has  given  the  results  of  over  three  hundred  experiments, 
and  has  cultivated  bacteria  in  order  to  determine  the  nature  of 
a  new  fungus  which  is  always  found  in  the  mouth  and  in  carious 
dentine,  and  which  is  said  to  be  always  accompanied  by  a  strong  acid. 
Dr.  Miller  maintains  that  caries  are  caused  either  by  the  casual  intro- 


CARIES   OF   THE   TEETH. 


329 


duction  of  strong  acids  into  the  mouth  or  by  the  weaker  acids  formed 
by  the  fermentation  of  farinaceous  or  saccharine  particles  of  food. 
After  the  destruction  of  the  enamel,  the  process  of  disintegration 
attacks  the  organic  matter,  and  first  of  all  the  micro-organism,  which 
.causes  an  endless  variety  of  changes  in  the  dentine,  until  finally  it 
presents  the  appearance  of  a  mass  of  decomposed  matter  intersected 
in  every  direction  with  fungi.  Dr.  Miller  asserts  that  he  has  been 
convinced,  by  an  examination  of  several  hundreds  of  specimens,  that 
after  decalcification  has  taken  place,  the  only  change  of  any  import- 
ance which  occurs  is  produced 
by  micro-organisms.  And  he 
further  says  that  he  sees  "  the 
need  of  little  or  nothing  more 
than  organic  acids  and  fungi 


Fig.  155. — Longitudinal  Section 
OF  A  Carious  Bicuspid. 


Fig.  156. — Undermining  Enamel  Decay. 
Masses  of  Bacteria  Lining  the  Cavity.     Magni 
fied  about  50  Diameters. 


to  account  for  all  the  phenomena  of  dental  caries."  "Give  me  these 
two  factors  and  I  can  produce  caries  which  will  deceive  the  most  ex- 
perienced operators  and  microscopists." 

Dr.  Miller  sums  up  in  the  following  propositions  the  results  of  his 
investigations  on  the  subject  of  dental  caries: — 

First.  The  contact  of  saliva  with  amylaceous  or  saccharine  food  (not 
to  speak  of  nitrogenous  food),  or  a  solution  of  sugar  or  starch  in  saliva, 
kept  at  body  temperature,  invariably  gives  rise,  in  four  or  five  hours,  to 
a  strong  acid  reaction,  due  to  the  generation  of  an  organic  acid. 


^^O  DENTAL    PATHOLOGY,    THERAPEUTICS. 

Second.  There  must  consequently  be  in  the  human  mouth  a  con- 
stant, though  variable,  generation  of  acid,  because  of  the  impossi- 
bility of  keeping  the  mouth  perfectly  free  from  food  and  from  solutions 
of  amyloids  in  saliva,  which  penetrate  cracks,  pits,  and  fissures,  or  are 
held  by  capillary  attraction  between  the  surfaces  of  the  teeth  in  con- 
tact and  there  become  acid  by  fermentation. 

Third.  The  degree  of  acidity  depends  somewhat  upon  the  length  of 
time  which  has  elapsed  since  partaking  of  food,  and  will  be  found 
greatest  on  rising  in  the  morning. 

Fourth.  A  cavity  of  decay  in  which  saccharine  or  amylaceous  food 
has  remained  for  some  hours  must  and  will  be  found,  always  and 
without  exception,  to  have  an  acid  reaction. 

Fifth.  The  extent  to  which  any  tooth  suffers  from  the  action  of  the 
acid  depends  upon  its  density  and  structure,  but  more  particularly 
upon  the  perfection  of  the  enamel  and  the  protection  of  the  neck  of 
the  tooth  by  healthy  gums.  What  we  might  call  the  perfect  tooth 
would  resist  indefinitely  the  same  acid  to  which  a  tooth  of  opposite 
character  would  succumb  in  a  few  weeks. 

Sixth.  An  occasional  possible  absence  of  an  acid  reaction  in  a  cavity 
of  decay  is  no  indication  that  acid  has  not  participated  in  the  produc- 
tion of  the  cavity.  Little  or  no  value  can  be  attached  to  tests  of  the 
saliva  alone. 

Seventh.  Any  general  or  special  disorder  or  condition  of  the  system 
which  results  in  the  withdrawal  of  lime  salts  from  a  tooth,  or  in  a 
lowering  of  its  density,  or  in  a  weakening  of  the  chemical  union 
between  the  organic  and  inorganic  matter  of  the  tooth,  renders  it  more 
liable  to  decay. 

Eighth.  Strong  acid  and  corroding  substances  brought  but  momen- 
tarily into  the  human  mouth  may  give  rise  to  lesions  of  the  enamel  at 
points  where  the  ordinary  agents  alone  could  never  have  begun. 

Ninth.  All  the  microscopic  appearances  and  characteristics  of  caries 
may  be  produced  with  the  greatest  exactness  out  of  the  mouth,  simply 
by  subjecting  teeth  to  those  acid  mixtures  which  are  constantly  to  be 
found  ifi  the  mouth. 

Tenth.  The  superficial  layers  of  carious  dentine  undergo  an  almost 
if  not  absolutely  complete  decalcification,  which  decreases  as  we  ap- 
proach the  normal  dentine.  The  same  is  true  of  dentine  decalcified 
in  saliva  and  bread. 

Eleventh.  The  destruction  of  the  organic  constituents  follows  (not 
precedes)  the  decalcification,  and  is  evidently,  for  the  most  part,  to  be 
ascribed  to  the  action  of  fungi. 

Twelfth.  The  fungi  found  in  the  human  mouth  do  not  participate 
directly  in  the  process  of  decalcification.     The  exact  part  which  they 


CARIES    OF   THE   TEETH. 


33^ 


J 


if 


^^ 


perform  in  the  production  of  an  acid  reaction  requires  further  investi- 
gation. 

Thirteenth.  The  fungi  produce  the  most  manifold  anatomical  changes 
in  the  softened  dentine,  re- 
sulting in  the  complete  oblit- 
eration of  the  structure  and 
final  disappearance  of  the  tis- 
sue in  a  mass  of  debris  and 
fungi. 

Fourteenth.  The  invasion 
of  the  micro-organisms  is 
always  preceded  by  the  extrac- 
tion of  the  lime  salts. 

Fifteenth.  The  destruction 
of  the  tissue  remaining  after 
decalcification  is  effected  al- 
most wholly  by  fungi  alone. 

Sixteenth.  Inflammation  can  hardly  be  looked  upon  as  a  very  im- 
portant factor  in  caries  of  the  teeth. 

Seventeenth.  Caries  of  the  enamel  is  purely  chemical,  the  decalcifica- 
tion resulting  at  once  in  the  complete  dissolution  of  the  tissue. 

Fighteenth.  Caries  of  cement  runs  a  course  analogous  to  caries  of 
dentine,  a  softening  of  the  tissues  by  acids,  and  following  this  its 
destruction  by  fungi ;  a  slight  inflammatory  action  on  the  part  of  the 
living  matter  in  the  corpuscles  is  not  to  be  excluded. 


R/i/#^^' 


Interglobular  Spaces  filled  with 
Micrococci. 


Fig.  157 

Magnified  about  400  Diameters.    (Bodecker.) 


Fig.  158.— Decayed  Dentine. 
Showing  total  liquefaction  of  the  basis-substance  by  bacteria.     Magnified  400  diameters. 

(Bodecker). 


Dr.  Frank  Abbott,  after  a  careful  investigation  of  the  etiology  of 
dental  caries,  concludes  that  the  first  lesion  is  due  to  the  action  of 
an  acid,  which  in  a  merely  chemical  way  dissolves  out  the  lime 
salts  from  the  enamel,  and  that  such  an  acid  is  generated  from  the 
decaying  material  found  in  the  food,  mainly  in  such  kinds  of  foods  as 
through  their  decomposition  are  apt  to  produce  an  acid  possessing  a 


332  DENTAL  PATHOLOGY,  THERAPEUTICS. 

high  degree  of  affinity  for  lime  salts,  viz.  :  lactic  acid.  He  also 
believes  that  the  organic  portion  of  teeth,  as  it  advances  to  the  stage 
of  decomposition  in  the  process  of  caries,  plays  a  very  important 
part  in  the  formation  of  this  acid  ;  and  that  perhaps  the  sour  decom- 
position is  assisted  locally  by  the  action  of  micrococci  and  lepto- 
thrix,  and  he  concurs  with  the  views  of  those  who  claim  that  the  re- 
sistance of  the  teeth  against  caries,  owing  to  their  amount  of  lime- 
salts,  greatly  varies  in  different  people  ;  that  on  a  dead  tooth,  natural 
or  artificial,  as  well  as  on  teeth  made  from  the  dentine  of  the  elephant 
or  the  hippopotamus,  the  process  will  remain  under  all  circumstances 
a  chemical  one,  assisted  only  by  the  putrefying  remains  of  the  organic 
material  of  the  tooth ;  while  on  a  live  tooth  either  acute  or  chronic 
reaction  changes  take  place.  Dr.  Abbott  sums  up  the  results  of  his 
researches  as  follows  :  "I.  In  enamel,  caries  in  its  earliest  stages  is  a 
chemical  process.  After  the  lime  salts  are  dissolved  through  the  in- 
flammatory reaction,  and  the  basis-substance  liquefied,  the  protoplasm 
reappears  and  breaks  apart  into  small,  irregularly  shaped,  so-called 
medullary  or  embryonal  bodies,  and  subsequently  the  lime  salts  are 
dissolved  by  acids  or  washed  away.  II.  Caries  of  dentine  consists 
of  a  dissolution  of  the  lime  salts  in  the  intertubular  substance  by 
the  inflammatory  reaction,  a  melting  down  of  the  glue-yielding 
basis  substance  (matrix)  around  and  between  the  canaliculi.  The 
living  matter  contained  in  the  canaliculi  proper  is  transformed  into 
nucleated  protoplasmic  bodies,  which,  together  with  protoplasmic 
bodies  originating  from  the  living  matter  in  the  basis-substance, 
form  the  so-called  indifferent  or  inflammatory  tissue.  III.  Caries 
of  cement  exhibits  first  all  phenomena  known  to  be  present  in  the 
early  stages  of  inflammation  of  bone.  The  protoplasmic  cement- 
corpuscles,  together  with  the  basis-substance,  after  its  liquefaction, 
produce  indifferent  or  inflammatory  elements.  IV.  The  indifferent 
elements  originating  through  the  carious  process  from  enamel,  dentine, 
and  cement  do  not  proceed  in  new  formation  of  living  matter,  but 
become  disintegrated  and  transformed  into  a  mass  crowded  with  mi- 
crococci and  leptothrix.  V.  Caries  of  a  living  tooth,  therefore,  is 
an  inflammatory  process,  which,  beginning  as  a  chemical  process,  in 
turn  reduces  the  tissues  of  the  tooth  into  embryonic  or  medullary  ele- 
ments, evidently  the  same  as  during  the  development  if  the  tooth 
have  shared  in  its  formation;  and  its  development  and  intensity  are 
in  direct  proportion  to  the  amount  of  living  matter  which  they  con- 
tain, as  compared  with  other  tissues.  VI.  The  medullary  elements, 
owing  to  want  of  nutrition  and  to  continuous  irritation,  become 
necrosed,  and  the  seat  of  a  lively  new  growth  of  organisms  common  to 
all  decomposing  organic  material.  VII.  Micrococci  and  leptothrix 
by  no  means  produce  caries;  they  do  not  penetrate  the  cavities  in  the 


CARIES    OF    THE    TEETH.  333 

basis-substance  of  the  tissues  of  the  tooth,  but  appear  only  as  second- 
ary formations,  owing  to  the  decay  of  the  medullary  elements.  VIII. 
In  dead  and  artificial  teeth  caries  is  a  chemical  process,  assisted  only 
by  the  decomposition  of  the  glue-yielding  basis-substance  of  dentine 
and  cement." 

Dr.  Abbott,  therefore,  does  not  consider  micro-organisms  as  the 
primary  cause  of  caries  of  the  teeth.  Dr.  Miller,  on  the  other  hand, 
believes  that  the  invasion  of  micro-organisms  is  the  only  cause  of 
dental  caries,  and  that  the  living  tissues  are  destroyed  by  the  micro- 
organisms without  reacting  upon  the  injury — in  other  words,  without 
any  inflammatory  reaction  whatsoever  in  the  affected  hard  tissue  of 
the  tooth.  Dr.  Bodecker,  however,  believes  that  the  full  truth  in 
regard  to  the  carious  process  can  be  established  only  by  a  combination 
of  both  Abbott's  and  Miller's  assertions,  and  further  remarks: — 
"  I  admit  that  micro-organisms  are  the  principal  cause  of  the  decay 
of  teeth  ;  but  only  dea^  material  will  be  destroyed  by  them  without 
the  least  reaction.  Living  tissue—-/,  e.,  enamel,  dentine,  and  ce- 
mentum — invariably  react  upon  the  invasion  of  the  micro-organisms  by 
an  inflammatory  process  similar  to  that  in  other  living  tissues  in  the 
manner  described  by  Abbott." 

Prevention  of  Caries. — It  is  an  old  adage,  no  less  true  than  trite, 
that  "an  ounce  of  prevention  is  better  than  a  pound  of  cure,"  and  in 
the  present  instance  it  may  be  applied  with  its  full  force.  Were  more 
attention  paid  to  the  practical  instruction  thus  conveyed,  many  of  the 
diseases  of  the  teeth  might  be  avoided.  Most  of  the  remarks  that 
might  be  made  on  this  subject  have  been  anticipated,  consequently  it 
will  only  be  necessary  to  observe  that  if  the  teeth  are  well  formed  and 
well  arranged  all  that  will  be  required  is  to  keep  them  clean  ;  if  any 
irregularity  occurs  it  should  be  remedied  by  the  means  to  be  described. 

For  cleansing  the  teeth,  when  they  are  in  a  sound  condition  and 
free  from  calcareous  deposits,  the  gums  healthy,  and  the  secretions  of 
the  mouth  normal  in  character,  the  regular  and  frequent  use  of  pure 
water  by  means  of  a  proper  brush  and  waxed  floss  silk  will,  in  most 
cases,  be  sufficient.  But  when  the  enamel  is  stained  and  discolored 
and  the  secretions  of  the  mouth  inclined  to  acidity,  with  a  tendency 
to  calcareous  deposits,  then  the  employment  of  a  dentifrice  is  neces- 
sary. 

Dentifrice — from  dens,  a  tooth,  zx^A  frico,  fricare ,  to  rub — is  a  medi- 
cinal preparation,  in  the  form  of  a  powder,  for  cleansing  the  teeth. 
An  almost  numberless  variety  of  dentifrices  are  in  use,  and  many  of 
them  highly  injurious.  In  the  preparation  of  an  agent  of  this  kind 
the  object  should  be  to  obtain  a  compound  pleasant  to  the  taste,  alto- 
gether free  from  acids  and  acrid  substances,  and  soluble  or  insoluble. 


334  DENTAL    PATHOLOGY,    THERAPEUTICS. 

according  to  the  nature  of  the  case  in  which  it  is  to  be  used — one 
capable  of  neutralizing  and  removing  acrid  and  fermenting  matters 
secreted  between  the  teeth  and  also  allaying  irritation.  A  dentifrice, 
then,  should  be  anti-acid  and,  moreover,  a  powder;  and  the  more 
simple  the  preparation  the  better.  A  preparation  composed  of  orris 
root,  prepared  chalk,  and  pure  Castile  or  white  Windsor  soap,  to  which 
may  be  added  very  finely-powdered  cuttle-fish  bone  or  pumice-stone,  for 
the  removal  of  calcareous  matter  when  there  is  a  tendency  to  deposits 
of  this  nature,  will  answer  every  purpose.  When  the  gums  are  in  a 
healthy  condition  there  is  no  use  for  such  ingredients  in  a  dentifrice 
as  Peruvian  bark  or  myrrh,  and  as  for  liquid  dentifrices,  they  are  of 
very  little  use,  for  the  object  in  using  the  brush  is  friction,  and  as  these 
liquid  preparations  are  generally  lubricating  alkaline  substances,  they 
cause  the  brush  to  pass  so  easily  over  the  teeth  as  to  render  them  al- 
most useless.  In  many  cases  an  unhealthy  condition  of  the  gums  is 
owing  to  the  irritation  produced  by  local  irritants,  and  their  removal 
is  all  that  is  needed  to  restore  them  to  health.  Soap  alone  will  not 
cleanse  the  teeth,  for  it  prevents  friction  ;  and  charcoal,  notwithstand- 
ing its  detergent  and  antiseptic  properties,  is  injurious  as  a  dentifrice 
or  as  an  ingredient  of  one,  on  account  of  its  insinuating  itself  under 
the  free  margin  of  the  gum  and  causing  it  to  recede  from  the  neck  of 
the  tooth,  no  matter  how  finely  it  may  be  pulverized.  Either  of  the 
following  dentifrices  may  be  used  : — 

B .     Prepared  chalk, S  i^- 

Powdered  orris  root, ^  iv. 

Powdered  cinnamon, ^i''* 

Sup.  carb.  of  soda, ^ss. 

White  sugar, ^j. 

Oil  of  lemon,      gtt.  xv. 

Oil  of  rose, gtt.  ij. 

or 

R.     Prepared  chalk, ^ij. 

Powdered  orris  root, 5  ij. 

Pumice  stone, 5J. 

Ingredients  in  both  prescriptions  to  be  thoroughly  pulverized  and  well  mixed. 

The  importance  of  keeping  the  teeth  clean  cannot  be  too  strongly 
impressed  upon  the  mind  of  every  individual.  Proper  attention  to 
the  cleanliness  of  these  organs  contributes  more  to  their  health  and 
preservation  than  is  generally  supposed.  Against  caries  it  is  a  most 
powerful  prophylactic.  "When  the  teeth,"  says  Dr.  L.  S.  Parmley, 
"are  kept  literally  clean,  no  disease  will  ever  be  perceptible.  Their 
structure  will  equally  stand  the  summer's  heat  and  winter's  cold,  the 
changes  of  climate,  the  variation  of  diet,  and  even  the  diseases  to 


CARIES    OF    THE    TEETH.  335 

which  the  other  parts  of  the  body  may  be  subject  from  constitutional 
causes. 

The  configuration  and  arrangement  of  some  teeth  is  such,  however, 
as  to  preclude  the  possibility  of  keeping  them  clean ;  but  this  should 
not  deter  any  one  from  using  the  proper  means,  for  if  disease  is  not 
wholly  prevented  they  will,  at  least,  contribute  very  greatly  to  the 
preservation  of  the  organs. 

The  subject  of  "  food  in  relation  to  the  teeth  "  has  claimed  the  at- 
tention of  eminent  writers,  many  of  whom  are  convinced  that  strict 
attention  on  the  part  of  the  mother  to  hygienic  laws,  from  the  time 
of  conception,  will  influence  for  good  the  structural  quality  of  the 
developing  tooth-tissues  of  the  child.  As  phosphate  of  lime  is  an 
important  ingredient  of  the  tooth-tissues,  it  is  urged  that  the  requisite 
quantity  of  this  lime  salt  should  be  supplied  with  the  food,  and  that 
due  attention  to  the  laws  of  health  in  regard  to  exercise,  rest,  ventila- 
tion, bathing,  etc.,  will  cause  the  lime  salt  to  be  assimilated  and 
properly  appropriated  in  the  formation  and  development  of  tooth- 
tissues.  Many  also  believe  that  foods  prepared  by  artificial  means  are 
very  serviceable  in  supplying  such  elements  as  fail  to  be  assimilated 
in  the  ordinary  manner;  hence  the  use  during  pregnancy  and  lacta- 
tion of  preparations  of  the  syrup  of  the  lactophosphate  of  lime, 
wheat  phosphate,  and  such  articles  of  diet  as  oatmeal,  cracked  wheat, 
etc.,  are  recommended  as  being  of  great  benefit.  No  doubt  the 
amount  of  phosphate  to  be  used  by  the  system  wiii  Jepend,  in  a  great 
measure,  upon  the  digestion. 


PART  THIRD. 


DENTAL  SURGERY. 


3i. 


Besides  the  operations  of  General  Surgery  which  are  performed  upon  the  mouth, 
in  common  with  other  parts  of  the  body,  Dental  Science  gives  specific  directions  for 
those  operations  of  Special  Surgery  demanded  in  the — 

1.  Correction  of  Irregularities  in  the  Arrangement  of  the  Teeth, 

2.  Treatment  of  Dental  Caries. 

3.  Extraction  of  Teeth. 

4.  The  Use  of  A.nesthetic  Agents. 

5.  Dislocation  and  Fracture  of  the  Jaw. 

6.  Diseases  of  the  Maxillary  Sinus  or  Antrum. 

7.  Caries  of  the  Maxillary  Bones. 


338 


CHAPTER  I. 

IRREGULARITY  OF  THE  TEETH— ORTHODONTIA. 

Method  of  Directing  Second  Dentition. — To  properly  direct  second 
dentition  a  knowledge  of  the  relative  position  of  the  permanent  and 
temporary  teeth  at  a  period  soon  after  the  appearance  of  the  first  teeth 
of  the  permanent  set  is  necessary.  Fig.  159  represents  the  jaws  of  a 
child  between  six  and  seven  years  of  age,  all  of  the  temporary  teeth 
being  in  position  and  the  six-year  molars  erupting. 


Fig.  159. 

The  developing  crowns  of  the  permanent  teeth  occupy  a  higher 
place  than  the  temporary  teeth,  and  the  superior  central  incisors  have 
a  more  outward  inclination,  on  account  of  their  size  and  the  increased 
width  of  the  arch  they  are  to  occupy  when  erupted.  The  crowns  and 
a  small  portion  only  of  the  roots  of  these  teeth  are  completed,  and 
they  are  placed  directly  under  and  in  contact  with  the  floor  of  the 
nares.  The  superior  lateral  incisors  are  not  so  far  advanced  in  their 
development  as  the  central  incisors,  and  their  crowns  are  situated  be- 
neath the  angle  of  the  nares  and  back  of  the  roots  of  the  temporary 
laterals  and  canines. 

The  canines  are  situated  on  a  higher  plane  than  either  the  central 

339 


340  DENTAL    SURGERY. 

or  lateral  incisors,  not  more  than  one-fourth  of  an  inch  below  the 
infra-orbital  canals  and  along  the  sides  of  the  outer  walls  of  the  nares, 
with  their  crowns  about  completed.  The  crowns  of  the  first  and 
second  superior  bicuspids  are  situated  on  the  same  plane  as  the  lateral 
incisors,  being  embraced  by  the  roots  of  the  first  and  second  tem- 
porary molars,  and  are  but  partly  developed.  The  crowns  of  the  first 
permanent  molars  of  both  jaws  have  erupted  and  are  about  antag- 
onizing with  each  other,  but  their  roots  are  only  one-half  formed. 
The  crowns  of  the  permanent  second  molars  are  but  partly  developed, 
and  are  situated  above  and  posterior  to  the  roots  of  the  first  permanent 
molars,  their  grinding  surfaces  having  a  direction  downward  and 
slightly  backward  toward  the  lower  portion  of  the  external  pterygoid 
processes.  The  dentes  sapientiae  of  the  upper  jaw  are  represented  by 
small  crypts  only,  in  a  higher  plane  in  the  maxillary  tuberosities. 

The  inferior  permanent  central  incisors  are  situated  directly  behind 
the  roots  of  the  temporary  incisors,  and  have  their  crowns  completed 
with  about  one-fourth  of  their  roots.  The  roots  of  the  permanent 
lateral  incisors  are  not  so  far  developed  and  are  situated  somewhat 
back  of  the  crowns  of  the  permanent  central  incisors  and  canines. 
The  permanent  central  and  lateral  incisors,  as  do  all  of  the  inferior 
teeth,  occupy  a  vertical  position  in  the  jaws,  on  account  of  the  inferior 
dental  arch  being  smaller  than  the  superior.  The  inferior  permanent 
canines  occupy  a  lower  plane  than  the  incisors,  and  the  partly  de- 
veloped roots  extend  very  near  to  the  under  surface  of  the  bone  of  the 
jaw.  The  position  and  stage  of  development  of  the  inferior  permanent 
bicuspids  and  first  molars  are  about  the  same  as  those  of  the  corre- 
sponding teeth  of  the  upper  jaw. 

The  developing  crowns  of  the  permanent  second  molars  occupy  a 
higher  plane  than  that  of  the  bicuspids,  and  their  grinding  surfaces 
have  a  direction  upward  and  forward.  The  inferior  dentes  sapientiae 
are  represented  by  small  crypts  only,  in  the  coronoid  processes. 

There  is  nothing  more  destructive  to  the  beauty,  health,  and  dura- 
bility of  the  teeth,  and  no  disturbance  more  easily  prevented,  than 
irregularity  of  their  arrangement.  Also,  in  proportion  to  the  deviation 
of  these  organs  from  their  proper  position  in  the  alveolar  arch  are  the 
features  of  the  face  and  the  expression  of  the  countenance  injured.  It 
also  increases  the  susceptibility  of  the  gums  and  peridental  mem- 
brane to  morbid  impressions. 

It  is  important,  therefore,  that  the  mouth,  during  second  dentition, 
should  be  properly  cared  for ;  and  so  thoroughly  convinced  is  the 
author  of  this,  that  he  does  not  hesitate  to  say  that  if  timely  precau- 
tions were  used  there  would  not  be  one  decayed  tooth  where  there  are 
now  a  dozen. 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA.  341 

Much  harm,  it  is  true,  may  be  done  by  improper  meddling  with 
the  teeth  during  this  period,  but  this,  so  far  from  inducing  a  total 
neglect,  should  only  make  those  having  the  care  of  children  more 
solicitous  in  securing  the  services  of  scientific,  accomplished  practi- 
tioners. 

For  the  judicious  management  of  second  dentition,  much  judgment 
and  a  correct  knowledge  of  the  normal  periods  of  the  eruption  of  the 
several  classes  of  teeth  are  required.  All  unnecessary  interference  with 
these  organs  at  this  early  period  of  life  should  certainly  be  avoided,  as 
it  will  only  tend  to  mar  the  perfection  at  which  nature  ever  aims.  The 
legitimate  duty  of  the  physician  being,  as  Mr.  Bell  correctly  observes, 
"the  regulation  of  the  natural  functions  when  deranged,"  he  should 
never  anticipate  the  removal  by  nature  of  the  temporary  teeth  unless 
their  extraction  is  called  for  by  some  pressing  emergency,  such  as  a 
deviation  of  the  permanent  ones  from  their  proper  place;  alveolar  ab- 
scess, or  exfoliation  of  the  alveolar  processes. 

The  mouth  should  be  frequently  examined  from  the  time  the  shed- 
ding of  the  deciduous  teeth  commences  until  the  completion  of  second 
dentition  ;  and  when  the  growth  of  the  permanent  teeth  so  far  out- 
strips the  destruction  of  the  roots  of  the  temporary  that  the  former 
are  caused  to  take  an  improper  direction,  such  of  the  latter  as  have 
occasioned  the  obstruction  should  be  immediately  removed.  In  the 
dentition  of  the  upper  front  teeth  this  should  never  be  neglected;  for 
when  they  come  out  behind  the  temporaries,  as  they  most  frequently 
do,  and  are  permitted  to  advance  so  far  as  to  fall  on  the  inside  of  the 
lower  incisors,  a  permanent  obstacle  is  offered  to  their  subsequent 
proper  adjustment. 

When  a  wrong  direction  has  been  given  to  the  growth  of  the  lower 
front  teeth,  they  are  rarely  prevented  from  acquiring  their  proper 
arrangement  by  an  obstruction  of  this  sort.  They  should  not,  how- 
ever, on  this  account  be  permitted  to  occupy  an  erroneous  position  too 
long ;  for  the  evil  will  be  found  easier  of  correction  while  recent  than 
after  it  has  continued  for  a  considerable  length  of  time.  The  irregu- 
larity should  be  immediately  removed. 

The  permanent  central  incisors  of  the  upper  jaw  being  larger  than 
the  temporaries  of  the  same  class,  it  might,  therefore,  be  supposed 
that  the  aperture  formed  by  the  removal  of  the  one  would  not  be 
sufficient  for  the  admission  of  the  other  without  an  increase  in  the  size 
of  this  part  of  the  maxillary  arch.  It  should  be  recollected,  how- 
ever, that  by  the  time  these  teeth  usually  emerge  from  the  gums,  the 
crowns  of  the  temporary  lateral  incisors  are  so  much  loosened  by  the 
partial  destruction  of  their  roots  as  to  yield  sufficiently  to  the  pres- 
sure of  the  former  to  permit  them  to  take  their  proper  position  within 


342 


DENTAL   SURGERY, 


the  dental  circle.  When  this  does  not  happen,  the  temporary  laterals 
should  be  extracted. 

Under  similar  circumstances  the  same  course  should  be  pursued  with 
the  permanent  lateral  incisors  and  the  temporary  cuspids,  and  also  with 
the  permanent  cuspids  and  the  first  bicuspids. 

But  from  the  fact  that  the  bicuspids  are  erupted  before  the  perma- 
nent cuspids,  the  premature  extraction  of  the  temporary  cuspids  is 
often  the  cause  of  the  projection  of  one  or  more  of  the  front  teeth ; 
sometimes  to  such  a  degree  as  to  produce  considerable  deformity. 

The  removal  of  the  temporary  cuspids  should  therefore  be  avoided 
when  there  is  reason  to  believe  that  the  growth  of  the  jaw  will  provide 
sufficient  space  for  a  deviating  permanent  lateral  incisor  to  take  a 
proper  position  within  the  dental  arch. 

The  bicuspids  being  situated  between  the  roots  of  the  temporary 
molars  are  seldom  caused  to  take  an  improper  direction  in  their  growth. 
Nor  are  they  often  prevented  from  coming  out  in  their  proper  place 
for  want  of  room. 

In  the  management  of  second  dentition  much  will  depend  on  the 
experience  and  judgment  of  the  practitioner.  If  he  be  properly  in- 
formed upon  the  subject,  and  gives  to  it  the  necessary  care  and  atten- 
tion, the  mouth  will  in  most  instances  be  furnished  with  a  healthful, 
well  arranged,  and  beautiful  set  of  teeth.  At  this  time  "an  oppor- 
tunity," says  Mr.  Fox,  "  presents  itself  for  effecting  this  desirable  ob- 
ject "  (the  prevention  of  irregularity),  "  but  everything  depends  upon 
a  correct  knowledge  of  the  time  when  a  tooth  requires  to  be  extracted, 
and  also  of  the  particular  tooth,  for  often  more  injury  is  occasioned 
by  the  removal  of  a  tooth  too  early  than  if  it  be  left  a  little  too  long; 
because  a  new  tooth  which  has  too  much  room  long  before  it  is  re- 
quired will  sometimes  take  a  direction  more  difficult  to  alter  than  a 
slight  irregularity  occasioned  by  an  obstruction  of  short  duration." 

The  temporary  teeth  by  remaining  too  long  are  likely  to  affect  the 
arrangement,  and  consequently  the  health,  of  the  permanent  teeth, 
and  they  should  be  extracted,  because,  in  that  case,  their  presence  is  a 
greater  evil  than  any  that  would  be  occasioned  by  their  removal.  As 
a  general  rule,  they  should  be  suffered  to  remain  until  their  presence  is 
likely  to  injure  the  permanent  teeth  and  their  contiguous  parts. 

When  the  permanent  teeth  are  crowded,  the  lateral  pressure  is  fre- 
quently so  great  as  to  fracture  the  enamel.  If  this  cannot  be  pre- 
vented in  any  other  way,  one  on  each  side  should  be  extracted.  It  is 
better  to  sacrifice  two  than  permanently  to  endanger  the  health  of  the 
whole. 

The  file  or  revolving  discs  and  points  upon  the  dental  engine 
should  never  be  used  with  a  view  to  remedy  irregularity  ;    the  ex- 


IRREGULARITY    OF    THE    TEETH ORTHODONTIA.  343 

traction  of  two  teeth,  one  on  each  side  of  the  jaw,  however  small 
the  space  required  to  be  gained  may  be,  is  far  preferable.  The  second 
bicuspids,  c(eteris  paribus,  should  always  be  removed  rather  than  the 
first,  but  sometimes  the  extraction  of  the  first  becomes  necessary. 

By  the  removal  of  the  teeth  ample  room  will  be  gained  for  the 
arrangement  of  all  the  remaining  ones,  and  the  injury  resulting  from  a 
crowded  condition  of  the  organs  prevented. 

The  author  does  not,  however,  wish  to  be  understood  as  conveying 
the  idea  that  cutting  away  a  portion  of  the  teeth  necessarily  causes 
them  to  decay,  for,  when  the  file  or  disc  is  used  for  any  other  purpose 
than  to  gain  room,  the  apertures  may  be  made  large  enough  to  prevent 
the  approximation  of  the  organs,  and  thus  the  bad  effects  resulting 
from  the  operation  will  be  prevented. 

The  extraction  of  the  root  of  a  superior  front  tooth,  a  central  incisor, 
for  example,  when  the  crown  has  been  greatly  disfigured  or  wholly 
destroyed  by  mechanical  violence,  may  cause  the  superior  front  teeth 
to  fall  behind  the  inferior  teeth.  Should  such  a  deformity  not  occur, 
it  frequently  happens  that  an  unsightly  space  is  left,  too  small  for  the 
insertion  of  an  artificial  tooth  to  correspond  in  size  with  the  adjoining 
natural  ones. 

To  avoid  such  results  the  root  should  be  allowed  to  remain  and  the 
proper  treatment  instituted  to  subdue  the  inflammation,  the  pulp 
removed  when  exposed,  and  the  root  filled  to  the  apex  with  gold  or 
other  suitable  material.  By  pursuing  such  a  course  the  root  is  retained 
until  such  a  time  as  its  removal  will  not  affect  the  adjoining  teeth.  In 
some  cases  the  portion  of  the  crown  destroyed  may  be  restored  with 
gold,  or  an  artificial  crown  inserted  on  a  pivot. 

When  the  deciduous  canines  are  extracted  on  the  approach  of  the 
permanent  lateral  incisors,  the  first  bicuspids  will  move  forward  and 
occupy  the  space  necessary  for  the  reception  of  the  permanent 
canines,  which  may  erupt  over  the  laterals,  and  by  their  pressure 
cause  these  latter  teeth  to  shut  within  the  lower  teeth. 

Fig.  160  illustrates  the  mischief 
attending  the  premature  extraction 
of  the  deciduous  canines. 

Nature,  when  permitted  to  pro- 
ceed with  her  work  without  inter- 
ruption,   is   able    to    perform    her       '^'lii,\^^'-"?'^   ""^^^'^^II^HIK^^X 
operations  in  a  perfect  and  harmo- 
nious manner.     But  the  functional 

operations  of  all  the  parts  of  the  body  are  liable  to  be  disturbed,  from 
an  almost  innumerable  number  and  variety  of  causes,  and  impairment 
of  one  organ  often  gives  rise  to  derangement  of  the  whole  organism, 


344  DENTAL    SURGERY. 

for  the  relief  of  which  the  interposition  of  art  not  unfrequently  be- 
comes necessary,  and  it  is  fortunate  for  the  well-being  of  man  that  it 
can  in  so  many  instances  be  applied  with  success. 

In  sound  and  healthy  constitutions  the  services  of  the  dentist  are 
seldom  required  to  assist  or  direct  second  dentition.  In  remarking 
upon  this  subject,  Dr.  Koecker  observes,  that  "  the  children  for  whom 
the  assistance  of  a  dentist  is  most  frequently  sought  are  those  who  are 
in  delicate,  or  at  least  imperfect,  constitutional  health;  in  whom  the 
state  not  only  of  the  temporary  teeth,  but  of  the  permanent  also,  is  to 
be  considered,  and  where  both  are  found  to  be  diseased  the  future  health 
and  regularity  of  the  latter  require  the  greatest  consideration  of  the 
surgeon. 

"Irregularity  of  the  teeth  is  one  of  their  chief  predisposing  causes 
of  disease,  and  never  fails,  even  in  the  most  healthy  constitutions,  to 
destroy,  sooner  or  later,  the  strongest  and  best  set  of  teeth  unless  pro- 
perly attended  to.  It  is  thus  not  only  a  most  powerful  cause  of  destruc- 
tion to  the  health  and  beauty  of  the  teeth,  but  also  to  the  regularity 
and  pleasing  symmetry  of  the  features  of  the  face  ,  always  producing, 
though  slowly  and  gradually,  some  irregularity,  and  not  unfrequently 
the  most  surprising  and  disgusting  appearance." 

Though  nature  is  generally  able  to  accomplish  the  task  assigned  her, 
yet  there  are  times  when  she  requires  aid,  and  it  is  then,  and  then  only, 
that  the  services  of  the  dentist  are  needed.  Therefore,  whilst  on  the 
one  hand  we  should  guard  against  any  uncalled-for  interference,  we 
should  on  the  other  always  be  ready  to  give  such  assistance  as  the 
nature  of  the  disturbance  presented  to  our  notice  may  require. 

The  progress  of'  caries  in  the  temporary  teeth  is  very  rapid,  as  a 
general  rule,  owing  to  the  large  proportion  of  organic  matter  compared 
with  the  inorganic.  Alveolar  abscess  is,  therefore,  a  common  result  of 
the  loss  of  vitality,  and  the  absorption  of  the  alveolar  processes  from 
such  a  cause  may  expose  the  apex  of  the  root  of  one  or  more  temporary 
teeth. 

In  the  case  of  the  necrosed  roots  of  the  superior  incisors  presenting 
such  a  condition,  and  it  is  necessary  that  such  teeth  should  be  pre- 
served in  order  to  prevent  an  irregular  arrangement  of  the  succeeding 
permanent  ones,  which  is  very  prone  to  occur  from  the  premature  loss 
of  the  temporary  teeth,  the  exposed  ends  of  the  roots  of  the  necrosed 
temporary  teeth  may  be  excised  and  carefully  rounded  off  with  the  file 
or  corundum  point.  By  such  a  method  the  necrosed  teeth  may  be 
retained  in  the  mouth  until  the  period  of  shedding  has  arrived,  and  the 
space  necessary  for  the  reception  of  the  corresponding  permanent  teeth 
be  preserved. 

The  eruption  of  the  permanent  teeth  begins  before  any  of  the  tern- 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


345 


porary  teeth  are  shed,  the  first  of  the  permanent  teeth  to  appear  being 
the  sixth-year  molars,  between  five  and  a  half  and  six  and  a  half 
years.  These  teeth  are  often  mistaken  for  temporary  teeth,  and 
being  prone  to  decay,  on  account  of  defective  structure  and  the  early 
period  of  their  eruption,  they  are  frequently  lost  early  in  life.  But  as 
the  sixth-year  molars  perform  an  important  part  in  the  preservation  of 
the  integrity  of  the  arch,  their  retention  is  desirable  if  possible.  Cases, 
however,  occur  v^^here  they  cannot  be  permanently  preserved,  when 
every  effort  should  be  made  to  preserve  them  up  to  a  certain  period, 
namely,  until  the  twelfth-year  molars  are  about  to  erupt,  or  until  a 
period  between  the  tenth  and  twelfth  years.     If  the  sixth-year  molars 


Sixth-Year  Molar. 
Fig.  i6i. 

are  lost  earlier  than  the  period  named,  the  adjoining  teeth  will  close  up 
and  cause  irregularity  when  the  other  teeth  appear.  On  the  other 
hand,  if  the  sixth-year  molars  are  lost  later  than  the  time  named,  the 
space  they  occupied  is  never  compactly  closed,  and  the  adjacent  teeth 
will  incline  toward  the  vacant  space,  and  the  continued  occlusion  in 
mastication  will  cause  them  to  tip  over  to  such  a  degree  as  to  result  in 
a  decided  impairment  of  the  occlusion.  Such  irregular  teeth  may  also 
become  painful  and  loose,  on  account  of  the  recession  of  the  gums  and 
the  absorption  of  the  alveolar  processes,  and  even  the  adjoining  teeth 
may  suffer  in  a  similar  manner. 

Fig.  i6i  represents  an  adult  lower  jaw,  side  view. 

Irregularity  of  Arrangement  of  the  Teeth.— TYtt  causes  of  the  various 


346  DENTAL    SURGERY. 

forms  of  irregularity  of  the  teeth  are  divided  into  accidental — those 
occurring  after  the  eruption  of  the  teeth,  and  congenital — those  occur- 
ring prior  to  their  eruption. 

The  accidental  forms  of  irregularity  are  most  commonly  caused  by 
the  presence  of  temporary  teeth  beyond  the  proper  time  of  shedding, 
owing  to  the  process  of  absorption  of  their  roots  not  being  commen- 
surate with  the  development  of  the  permanent  teeth,  or  to  the  presence 
of  necrosed  roots  of  temporary  teeth  which  are  not  absorbed.  The 
congenital  forms  of  irregularity  are  generally  caused  by  a  want  of 
development  of  the  jaws  commensurate  with  the  size  of  the  teeth.  In 
some  rare  cases  the  excessive  development  of  the  maxillae  may  result 
in  abnormal  spaces  between  the  teeth. 

The  temporary  teeth  seldom  deviate  from  their  proper  place  in  the 
alveolar  arch ;  but  irregularity  of  arrangement  is  of  frequent  occur- 
rence in  the  permanent  teeth,  especially  the  cuspids  and  incisors.  The 
first  and  second  molars  are  seldom  irregular,  for,  like  the  teeth  of  first 
dentition,  they  rarely  encounter  obstruction  in  their  growth  and  erup- 
tion. The  sixth-year  molars  being  the  first  of  the  permanent  set  to 
appear,  the  ten  anterior  teeth  are  limited  to  that  part  of  the  arch 
occupied  by  the  ten  temporary  teeth  ;  if  this  space  is  too  small,  irregu- 
larity must  of  necessity  ensue. 

The  dentes  sapientiae  are  sometimes  irregularly  erupted,  in  conse- 
quence of  a  want  of  correspondence  between  the  development  of  the 
tooth  and  the  growth  of  the  maxilla.  The  tooth  in  such  cases  takes 
usually  the  direction  of  least  resistance,  the  crown  presenting  more  or 
less  obliquely  forward,  backward,  outward,  or  inward.  Of  these  four 
positions  the  first  and  fourth  are  found  usually  in  the  lower  jaw;  the 
second  and  third  are  most  common  in  the  upper  jaw. 

When  a  bicuspid  is  forced  from  its  proper  place  it  turns  inward 
toward  the  tongue  or  outward  toward  the  cheek,  accordingly  as  it  is  in 
the  upper  or  lower  jaw  ;  or  it  may  be  so  turned  in  its  cavity  by  the 
occlusion  of  the  teeth  in  the  opposite  jaw,  the  loss  of  an  adjoining 
tooth  giving  the  necessary  space,  as  to  present  one  of  its  proximate 
surfaces  toward  the  cheek.  The  cuspids,  when  prevented  from  coming 
out  in  their  proper  place,  make  their  appearance  either  before  or  be- 
hind the  other  teeth.  When  they  come  out  anteriorly,  which  they  do 
more  frequently  than  posteriorly,  they  often  become  a  source  of  annoy- 
ance to  the  upper  lip,  excoriating  and  sometimes  ulcerating  the  mucous 
membrane. 

The  incisors  of  the  upper  jaw  present  a  greater  variety  of  abnor- 
mal arrangement  than  any  of  the  other  teeth.  The  centrals  come  out 
sometimes  before  and  sometimes  behind  the  arch  ;  at  other  times  their 
median  sides  are  turned  either  directly  or  obliquely  forward  toward 


IRREGULARHY    OF    THE    TEETH — ORTHODONTIA. 


347 


the  lip.  The  laterals  sometimes  appear  half  an  inch  behind  the  arch, 
looking  toward  the  roof  of  the  mouth ;  at  other  times  they  come  out 
in  front  of  the  arch,  and  at  other  times,  again,  they  are  turned 
obliquely  or  transversely  across  it. 

When  any  of  the  upper  incisors  are  transversely  inclined  toward  the 
interior  of  the  mouth,  the  lower  teeth  at  each  occlusion  of  the  jaws 
shut  before  them  and  become  an  obstacle  to  their  adjustment.  This 
form  of  irregularity  often  interferes  with  the  lateral  motion  of  the  jaw. 

The  lower  incisors  sometimes  shut  in  this  manner  even  when  there 
is  no  inward  deviation  of  the  upper  teeth.  In  this  case  the  irregularity 
is  owing  to  preternatural  elongation  of  the  lower  jaw,  which  arises 
more  frequently  from  some  fault  of  dentition  than  from  any  con- 
genital defect  in  the  jaw  itself. 

Sometimes  the  superior  maxillary  arch  is  so  much  contracted,  and 
the  front  teeth  in  consequence  so  prominent,  that  the  upper  lip  is 
prevented  from  covering  them.  Cases  of  this  kind,  however,  are 
rarely  met  with,  but  when 
they  do  occur  it  occasions 
much  deformity  of  the 
face  and  forms  a  species 
of  irregularity  very  diffi- 
cult to  correct.  From  the 
same  cause  the  lateral 
incisors  are  sometimes 
forced  from  the  arch  and 
appear  behind  the  cen- 
trals and  cuspids,  the 
dental  circle  being  filled 
with  the  other  teeth. 

An  abnormal  promi- 
nence of  the  superior 
incisors  may  be  either 
congenital  or  accidental, 
and  when  of  the  former  origin  it  is  almost  invariably  accompanied 
with  a  contracted  arch,  especially  between  the  bicuspids  of  the  right 
and  left  sides  of  the  mouth,  the  incisors  occupying  a  V-shaped  posi- 
tion (Fig.  162). 

When  this  form  of  irregularity  has  an  accidental  origin,  it  is 
generally  caused  by  a  pernicious  habit  of  thumb,  tongue,  or  artificial 
nipple-sucking.* 

*  Such  a  habit  as  thumb-sucking  may  be  prevented  by  the  appHcation  of  some 
bitter  substance,  such  as  aloes,  to  the  thumb,  tying  the  arms  close  to  the  body  at 
night,  or  the  wearing  of  coarse,  heavy  gloves. 


Fig.  162. 


348 


DENTAL   SURGERY. 


Figs.  163  and  164  represent  the  form  of  irregularity  caused  by 
thumb'Sucking. 

An  unusual  prominence  of  the  superior  incisors,  attended  with  a 
diminution  of  space  between  the  bicuspids  and  an  abnormally  high 

vaulting  of  the  palate,  has 
been  thought  by  some  to 
be  very  common  to  con- 
genital idiots.  But  Drs. 
N.  W.  Kingsley  and  J.  W. 
White,  who  examined  the 
inmates  of  some  large  in- 
stitutions for  the  care  of 
the  feeble-minded,  found 
that  such  a  defect  is  not 
an  invariable  rule,  as  only 
a  small  percentage  of  pro- 
nounced irregularity  in 
form  of  the  jaws  or  ar- 
rangement of  the  teeth, 
and  that  generally  associ- 
ated with  the  lowest  type 
of  idiocy,  was  common  to 
such  a  class  of  persons. 

Tonsillitis  has  also  been 
named  by  Mr.  Tomes  as 
a  cause  for  a  contracted 
arch  between  the  opposite 
bicuspids,  the  labored 
breathing  from  the  filling 
up  of  the  fauces  by  the 
enlarged  tonsils,  with  the 
mouth  open,  causing  in- 
creased compression  of  the  cheeks  over  the  lateral  parts  of  the  mouth, 
while  the  median  portion  escapes  the  controlling  pressure  which  would 
be  exercised  when  the  mouth  is  closed. 

Dr.  Kingsley  is  of  the  opinion  that  the  V-shaped  arch  is  nearly 
always  of  congenital  origin — that  is,  an  inherited  tendency,  while 
the  broad  or  rounded  form  of  arch  is  often  due  to  mechanical  causes. 

Inflammation  of  the  throat  early  in  life  in  children  of  a  strumous 
diathesis  will  not  only  produce  deformity  of  these  parts,  but  irregu- 
larity of  arrangement  of  the  teeth,  by  causing  tension  of  the  muscles, 
which  has  the  effect  of  contracting  the  oro-naso-pharyngeal  space  by 
pressing  the  lateral  portions  of  the  walls  inward. 


Fig.  164. 


IRREGULARITY   OF   THE   TEETH — ORTHODONTIA.  349 

The  retention  in  the  jaw  of  permanent  teeth  is  also  a  cause  of 
irregularity,  as  in  some  cases  bicuspids  and  molars  may  not  erupt  suffi- 
ciently to  meet  the  opposing  teeth. 

There  are  many  other  deviations  in  the  arrangement  of  the  incisors. 
Mr.  Fox  mentions  one  that  was  caused  by  the  presence  of  two  super- 
numerary teeth  of  a  conical  form,  situated  partly  behind  and  partly 
between  the  central  incisors,  which  in  consequence  were  thrown  for- 
ward, while  the  laterals  were  placed  in  a  line  with  the  supernumera- 
ries. The  central  incisors,  though  half  an  inch  apart,  formed  one 
row,  and  the  laterals  and  supernumeraries  another.  Mr.  Fox  says  he 
has  seen  three  cases  of  this  kind.  This  description  of  irregularity  is 
rarely  met  with. 

M.  Delabarre  says  that  cases  of  transposition  of  the  germs  of  the 
teeth  occasionally  occur,  so  that  a  lateral  incisor  takes  the  place  of  a 
central,  and  a  central  the  place  of  a  lateral.  A  similar  transposition 
of  a  cuspid  and  lateral  incisor  is,  also,  sometimes  seen.  Two  cases 
of  this  sort  have  fallen  under  the  observation  of  the  author. 

The  incisors  of  the  lower  jaw,  being  smaller  than  those  of  the  upper 
and  in  other  respects  less  conspicuous,  do  not  so  plainly  show  an  irreg- 
ularity in  their  arrangement,  nor  is  the  appearance  of  an  individual 
so  much  affected  by  it.  Still  it  should  be  guarded  against ;  for  such 
deviation,  whether  in  the  upper  or  lower  jaw,  may  prove  injurious  to 
the  health  of  the  teeth  and  the  beauty  of  the  mouth.  The  growth  of 
the  inferior  permanent  incisors  is  sometimes  more  rapid  than  the  de- 
struction of  the  roots  of  the  corresponding  temporaries.  In  this  case 
the  former  emerge  from  the  gum  behind  the  latter,  and  sometimes  so 
far  back  as  greatly  to  annoy  the  tongue  and  interfere  with  enunciation. 
At  other  times  the  permanent  centrals  are  prevented  from  assuming 
their  proper  place,  because  the  space  left  for  them  by  the  temporaries  is 
not  sufficient.  The  irregularity  in  the  former  of  these  two  cases  is 
greater  than  in  the  latter.  The  same  causes  in  like  manner  affect  the 
laterals. 

M.  Delabarre  mentions  a  defect  in  the  natural  conformation  of  the 
jaws,  by  which  the  upper  temporary  incisors  on  one  side  of  the  median 
line  are  thrown  on  the  outside  of  the  lower  teeth,  while  the  correspond- 
ing teeth  on  the  other  side  of  the  same  line  fall  within.  The  same 
arrangement,  he  says,  may  be  expected,  unless  previously  remedied,  in 
the  permanent  teeth.  The  author  has  met  with  but  two  cases  of  this 
sort,  and  the  subjects  of  these  he  did  not  see  until  after  they  had 
reached  maturity. 

Referring  to  an  ingrafted  tendency  in  all  living  matter  to  reproduce 
itself,  Dr.  Kingsley  remarks  :  "I  am  of  the  opinion  that  such  deformi- 
ties, even  when  transmitted  for  generations,  may  have  the   tendency 


350  DENTAL    SURGERY. 

Stamped  out  by  being  corrected  immediately  on  their  development ; 
that  is,  before  the  deformity  has  made  its  fixed  impression  upon  the 
individual." 

Mr.  Mummery  is  of  the  opinion  that  a  large  amount  of  dental  dis- 
ease is  originated  by  overtaxing  the  brain  action  of  children,  and  Dr. 
Kingsley  remarks  that  "  the  next  generation  will  see  more  abnormal- 
ity in  dental  development  and  an  increase  of  nervous  and  cerebral 
diseases,  and  that  the  two  are  correlated  and  spring  from  the  same 
cause. 

Treatment  of  Irregularity. — Orthodontia,  or  the  treatment  of  irregu- 
larity, should  accord  with  the  indications  of  nature.  When  the 
irregularity  is  neither  great  nor  complicated,  and  its  causes  are  removed 
before  the  nineteenth  or  twentieth  year,  the  teeth,  without  the  aid  of 
art,  will  in  many  cases  assume  the  proper  position.  When,  however, 
the  efforts  of  the  economy  are  unavailing,  recourse  should  be  had  to 
the  dentist,  who  can,  in  most  instances,  bring  the  deviating  organs  to 
their  proper  position  in  the  arch.  The  general  rule  is,  that  as  soon 
after  the  eruption  of  a  tooth  as  it  becomes  certain  that  it  will  assume 
an  irregular  position,  interference  is  justifiable,  as  every  year  not  only 
increases  the  difficulties,  but  impairs  the  stability  of  the  dental  organs. 
Teeth  incline  to  return  to  their  places  on  the  removal  of  the  cause 
of  irregularity.  They  may  be  also  made  to  change  position  under 
the  influence  of  pressure.  The  pressure  must  be  constant ;  it  must  be 
sufficient  to  cause  motion,  yet  not  so  great  as  to  set  up  destructive 
inflammation  ;  lastly,  it  must  be  continued  until  the  teeth  can  be  kept 
in  place  by  antagonism  with  the  opposing  teeth  ;  or  in  case  there  is 
no  such  antagonism,  a  retaining  appliance  must  be  worn  more  or  less 
constantly  for  a  year,  or  even  longer.  The  regulating  appliance  should 
be  as  simple  in  its  construction  as  is  possible  to  accomplish  the  pur- 
pose, so  that  both  time  and  labor  may  be  saved  and  the  patient  be 
able  to  attend  to  its  removal  and  adjustment  when  it  becomes  neces- 
sary to  cleanse  it ;  this  should  frequently  be  done. 

Teeth  artificially  regulated  change  position  chiefly,  if  not  entirely, 
by  the  double  process  of  absorption  from  one  side  of  the  socket,  fol- 
lowed by  the  slower  process  of  ossific  deposit  on  the  opposite  side.  It 
is  therefore  essential  to  success  that  the  tooth  be  retained  in  its  new 
position,  either  by  the  other  teeth  or  by  mechanical  appliance,  until 
such  deposit  is  formed.  Many  cases  fail  from  a  want  of  persistence  on 
the  part  of  patient  or  dentist. 

How  far  and  in  what  direction  a  tooth  may  be  removed  will  depend 
partly  upon  the  position  of  the  apex  of  the  root,  partly  upon  the  an- 
tagonism of  the  opposing  teeth. 

Cuspids  growing  out  far  upon  the  alveolar  arch  will  usually  be  found 


IRREGULARITY    OF     IHE    TEETH — ORTHODONTIA.  35  I 

to  have  short  and  curved  roots.  The  attempt  to  move  them  might 
cause  the  curved  apex  to  pierce  the  alveolus.  Even  when  not  curved, 
the  root  is  short,  and  the  regulated  tooth  will  not  possess  that  durabil- 
ity which  is  characteristic  of  the  cuspids.  It  should  always  be  borne 
in  mind  that  in  regulating  the  teeth  the  crown  is  the  movable  point, 
whilst  the  apex  of  the  root  is  the  fixed  point,  and  must  determine  in 
great  degree  the  extent  and  direction  of  motion. 

Again,  the  natural  or  artificial  movement  of  bicuspids  backward  to 
make  room  for  front  teeth  may  be  aided  or  hindered  by  the  opposing 
teeth.  An  upper  bicuspid,  for  instance,  once  carried  back,  so  that  the 
posterior  slope  of  the  lower  bicuspid  strikes  it,  will  retain  its  position 
or  may  be  thrown  even  further  back. 

Upper  incisors  striking  inside  the  lower,  or  lower  incisors  unnatu- 
rally prominent,  may  be  regulated,  and  the  opposing  teeth  will  tend 
to  keep  them  in  their  corrected  position.  But  it  will  require  long  and 
patient  use  of  the  regulating  apparatus  to  keep  in  place  upper  incisors 
which  project  outward,  or  lower  incisors  inclining  inward. 

In  deciding  upon  the  removal  or  extraction  of  an  irregular  tooth,  it 
should  not  be  forgotten  that  a  tooth  moved  by  mechanical  appliance, 
especially  if  the  change  in  position  is  considerable,  will  not  prove  as 
durable  as  if  no  movement  had  been  necessary.  Hence  it  may  some- 
times be  advisable  to  extract  irregular  cuspids  in  cases  where  their  cor- 
rection requires  much  change  in  their  position  and  that  of  the  bicus- 
pids, and  the  arch  is  completely  and  regularly  filled  by  the  remaining 
teeth. 

In  a  case  presented  to  the  late  Prof.  Austen  the  superior  arch  was 
perfectly  regular  and  closely  filled,  but  both  cuspids  had  come  out 
above  the  arch.  The  cuspid  roots  were  normal,  and  it  seemed  prac- 
ticable to  bring  these  teeth  down  into  the  places  of  the  first  bicuspids. 
But  the  four  bicuspids  were  sound,  and  the  first  bicuspids  gave  very 
much  the  appearance  of  the  natural  arrangement.  Hence,  as  in  point 
of  expression  there  would  be  no  great  gain  and  in  point  of  durability 
a  probable  loss,  it  was  not  thought  advisable  to  subject  the  patient  to 
the  tedious  annoyance  of  regulation. 

In  describing  the  treatment  of  irregularity  we  shall  notice  the  means 
by  which  some  of  its  principal  varieties  may  be  remedied  ;  otherwise, 
the  application  of  the  principles  of  treatment  would  not  be  well  under- 
stood, since  it  must  be  varied  to  suit  each  individual  case. 

As  a  general  rule,  the  sooner  irregularity  in  the  arrangement  of  the 
teeth  is  remedied  the  better ;  for  the  longer  a  tooth  is  allowed  to  oc- 
cupy a  wrong  position,  the  more  difficult  will  be  its  adjustment.  The 
position  of  a  tooth  may  sometimes  be  altered  after  the  eighteenth, 
twentieth,  or  even  the  thirtieth  year  ;  but  it  is  better  not  to  delay  the 


352  DENTAL   SURGERY. 

application  of  the  proper  means  until  so  late  a  period.  A  change  of 
this  kind  may  be  much  more  easily  effected  before  the  several  parts  of 
the  osseous  system  have  reached  their  full  development,  and  while  the 
formative  process  is  in  vigorous  operation,  than  at  a  later  period  of 
life.  The  age  of  the  subject,  therefore,  should  always  govern  the  prac- 
titioner in  forming  an  opinion  as  to  the  practicability  of  correcting 
irregularity.  Previously  to  the  twentieth  year  the  worst  varieties  of 
irregularity  may  in  most  cases  be  successfully  treated. 

The  first  thing  claiming  attention  in  the  treatment  is  the  removal 
of  its  causes.  Whenever,  therefore,  the  presence  of  any  of  the  tem- 
porary teeth  has  given  a  false  direction  to  one  or  more  of  the  perma- 
nent, they  should,  as  a  general  rule,  be  extracted,  and  the  deviating 
teeth  pressed  several  times  a  day  with  the  finger  in  the  direction  they 
are  to  be  moved.  This,  if  the  irregularity  has  been  occasioned  by 
the  presence  of  a  deciduous  tooth,  will  generally  be  all  that  is  required. 

But  when  it  is  the  result  of  narrowness  of  the  jaw,  either  congenital 
or  acquired,  a  permanent  tooth  on  either  side  should  be  removed  to 
make  room  for  such  as  are  improperly  situated.  All  the  teeth  being 
sound  and  well  formed,  the  second  bicuspids  are  the  teeth  which  should 
be  extracted;  but  if,  as  is  often  the  case,  the  first  permanent  molars 
are  so  much  decayed  as  to  render  their  preservation  impracticable,  or, 
at  least,  doubtful,  these  teeth  should  be  removed  in  their  stead.  After 
the  removal  of  the  second  bicuspids,  the  first,  usually,  very  soon  fall 
back  into  the  places  which  they  occupied,  and  furnish  ample  room  for 
the  cuspids  and  incisors.  But  if  they  fail  to  do  this,  they  may  be 
gradually  forced  back  by  inserting  wedges  of  wood  or  rubber  between 
them  and  the  cuspids,  or  by  means  of  a  ligature  of  silk  or  rubber 
securely  fastened  to  the  first  molar  on  each  side,  or  by  other  proper 
appliances.  These  should  be  renewed  every  day  until  the  desired 
result  is  produced. 

The  most  frequent  kind  of  irregularity  resulting  from  narrowness 
of  the  jaw  is  the  prominence  of  the  cuspids.  These  teeth,  with  the 
exception  of  the  second  and  third  molars,  are  the  last  of  the  teeth 
of  second  dentition  to  be  erupted,  consequently  they  are  more  liable 
to  be  forced  out  of  the  arch  than  any  others,  especially  when  it  is  so 
much  contracted  as  to  be  almost  entirely  filled  before  they  make  their 
appearance.  The  common  practice  in  such  cases  was  to  remove  the 
projecting  teeth.  But  as  the  cuspids  contribute  more  than  any  of  the 
other  teeth,  except  the  incisors,  to  the  beauty  of  the  mouth,  and  can 
in  almost  every  case  be  brought  to  their  proper  place,  the  practice  is 
injudicious.  Instead  of  removing  these,  a  bicuspid  should  be  ex- 
tracted from  each  side.  When  the  space  between  the  lateral  incisor 
and  the  bicuspid  is  equal  to  one-half  the  width  of  the  crown  of  the 


IRREGULARITY    OF   THE   TEETH — ORTHODONTIA.  353 

cuspid  the  second  bicuspid  should  be  removed,  but  when  it  is  less, 
the  first  should  be  taken  out,  because,  although  the  crown  of  the 
latter  may  be  carried  far  enough  back  after  the  removal  of  the  former 
to  admit  the  crown  of  the  cuspid  between  it  and  the  lateral  incisor, 
the  root  of  this  tooth  will  remain  in  front  and  partly  across  the  root 
of  the  first  bicuspid,  leaving  a  more  or  less  prominent  vertical  ridge  on 
the  anterior  part  of  the  alveolar  border,  which,  to  some  extent  at  least, 
acts  as  an  irritant  to  the  gums  and  periosteum. 

As  the  incisors  of  the  upper  jaw  are  more  conspicuous  than  those 
of  the  lower,  and  when  well  arranged  contribute  more  to  the  beauty  of 
the  mouth,  their  preservation  and  regularity  are  of  greater  relative 
importance.  Hence,  the  removal  of  a  lateral  incisor,  when  it  is  situ- 
ated behind  the  dental  arch,  as  is  often  done  with  a  view  to  remedy 
the  deformity  produced  "by  false  position,  is  a  practice  which  cannot  be 
too  strongly  deprecated,  provided  sufficient  space  can  be  made  for  it 
between  the  cuspid  and  central  incisor  by  the  removal  of  a  bicuspid 
from  each  side  of  the  jaw. 

Dr.  Kingsley  remarks  that  "cases  are  of  frequent  occurrence 
which  show  that  a  pair  of  any  of  the  teeth  in  the  mouth  may  be 
removed  to  correct  an  irregularity,  excepting  the  canines  of  both  jaws 
and  the  superior  central  incisors."  "It  would  be  an  inconceivable 
case  which  would  justify  the  extraction  of  the  superior  central  incisors  ; 
but  the  upper  lateral  incisors  and  any  pair  of  the  lower  incisors  may 
be  removed,  in  certain  cases,  without  any  serious  detriment  to  the 
appearance  of  the  mouth."  "It  is  not  necessary  to  the  contour, 
symmetry,  or  harmony  of  the  features  that  every  one  of  the  masti- 
cating organs  should  be  retained  in  the  mouth."  "  The  articulation 
of  masticating  organs  is  of  much  more  importance  than  their  num- 
ber, and  a  limited  number  of  grinding  teeth  fitting  closely  on  occlu- 
sion will  be  of  far  greater  benefit  to  the  individual  than  a  mouthful 
of  teeth  with  the  articulation  disturbed."  "It  is  a  disputed  point 
as  to  which  of  the  teeth  behind  the  six  front  teeth  can  be  best  spared 
from  the  mouth."  "  If  the  sixth-year  molars  are  badly  decayed  their 
removal  would  be  indicated.  If  they  were  sound,  and  also  the  bicus- 
pids, there  might  be  no  greater  reason  for  their  removal  than  either  of 
the  bicuspids.  In  fact,  sound  molars  in  the  jaw  are  of  more  value  as 
masticating  organs  than  equally  sound  bicuspids."  The  same  writer  is 
also  of  the  opinion  that  extraction  of  any  teeth  from  a  V-shaped  jaw 
before  it  is  widened  would  be  likely  to  prove  bad  practice. 

Many  different  forms  of  appliances  are  necessary  in  correcting  an 

irregular  arrangement  of  the  teeth,  as  almost  every  case  presents  its 

own  peculiarities.     It  is  therefore   not   only  impossible   to  describe 

every  form  of  irregularity  to  which  the  teeth  are  subject,  but  also  the 

23 


354 


DENTAL   SURGERY. 


forms  of  appliances  necessary.  The  attention  of  the  reader  will, 
therefore,  be  directed  to  the  treatment  of  the  most  common  forms  and 
the  necessary  appliances  for  their  correction,  modifications  of  which 
can  be  constructed  according  to  the  peculiarities  presenting  them- 
selves. The  most  simple  appliances  for  correcting  irregularity  consist 
of  rings  cut  from  rubber  tubing  and  silk  or  rubber  ligatures,  which 
have  their  uses  in  the  management  of  some  of  the  easily  manipulated 
cases.  The  value  of  such  simple  appliances,  however,  depends  upon 
the  skill  exercised  in  applying  and  securing  them.     A  simple  band  or 

ring  cut  from  rubber  tubing,  and  pre- 
vented from  slipping  up  to  and  injuring 
the  gum  by  means  of  waxed  floss-silk 
tightly  tied  about  the  necks  of  the  teeth, 
will  answer  for  drawing  two  teeth,  in- 
cisors for  example,  together,  between 
which  there  is  an  unsightly  space.  A 
similar  ring  may  be  employed  for  cor- 
recting an  irregular  front  tooth  which 
projects  beyond  the  arch. 

The  following  figures  represent  some 
of  the  most  useful  knots  for  applying 
silk  ligatures  :  — 

Fig.  165  represents  13  forms  of  the 
most  useful  knots:  i,  thumb-knot;  2 
(12,  15,  16),  various  stages  of  the  clove- 
hitch;  3,  drag-rope,  or  lever-hitch;  4, 
draw-knot;  5,  garrick  bend;  6,  com- 
mon or  sheet-bend  ;  7,  running-knot  ; 
9,  men's  harness-hitch;  10,  sheep- 
shank; II,  double  bowline-knot;  12, 
first  stage  of  clove-hitch;  13,  single 
bow-line-knot;  14,  half-hitch  ;  15,  sec- 
ond stage  of  clove-hitch. 

In  describing  the  treatment  of  irregu- 
larity we  shall  commence  with  an  inci- 
sor occupying  an  oblique  or  transverse 
position  across  the  alveolar  ridge ;  so  that  the  cutting  edge  of  the 
tooth  instead  of  being  in  a  line  with  the  arch  forms  an  angle  with  it 
of  from  forty  to  ninety  degrees.  This  variety  of  deviation  is  rarely 
met  with  in  both  centrals,  but  often  occurs  with  one.  Some  dentists 
have  recommended  in  cases  of  this  kind,  when  the  space  between  the 
adjoining  central  and  lateral  incisor  is  equal  to  the  width  of  the  devi- 
ating tooth,  to  turn  the  latter  in  its  socket  with  a  pair  of  forceps,  or  to 


Fig.  165. 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


355 


extract  and  immediately  replace  it  in  its  proper  position.  It  is  scarcely 
necessary  to  say  that  if  a  tooth  is  turned  in  its  socket,  without  great 
care  is  exercised  and  the  operation  gradually  performed,  the  vessels  and 
nerves  from  which  it  derives  nourishment  and  vitality  are  strangulated  ; 
hence,  though  its  connection  with  the  alveolus  may  be  partially  re- 
established, it  will  be  liable  to  act  as  a  morbid  irritant  and  be  subject 
to  inflammation  from  comparatively  slight  causes. 

The  tooth,  however,  may  be  brought  to  its  proper  position,  without 
incurring  the  risk  of  injury,  by  accurately  fitting  a  gold  ring  or  band 
with  knobs  on  the  labial  and  palatine  sides;  to  each  of  these  a  ligature 
should  be  attached.  Thus  fastened  to  the  ring,  each  end  should  be 
carried  back,  one  on  either  side,  in  front  and  behind  the  arch  and 
secured  to  the  bicuspids,  as  represented  in  Fig.  i66,  so  as  to  act  con- 
stantly upon  the  irregular  tooth.  The  ligatures  should  be  renewed 
from  day  to  day  until  the  tooth  assumes  its  proper  position.  Should 
the  space  not  be  sufficient  to  permit  the  use  of  the  band  the  method 


Fig,  167. 


practised  by  Mr.  Tomes  is  shown  in  Fig.  167.  A  plate  is  fitted  to  the 
inside  of  the  arch  and  a  band  carried  in  front  and  soldered  to  projec- 
tions from  the  plate,  which  pass  between  the  bicuspids.  On  each  side 
of  the  irregular  tooth  a  metallic  dovetail  is  fastened  and  pieces  of 
compressed  wood  inserted  into  them.  The  swelling  of  the  wood  grad- 
ually turns  the  tooth.  In  a  few  days  the  metal  sockets  will  require  to 
be  changed  in  position,  and  in  a  few  weeks  the  tooth  may  be  thus 
brought  nearly  or  quite  to  its  natural  place. 

If  the  space  permits,  these  two  methods  may  be  advantageously  com- 
bined. Use  the  plate  as  in  Fig.  167,  with  the  inner  dovetail,  but  for 
the  long  outside  band  substitute  the  band  (Fig.  166)  around  the  tooth, 
with  a  loop  on  the  median  side  ;  from  this  pass  an  elastic  ligature  to  a 
hook  attached  to  the  plate.  The  tooth  is  turned  on  its  axis  by  the 
combined  pull  of  the  ligature  and  thrust  of  the  wood. 

For  turning  or  twisting  a   tooth  upon  its  axis,  Dr.  J.  F.  Flagg  re- 


356 


DENTAL   SURGERY. 


commends  the  clove-hitch,  Fig.  165^,  over  which  the  ends  of  the  liga- 
tures are  passed  and  then  tied  tightly  with  a  surgeon's  knot,  which 
holds  so  firmly  to  the  tooth  that  it  will  not  slip  ;  the  ends  are  then 
carried  to  a  rubber  ring  attached  to  a  neighboring  tooth,  which  by  its 
elasticity  keeps  up  a  constant  torsion  force. 

For  rotating  a  single  tooth  as  well  as  drawing  out  teeth  that  incline 
within  the  arch,  the  screws  represented  in  Fig.  168  and  designed  by 

Dr.  Farrar  will  be  found  as  useful  as  any 
other  means. 

Before  attempting  to  turn  the  deviat- 
ing organ  it  should  be  ascertained  if  the 
aperture  between  the  adjoining  teeth  is 
sufficient  to  admit  of  the  operation.  If 
not,  it  should  be  increased  by  the  extraction  of  a  bicuspid  from  each 
side  of  the  jaw  and  moving  the  teeth  in  front  of  them  backward  until 
sufficient  room  is  obtained.  The  time  required  to  do  this  will  vary 
from  three  to  eight  or  ten  weeks,  depending  upon  the  number  of  teeth 
to  be  acted  on  and  the  age  of  the  patient.  A  sufficient  space  may 
sometimes  be  gained  by  pressing  outward  the  adjoining  teeth  in  cases 
where  they  fall  within  the  normal  curve  of  the  arch.  This  may  be 
done  by  the  use  of  the  "Coffin  Split  Plate,"  or  by  the  "Norton- 
Talbot  Regulating  Springs,"  both  of  which  appliances  are  described 
further  on. 

Fig.   169,   170,   and   171  represent   favorite   devices   of    Dr.  J.  N. 


Fig.  168. 


m  U 


Fig.  169. 


Fig.  171. 


Farrar  for  rotating  teeth,  the  simplicity  of  which  requires  no  further 
explanation  except  that  it  is  constructed  entirely  of  gold  or  platinum, 
and  bound  upon  the  tooth  to  be  rotated  by  a  slip-noose  as  thin  as 
writing  paper  and  about  one-twelfth  to  one-fifteenth  of  an  inch  wide, 
which  is  tightened  by  means  of  a  nut  screwed  against  a  small  strip  of 
plate  resting  against  other  teeth. 

Irregular  and  protruding  front  teeth  may  be  partially  rotated  and 
drawn  into  position  by  a  very  simple,  but  at  the  same  time  ingenious 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


357 


appliance  devised  by  Dr.  S.  H.  Guilford.     Figs.  172,  173,  174,  175, 
and  176  represent  two  cases  of  the  kind  referred  to  and  Dr.  Guilford's 


Fig  172. 


Fig   173 


3E.- 


% 
Fig.  174. 


>^x^ 


Fig.  175. 


appliance.  According  to  Dr.  Guilford's  description,  this  appliance 
is  made  on  a  model  of  the  teeth,  and  is  constructed  as  follows: 
"A  piece  of  gold  backing  cut  an  eighth  of  an  inch  wide,  and  of 
sufficient     length     to     extend 

along  and  a  trifle  beyond  the  f, j   | ^ 

palatal  surfaces  of  the  centrals, 
is  bent  to  conform  as  closely  as 
possible  to  the  lingual  surfaces 
of  these  teeth,  and  forward  so 
as  to  slightly  clasp  the  disto- 
palatal  angles  as  shown  in  a, 
Fig.  1 74.  To  this  are  soldered 
two  strips  cut  from  upper  plate 
scrap,  a  little  narrower  than 
the  first  piece,  and  bent  in  the 
form  of  ^  and  c,  Fig.  174,  re- 
spectively, which  are  suffici- 
ently long  to  extend  slightly 
over  the  anterior  and  posterior 
surfaces  of  the  teeth.  After 
being  properly  shaped  to  fit 
the  model,  their  backs  are  sol- 
dered together,  and,   in  turn, 

soldered  to  the  part  (a),  as  shown  in  Fig.  174.  The  only  thing  then 
to  be  done  is  to  reduce  with  a  file  the  thickness  of  the  part  i,  c,  which 


35^ 


DENTAL    SURGERY. 


passes  between  the  teeth,  Fig.  175.  Before  applying  such  a  fixture, 
it  may  be  necessary  to  place  a  piece  of  wood  between  the  teeth  for  a 
few  hours,  to  separate  them  sufficiently  to  admit  the  appliance. 
The  labial  part  of  the  apparatus  should  rest  against  the  teeth  just  at 
or  slightly  above  the  most  prominent  part  of  their  convexity,  while 
the  lingual  portion  should  be  near  the  gum  (not  quite  touching  it), 
and  the  slightly  curved  ends  of  this  part  will  catch  just  above  the 
little  nodule  usually  found  on  the  disto-palatal  angle  near  the  gum. 
When  thus  secured  it  cannot  easily  be  displaced  by  the  action  of  the 
lip  or  tongue.  Bend  the  long  palatal  arms  slightly  toward  the 
short  labial  ones  daily,  and  spring  it  back  into  position  on  the  teeth. 
The  elasticity  ot  the  gold  stiffened  by  the  solder  will  do  the  work. 
To  guard  against  its  accidental  loosening  tie  it  to  the  tooth  with  a 
thread." 

Fig.  177  represents  an  appliance  designed  by  Dr.  Kingsley  for 
twisting  the  central  incisors.  After  the  arch  was  expanded,  as  it  was 
a  case  of  contracted  arch,  a  vulcanite  plate  was  required  to  retain 
the  teeth  in  their  spread  condition,  and  its  presence  was  made  avail- 
able for  attachments  for  elastic  ligatures.  A  small  hook  of  gold 
wire  was  inserted  opposite  the  canine  teeth,  and  a  little  staple  or  loop 
of  the  same  wire  at  the  apex  of  the  plate  between  the  centrals. 
Previous  to  insertion   a  ring  of  rubber  cut  from  tubing  was  caught 

over  one  hook,  passed  through 
the  loop  at  the  apex  and 
caught  on  to  the  other  hook. 
The  plate  was  then  intro- 
duced into  the  mouth  and  the 
elastic  band  drawn  over  each 
lateral  incisor,  as  seen  in  the 
figure.  The  tendency  of  the 
elastic  band  to  contract  in  a 
straight  line  operated  only  on 
the  inverted  corners  of  the 
centrals,  and  by  this  means 
the  centrals  were  turned  into 
their  proper  positions. 

Figs.  1 78  and  179  represent 
a  case  of  irregularity  before  and  after  treatment,  where  the  overlap- 
ping central  incisors  were  turned  and  a  deviating  lateral  incisor  forced 
outward  by  the  ai)pliances  just  described. 

The  operation  known  as  '^torsion,'"  which  has  been  recommended 
by  Mr.  Tomes,  consists  in  forcibly  turning  a  tooth  in  its  cavity  by 
grasping  it  near  its  neck  with  a  pair  of  forceps,  the  beaks  of  which  are 


Fi(j    177 


IRREGULAKITV    OF    THE    TEETH — ORTHODONTIA. 


359 


guarded  with  chamois-skin  or  other  substances,  to  prevent  injury. 
Where  the  deviating  tooth,  such  as  an  incisor,  requires  but  one-fourth 
of  a  turn  or  twist,  or  less, 
this  is  accomplished  by  one 
operation  ;  but  where  one- 
half  turn  is  required  several 
operations,  after  intervals 
of  a  few  days,  are  necessary. 
The  tooth  is  then  secured 
in  its  new  position  by 
means  of  ligatures  until  a 
retaining  plate  is  con- 
structed and  the  necessary 
antiphlogistic  treatment 
pursued.  The  danger  of 
such  an  operation  as  tor- 
sion is  the  injury  likely  to 

occur  to  the  vessels  and  nerves  resulting  in  devitalization,  and  in  no 
case  should  it  be  attempted  until  the  root  of  the  deviating  tooth  is  fully 
formed  and  sufficient  space  exists  for  its  reception. 

The  use  of  vulcanized  India-rubber  is  of  great  value  in  the  correc- 
tion of  irregularities.  The  peculiar  manipulations  it  requires  wilt  be 
found  in  another  portion  of  this  work  ;   it  is  only  necessary,  therefore, 

in  concluding  this  chap- 
ter, to  briefly  mention  the 
properties  which  fit  it  for 
this  imi)ortant  branch  of 
dental  practice. 

It  admits  of  absolutely 
perfect  adaptation  to  the 
teeth.  If  only  a  part  of 
the  crowns  of  the  teeth 
require  fitting,  a  wax  im- 
pression will  be  sufficient- 
ly accurate.  But  if  the 
gum  and  under-cut  sur- 
faces of  the  teeth  are  to  be 
fitted,  a  plaster  impression 
is  necessary.  Prof.  Austen's  method  of  taking  plaster  impressions  in 
gutta-percha  cups  will  enable  a  skillful  operator  to  take  an  accurate 
impression  of  any  mouth,  however  irregularly  the  teeth  may  be 
arranged. 

A  closely-fitting  vulcanite  plate  can  be  worn  with  comfort ;  hence 


360  DENTAL    SURGERY. 

the  patient  is  not  tempted  to  remove  it.  It  has  no  motion ;  hence  does 
not  wear  the  teeth  or  irritate  the  gums.  Its  firmness  of  adaptation 
makes  it  an  excellent  "  fixed  point  "  from  which  to  make  pressure  or 
traction  in  any  required  direction  upon  the  irregular  teeth;  the 
counter-pressure,  being  distributed  all  over  the  regular  teeth,  is  not 
felt.  When  it  is  necessary  to  cap  the  molars,  a  layer  of  varying  thick- 
ness should  be  carried  over  them  all,  to  prevent  the  soreness  caused  by 
mastication  upon  any  one  tooth. 

Any  variety  of  appliances  may  be  used  in  connection  with  the  plate 
that  the  judgment  of  the  operator  suggests  as  best  adapted  to  bring 
about  the  required  change.  The  plastic  nature  of  the  crude  material 
permits  enlargement  or  extension  in  any  direction,  without  the  neces- 
sity of  soldering,  as  in  metallic  plates,  and  with  sufficient  exactness. 

Thus,  prominences  may  be  left  behind  teeth  which  are  to  be  moved 
outward,  in  which  may  be  made  dovetails  for  the  insertion  of  com- 
pressed wood,  slits  or  holes  for  India-rubber,  which  makes  more  rapid 
pressure  than  the  wood,  or  holes  for  the  insertion  of  small  screws. 
These  screws  may  bear  directly  against  the  tooth,  and  be  turned 
slightly  each  day  or  two.  Or  the  portion  of  the  plate  next  the  tooth 
or  teeth  to  be  moved  may  be  separated,  with  a  delicate  saw,  from  the 
plate  ;  the  ends  of  the  screw  or  screws  playing  into  this  move  the  tooth 
or  teeth  by  a  broad  bearing,  which  will,  in  certain  cases,  be  better 
than  the  point  of  the  screw. 

Or  a  small  piece  of  vulcanized  rubber  may  be  taken,  one  end  fit- 
ting against  a  molar  or  bicuspid,  and  into  the  other  end  a  screw  thread 
cut  to  receive  a  delicate  screw ;  on  the  head  of  this  screw  a  second 
piece  of  rubber  may  be  fitted  against  the  tooth  to  be  moved,  so  as  to 
allow  the  screw  to  be  turned  without  changing  its  position  on  the 
tooth.  This  combination  forms  a  miniature  jack-screw  similar  to 
those  recommended  some  years  since  by  Dr.  Dwindle,  and  will  often 
be  found  useful.  It  may  be  used  in  combination  with  the  rubber 
plate  by  attaching  one  end  to  the  plate  instead  of  resting  it  against  a 
tooth. 

If  it  is  desired  to  move  a  tooth  by  the  elasticity  of  a  spring,  a  vul- 
canite plate  is  made  to  fit  closely  to  the  mouth  and  teeth  ;  one  end  of 
a  metal  spring  is  fitted  tightly  into  a  groove  cut  in  the  plate,  so  that 
the  free  end  shall  bear  with  the  requisite  force  against  the  tooth.  The 
elastic  slip  or  spring,  when  made  of  vulcanized  rubber,  can  readily  be 
bent  by  means  of  a  warm  burnisher,  so  as  to  press  with  greater  or  less 
force,  as  the  case  may  demand.  Fig.  180,  taken  from  Mr.  Tomes' 
work,  will  illustrate  one  variety  of  the  application  of  metal  springs  on 
a  vulcanite  plate,  in  this  case  pressing  outward  and  laterally  the  left 
central  and  right  lateral  incisors.     This  mode  of  making  pressure  will 


IRREGULARITY    OF    THE    TEETH ORTHODONTIA. 


361 


be  found  very  useful.  It  acts  steadily,  is  under  control,  and  does  not 
need  renewal  so  often  as  the  wedges  of  wood  or  rubber.  What  are 
known  as  seamless  collars  can  also  be  employed  for  rotating  teeth,  as 
follows : — 

"To  rotate  a  central  incisor,  take  a  fine  wire  and  wrap  it  around 
the  tooth,  close  to  but  not  under  the  gum,  and  cut  the  wire  so  that  its 
ends  exactly  meet  to  measure  the  circumference  of  the  tooth.  Straighten 
the  wire  without  stretching  it ;  find  its  equal  in  length  on  the  collar 
diagram,  and  select  the  medium  width  collar  numbered  under  that 
line.  Take  a  piece  of  thick  gold  plate,  shape  it  like  Fig.  181,  and 
solder  it  to  the  collar  as  seen  in  Fig.  182,  using  only  solder,  enough  to 
unite  the  end  of  the  lever,  without  flowing  any  solder  over  the  collar 
to  prevent  it  from  fitting  close  on  the  tooth.  Dry  the  tooth,  smear  its 
neck  all  around  with  oxyphosphate  cement,  and  force  the  collar  over 


Fig.  180. 


Fig.  183. 


the  tooth  so  that  the  lever  will  be  in  position  to  be  pulled  by  a  ligature, 
or  rubber  ring,  after  the  cement  has  become  hard,  which  should  take 
at  least  ten  minutes.  The  applied  fixture  is  shown  by  Fig.  183.  A 
bar  regulator  that  is  to  be  anchored  to  molars  or  bicuspids  may  be 
likewise  soldered  to  collars,  which  can  then  be  cemented  on  the  anchor 
teeth  ;  or  the  bar  may  be  adjustably  connected  w^ith  the  collars,  which 
are  then  fixed  by  cement  on  the  teeth." 

"  Such  fixed  collars  also  serve  as  fulcra  for  jack-screws,  the  points  of 
which  will  take  on  the  metal  of  the  collars  so  as  not  to  slip,  and  yet 
leave  the  enamel  uninjured.  Other  similar  functions  will  be  found 
available  in  the  collars  for  regulating  purposes." 

Where  ligatures  are  required,  the  vulcanite  plate  affords  an  easy 
means  of  attaching  them  in  any  desired  position ;  passing  them 
through  holes  and  tying ;  looping  them  over  projecting  knobs  of  vul- 


362 


DENTAL    SURGERY. 


canite,  -or  over  small  metal  hooks  set  in  the  plate  ;  or  stretching  them 
through  slits  sawn  in  the  plate. 

If  a  band  is  to  be  carried  for  any  purpose  in  front  of  the  arch,  it 
may  be  connected  with  the  plate  on  the  inside  of  the  arch,  through 
any  spaces  occurring  between  the  bicuspids  or  molars ;  if  there  are  no 
such  spaces,  or  if  they  are  to  be  closed  up  in  the  process  of  regulation, 
the  cap  which  is  often  required  to  pass  over  the  molars  will  connect  the 
two.  But  the  outside  band  is  not  often  necessary.  The  inside  plate 
is  less  awkward  to  the  patient  ;  it  is  out  of  sight;  and  almost,  if  not 
quite,  every  required  movement  can  be  obtained  from  it. 

Where  the  irregularity  consists  in  some  of  the  teeth  projecting  while 
others  incline  inward,  such  a  case  can  be  advantageously  treated  by 
the  use  of  a  vulcanite  plate,  the  various  stages  progressing  nearly  at 
the  same  time.  The  impression  in  this  case  to  be  taken  in  plaster ; 
the  plate  capping  the  second  molars  ;  first  molars  and  first  bicuspids 
carried  outward  by  wooden  or  elastic  wedges,  or  by  a  double  spring  of 
vulcanite  fastened  to  the  plate  opposite  each  space  of  the  extracted 
second  bicuspids;  the  left  central  and  right  lateral  carried  out  by 
wedges  or  screws  ;  the  right  central  and  left  lateral  brought  in  by  liga- 
tures looped  over  hooks  in  the  plate.  At  the  completion  of  the  work 
a  new  impression  to  be  taken  and  a  plate  worn  until  the  teeth  become 

firmly  fixed,  the  use  of  such  a  re- 
taining plate  preventing  a  return 
of  the  teeth  to  their  old  positions. 
Ligatures  in  connection  with  a 
vulcanite  plate  can  also  be  em- 
ployed for  drawing  irregular  pro- 
jecting front  teeth  to  their  nor- 
mal positions,  after  the  removal 
of  posterior  teeth  (the  second 
right  and  left  bicuspids,  for 
example),  to  afford  the  requisite 
space.  Fig.  184  represents  a 
case  of  torsion  and  retraction  of  the  central  incisors,  with  pins  im- 
bedded in  the  vulcanite  plate  for  the  attachment  of  the  ends  of  the 
ligature. 

Studs  of  vulcanized  rubber  or  celluloid,  Figs.  185,  186,  187,  188, 
can  be  attached  to  rubber  plates  for  the  support  of  elastic  rings,  and 
moved  from  one  position  to  another,  as  suggested  by  Dr.  S.  J.  Shaw. 
The  late  Prof.  J.  H.  McQuillen  recommended  a  strip  of  thick  gold 
plate,  similar  to  what  is  used  for  clasps,  and  curved  to  suit  the  arch, 
and  so  applied  by  means  of  rubber  ligatures  or  rings  as  to  draw  forward 
irregular  teeth.     The  ends  of  the  bar  are  screwed  to  the  bicuspid  or 


Fig.  184. 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


563 


molar  tooth  on  either  side,  and  the  rubber  ligatures  or  rings  pass  over 
the  dovetail-shaped  parts  and  the  irregular  teeth. 


© 


Fig.  185. 


Fig.  187. 


Fig.  i88. 


Fig.  189  represents  portions  of  metallic  bars,  a  and  b,  with  holes  and 
slits  for  elastic  ligatures  or  rings  ;  c  ef,  portions  of  bars  with  hooks 
and  prominences  for  ligatures  ;  d,  plate,  with  holes 
for  ligatures  (Farrar). 

Where  the  irregularity  consists  in  one  or  more 
of  the  superior  front  teeth  shutting  within  the 
inferior  teeth  various  appliances  have  been  recom- 
mended, the  oldest,  perhaps,  being  the  grooved 
plate  of  Duval,  and  inclined  plane  of  Catalan, 
which  consisted  of  a  simple  circular  bar  or  plate 
of  gold,  passing  in  front  of  the  teeth  from  the 
first  molar  on  one  side  to  the  first  molar  on  the 
other,  to  which  the  inclined  plane  was  soldered. 

In  the  application  of  this  principle  for  the  cor- 
rection of  irregularity  the  author  has  been  in  the  habit  of  constructing 
the  apparatus  somewhat  differently.  With  a  metallic  die  and  counter- 
dies,  he  has  a  plate  of  gold  struck  up  over  all  the  teeth,  when  practic- 
able, as  far  back  as  the  first  or  second  molar,  completely  encasing  them 
and  the  alveolar  ridge.  An  encasement  of  this  sort  (Fig.  190)  possesses 
greater  stability  than  can  be  obtained  for  an  appliance  like  the  one  in- 
vented by  Catalan.  The  inclined  plane  represented  by  Fig.  190  can 
be  more  conveniently  constructed  of  vulcanized  rubber,  which  pos- 
sesses advantages  over  metal  for  such  an  appliance. 

If  considerable  time  is  required  for  the  wearing  of  such  an  appli- 
ance as  an  inclined  plane,  injury  may  result,  as  the  masticating  teeth 
are  prone  to  elongate  and  the   proper   articulation  of  the  teeth  be 


Fig.  189. 


364 


DENTAL   SURGERY. 


impaired  ;  again,  if  the  patient  refuses  to  press  the  deviating  teeth,  on 
account  of  their  sensitive  condition  while  moving  upon  the  inclined 
plane,  the  result  desired  will  not  be  accomplishedo 


Fig.  190. 


Fig.  191. 


In  Fig.  192  the  letters  A  and  B  show  a  combination  of  an  inclined 
plane  with  elastic  ligatures,  designed  by  Dr.  N.  W.  Kingsley,  to 
correct  an  irregularity  of  both  upper  and  lower  incisors,  and  the  same 
apparatus  was  used  as  a  retaining  plate  when  the  change  was  completed. 

Two  things  are  necessary  in  the  treatment  of  this  form  of  irregu- 
larity; first,  to  prevent  the  upper  and  lower  teeth  from  coming 
entirely  together  by  placing  between 
them  some  hard  substance,  so  that  the 
overlapping  incisors  may  not  interfere 
with  the  necessary  outward  movement. 
The  second  is  the  application  of  some 


\ 


Fig.  192. 


Fig.  193. 


fixture  that  will  exert  a  constant  and  steady  pressure  upon  the  deviating 
teeth  until  they  pass  those  of  the  lower  jaw. 

Fig.  193  represents  another  appliance  of  Dr.  Farrar  for  correcting 
a  form  of  irregularity  where  the  teeth  incline  to  the  inside  of  the 
arch.  The  bar  (ti),  in  Fig.  193,  is  made  of  thick  plate,  about  one- 
eighth  of  an  inch  wide,  and  is  secured  at  one  end  {c)  to  a  molar  or 
bicuspid  (or  both)  by  means  of  a  clamp-band  (a  c  ox  g),  while  the 
other  extremity  rests  upon  a  lateral  incisor.     This  forms  a  bridge  of 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


36: 


the  bar,  which  is  pierced  midway  by  an  oblong  hole,  through  which 

is  passed  a  flat  screw  {b  b),  made  by  filing  two  sides,  which  prevents 

its  turning,  one  end  of  which  is  soldered  to  a  thin  plate  (or  it  may 

be  hammered  thin)  at  the  free  extremity  of  which  is  soldered  a  thin 

band  {h  F),  which  fits  tightly  around  the 

crown  of  the  cuspid   to  be  moved.     To 

prevent  the  band  from  slipping  a  metallic 

pin-point  may  be  soldered  on  its  inside, 

to  fit  into  a  little  hole  drilled  into  the 

tooth  (or  the  band  may  be  attached  to 

the  crown  by  the  oxychlorid  or  oxyphos- 

phate  of  zinc  preparations  and  no  hole 

drilled  into  the  tooth).     A   nut    (Ji)  is 

then  tightened,  which  draws  the  cuspid  into  position  and  at  the  same 

time  forces  the  lateral  incisor  (which,  in  the  case  represented  by  the 

cut,  is  projecting)  inward. 

Fig.   194  represents  another  appliance  designed   by  Dr.  Farrar  for 
drawing  irregular  front  teeth  outward,  which  needs  no  explanation. 


Fig.  194. 


Fig.  195. 


For  drawing  irregular  projecting  teeth,  such  as  canines,  into  posi- 
tion, the  following  appliance  of  Dr.  F.  H.  Lee,  which  was  designed  a* 
an  improvement  on  a  somewhat  similar  appliance  designed  by  Dr. 
Littig,  answers  the  purpose  admirably  : — 

The  Pull-back  Jack-screw's  special  use  is  for  drawing  in  obstinate 
canines  which  have  erupted  outside  of  the  line  of  the  arch,  but  it  will 
work  with  equal  satisfaction  on  any  of  the  other  teeth. 

The  post  or  nut  is  set  in  position  and  held  by  vulcanizing  into  a 


366 


DENTAL    SURGERY. 


rubber  plate  fitting  the  mouth  as  shown  in  the  cut  (Fig.  195);  the 
screw-bolt  is  then  placed  through  the  post  and  a  wire  or  ligature 
(wire  preferred)  is  passed  around  the  tooth,  the  ends  being  secured 
to  the  holes  in  the  cross-head  or  swivel-block.  The  wire  is  then 
tightened  from  time  to  time  as  the  tooth  is  brought  to  its  place.  To 
prevent  the  plate  from  being  moved  out  of  position  by  the  strain  upon 
it,  it  should  be  fastened  to  the  teeth  of  the  arch. 

Figs.  196,  197,  and  198  represent  a  form  of  irregularity  consisting 

of  the  misplacement  of 
the  superior  canines  and 
lateral  incisors,  and  the 
appliance     designed     by 


Fig.  196. 


Fig.  197. 


Dr.  Joseph  Richardson  for  correcting  it,  the  principle  of  which  was 
suggested  a  number  of  years  ago  by  Dr.  Redman. 

In  addition  to  the  malplacement  of  the  lateral  incisors  and  canines 
there  was  some  lateral  contraction  of  the  arch.     After  the  extraction 

of  the  first  bicuspids  a  narrow 
band  of  vulcanized  rubber 
(Fig.  198)  was  constructed, 
embracing  the  six  anterior 
teeth.  Pressure  was  made 
upon  the  misplaced  teeth  by 
means  of  wooden  pegs  in- 
serted in  holes  drilled  through 
the  band  at  such  points  as 
were  indicated  by  the  direction  in  which  it  was  desired  the  teeth 
should  take.  The  pegs  rested  against  the  posterior  mesial  angles  of 
the  lateral  incisors  in  such  a  way  as  to  force  them  outward  and  back- 
ward, while  those  inserted  into  the  opposite  or  labial  portion  of  the 
band  carried  the  canines  backward  and  inward.  These  pegs  projected 
but  slightly  at  first  and  were  lengthened  from  time  to  time  as  the 
teeth  moved. 

What  is  known  as  the  "Lee-Bennett  jack-screw"  is  an  appliance 
suggested  by  Dr.  G.  W.  Bennett  (Fig.  199).  It  combines  a  swiveled 
jack-screw  with  the  forked  post-nut  of  Dr.  Lee's  Pull-back  (Fig.  J95), 
so  that  any  tooth  may  be  pushed  outward  into  line,  as  shown  by  the 


IRREGULARITY    OF    THE    TEETH  — ORTHODON'IIA. 


567 


cut.      On  occasion  both  devices  may  be  fixed  in   the  same   jjlate  and 
be  simultaneously  operated,  the  Lee  to  pull  back  one  tooth  and  the 


Fig.  199. 

Lee-Bennett  to  push  out  another.  Both  of  the  operating  screws  may 
be  turned  by  the  same  lever. 

Figs.  200,  201,  202,  represent  a  simple  yet  effective  appliance  sug- 
gested by  Dr.  E.  S.  Talbot  for  forcing  out  a  tooth  situated  inside  the 
arch,  and  which  is  described  as  follows: — 

Fig.  200  represents  a  second  inferior  bicuspid  within  the  arch,  and 
the  appliance,  which  consists  of  a  thin,  narrow,  close-fitting  vulcanite 


Fig.  200. 


Fig.  202. 


plate,  with  a  hole  drilled  through  its  middle,  opposite  the  centre  of 
the  tooth  to  be  moved.  In  the  other  side  is  another  hole,  but  not 
drilled  quite  through  the  plate.  Fig.  201  represents  a  spring  made 
of  piano-wire,  having  a  single  coil,  A,  with  the  ends  of  its  arms  bent 
at  a  right  angle.  One  of  these  ends,  C,  is  cut  short  to  enter  the 
corresponding  hole  in  the  plate,  and  the  other  end,  B,  is  left  long 


368 


DENTAL    SURGERY. 


enough  to  go  through  the  plate  and  press  upon  the  lingual  surface  of 
the  irregular  bicuspid,  leaving  a  full  eighth  of  an  inch  between  that 
arm  of  the  spring  and  the  plate,  as  is  shown  in  Fig.  200,  which 
represents  the  spring  in  position.  The  plate  and  spring  being  separate 
can  be  readily  removed  for  cleansing  and  to  increase  the  power  by 
spreading  the  arms  of  the  spring.  Fig.  202  represents  a  spring  for  the 
same  appliance,  having  two  long  ends,  B,  B,  which  are  designed  for 
a  case  where  two  such  teeth  are  to  be  likewise  moved  in  opposite 
directions  ;  the  two  holes  in  this  case  to  be  drilled  entirely  through 
the  plate,  so  that  the  ends  of  the  springs  can  be  made  to  press  against 
the  lingual  surfaces  of  the  two  deviating  teeth. 

Dr.  Richardson  also  designed  the  following  appliance,  represented 
by  Fig.  203,  for  shortening  teeth  elongated  during  the  treatment  for 
irregularity. 

It  consists  of  a  plate  affording  fixed  points  of  resistance  and  having 

clasps  attached  and  pinned  to  the 
centrals  with  wooden  pegs  resting 
against  their  anterior   and   the   plate 


Fig.  203. 


Fig.  204. 


against  their  posterior  surfaces,  as  represented  in  Fig.  203.  To  this 
plate  firm  elastic  cords  were  attached,  stretching  across  the  openings 
for  the  elongated  teeth.  When  this  plate  was  pressed  firmly  to  its 
place  upon  the  teeth  and  held  securely  by  the  means  already  referred 
to,  the  contractile  force  of  the  cords  produced  the  necessary  shortening 
of  the  elongated  teeth.  Fig.  198  represents  the  elongated  laterals,  as 
shown  in  Fig.  204,  in  their  proper  positions. 

A  system  of  regulating  teeth,  designed  by  Dr.  Jno.  J.  R.  Patrick,  is 
simple  and  also  effectual,  and  differs  from  any  heretofore  referred  to. 
No  cast  of  the  mouth  is  required,  and  the  appliances  can  be  readily 
cleansed,  and  may  be  used  for  an  indefinite  number  of  times.  The 
power  employed  is  the  elasticity  of  a  bow-spring  (see  Fig.  205),  which 
consists  of  a  half-round  gold  wire  and  platinum  bar  (A  A),  curved  to 
correspond  with  the  shape  of  the  arch,  having  upon  it  a  number  of 
sliding  rings,  by  means  of  which  anchorage  is  secured  and  attach^ 
ment  made  to  the  teeth  to  be  moved.     The  bar  is  bent  with  its  flat 


IRREGULARITY    OF    THE    TEETH ORTHODONTIA.  369 

surface  inward,  and  is  of  sufficient  length  to  allow  its  ends  to  rest 
gently  on  the  external  lateral  surfaces  of  the  first  and  second  molars  as 
desired.  The  slides  are  fitted  accurately,  so  as  to  move  steadily.  Two 
of  these,  which  are  made  longer  for  the  purpose,  are  used  to  secure 
anchorage  by  soldering  to  their  inner  surfaces  thin  gold  bands  (B  B), 
previously  fitted  to  the  teeth  selected.  The  bar  is  held  in  position  by 
set-screws  (C  C)  passing  through  them.  Small  buttons  are  soldered 
to  their  external  surfaces,  through  which  the  screws  pass,  to  give  them 
greater  purchase.  To  the  smaller  slides  the  different  appliances  for 
moving  teeth  are  attached,  as  wedges,  hooks,  V-bars,  loops,  and  bands 
(D  E  F  G  H  I),  of  various  sizes  and  shapes,  as  required.  The  appa- 
ratus acts  as  a  lever,  of  which  the  power  is  the  elasticity  of  the  bow- 
spring,  the  fulcrums  the  points  used  for  anchorage,  and  the  resistance 
the  tooth  or  teeth  to  be  moved.  If  these  are  outside  the  arch  the  bow- 
spring  is  adjusted  so  that  its  flat  surface  touches  all  of  the  projecting 


Fig.  205. 


teeth,  and  is  firmly  set  with  the  set-screws.  The  w^edges  are  then 
forced  together  between  the  teeth  to  be  moved  and  the  bar ;  should 
the  wedges  cease  to  act  before  the  teeth  are  properly  placed,  the  set- 
screws  are  loosened,  the  wedges  separated,  and  the  bar  taken  up  until 
its  inner  surface  is  again  pressed  against  the  projecting  teeth,  when  it 
is  again  set  firmly,  and  the  w^edges  are  again  brought  into  play.  To 
move  teeth  outward  the  elasticity  of  the  bow-spring  is  made  to  draw 
upon  them  by  means  of  the  proper  appliance.  Rubber  bands  or  liga- 
tures may  be  made  useful  auxiliaries.  This  appliance  can  be  used  on 
either  jaw.  Should  the  bar  at  any  time  exhibit  a  tendency  to  slip  to- 
ward the  gum,  it  can  be  held  in  place  by  snapping  one  of  the  slides 
provided  with  a  hook  over  the  cutting  edge  of  a  tooth. 

What  are  denominated  "Yoke  Regulators"  are  designed  for  use 
with  Dr.  Patrick's  appliance.  The  yokes  can  be  immediately  fixed  upon 
the  teeth,  and  the  manner  of  applying  them  is  described  as  follows :  — 

The  bow  is  to  be  passed  from  behind  and  between  the  teeth,  however 
24 


37° 


DENTAL    SURGERY. 


close  together  these  may  be.  The  coupler  is  then  put  over  the  bow 
ends,  a  nut  placed  in  the  end  of  the  key  and  carried  to  place  on  the 
bow.     When  the  nuts  have  been  screwed  on,  if  the  bow  ends  project 


Fig.  206. 
Molar  Bow,  A. 


Fig.  207. 
Molar  Coupler. 


Fig.  208. 
Molar  Yoke. 


-«»»«^ 


Fig.  209. 
Bicuspid  Bow,  D. 


they  can  be  dressed  off  with  a  corundum  point  or  be  covered  by  a  sec- 
tion of  small  rubber  tubing  stretched  from  nut  to  nut,  or  be  wound  with 
ligature  silk. 


.0 


Fig.  2X0.— Bicuspid  Coupler. 


Fig.  211.— Molar  Yoke  in  Place  as  an  Anchorage 
FOR  A  Spring  or  Rubber  Ring  or  Ligature. 


Figs.  206,  207,  208,  209,  210,  211,  and  212  represent  these  yokes, 
bows,  couplers,  and  their  application  to  Patrick's  bow-spring. 


Fig.  212.— Molar  and  Bicuspid  Yoke  Regulators  with  Patrick's  Bow- 
Spri.ng,  Wedgks,  and  Hook  in  Plack. 


As  comparatively  few  cases  of  irregularity  occur  which  in  their  treat- 
ment do  not  require  expansion  of  the  arch,  a  number  of  appliances 
have  been  designed  to  accomplish  such  an  object,  such  as  a  hinged 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


371 


metallic  plate,  the  jack-screws,  either  by  direct  force  or  acting  on  split 
plates. 

One  of  the  most  satisfactory  appliances,  however,  for  expanding  the 
arch  is  the  invention  of  Dr.  Coffin,  of  London,  Eng.,  which  is  repre- 
sented by  Figs.  213,  214.  It  consists  of  a  thin  vulcanite  plate  capping 
some  or  all  of  the  bicuspids  and  molars  and  fitting  the  palatal  or 
lingual  surfaces  of  the  anterior  teeth,  but  divided  along  the  median 
line  into  two  distinct  halves,  connected,  however,  by  a  steel-wire 
spring,  so  arranged  that,  while  guiding  and  limiting  the  relative  motion 


Fig.  213. 


Fig.  214. 
Figs.  213  and  214  are  typical  appliances  for  the  upper  and  lower  jaws.     The  wire  in  Fig.  213 
shows  the  form  best  adapted  for  expanding  the  anterior  portion  ot  the  arch  ;   that  in  Fig. 
214  the  form  adapted  to  enlarging  the  posterior  portion.     The  additional  wire  on  the  left 
of  Fig.  213  was  used,  in  the  case  above  mentioned,  to  force  the  lateral  incisor  outward. 

of  the  two  halves  of  the  plate,  its  tension  exerted  between  them  may  be 
perfectly  varied  in  direction  and  magnitude.  The  impression  of  the 
mouth  should  be  obtained  with  gutta-percha,  as  it  is  elastic,  and  by  its 
slight  contraction  in  cooling  affords  a  tightly-fitting  plate,  which,  how- 
ever, is  not  inserted  in  the  mouth  until  it  is  divided. 

The  steel  spring  is  made  of  pianoforte  wire,  and  is  of  the  form 
shown  in  Fig.  215.  To  construct  the  spring  two  pairs  of  pliers  are 
necessary  and  a  pair  of  clasp  benders.  After  cutting  the  proper 
length  of  wire,  from  one  to  two  and  a  half  inches  in  average  cases, 
the  wire  being  of  a  diameter  between  three-  and  four-hundredths  of  an 


372  DENTAL   SURGERY. 

inch  (about  0.035  inch),  it  should  be  bent  first  in  the  centre  and  then 
back  on  each  side,  with  the  clasp-benders, 
holding  it  with  the  pliers,  and  thus  giving 
the  spring  (as  a  serviceable  form)  the  shape 
of  a  three-  or  five-curved  serpentine  figure, 
like  a  rounded  capital  W.  It  should  also  be 
bent  to  fit  as  nearly  as  possible  the  palatal 
Fig.  215.  ~     surface  of  an  upper   model    or  the  lingual 

surface  of  a  lower  model,  and  its  ends 
should  be  flattened  and  roughened,  without  being  softened  by  heat, 
for  half  an  inch  from  the  extremities.  The  plate  being  modeled 
in  wax,  the  spring  is  placed  on  the  surface,  with  its  ends  buried 
within,  and  when  removed  by  the  counterpart,  protected  from  the 
rubber  by  tin-foil  before  packing.  In  making  the  spring  the  flat- 
tened ends  should  be  coated  with  tin  ;  some  are  in  the  habit  of  coat- 
ing over  the  entire  spring,  but  this  is  not  necessary,  as  the  wire  after 
it  is  worn  becomes  discolored  with  a  polished  appearance.  Some 
recommend  the  insertion  of  a  small  piece  of  zinc  in  contact  with 
each  of  the  ends  of  the  wire,  to  prevent  oxidation.  Old  pianoforte 
wire  is  considered  to  be  the  best  for  these  springs.  The  plate,  after 
being  vulcanized,  is  finished  in  the  usual  manner,  and  is  then  divided 
with  a  fine  saw,  the  edges  and  corners  of  the  cleft  being  made  round 
and  smooth.  It  is  recommended  to  have  the  patient  wear  the  plate  in 
the  mouth  for  a  day  or  two,  to  first  eliminate  any  causes  of  irritation 
not  due  to  its  expansive  action,  before  the  tension  is  made  by  opening 
the  spring.  The  patient  can  be  instructed  to  increase  the  tension  from 
time  to  time  by  slightly  pulling  apart  the  two  halves  of  the  plate  and 
replacing  it  in  the  mouth. 

Figs.  216  and  217  represent  modifications  of  the  Coffin  plate  used 


Fig.  ?i6  Fig.  217. 

for  spreading  the  arch  anteriorly  and  posteriorly,  and   by  which  the 
force  is  distributed  over  considerable  surface. 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


373 


Fig.   2x8  represents  a  slit  plate  and  springs  for  pressing   outward 
bicuspids  and  molars. 


Fig.  2i8. 


Another  very  satisfactory  appliance  for  expanding  either  of  the 
dental  arches  is  the  Talbot  regulating  spring,  represented  by  Figs< 
219,  220,  721,  and  222. 


Fig.  220. 


On  an  accurate  plaster  model  of  the  case  to  be  regulated  a  thin, 
narrow  vulcanite    plate  is  formed,   with    a  short  vertical  post  fixed, 


374 


DENTAL    SURGERY. 


either  before  vulcanizing  or  afterward,  by  drilling  centrally  in  the 
plate  on  the  median  line.  By  means  of  a  wheel-bur,  grooves  or  slots 
are  cut  in  the  sides  of  the  plate  to  receive  the  ends  of  the  spring  and 
prevent  its  displacement  after  the  coil  has  been  placed  on  the  post. 
The  tension  of  the  spring  can  be  changed  by  bending  its  arms  out- 
ward or  inward.  In  the  other  cases  grooves  may  be  cut  into  the 
anterior  and  posterior  parts  of  the  plate,  to  correspond  with  and 
receive  the  points  b  b  and  c  c,  Fig.  222,  and  holes  drilled  at  these 


Fig.  221. 


Fig.  222. 


points  and  the  wire  tied  to  the  rubber  plate.  To  move  the  anterior 
teeth  with  the  greatest  force  the  arms  can  be  so  adjusted  that  the  pres- 
sure exerted  is  greatest  on  the  anterior  parts  of  the  plate.  These 
springs,  connected  with  split-rubber  plates,  can  also  be  utilized  for 
pressing  outward  bicuspid  and  molar  teeth.  They  can  also  be  cm- 
ployed  in  connection  with  platinum  bands  or  collars  fitted  about 
the  necks,  to  press  deviating  teeth  outward,  Figs.  223  and  224.     The 

collars  are  attached  to  the  teeth 
by  oxyphosphate  of  zinc,  after  a 
hole  is   drilled    in  the  side   of 


Fig.  223. 


Fig.  224. 


each,  and  the  spring  is  bent  into  form  and  the  ends  turned  at  a  sharp 
angle  so  as  to  enter  the  holes  in  the  collars.  These  springs  can  also 
be  used  for  pressing  out  the  central  incisors  when  they  shut  within 
the  inferior  front  teeth.     A  rubber  plate  is  made  to  fit  the  mouth  as 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


375 


shown  in  Fig.  225,  and  two  of  these  springs  are  vulcanized  into  't  at 
the  lateral  incisor  region.  The  arms  are  turned  into  loops  at  the 
extremities  to  secure  a  ligature.     When  the  plate  is  adjusted  the  arms 


Fig.  225. 


are  bent  horizontally  and  brought  in  close  proximity  to  the  labial  sur- 
faces of  the  deviating  central  incisors,  and  securely  tied. 

Fig.    226   represents  appliances  of    Dr.  Farrar's  to  move  irregular 


Fig.  226. 


teeth — the  first  to  draw  teeth  together  and   the  second  to  separate 
irregular  teeth  in  making  space  for  another. 


376 


DENTAL    SURGERY. 


Fig.  227. 


Fig.  227  represents  an  appliance,  also  of  Dr.  Farrar's,  in  position 
for  drawing  a  cuspid  toward  a  second  bicuspid,  after  a  first  bicuspid 
has  been  extracted. 

For  moving  a  projecting  incisor  or  cuspid  backward,  a  gold  spiral 

spring  was  formerly  em- 
ployed. It  was  found  to 
be  more  efficient  than  a 
ligature  of  silk,  inasmuch 
as  it  kept  up  a  constant 
traction  upon  the  deviating 
tooth.  But  it  is  objection- 
able on  account  of  the  an- 
noyance it  causes  the  pa- 
tient. A  ligature  of  rubber 
is  far  preferable,  and  this 
material  is  now  very  gen- 
erally employed  in  the 
treatment  of  every  descrip- 
tion of  irregularity  in 
which  simple  appliances 
are  required.  The  diffi- 
culty of  tying  India-rubber  ligatures  is  obviated  by  the  use  of  several 
sizes  of  delicate  elastic  tubing  (French  manufacture),  from  which  sec- 
tions may  be  cut,  more  or  less  thick,  according  to  the  required  length 
and  power  of  the  ligature.  Each  strip  becomes  thus  an  endless  band, 
which  may  be  readily  passed 
from  one  tooth  to  another  or 
to  a  hook  on  the  plate. 

Where  the  superior  central 
incisors  project  beyond  the 
inferior  so  much  as  to  give  a 
pointed  appearance  to  the  lip, 
Dr.  Kingsley  recommends  the 
following  regulating  appli- 
ance (Fig.  228)  :  a  rubber 
plate  fitting  the  roof  of  the 
mouth  is  constructed  on  a 
plaster  model,  taken  from  a 
plaster  impression,  in  the  same 
manner  as  any  other  vulcan- 
ized rubber  plate  would  be  made.  This  plate,  which  is  made  as  deli- 
cate as  strength  and  durability  will  permit,  is  cut  away  opposite  the 
irregular  incisors,  so  that  there  may  be  room  for  these  to  be  pressed 


Fig.  228. 


IRREGULARITY    OF    THE    TEETH — OkTHODONTlA. 


37: 


Fig   229. 


in.  The  pressure,  which  is  brought  to  bear  in  such  a  manner 
as  not  only  to  move  these  incisors,  but  act  more  or  less  upon  the 
whole  arch,  is  made  by  means  of  a  very  simple  contrivance,  such  as 
a  piece  of  gold,  formed  in  the  shape  of  a  T,  about  a  quarter  of  an 
inch  in  length,  and  with  a  staple  or  ring  at  the  bottom  of  the  upright 
portion  of  the  T,  through  which  a  ligature  may  be  passed.  This 
ligature  is  a  rubber  ring,  cut  from  a  piece  of  small  rubber  tubing,  and 
is  passed  through  the  eyelet  in  the  T  and  then  attached  to  the  plate, 
reaching  directly  to  the  second  molars  on  either  side. 

The  plate  being  intro- 
duced into  the  mouth, 
the  T  is  brought  forward 
and  passed  between  the 
central  incisors,  so  that 
the  cross-bar  of  the  T  is 
brought  to  bear  upon 
their  labial  surfaces.  If 
the  incisors  are  in  close 
contact,  space  is  made 
for  the  gold  bar  forming 
the  part  of  the  T  which 
projects  into  the  mouth 
by  wedging.  The  effect 
of  this  appliance  will  be 
to  draw  the  central  inci- 
sors inward  and  at  the 
same  time  to  force  the 
side  teeth  outward.  To 
prevent  the  incisors  from 
returning  to  their  abnor- 
mal position  delicate  rub- 
ber rings  may  be  used, 
being  slipped  over  the 
incisors  and  attached  to 
a  close-fitting  retaining 
plate  of  rubber  covering 
the  roof  of  the  mouth. 

Figs.  229  and  230  will  represent  a  case  of  irregularity  before  and 
after  treatment,  in  the  treatment  of  which  the  appliance  above  de- 
scribed is  applicable. 

Fig.  231  represents  a  similar  appliance  for  correcting  a  form  of 
irregularity  consisting  of  the  projection  of  the  superior  front  teeth, 
where  the  force  is  applied  to  all  of  the  projecting  teeth  at  once. 


Fig.  230. 


378 


DENTAL    SURGERY. 


Fig.  232  represents  a  vulcanite  plate,  with  an  alloyed  gold  and 
platinum  band  attached  by  means  of  screws  suitable  for  moving 
back  projecting  front  teeth  after  the  necessary  space  is  obtained  by 
extraction  of  a  bicuspid  on  each  side.  This  appliance  is  very  effec- 
tual and  can  be  regulated  by  the  patient  using  a  common  watch-key, 


Fig.  231. 


or  one  made  for  the  purpose,  in  order  to  increase  the  pressure  of  the 
band  upon  the  projecting  teeth.  Small  hooks  attached  to  the  front 
portion  of  the  band  and  passing  over  the  cutting  edges  of  the  incisors 
prevent  the  band  from  slipping  up  to  the  gum. 


Fig.  232. 


Fig.  233  represents  a  form  of  special  loop  for  drawing  back  the 
canines,  and  which  is  attached  to  the  same  plate,  the  band  being 
removed  until  after  these  teeth  are  moved. 

A  special  plate  may  be  constructed  for  the  moving  of  the  canines,  or 


IRREGULARITY    OF    THE    TEETK ORTHODONTIA. 


379 


but  one  plate  be  employed,  made  of  the  form  represented  by  Fig.  232, 
and  which  can  be  afterward  modified,  as  in  Fig.  234. 

Dr.  B.  S.  Byrnes  has  suggested  a  method  of  correcting  certain  forms 
of  irregularities  of  the 
teeth  by  the  motive- 
power  of  the  ' '  spring ' ' 
or  elastic  force  of  thin 
gold  bands,  which  he 
described  at  a  meeting 
of  the  Southern  Den- 
tal Association,  as  fol- 
lows : — 


Fig.  234. 


Fig.  233. 


"My  preference  is  gold  of  20k.  to  22k.  fine,  and,  as  a  rule,  the 
thinner  the  bands  the  better  the  result.  It  frequently  occurs,  of  course, 
that  for  special  cases  or  for  a  special  purpose  during  the  progress  of 
any  case  the  band  must  be  doubled  in  thickness,  but  this  fact  does  not 
change  the  rule  as  stated.  The  pressure  exerted  by  the  bands  is  gentle 
but  constant,  and  the  teeth  upon  which  they  operate  are  moved  rapidly, 
with  only  the  slightest  inconvenience  to  the  patient.  No  plates  are 
used,  the  fixed  points  for  the  application  of  the  motive  power  being 
supplied  by  such  of  the  teeth  as  are  suited  to  the  purpose. 

"  The  method  of  application  is,  in  a  general  way,  as  follows  :  The 
fixed  points  having  been  determined,  the  tooth  or  teeth  to  be  regulated 
are  connected  to  them  by  means  of  a  thin  gold  band.  In  selecting 
the  fixed  points  care  should  be  observed  to  choose  teeth  which  will 
offer  greater  resistance  to  the  force  to  be  applied  than  those  which  are 
to  be  moved  will.  The  band  is  then  manipulated  so  as  to  form  it  into 
a  spring  or  series  of  springs,  so  adjusted  as  to  bear  most  powerfully  on 
the  misplaced  tooth.  Thus,  suppose  a  projecting  superior  central  in- 
cisor is  to  be  drawn  inward  to  align  properly  with  the  remainder  of  the 
teeth  in  the  arch.  A  continuous  gold  band  embracing  the  first  molars 
on  both  sides  is  fitted  around  the  outside  of  the  arch.  With  a  dull- 
pointed  instrument  like  a  burnisher  the  ribbon  is  then  pressed  into  the 
interstices  of  the  teeth  over  which  it  passes,  thus  forming  it  into  a  series 
of  small  springs.  The  incisor,  being  the  most  prominent  point,  will 
naturally  be  most  affected  by  the  pressure  exerted  by  the  springs,  and 
in  a  short  time  it  will  be  found  to  have  moved  away  from  the  band  so 
that  it  is  no  longer  affected  by  the  tension  of  the  springs.     As  soon  as 


380  DENTAL    SURGERY. 

this  occurs  the  apparatus  is  removed,  the  ribbon  is  annealed,  straight- 
ened, and  a  small  portion,  say  a  thirty-second  to  a  sixteenth  of  an  inch, 
as  may  be  required,  is  cut  out  of  it.  The  ends  are  then  soldered  and 
the  appliance  is  replaced  upon  the  teeth,  the  connecting  band  being 
formed  into  a  spring  as  before.  Tension  is  thus  kept  up  until  the  tooth 
has  assumed  the  desired  position. 

"  This  is  the  plan  of  procedure  in  ordinary,  simple  cases  of  irregu- 
larity, but  the  method  is  equally  applicable  to  more  complex  condi- 
tions. I  have  not  yet  seen  a  case  since  my  adoption  of  this  device 
where  it  could  not  be  made  to  do  the  work  of  moving  the  teeth  readily. 
Sometimes  the  spring  of  the  band  may  be  advantageously  supplemented 
by  other  aids,  as  the  insertion  of  a  rubber  wedge  at  points  where  a 
particular  gain  is  desired,  in  accordance  with  the  recognized  principle 
that  in  regulating  teeth  the  movement  is  greatest  where  the  elasticity  is 
greatest. 

"  One  ofthe  most  important  points  to  observein  the  treatment  of  a  case 
of  irregularity  is  to  always  have  the  fixture  so  tight  that  it  is  not  neces- 
sary to  tie  it  on  to  the  teeth.  I  frequently  apply  fixtures  by  degrees ; 
that  is,  after  making  a  snug  fit,  force  the  appliance  partially  to  place, 
then  allow  an  interval,  sometimes  of  half  an  hour,  before  proceeding  to 
complete  the  adjustment.  I  find  this  plan  lessens  the  severity  of  the 
operation  to  the  patient,  not  only  because  of  the  rest  afforded,  but 
because  the  teeth  seem  more  inclined  to  yield,  and  thus  allow  the  fix- 
ture to  be  placed  more  readily. 

"  To  apply  the  rubber  wedge,  select  a  strip  of  rubber  of  the  desired 
thickness.  Place  the  gold  fixture,  which  should  fit  perfectly  tight,  in 
position,  and  insert  the  rubber  behind  the  band  opposite  to  one  of  the 
interstices.  Take  the  ends  of  the  rubber  in  either  hand,  stretch  it  to 
its  fullest  extent,  and  gradually  work  it  to  the  desired  spot ;  then  clip 
off  the  ends.  Press  the  teeth  forcibly  in  the  direction  in  which  you 
wish  to  move  them  with  one  hand,  while  with  the  burnisher  in  the  other 
the  band  is  pressed  into  the  interstices. 

"  Case  L — The  first  case  which  I  shall  describe  is  that  of  a  young 
lady  who  at  the  time  she  came  to  me  was  in  her  eighteenth  year.  The 
condition  of  her  teeth  at  that  time  is  well  shown  in  Fig.  235.  The 
missing  right  superior  central  had  been  extracted  when  the  patient  was 
about  eleven  years  old,  as  the  only  relief  from  the  unendurable  pain 
following  devitalization  of  the  pulp  at  the  hands  of  an  itinerant  den- 
tist. To  supply  the  deficiency  a  partial  plate  of  vulcanite  had  been 
worn  for  the  last  three  and  a  half  years.  The  remaining  anterior  teeth 
of  the  upper  jaw  had  been  gradually  forced  outward  until  at  the  time 
I  first  saw  them  they  protruded  at  an  angle  of  forty-five  degrees.  In 
.the  lower  denture  the  incisors  stood  within  the  arch,  the  cuspids  inclin- 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


?8l 


ing  forward.  AS  a  result  of  this  conformation  the  chin  was  somewhat 
wrinkled  and  slightl)^  upturned.  The  lips  wore  a  constant  pout,  the 
mouth  being  what  maybe  termed  'peaked.'     The  molars  being  the 


Fig.  235. 

only  teeth  which  occluded   properly,  the  mouth  was  never  naturally 
closed  and  the  patient  was  unable  to  make  an  incisive  bite. 

"In  treating  this  case  I  aimed  to  compass  four  principal  points: 
ist,  the  destruction  of  the  'peakedness'  by  producing  a  broader  or 
more  oval  arch;  2d,  the  reduction  of  the  projecting  teeth  to  their 
proper  position  ;  3d,  the  improvement  of  the  articulation ;  and,  4th, 
the  closure  of  the  space  caused  by  the  loss  of  the  right  superior  central. 

"  The  last  mentioned  was  first  undertaken.  For  the  first  two  days 
a  heavy  band  was  used  to  force  the  ends  or  cutting-edges  of  the 
right  lateral  and  left  central  together,  A  very  thin,  narrow  gold 
band  was  then  fitted  to  embrace  the  necks  of  these 
two  teeth,  and  a  wedge  of  wood  was  inserted  under  it  t  T  —  ,  ^  ^ 
on    the   side   toward  the  cutting-edges,    causing  the  fig.  236. 

teeth  to  move  vertically  toward  each  other.  The  band 
being  placed  around  the  necks,  and  the  wood  spreading  it  toward  the 
cutting-edges,  caused  very  great  pressure  at  the  apex  of  the  root. 
Another  band  (Fig.  237)  was  then  constructed  to  move  the  incisors 
backward  and  bring  them  into  a  more  vertical  position.  This  was 
placed  in  position  without  removing  the  first  (Fig.  236).  It  consisted 
of  two  bands  embracing  the  cuspids  and  bicuspids  of  each  side,  con- 
nected by  another  band  of  the  same  material  passing  outside  of  the 
incisors.  The  connecting  band  w^as  then  pressed  into  the  interstices 
between  the  teeth  and  rubber  wedges  were  inserted.  This  fixture 
caused  constant  pressure  backward  on  the  anterior  teeth  and  an  out- 
ward pressure  on  the  cuspids  and  bicuspids.  The  gold  band  acted  as  a 
lever,  the  lateral  teeth  as  the  fulcrum,  and  the  posterior  teeth  as  the 
weight  to  be  moved.     The  connecting  band  was  cut  and  shortened 


382 


DENTAL    SURGERY. 


every  other  day,  the  patient  having  a  sitting  every  day  to  allow  the 
gold  to  be  sprung  more  as  the  teeth  moved  away  from  it. 

"  At  the  end  of  three  weeks  the  narrow  band  at  the  necks  of  the  in- 
cisors was  discarded,  its  work  having  been  accomplished,  and  that 
shown  in  Fig.  237  was  substituted  by  another,  which  passed  around 
the  outside  of  the  whole  arch  from  the  first  molar  on  one  side  to  the 
corresponding  tooth    on   the  other.     This  appliance  (Fig.   238)  was 


Fig.  237. 


Fig.  238. 


required  to  do  little  actual  work,  its  principal  office  being  to  hold  the 
gain  already  made  and  to  close  the  spaces  between  the  teeth,  which 
were  now  about  equal  in  extent,  and  to  bring  the  teeth  to  a  vertical 
position.  The  gold  was  doubled  in  thickness  over  the  incisors  and 
cuspids,  to  prevent  its  yielding  while  the  backward  movement  was 
progressing,  which  would  allow  the  arch  to  again  assume  the  peaked 
appearance  which  the  treatment  was  undertaken  to  correct.  The 
small  hook  or  catch  was  to  prevent  the  band  from  slipping  up  toward 
the  gum,  which  it  showed  a  tendency  to  do  when  first  applied.     The 

patient  now  wears  a  similarly 
shaped  band,  but  only  one-third 
as  Avide,  as  a  retaining  piece, 
which  she  removes  and  reapplies 
at  pleasure. 

"  The  treatment  of  the  irregu- 


FiG.  239. 


Fig.  240. 


larity  in  the  lower  anterior  teeth  was  begun  about  a  week  after  work  on 
the  upper  jaw  was  commenced,  and  was  completed  in  three  weeks.  A 
band,  constructed  as  shown  in  Fig.  239,  was  applied,  clasping  the  first 
molars  on  both  sides  and  passing  around  the  cuspids  and  behind  the 
incisors.  A  wooden  wedge  was  placed  between  the  incisors  and  the 
band  and  springs  formed  by  pressing  the  band  into  the  interstices  be- 
tween the  cuspids  and  bicuspids,  cutting  and  readjusting  as  before.    In 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


3^3 


two  weeks  this  fixture  was  substituted  by  another  (Fig.  240).  This  was 
a  plain  band  clasping  the  incisors,  with  wings  tipping  upon  the  cus- 
pids, and  having  the  portion  behind  the  incisors  doubled  in  thickness. 
A  little  block  of  rubber  inserted  under  each  of  the  wings  completed 
the  work  in  a  week's  time.  The  wings  were  then  pressed  back  to  hold 
the  gain,  and  a  piece  given  to  the  patient  to  wear  as  a  retaining  plate. 

"Fig.  241  is  an  accu- 
rate representation  of  a 
cast  of  the  mouth  taken 
at  the  conclusion  of  the 
operation.  The  correc- 
tion of  the  irregularities 
in  this  case  was  accom- 
plished in  a  month, 
work  being  carried  for- 
ward simultaneously  in 
both  jaws  after  the  treat- 
ment of  the  lower  teeth 
was  commenced.  The 
work  of  moving  the  up- 
per teeth  was  pushed  so  rapidly  as  to  slightly  '  spring  '  the  maxillary  at 
the  attachment  of  the  compressor  nasi  and  the  depressor  alee  nasi,  so 
that  the  wings  of  the  nose  were  pulled  laterally  inward  and  downward, 
causing  a  slight  bulging  or  bridge  on  the  centre  of  the  nose.  But  I 
saw  the  patient  some  six  months  after  the  case  was  dismissed,  and  the 
muscles  had  adjusted  themselves  and  no  deformity  was  visible.  The 
patient  then  informed  me  that  she  never  had  any  trouble  with  either  of 
the  retaining  fixtures." 

Figs.  242  and  243  represent  an  inge- 
nious appliance  of  Dr.  Farrar  for  laterally 
moving  the  apices  of  the  roots  as  well  as 
the  crowns  of  teeth.     It  consists  of  gold 


Fig.  241. 


Fig.  242. 


Fig.  243. 


clamp-bands  operated  with  a  screw ;  fulcrums  are  jilaced  between  the 
teeth,  to  prevent  the  crowns  from  moving  faster  than  the  entire  roots, 
these  fulcrums  being  replaced  by  smaller  ones  as  the  teeth,  under  the 
pressure  of  the  clamp-band,  approach  each  other. 


384 


DENTAL    SURGERY. 


Retaining  plates  are  generally  required  after  the  operation  of  mov- 
ing teeth  from  irregular  to  regular  positions  is  completed,  for  the 
greatest  difficulty  in  correcting  irregularity  of  the  teeth  is  often  caused 
by  the  tendency  of  such  teeth  to  return  to  their  old  positions.  It  is 
necessary,  therefore,  that  retaining  plates  should  be  worn  until  the 
corrected  teeth  become  firmly  fixed ;  and  no  definite  time,  although 

the  average  time  may  be 
stated  as  that  of  one  year, 
can  be  given  for  the  comple- 
tion of  such  a  process.  Be- 
fore permanently  removing  a 
retaining  plate  its  use  may  be 
dispensed  with  for  a  short 
time,  an  examination  being 
made  daily  to  determine  if 
there  is  any  tendency  of  the 
corrected  teeth  to  return  to 
their  irregular  positions. 

A  simple  form  of  retaining 
plate,  to  be  worn  after  the 
correction  of  an  irregularity 
caused  by  the  projection  of  the  superior  front  teeth,  is  represented 
by  Fig.  244,  which  is  a  simple  vulcanite  plate  with  a  small  gold  wire 
attached  to  it  and  passing  to  the  outside  of  the  front  teeth  through 
a  small  opening  between  the  canine  and  bicuspid  teeth  on  each 
side.  After  the  correction  of  a  contracted  arch  a  simple  vulcanite 
plate,  such  as  is  represented  by  Fig.  245,  will  answer  as  a  retaining 


Fig.  244. 


Fig.  245. 


Fig.  246. 


plate.     A  plate  of  this  kind  should  be  adapted  to  the  palatal  surfaces 
of  all  the  superior  teeth. 

Fig.  246  represents  an  ingenious  application  of  the  rubber  dam  for 
the  retention  of  replanted  teeth  and  which  may  also  be  utilized  for  the 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


385 


retention  of  one  or  more  irregular  teeth  after  treatment,  which  is  the 
suggestion  of  Dr.  Herbst.  The  idea  is  so  plainly  shown  by  the  illus- 
trations that  further  description  is  unnecessary. 

Wedges  of  elastic  rubber  are  often  useful  in  cases  where  the  lower 
teeth  shut  outside  the  upper  ones.  They  should  be  used  of  such  a 
thickness  as  will  exert  a  gentle  pressure  only  upon  the  upper  teeth. 

Fig.  247  represents  a  case  of  this  kind,  with  the  wedges  in  posUio>j- 


FiG.  247. 


The  jack-screw  is  also  a  valuable  appliance  for  regulating  teeth.  Its 
use  was  first  suggested  by  Dr.  AVilliam  H.  Dwindle,  and  it  has  been 
applied  alone  or  in  connection  with  a  split-vulcanite  plate.  Figs.  248 
and  249  represent  different  styles  of  jack-screws,  the  old  and  new, 


Fig.  248. 


Fig.  249. 


which  are  operated  by  holes  in  the  middle  bar;  other  holes  render 
them  capable  of  being  secured  to  a  tooth,  thus  avoiding  the  danger  of 
being  swallowed  if  accidentally  detached.     In  some  cases  one  end  of 
25 


386 


DENTAL   SURGERY. 


the  first  style  of  screw  has  been  permanently  imbedded  in  the  rubbei 
plate. 

Dr.  M.  H.  Cryer  has  designed  an  appliance  by  the  use  of  which  no 
injury  results  to  the  teeth  while  the  jack-screws  are  in  operation. 
It  consists  of  thin  platinum  bands  or  clasps  fitted  to  the  teeth,  the 
ends  either  soldered  or  held  together  by  a  small  screw.  The  clasp 
which  encircles  the  tooth  to  be  forced  outward  contains  a  small 
hole  for  the  reception  of  the  point  of  the  jack-screw,  and  upon  the 
other  clasp,  which  may  encircle  several  teeth  used  as  a  fulcrum,  small 
lugs  are  soldered,  between  which  the  other  end    of  the  jack-screw, 

which  is  of  the  form  of  a  crotch, 
fits  tightly,  and  is  thus  prevented 
from  slipping. 


Fig.  250. 


Fig.  251. 


Fig.  250  represents  a  vulcanite  split-plate  with  a  jack-screw  in  posi- 
tion. 

Fig.  251  represents  a  screw  which  is  a  combination  of  the  two 
forms  already  alluded  to,  having  upon  its  end  a  revolving  crutch. 
Levers  are  also  used  with  advantage  on  the  outside  of  the  arch,  to 


Fig.  252. 

press  with  a  gentle  force  a  deviating  tooth,  and  thus  move  it  into  a 
proper  position. 

Fig.  252  represents  a  plate  of  vulcanized  rubber  with  levers  or 
springs  attached. 

Shortening  the  teeth  has  already  been  referred  to  in  several  of  the 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


387 


cases  presented,  and  it  remains  only  to  allude  to  an  apparatus  de- 
signed by  Dr.  Kingsley  for  such  an  object.  It  consists  of  a  frame 
of  gold  adapted  to  the  cutting  edges  of  the  incisors  and  lapping  on 


Fig.  2S4- 
Figs.  253  and  254  represent  the  spriuj;  jack-screws  of  Dr.  T.  S.  Holmes,  which  combine  the 
pusiiing  and  pulling  actions. 


388 


DENTAL    SURGERY. 


to  the  canines,  to  which  is  added  a  stud  or  post  about  half  an  inch  in 
length,  soldered  to  it  opposite  the  canines,  and  coming  out  of  each 
corner  of  the  mouth.     This  apparatus  is  shown  by  Fig.   255.     The 


Fig.  255. 

arms  extend  upward,  passing  outside  the  cheeks,  and  consist  of  metal 
connected  by  elastic  ligatures  to  a  skull-cap.     Fig.  256  represents  the 

entire  apparatus  in  action. 

For  lengthening  a  short 
tooth  Dr.  J.  D.  White  sug- 
gests the  simple  method  of 
tying  a  thread  ligature  tight- 
ly around  the  neck  of  the 
tooth,  under  the  free  margin 
of  the  gum,  and  if  much  irri- 
tation and  pain  result,  to  re- 
move the  ligature  and,  keep- 
ing the  tooth  at  rest,  apply  a 
little  pounded  ice,  in  a  bag, 
to  the  gum.  After  a  week's 
rest  the  same  treatment  is  to 
be  pursued  every  alternate 
week,  until  the  end  is  accom- 
plished. But  great  care  is 
necessary  to  keep  the  irrita- 
tion within  proper  bounds, 
this  treatment  being  applicable  only  to  growing  teeth,  although  occa- 
sionally to  matured  teeth  also. 

The  following  is  an  appliance  designed  by  Dr.  Farrar  to  bring  into 


Fig.  236. 


IRREGULARITY    OF    THE    TEETH ORTHODONTIA. 


389 


Its  proper  place  in  the  arch  an  impacted  canine,  represented  by  Fig. 
257,  which  will  also  prove  effectual  for  elongating  a  tooth.  It  con- 
sists of  a  narrow  gold  plate 
(see  Fig.  258),  swaged  to  fit 
the  palatal  margins  of  the 
gum  and  surfaces  of  the  lat- 
eral incisors  and  bicuspids, 
with  thin  crossbars,  or  a  clasp 
around  the  first  bicuspid, 
connecting  this  plate  with  a 
smaller  one  adapted  to  the 
labial  margin  of  the  gum. 
To  the  small  plate  or  pad,  as 
it  is  termed,  a  smooth  nut 
is  soldered,  through  which 
passes  a  screw,  its  lower  end 
bent  so  as  to  enter  a  small 
hole  drilled  into  the  crown 
of  the  short  tooth,  which, 
by  means  of  a  thread-nut,  is  forced  downward. 

The  elongated  tooth  is  retained  in  its  new  position  by  the  delicate 
apparatus  represented  by  Figs.  259  and  260. 


•R 


Fig.  259. 


Fig.  258. 


The  action  of  an  elastic  spring,  the  free  end  of  which  acts  upon 
the  short  tooth  while  the  other  is  imbedded  firmly  in  a  rubber  plate, 
will  often  answer  the  purpose  of  elongating  a  tooth. 


390 


DENTAL    SURGERY. 


Dr.  A.  E.  Matteson  has  suggested  an  appliance  to  force  the  erup- 
tion of  teeth  which  are  impacted  in  the  jaw  in  such  a  manner  as  to 
prevent  their  occluding  or  meeting  with  the  opposite  ones  when  the 
jaws  are  closed.  It  is  described  as  follows :  A  rubber  plate  is  made 
to  cover  the  roof  of  the  mouth  and  to  fit  the  necks  of  the  teeth 
closely.  A  French  clock  spring  is  adjusted  to  the  rubber  plate  in  such 
a  manner  that  one  end  is  riveted  into  the  central  posterior  part,  so 
that  when  the  spring  is  forced  up  against  the  plate  its  distal  end 
touches  the  necks  of  the  teeth  to  be  drawn  out.  Ligatures  are  then 
fastened  to  the  necks- of  the  teeth  and  the  spring  carried  up  to  the 
plate  and  secured  to  the  teeth  (Fig.  261).  With  a  sufficiently  power- 
ful spring  from  two  to  four  teeth  may  be  operated  upon  at  one  time. 

Fig.    262    shows   a   similar    appliance 
.■«^  for     operating     upon     impacted     lower 

teeth. 


Fig.  261. 


Fig.  262. 


For  the  same  purpose,  Dr.  E.  S.  Talbot  suggests  the  following  appli- 
ance :  A  rubber  plate  is  made  to  fit  the  jaw  and  the  teeth,  into  which 
a  hole  is  drilled  at  a  point  in  the  center  of  the  space  made  by  the 
missing  or  impacted  tooth,  smaller  than  the  one  arm  of  the  coil-wire 
spring  it  is  to  hold.  The  other  arm  of  the  spring,  upon  the  end  of 
which  is  a  loop  (Fig.  263),  meets  the  neck  of  the  tooth  to  be  moved, 
and  is  there  secured  with  a  ligature.  When 
the  tooth  is  so  imbedded  in  the  process  that 
a  ligature  cannot  be  fastened  to  it,  a  plati- 
num band  with  a  hook  soldered  upon  it  may 
be  forced  up  under  the  gum  and  secured 
with  oxyphosphate  of  zinc.  If  this  fails,  a 
hole  may  be  drilled  into  the  crown  of  the 
tooth  and  an  eye-bolt  fastened  in  with  ce- 
ment, to  which  the  spring  can  be  secured 
by  means  of  a  ligature.  By  drilling  the 
hole  in  the  rubber  plate  at  a  longer  distance  from  the  impacted  tooth, 
a  greater  spring  is  given  to  the  wire. 

Deformity  from  Excessive  Develop77icnt  of  the  Teeth   and  Alveolar 


Fig.  263. 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


391 


Ridge  of  Lozuer  Jaiv. — When  the  teeth  of  the  lower  jaw  form  a  larger 
arch  than  those  of  the  upper,  the  incisors  and  cuspids  of  the  former 
shut  in  front  of  those  of  the  latter,  causing  the  chin  to  project,  and 
otherwise  impairing  the  symmetry  of  the  face.  Figs.  264  and  265 
present  a  front  and  a  side  view  of  this  deformity.  It  may  result  from 
a  want  of  correspondence  in 
the  development  of  the  teeth 
and  alveoli  of  the  two  maxilla, 
the  upper  jaw  being  defective 


Fig.  265. 


in  size,  while  the  lower  jaw  is  natural ;  or  the  former  being  natural, 
the  latter  may  be  in  excess.  It  may  also  arise  from  a  simple  eversion 
of  the  lower  teeth  or  inversion  of  the  upper. 

Treatment. — The  remedial  indications  of  the  deformity  in  question 
consist  in  diminishing  the  size  of  the  dental  arch,  which  is  always  a 
tedious  and  difficult  operation,  requiring  great  patience  and  persever- 
ance on  the  part  of  the  patient  and  much  mechanical  ingenuity  and 
skill  on  the  part  of  the  dentist.  The  appliances  to  be  employed  have 
of  necessity  to  be  more  or  less  complicated,  requiring  the  most  perfect 
accuracy  of  adaptation  and  neatness  of  execution ;  they  must  also  be 
worn  for  a  long  time,  and,  as  a  natural  consequence,  are  a  source  of 
considerable  annoyance.  The  first  thing  to  be  done  is  to  extract  the 
first  inferior  bicuspids.  Sufficient  room  will  thus  be  obtained  for  the 
contraction  which  it  will  be  necessary  to  effect  in  the  dental  arch  for 
the  accomplishment  of  the  object.  An  accurate  impression  of  the 
teeth  and  alveolar  ridge  should  be  taken  with  wax  softened  in  warm 
water,  and  from  this  impression  a  plaster  model  is  procured,  and  after- 
ward a  metallic  die  and  counter-die,  in  the  manner  to  be  described  in 
a  subsequent  chapter. 

This  done,  a  gold  plate  of  the  ordinary  thickness  should  be  swaged 
to  fit  the  first  and  second  molars  (if  the  second  has  made  its  appear- 
ance, and  if  not,  the  second  bicuspid  and  first  molar  on  each  side^,  so 
as  completely  to  encase  these  teeth.  If  these  caps  are  not  thick 
enough  to  prevent  the  front  teeth  from  coming  together,  a  piece  of 


392  DENTAL    SURGERY. 

gold  plate  may  be  soldered  on  that  part  of  each  which  covers  the  grind- 
ing surfaces  of  the  teeth.  Having  proceeded  thus  far,  a  small  gold 
knob  is  soldered  to  the  inner  and  outer  front  corner  of  both  caps,  and 
to  each  of  these  a  ligature  of  silk  or  rubber  is  attached.  These  liga- 
tures are  to  be  brought  forward  and  tied  tightly  around  the  cuspids. 
When  thus  adjusted  the  lower  arch  will  present  the  appearance  exhibited 
in  Fig.  266.  By  this  means  the  cuspids  may,  in  fifteen  or  twenty 
days,  be  taken  back  to  the  bicuspids.  If  in  their  progress  they  are  not 
carried  toward  the  inner  part  of  the  alveolar  ridge,  the  outer  ligatures 
may  be  left  off  after  a  few  days,  and  the  inner  ones  alone  employed  to 
complete  the  remainder  of  the  operation. 

After  the  positions  of  the  cuspids  have  been  thus  changed,  a  circu- 
lar bar  of  gold  should  be  made,  extending  from  one  cap  to  the  other, 
so  as  to  pass  about  a  quarter  of  an  inch  behind  the  incisors,  and  be 
soldered  to  the  inner  side  of  each  cap.  A  hole  is  to  be  made  through 
this  band,  behind  each  of  the  incisors,  through  which  a  ligature  of 


Fig.  266.  Fig.  267. 

silk  may  be  passed  and  brought  forward  and  tied  tightly  in  front  of 
each  tooth.  These  ligatures  should  be  renewed  every  day  until  the 
teeth  are  carried  far  enough  back  to  strike  on  the  inside  of  the  corre- 
sponding teeth  in  the  upper  jaw. 

Fig.  267  represents  the  appearance  which  the  lower  jaw  presents 
with  the  last-named  apparatus  upon  it,  and  will  better  convey  an  idea 
of  its  construction,  the  manner  of  its  application,  and  its  mode  of 
action,  than  any  description  which  can  be  given. 

An  appliance  of  this  sort  may  be  made  to  act  with  great  efficiency 
in  remedying  the  deformity  in  question;  but  in  its  application  it  is 
necessary  that  the  caps  be  fitted  with  the  greatest  accuracy  to  the  teeth, 
and  they  should  be  removed  every  day  and  thoroughly  cleansed,  as 
well  as  the  teeth  they  cover.  If  this  precaution  is  neglected,  the  se- 
cretions of  the  mouth,  which  collect  between  the  gold  caps  and  teeth, 
will  soon  become  acid  and  corrode  the  latter. 


IRREGULARITY    OF    THE    TEETH ORTHODONTIA. 


393 


The  remarks  made  in  the  previous  chapter  upon  the  use  of  the  vul- 
canite are  applicable  here.  Such  a  plate,  for  this  class  of  cases,  is 
readily  made,  and  inflicts  no  injury  upon  teeth  or  gums.  Elastic  in- 
stead of  silk  ligatures  might  be  used,  and  the  retraction  of  the  incisors 
carried  on  simultaneously  with  that  of  the  cuspids.  The  use  of  vul- 
canized rubber  instead  of  gold  is  of  great  value  in  correcting  irregu- 
larities of  this  nature,  the  form  of  the  appliances  being  the  same. 

The  employment  of  elastic  rubber  ligatures  in  connection  with 
vulcanite  plates  is  generally  found  to  be  effectual  in  correcting  the 
irregularity  of  the  inferior 
front  teeth.  The  follow- 
ing appliances,  from  de- 
signs of  Dr.  Kingsley,  will 
be  found  serviceable: — 

Fig.  268  represents  an 
appliance  for  correcting  an 
irregularity  where  the  in- 
ferior canine  teeth  stand 
outside  the  arch,  which  is 
somewhat  narrow,  the  first 
permanent  molars  being 
first  extracted.  Hooks  of 
gold  ware  are  inserted  in 
the  plate  as  points  of  attachment  for  the  elastic  bands,  which  are  drawn 
forward  and  attached  to  the  canines  by  silk  or  linen  threads.  By  such 
means  the  canines  were  drawn  into  position  and  the  arch  widened. 

Fig.  269  represents  other 
forms  of  attachment  for  elas- 
tic bands  and  ligatures. 


Fig.  268. 


Fig.  269. 


Fig.  270. 


Fig.  270  shows  an  appliance  for  correcting  the  irregular  arrangement 
of  the  four  inferior  incisors.  Gold  wire  hooks  (A  A)  pass  over  the 
arch  between  the  canines  and  adjoining  teeth,  in  order  to  give  an  in- 
dependent attachment  for  the  elastic  ligatures  outside  as  well  as  within 
the  arch,  and  movements  in  almost  any  direction  can  be  obtained. 


394  DENTAL    SURGERY. 

For  cleansing  purposes  such  appliances  can  be  removed  and  replaced 
b}'  the  patient. 

Protrusion  of  the  Lower  Jaw. — This  deformity,  although  produced 
by  a  different  cause  from  the  one  last  described,  is  similar  to  it,  and 
gives  to  the  lower  part  of  the  face  an  unnatural  and  sometimes  dis- 
agreeable appearance.  It  also  interferes  with  mastication,  and  often 
with  prehension  and  distinct  utterance.  It  wholly  changes  the 
relationship  which  the  teeth  should  sustain  to  each  other  when  the 
mouth  is  closed.  The  cusps  or  protuberances  of  the  bicuspids  and 
molars  of  one  jaw,  instead  of  fitting  into  the  depressions  of  the  cor- 
responding teeth  of  the  other,  often  strike  their  most  prominent 
points ;  at  other  times  the  outer  protuberances  of  the  lower  molars 
and  bicuspids,  instead  of  fitting  into  the  depressions  of  the  same  class 
of  teeth  in  the  upper  jaw,  shut  on  the  outside  of  these  teeth. 
The  trituration  of  aliments  is  consequently  rendered  more  or  less 
imperfect. 

This  protrusion  of  the  lower  jaw  is  supposed  by  some  to  be  the 
result  of  a  "  natural  partial  luxation."  In  fact,  its  causes  are  by  no 
means  clearly  understood.  It  is  often  hereditary,  and  would  seem 
to  be  caused  by  that  mysterious  agency  which  impresses  peculiarities 
of  growth  and  shape,  not  only  upon  the  lower  maxilla,  but  upon 
every  bone  in  the  body.  The  agency  is  so  constant  and  overruling 
that  we  must  be  prepared  to  find  the  jaw  returning  to  its  position  after 
the  discontinuance  of  treatment,  unless,  by  the  interlocking  of  the 
cusps  of  the  upper  teeth  and  the  overlapping  of  the  upper  incisors,  we 
can  restrain  the  tendency.  It  is  of  more  frequent  occurrence  than  the 
one  which  results  from  excessive  development  of  the  teeth  and  alveolar 
ridge,  and  requires,  as  before  stated,  an  entirely  different  plan  of 
treatment.     It  rarely  occurs  previously  to  second  dentition. 

Treatment. — The  plan  of  treatment  formerly  adopted  consisted  in 
fastening  on  each  side  a  cap  of  vulcanite  on  one  of  the  lower  molars, 
thick  enough  to  keep  the  front  teeth  about  a  quarter  of  an  inch  apart 
when  the  jaws  were  closed.  Fox's  bandage  was  then  applied.  This 
was  buckled  as  tightly  as  the  patient  could  bear  with  convenience, 
pressing  the  chin  upward  and  backward.  A  piece  of  tough  wood, 
slightly  hollowed  so  as  to  fit  the  arch  of  the  lower  teeth,  made  narrow 
at  the  upper  end,  was  introduced  between  the  teeth  several  times  a 
day,  the  concave  portion  resting  upon  the  outside  of  the  lower  and 
against  the  inside  of  the  upper,  employing  at  each  time  as  much  pres- 
sure as  could  be  safely  applied.  By  continuing  this  operation  from 
day  to  day,  for  several  weeks,  the  natural  relationship  of  the  jaws 
would,  in  most  cases,  be  restored. 

The  description  of  bandage  here  alluded  to,  and  the  manner  of  its 


IRREGULARITY    OF    THE    TEETH ORTHODONTIA. 


395 


Fig.  271. 


application,  is  represented  in  Fig.  271.  When  the  protrusion  of  the 
lower  jaw  is  accompanied  by  irregularity,  means  should  at  the  same 
time  be  employed  for  remedying  it. 
The  earlier  the  treatment  is  instituted 
the  more  easily  will  the  deformity  be 
overcome.  It  may,  however,  be  suc- 
cessfully remedied  at  any  time  previ- 
ously to  the  twentieth  year  of  age,  and 
sometimes  at  a  much  later  period,  but 
after  this  time  the  operation  becomes 
more  difficult. 

An  appliance  designed  by  Dr.  G.  S. 
Allan  (Fig.  272),  and  which  he  em- 
ployed successfully,  consists  of  a  brass 
plate  to  fit  the  chin,  having  arms  with 
hooked  ends  reaching  to  a  point  just 
below  the   point   of    the  chin.     The 

arms  are  arranged  in  such  a  way  that  the  distance  between  them  can 
be  altered  at  will  by  simply  pressing  them  apart  or  together.  The 
upper   part   consists  of  a  simple   network  going  over  the  head   and 

having  two  hooks  on  each 
side,  one  hook  being  above 
and  the  other  below  the 
ear.  The  network  and  the 
chin-plate  are  connected 
by  four  elastic  rubber  liga- 
tures exerting  pressure  in 
such  a  manner  as  to  force 
the  lower  jaw  almost  di- 
rectly backward.  The 
upper  elastics  are  used 
simply  to  keep  the  mouth 
closed  so  that  the  lower 
elastics  will  not  pull  it 
open,  the  upper  being 
made  just  strong  enough 
so  that  the  muscles  of  the 
mouth  need  not  be  strained 
to  keep  the  jaw  open  dur- 
ing the  operations  of  eat- 
ing and  talking. 

In  cases  where  the  lower  front  teeth  close  over  the  upper,  and  thus 
cause  a  deformity  of  the  face,  it  is  important  to  discriminate  correctly 


Fig.  272. 


396  DENTAL   SURGERY. 

between  those  which  result  from  malformation  and  a  protrusion  of  the 
jaw  occasioned  by  partial  luxation,  as  the  remedial  indications  in  the 
two  are  entirely  different.  Those  which  would  prove  successful  in  the 
one  would  prove  unsuccessful  in  the  other.  But,  fortunately,  deformity 
arising  from  the  last-mentioned  cause  is  comparatively  of  rare  occur- 
rence; hence,  the  dentist  is  seldom  called  upon  to  exercise  his  inge- 
nuity and  skill  in  its  treatment. 

Dr.  Edward  H.  Angle's  system  of  correcting  irregularities  of  the 
teeth  is  described  by  him  as  follows  : — 

"  In  studying  the  conditions  by  which  we  may  best  accomplish  the 
movements  of  the  teeth,  we  may  simplify  the  process  if  we  remember 
the  movements  in  the  line  of  the  arch,  which  are  five  :  forward,  back- 
ward, inward,  outward,  and  partial  rotation.  These  and  their  slight 
modifications,  with  the  exception  of  elongation  and  depression,  which 
are  rare,  are  all  we  are  called  on  to  perform.  The  principles  govern- 
ing all  of  these  movements  are  the  same.  So  that,  by  understanding 
the  principles  governing  one,  we  may  comprehend  all. 

"  In  applying  force  to  a  tooth,  it  should  be  sufficient  to  accomplish 
the  movements  as  rapidly  as  is  consistent  with  physiological  law. 
When  pressure  is  once  applied  it  should  be  continued  without  relin- 
quishment, for  there  should  be  no  retrogression  of  the  tooth. 

"  After  the  mal-posed  tooth  has  been  moved  into  the  desired  position 
and  proper  occlusion  secured,  it  should  be  firmly  supported  and 
retained  till  it  has  become  firm  in  its  new  socket. 

'^Appliances. — The  Set  No.  i.  Fig.  273,  consists  of  the  retaining-wire 
G,  and  ten  sections  of  retaining  and  anchor  pipes  R,  R,  which  will 
closely  slide  on  wire  G.  The  traction-screw  A  has  its  smooth  end  bent 
for  insertion  in  the  short  tube  D.  When  the  nut  is  against  the  A  end 
of  the  long  tube,  and  that  tube  soldered  to  a  tooth-band,  turning  for- 
ward the  nut  will  puil  the  hook  in  the  tube  D  when  that  has  been 
soldered  to  a  tooth-band  ;  if  the  nut  is  against  the  other  end  of  the 
long  tube,  it  wxWpush  D  and  its  tooth-band.  B,  C  is  alike  but  smaller 
combination,  of  the  same  diametric  size  as  the  jack-screw  J.  When 
the  tube  of  J  is  soldered  to  a  tooth-band  on  one  tooth,  it  will  push 
directly  against  a  notched  tooth-band  or  a  tooth.  E  is  a  longer  piece 
of  the  tube  than  is  shown  on  J,  with  which  a  longer  jack-screw  may  be 
made  when  required.  The  thinner  coil  of  band-material  is  seen  at  F, 
the  thicker  at  H,  either  of  which  is  sufficient  to  make  about  twenty-five 
tooth-bands.  The  rotating  levers  L,  three  sizes  of  two  each,  and 
wrench  W,  complete  the  set,  which  will  suffice  for  several  regulating 
cases. 

"  It  will  thus  be  seen  that  the  appliances  of  this  set  are  very  simple 
and  few  in  number,  being  limited  i)ractically  to  three, — viz.  :  the  lever 


IRREGULARITY    OF    THE    TEETH ORTHODONTIA. 


397 


for  rotating,  the  screw  for  pushing,  and  the  traction-screw  for  pulling  ; 
and  the  other  pieces  for  the  purpose  of  securing  attachments.  Aside 
from  their  advantages  of  simplicity,  efficiency,  and  cleanliness,  their 


Fig.  273.— Set  No.  i,  Angle's  Appliances. 

intelligent  application  will  effect  a  stationary  anchorage  upon,  a  posi- 
tive movement  of,  and  afterward  a  firm  retention  of,  the  teeth. 


Fig.  274.— Set  No.  2,  Angle's  Appliances. 


"  Set  No.  2  is  designed  for  the  treatment  of  a  special  class  of  irregu- 
larities, or  that  prognathic  type  known  as  excessive  protrusion  of  the 


398 


DENTAL    SURGERY. 


upper  incisors.  The  plan  of  this  set  (No.  2)  differs  principally  from 
that  of  Set  No.  i  in  that  the  anchorage  is  occipital,  or  by  means  of  a 
cap  covering  the  back  of  the  head  (as  seen  in  Fig.  275),  to  which  heavy 
elastic  bands  are  attached  and  received  by  the  hooks  upon  the  ends  of 

traction-bar  A.  The  wire  arch 
B  encircles  the  dental  arch  and 
bears  against  the  protruding 
teeth,  receiving  the  necessary 
pressure  from  the  standard  in 
the  center  of  the  traction-bar. 
D,  D  represent  adjustable  anchor 
clamp-bands  and  pipes  for  secur- 
ing the  ends  of  the  arch  B  upon 
the  molar  teeth,  while  C,  C  repre- 
sent plain  bands  for  holding  in 
position  upon  the  teeth  the  an- 
terior part  of  the  arch.  C  is  a 
coil  of  band-material,  from  which 
the  bands  C,  C  are  to  be  made 
for  each  case.  This  coil  is  the 
same  as  F,  Fig.  273,  Set  No.  i. 
E,  E  represent  small  rubber  rings  to  retain  the  teeth  during  intervals 
of  rest,  when  not  wearing  the  head-cap  and  traction-bar. 

"  Fig.  276  shows  an  extra  wire  expansion-arch.     Its  use  is  directly 
the  opposite  that  of  wire  arch  B,  in  that  it  is  used  for  expanding  the 


Fig.  275. 


Fig.  276. 


arch,  and  is  to  be  known  as  the  expansion-arch  E.  The  ends  of  this 
arch  are  threaded  and  provided  with  nuts.  By  putting  the  threaded 
ends  into  the  anchor-tubes  upon  the  clamp-bands  D,  Set  No.  2,  se- 
cured to  anchor-teeth,  the  arch  may  be  pushed  forward  by  tightening 


IRREGULARITY    OF    THE    TEETH  —  ORTHODONTIA. 


399 


the  nuts,  thus  exerting  force  against  other  teeth  which  may  have  been 
secured  to  the  arch  by  means  of  ligatures  or  bands. 

"In  Fig.  277  is  shown  a 
metal  cap  covering  the 
chin,  and  in  connection 
with  the  head-gear  and 
heavy  elastic  bands  it  is 
used  in  the  retraction  of 
the  inferior  maxilla,  as 
shown  in  the  figure.  This 
cap  is  light,  nicely  made, 
highly  polished,  and  will 
fit  all  cases,  as  it  is  neces- 
sary for  the  fit  to  be  only 
approximately  accurate.  A 
layer  of  absorbent  cotton 
should  always  be  placed 
between  the  metal  and  the 
chin  while  it  is  being 
worn. 

"Fig.  278  represents  adjustable  clamp-bands  for  encircling  the  molars 
and  bicuspids,  to  which  are  attached  the  various  appliances.  Nos.  3 
and  4  have  pins  soldered  to  their  sides,  to  which  ligatures  may  be 
attached.  This  style  of  band  is  especially  designed  for  the  treatment 
of  fractures  of  the  maxillae,  and  its  use,  therefore,  is  fully  shown  in 


Fig.  277. 


No.  I — Bicuspid. 


No.  2— Molar. 


Fig.  27S. 

No.  3- 


No.  4— Molar. 


that  portion  of  this  work  devoted  to  such  treatment,  but  it  is  also 
useful  in  the  regulation  of  teeth,  as  described  later. 

"The  head-cap  represented  as  covering  the  back  of  the  head  (Fig. 
277)  is  also  an  extra.  It  is  beautifully  made  and  presents  a  very  neat 
appearance,  is  strong,  durable,  and  may  be  quickly  adjusted  to  fit  any 
size  of  head.  As  auxiliaries  to  the  above  appliances,  ligatures  made 
from  waxed  floss  silk,  or  wire,  are  necessary. 

''Direction  of  Forces  for  Tooth- Movement. — In  the  correction  of 
dental  irregularities,  an  appliance  must  act  either  by  pulling,  pushing, 
or  twisting  a  tooth  into  proper  position  ;  and  the  movements  of  the 
tooth  are  limited  to  six  :  backward  or  forward  in  the  line  of  the  arch, 


400 


DENTAL    SURGERY. 


Fig.  279.— Retraction  of  Cuspid. 


outward  or  inward  in  the  line  of  the  arch,  elongation  or  depression  of 
the  tooth  in  its  socket. 

"  The  backward  movement  of  the  teeth  in  the  line  of  the  arch  is 
accomplished  in  two  principal  ways.  First,  by  the  large  traction- 
screw  A  and  D,  Set  No.  i,  shown  in  Fig.  279,  for  the  retraction  of  a 

superior  cuspid.  The  first  molar  is 
encircled  by  a  No.  2  clamp-band 
(Fig.  278),  to  which  is  soldered  the 
long  sheath  of  the  traction-screw 
A,  Fig.  273.  The  cuspid  is  also  en- 
circled by  a  band,  having  the  short 
tube  D,  Set  No.  i,  soldered  hori- 
zontally to  it  on  its  distal  surface, 
with  which  tube  the  smooth  bent 
end  of  the  traction-screw  engages. 
'"^    j    '  '"iiP   f-^T^^   The    nut,    operating    against    the 

*  "  distal  end  of  the  tube,  will  move 
the  cuspid  backward  into  position. 
The  easiest  way  to  adjust  this  appli- 
ance is  to  first  cement  the  band  upon  the  cuspid ;  after  the  cement  has 
become  thoroughly  set,  the  angle  of  the  traction-screw  is  hooked  into 
the  short  tube,  and  the  adjustable  band  latched  over  the  molar.  It  is 
very  important  that  the  bent  end  be  passed  into  the  tube  its  full 
length,  otherwise  it  will  be 
broken  when  force  is  exerted. 
The  screw  may  be  employed 
on  the  outside  of  the  arch  ; 
the  short  tube,  in  that  event, 
should  be  attached  to  the 
mesio-buccal  angle  of  the 
band,  as  shown  on  the  right 
cuspid  of  Fig.  280. 

*'  If  a  movement  of  rota- 
tion as  well  as  retraction  is 
desirable,  the  angle  of  the 
screw  should  be  hooked  over 
a  spur,  as  shown  on  the  left 
cuspid  of  Fig.  2S0,  thus  con- 
centrating all  the  force  upon  one  side  of  the  moving  tooth.  Recent 
experience  has  shown  that  a  staple  made  from  the  wire  G,  Set  No.  i, 
is  stronger  and  better  than  the  spur  for  making  this  attachment. 
Should  the  cuspid  be  very  prominent,  requiring  the  movement  to  be 
inward  as  well  as  backward,  that  may  be  accomplished  at  the  same 


IRREGULARITY    OF    THE    TEETH  —  ORTHODONTIA. 


401 


time  by  bending  the  screw,  which,  as  the  nut  is  turned,  will  be  gradu- 
al!)'straightened.      (See  Fig.  281.) 

"A  method  of  reinforcing  the  anchor-tooth  is  also  shown  in  this 
engraving,  by  enlisting  the  resistance  of  the  lateral  incisor.  This 
tooth  is  banded  and  provided  with  one  of  the  pipes  R,  Set  No.  i, 
soldered  to  its  distal  angle ;  one  end  of  a  piece  of  the  wire  G,  Set 


Fig.  281. 


Fig.  2S2. — Stationary  Anchorage. 


No.  I,  is  soldered  to  the  sheath  of  the  traction-screw  and  made  to 
rest  in  this  pipe. 

"In  making  the  attachments  for  retraction  after  the  manner  de- 
scribed, it  is  of  the  utmost  importance  that  the  band  encircling  the 
molars  should  be  tightly  clamped,  burnished,  and  firmly  cemented,  so 
that  the  attachment  will  be  perfectly  rigid.  In  this  way  the  resistance 
of  the  anchorage  will  be  greatly  increased,  and  tipping  of  the  anchor- 
teeth  will  be  prevented  ;  while  if  moved  at  all,  they  must  be  dragged 
bodily  through  the  alveolus,  because  the  apices  of  the  roots  move  equally 
with  the  crown,  as  shown  in  Fig.  282,  which  represents  a  side  view  of  the 
appliance  in  position,  the  dotted  lines  showing  the  movements  which 
must  take  place  if  the  attachment  is  properly  made.  This  is  a  most 
perfect  form  of  anchorage,  and  I  am 
indebted  to  Dr.  W.  C.  Barrett  for 
first  suggesting  it. 

"If  the  nut  is  placed  upon,  the 
screw  in  front  of  the  sheath  and 
tightened,  force  with  the  same  re- 
sistance of  anchorage  may  be  exerted 
in  moving  the  tooth  forward  instead 

of  backward.     When  the  jack-screw  is    .j^- ,L-.T;,^:A%>*t-v-.'*v^,^  ^,^  . 
employed  for  pushing,  the  same  firm-   ^^'''^■•'^■^■■''^':^^^'^'''*''^-''-'^'^'-<r^ 
ness  of  anchorage  may  be  gained  by 

soldering  the  base  of  the  sheath  to  the  anchor-band,  which  is  to  be 
firmly  clamped  and  cemented  in  position  upon  the  anchor-tooth,  as 
shown  in  Fig.  283. 

"  Another  way  of  moving  teeth  backward  in  the  line  of  the  arch  is 
26 


40  2 


DENTAL   SURGERY. 


Fig.  284. 


by  means  of  Set  No.  2,  and  will  be  described  in  the  treatment  of  cases 
of  excessive  protrusion  of  the  superior  incisors. 

"  The  movement  of  a  tooth  forward  in  the  line  of  the  arch  may  be 
accomplished  by  means  of  the   traction-screw,  in  the   same  way  as 

already  described  for  re- 
traction, by  selecting  an- 
chor-teeth on  the  opposite 
side  to  be  used  in  over- 
coming the  resistance  of 
the  tooth  that  is  being 
moved,  as  shown  in  Fig. 
284,  which  represents  a 
case  in  practice,  and  shows 
the  screw  employed  in 
pulling  both  incisors  for- 
ward in  the  line  of  the 
arch  to  close  the  wide 
space  between  the  centrals ;  at  the  same  time  providing  space  for  the 
cuspid,  which  is  being  moved  out  of  inlockby  means  of  the  jack-screw. 
In  this  case  the  traction-screw  was  beaten  flat,  polished,  and  bent  to 
conform  to  the  curve  of  the  arch. 

"The  movement  of  a  tooth  from  within  outward  into  the  line  of 
the  arch  is  accomplished  in  four  principal  ways :  first,  by  means  of  the 
jack-screw  E  and  J,  Set  No.  i,  the  sheath  of  which  is  secured  to  a 
suitable  anchor-tooth,  the  point  acting  upon  the  moving  tooth  by  turn- 
ing the  nut.  The  base  of  the  sheath  of  the  jack-screw  may  be  secured 
in  various  ways,  as  shown  in  Fig.  285  :  first,  by  a  dowel  made  by  soft- 
soldering  a  piece  of  the  wire  G,  Set  No.  i,  into  the  end  of  the  sheath 
which  rests  in  a  pit  in  the  anchor-tooth,  as  in  A  ;  by  a  spur  made  from 
the  same  wire  soldered  to  the  anchor-band,  over  which  the  end  of  the 
sheath  is  slipped,  as  in  B  ;  by  a  dowel  made  from  the  same  wire, 
slipped  into  one  of  the  pipes  R,  Set  No.  i,  soldered  to  the  anchor- 
band,  as  in  C  (in  this  way  the  length  of  the  sheath  may  also  be 
increased)  ;  by  pointing  the  end  of  the  sheath  with  a  file  and  letting 
the  point  rest  in  the  pipe  on  the  anchor-band,  as  in  D  ;  by  soldering 
the  sheath  directly  to  the  anchor-band,  as  in  E  and  F;  by  notching 
the  end  of  the  sheath,  which  shall  engage  the  anchor-wire  as  in  G, 
Fig.  285  ;  by  soldering  the  end  of  the  sheath  directly  to  another 
sheath,  as  in  H  ;  by  means  of  a  spur  made  from  the  wire  G,  Set  No. 
I,  soldered  to  the  sheath  which  shall  engage  one  of  the  pipes  R,  Set 
No.  I,  soldered  to  the  anchor-band,  as  in  I ;  by  slipping  the  end  of 
the  sheath  over  the  screw  upon  the  clamp-band,  as  in  J.  Of  these 
various  ways  I  prefer  that  of  attaching  the   sheath    directly  to    the 


IRREGULARITY    OF    THE    TEETH  —  ORTHODONTIA. 


403 


anchor-band,  as  in  E  and  F,  or  by  means  of  the  snur,  as  in  B  (the  spur 
being  quickly  and  easily  made  by  soldering),  by  holding  a  long  piece 
of  the  wire  G,  Set  No.  i,  between  two  of  the  fingers  of  one  hand, 
while  the  end  of  the  screw  upon  the  clamp-band  is  grasped  between 
the  thumb  and  finger  of  the  other  hand,  carrying  it  in  contact  with  the 
fine  point  of  the  flame,  presenting  the  appearance  after  soldering 


B 


Fig.  285. 


shown  in  K,  Fig.    285,   after  which  the  wire  is  cut  off,  leaving  the 
desired  length  of  the  spur. 

"  The  point  of  the  screw  is  held  firmly  in  position  by  six  principal 
ways,  as  shown  in  Fig.  286.  First :  By  notching  the  point  of  the 
screw  with  a  separating  file,  which  notch  will  engage  a  similar  notch  in 
the  united  ends  of  the  band,  as  in  A  ;  by  pointing  the  end  of  the  screw 
to  engage  one  of  the  small  pipes  R,  Set  No.  i,  soldered  to  the  band  as 


40  4 


DENTAL    SURGERY. 


in  B  ;  by  a  mortise  in  tlie  band  to  engage  the  point  of  the  screw,  as  in 
C  ;  by  soldering  an  elliptical  ring  (formed  by  bending  the  wire  G,  Set 
No.  I,  as  at  G,  Fig.  286),  in  which  to  rest  the  point  of  the  screw,  as  in 
D ;  by  a  staple,  made  from  the  same  wire,  soldered  (see  H)  to  the  band, 


Fig.  286. 


as  in  E,  the  point  of  the  screw  being  suitably  notched  ;  by  pointing 
the  screw  to  be  received  in  the  pit  formed  in  the  enamel  or  filling,  as 
in  F.  Of  these  various  ways  of  securing  the  point  of  a  jack-screw,  I 
prefer  the  plan  shown  in  D  and  E,  forming  the  ring  and  staple  upon 

the  ends  of  long  pieces 
of  the  wire,  which  serve 
as  handles  while  solder- 
ing, as  in  G  and  H, 
after  which  the  superflu- 
ous portions  are  clipped 
off.  The  roughened 
ends  are  then  rounded 
and  made  smooth  with 
a  fine  file. 

"  Fig.  287  shows  an 
inlocked  cuspid  being 
moved  outward,  the 
point  of  the  screw  rest- 
ing in  a  mortise  formed  in  the  band  upon  the  moving  tooth,  the  base 
of  the  sheath  being  notched  to  engage  a  piece  of  the  anchor-wire  G, 
Set  No.  I,  passing  through  a  tube  soldered  to  the  lingual  surface  of  the 


Fig.  287. 


IRREGULARITY    OF    THE    TEETH ORTHODONTIA. 


4&5 


left  cuspid.  The  anchorage  is  greatly  reinforced  by  means  of  this 
wire,  which  is  beaten  flat  where  it  passes  between  the  central  and  lat- 
eral, the  end  being  bent  around  the  labial  surface  of  the  central. 
Force  is  obtained  by  turning  the  nut.  After  a  tooth  has  been  moved 
into  the  desired  position,  it  is  retained  by  a  piece  of  the  wire  G,  Set 
No.  I,  passed  through  a  pipe  R,  Set  No.  i,  soldered  to  the  band,  the 
wire  ends  resting  upon  the  labial  surfaces  of  the  lateral  incisor  and 
first  bicuspid.  This  wire  is  held  in  place  by  a  very  delicate  pin  pass- 
ing through  the  pipe  and  one  side  of  the  wire,  as  in  Fig.  288. 

"  Fig.  289  shows  a  favorite  method  of  reinforcing  the  anchorage.    In 
this  case  the  sheath  of  the  jack  screw  was  placed  on  a  spur  soldered  to 
a  bicuspid  clamp-band,  as  at  B,  Fig.  285.    The 
point  of  the  screw  was  sharpened  and  rested  in 
a  pit  formed  in   the  enamel.     Reinforcement 
was  gained  by  hooking  a  piece  of  the  wire  G, 


soldered  to  the  sheath  of  the  jack-screw  near,  its 

base,  the  other  soldered  to  the  lingual  surface 

of  a  lateral  incisor  band.     If  the  appliance  has  been  carefully  adjusted 

the  patient  may  be  provided  with  a  wrench,  and  instructed  in  turning 

the  nuts  at  proper  intervals. 

"  Recent  experience  has  proven  that  an  easier  way  of  attaching  the 
reinforcement  wire  is  to  omit  the  pipe  attached  to  the  band  on  the 
lateral,  soldering  the  straight  end  of  the  wire  directly  to  the  band. 

The  other  end  of  the  wire 
should  be  passed  through 
the  pipe,  on  the  sheath, 
and  secured  by  bending  the 
end  around  the  pipe  end. 

"Fig.  290  shows  a  left 
lateral  being  moved  out- 
ward, reinforcement  hav- 
ing been  gained  in  the 
manner  already  described, 
using  two  pieces  of  wire  at- 
tached to  bands  on  the  cen- 
tral and  cuspid.  Not  only 
was  the  anchorage  reinforced,  but  the  incisor  and  cuspid  were  prevented 
from  being  pushed  out,  the  moving  tooth  providing  space  for  itself  by 
forcing  the  adjoining  teeth  laterally.  By  this  means  the  most  perfect 
form  of  anchorage  is  secured,  employing,  preferably,  the  method  of 
attaching  the  reinforcement  wires  described  in  the  last  case. 


Fig.  289. 


4o6 


DENTAL    SURGERY. 


"  The  second  mode  of  moving  a  tooth  from  within  outward  is  shown 
in  Fig.  290,  where  a  right  lateral  is  being  forced  outward  by  means 

of  the  small  traction-screws  B  and 
C,  Set  No.  I.  A  strip  of  the 
band-material  (F,  Set  No.  i)  is 
looped  around  the  lateral,  the 
ends  resting  upon  the  labial  sur- 
faces of  the  adjoining  teeth.  On 
one  end  is  soldered  a  short  tube, 
C  (accompanying  the  screw),  at- 
tached vertically,  while  on  the 
other  end  a  similar  tube  is  at- 
tached horizontally.  Into  these 
tubes  the  traction-screw  B,  Set 
No.  I,  is  placed,  being  bent  to  conform  to  the  circle  of  the  arch,  and 
used,  in  this  case,  to  push  instead  of  pull.  This  appliance  should  be  fre- 
quently tightened  by  turning  the  nut,  or  it  will  become  loose  and  cause 
trouble.     The  parts  of  this  device  are  shown  separately  in  Fig.  291. 


Fig.  290. 


jj     '    a* 


Fig.  291. 


Fig.  292. 


"Fig.  292  shows  the  teeth  as  retained  by  means  of  pieces  of  the 
anchor-wire  (G,  Set  No.  i)  passing  through  pipes  attached  to  the 
labial  surfaces  of  the  bands,  as  described  and  shown  in  Fig.  288. 

"The  third  method 
of  moving  a  tooth  from 
within  outward  is  by 
lacing  the  teeth  to  the 
expansion  arch,  as  in 
Fig.  293,  force  being 
derived  from  the  spring 
of  the  arch  and  sus- 
tained by  occasionally 
turning  the  nuts. 

"  The  fourth  method 
is  by  means  of  the  wire 
ligature  encircling  the 

tooth  and  arch,  force  being  exerted  by  occasionally  twisting  the  wire 
as  in  A,  A,  Fig.  293. 


Fig.  293. 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


407 


Fig.  294. 


"A  tooth  may  be  moved  inward  by  the  small  traction-screw  B  and  C, 
Set  No.  I,  as  shown  in  Fig.  294,  in  which  a  cuspid  is  being  drawn 
into  line,  the  bent  end  of  the  screw  being  hooked  into  the  small  tube 
C,  Set  No.  I,  soldered  to  the  band  upon  the  anchor-tooth.  The  other 
end  of  the  screw  passes  through  a  similar  tube,  against  the  end  of 
which  the  nut  works.  To 
the  tube  is  soldered  apiece 
of  the  wire  G,  Set  No.  i, 
bent  at  right  angles  and 
hooked  into  a  pipe  (R,  Set 
No.  i),  soldered  to  the 
lingual  surface  of  the  band 
on  the  cuspid.  Force  is 
exerted  by  turning  the  nut. 
The  anchor-tooth  was  rein- 
forced by  a  piece  of  the 
wire  G,  Set  No.  i,  resting 
in  contact  with  the  buccal 
surfaces  of  the  adjoining  teeth,  and  held  in  position  by  one  of  the  small 
pipes  R,  Set  No.  i.  This  anchor-wire  was  kept  from  turning  by  a 
very  delicate  pin  passing  through  the  pipe  and  one  side  of  the  wire, 
as  in  Fig.  288.  Another  way  of  securing  this  wire  is  by  soldering  it 
directly  to  the  band. 

"Prominent  teeth  may  also  be  forced  into  the  line  of  the  arch  by 
means  of  the  wire  arch  B,  Set  No.  2,  or  the  expansion-arch  E,  Fig. 
276,  made  to  encircle  the  dental  arch  and  bear  against  the  promi- 
nent tooth,  and  the  force  may  be  intensified  by  an  intervening 
wedge  of  rubber.  The  adjoining  teeth  are  firmly  laced  to  the  arch 
by  means  of  wire  ligatures 

"There  are  three  principal  modes  of 
rotation  by  this  system.  First :  By  means 
of  the  lever,  band,  and  tube,  as  shown  in 
Fig.  295,  which  represents  a  lateral  incisor 
in  process  of  rotation.  The  incisor  was 
cemented  in  position  with  an  accurately- 
fitting  band  having  soldered  to  it  one  of 
the  small  pipes  R,  Set  No.  i,  into  which  is 
inserted  the  end  of  one  of  the  levers  L,  Set 
No.  I,  the  other  end  being  sprung  around 
and  secured  to  a  suitable  anchor-tooth. 
This  attachment  of  the  end  of  the  lever 
may  be  made  in  various  ways, — either  by  being  latched  into  a  notch 
formed  in  the  united  ends  of  the  band  as  shown  in  Fig.  295,  or  by  a 


Fig.  295.— Rota  1  ion. 


4o8 


DENTAL    SURGERY. 


wire  ligature  made  to  encircle  the  anchor-tooth  and  lever,  or  by  a 
wire  ligature  encircling  the  button  on  the  clamp-band  (No.  3  or  4, 
Fig.  278),  and  attached  to  the  end  of  the  lever  bent  in  the  form  of 
an  eye,  which  is  now  my  favorite  method.  The  anchor-tooth  may  be 
reinforced  by  a  piece  of  the  wire  G,  Set  No.  i,  resting  in  contact  with 
the  lingual  surface  of  the  adjoining  teeth,  and  held  in  position  by  one 
of  the  pipes  R,  Set  No.  i,  soldered  to  the  anchor-band  as  shown.  It 
will  be  seen  that  thus  a  constant,  powerful,  rotative  force  may  be  ex- 
erted upon  the  tooth. 

"  Care  should  be  exercised  that  the  lever  be  not  allowed  to  pry 
against  the  intervening  teeth,  to  force  the  tooth  outward. 

"  It  is  often  desirable  to  lace  one  or  more  of  the  intervening  teeth 
to  the  lever  by  means  of  the  wire  ligature,  to  prevent  overlapping  of 
the  teeth.  The  leverage  may  be  increased  by  allowing  the  end  to  pass 
through  the  pipe,  and  to  bear  against  the  labial  surface  of  the  adjoin- 
ing tooth.  This  may  be  intensified  by  an  intervening  wedge  of  rubber. 


Fig.  296. — Retainer. 


Fig.  297 


Fig.  29 


"  Fig.  296  shows  the  rotated  incisor  retained  by  a  short  piece  of  the 
wire  G,  Set  No.  i,  slipped  into  the  pipe  from  the  opposite  side  and 
made  to  bear  against  the  labial  surface  of  the  central  incisor.  There 
should  also  be  soldered  a  spur  to  the  disto-lingual  angle  of  the  band 
and  made  to  bear  against  the  cuspid. 

"Fig.  297  shows  two  cuspids  being  rotated  by  this  method.  It  will 
also  be  seen  that  the  lever  may  be  employed  on  the  inside  of  the'arch, 
and  in  this  case  there  was  the  advantage  of  reciprocal  anchorage  re- 
sulting from  the  ends  of  the  levers  acting  in  opposite  directions  upon 
the  anchor-tooth. 

"  In  all  similar  cases  where  the  lever  is  being  employed  on  the  outside 
of  the  arch  it  should  be  bent  at  the  point  nearest  the  labial  surface  of 


IRREGULARITY    OF    THE    TEEIH — ORTHODONTIA. 


409 


the  cuspid,  so  as  to  concentrate  all  the  spring  in  the  region  of  the 
moving  tooth. 

"  Second  :  Rotation  may  also  be  performed,  as  shown  in  Fig.  298^ 
by  means  of  the  jack-screw  E  and  J,  Set  No.  i,  secured  by  staple, 
clamp-band,  and  spur,  and  pushing  against  one  side  of  the  tooth  to  be 
moved,  while  the  small  traction-screw,  attached  by  pipe  R,  Set  No.  i, 
and  piece  of  anchor-wire  G,  Set  No.  i,  soldered  to  the  base  of  the 
sheath  of  the  jack-screw,  is  made  to  pull  upon  the  other  side  of  the 
tooth.  In  this  way  perfect  control  of  the  tooth  is  gained,  not  only  in 
rotation  but  also  in  pushing  it  outward  or  pulling  it  inward  into  the 
line  of  the  arch,  according  as  the  nuts  are  adjusted.  This  method  of 
rotation  is  principally  limited  to  the  superior  central  incisors  or  cus- 
pids. It  should  be  said  that  because  of  the  powerful  force  they  exert 
the  nuts  should  be  turned  but  slightly  at  each  sitting.  This  is  also 
another  instance  where  use  is  made  of  reciprocal  anchorage,  which  is 
to  be  taken  advantage  of  whenever  possible. 

"Third:  Rotation  may  be  accomplished  by  exerting  force  on  one 
side  of  a  tooth  by  means  of  a  wire  ligature  on  the  expansion-arch  E, 
and  a  spur  soldered  to  a  band  encircling  the  tooth  to  be  moved,  as  at 
B,  Fig.  293.  This  force  may  be  intensified  by  a  wedge  of  rubber 
stretched  between  the  band  and  arch  and  acting  upon  the  opposite 
side  of  the  tooth.  A  modification  of  this  plan  of  rotation  is  shown 
at  C,  Fig.  293,  in  which  the  band  is  dispensed  with  and  the  double  or 
loop  ligature  is  continued  around  the  tooth,  including  the  wire  arch. 
This  plan  is  less  certain  on  account  of  the  liability  to  slip  :  it  is  also 
less  powerful,  since  the  wedge  of  rubber  cannot  be  used.  It,  however, 
will  be  found  useful  where  teeth  are  to  be  but  slightly  rotated.  At 
the  same  time  a  number  of  other  teeth  should  be  ligatured  to  the  arch 
to  secure  greater  firmness. 

"  When  two  teeth  are  to  be  rotated  in  opposite  directions  at  the  same 
time,  as  the  central  incisors  shown  in  Fig.  299,  double  rotation  may 


Fig.  299. 


Fig.  300. — Double  Rotation. 


be  accomplished  by  a  single  lever.  In  this  instance  both  the  teeth 
are  banded,  and  a  tube  soldered  to  each  band.  A  straight  lever  is 
inserted  in  one  tube,  springing  and  sliding  it  into  the  other  tube  in 
the  same  manner  in  which  a  door-bolt  is  slid  into  position,  as  also  shown 
in  Fig.  300.    It  may  be  necessary  to  occasionally  remove  and  straighten 


41 0  DENTAL    SURGERY. 

the  lever  a  little,  in  order  to  maintain  the  pressure.  Should  one  tooth 
be  rotated  sufficiently  before  the  other,  further  movement  may  be 
arrested  by  removing  the  band  and  soldering  a  lug  on  the  lingual  sur- 
face to  rest  against  the  lateral  incisor.  And  should  the  teeth  in  rota- 
tion assume  too  much  prominence,  by  reason  of  pressure  from  the 
adjoining  teeth,  it  maybe  effectually  corrected  by  requiring  the  patient 
to  wear,  for  a  few  nights,  the  head-gear,  traction-bar,  and  heavy 
elastic  bands  shown  in  Figs.  274  and  275,  filing  a  deep  notch  in  the 
end  of  the  standard  to  engage  the  rotating  lever. 

"If  the  teeth  show  a  tendency  to  separate  as  they  rotate,  they 
should  be  drawn  tightly  together  by  a  ligature,  made  to  encircle  both 
tubes  and  held  in  position  by  the  ends  of  the  lever,  slightly  protruding 
through  the  tubes. 

"When  the  teeth  are  in  position  they  are  retained  by  substituting  a 
piece  of  the  non-elastic  wire  G,  Set  No.  i ,  for  the  spring  wire,  or,  better 
still,  by  uniting  the  bands  with  solder,  and  recementing  them,  as  first 
suggested  by  Professor  Guilford. 

"Of  the  levers  shown  at  L,  Set  No.  i,  four  different  sizes  are  fur- 
nished. The  smallest  size  is  quite  strong  enough,  in  most  instances, 
for  double  rotation,  and  is  most  commonly  used  by  me,  especially  on 
the  teeth  of  children. 

"  These  levers  are  plated  in  such  a  manner  as  to  nearly  overcome 
the  annoyance  of  oxidation  and  discoloration  of  the  teeth  in  their 
use,  thus  obviating  an  objection  to  the  employment  of  steel  wire  in  the 
construction  of  regulating  appliances. 

"The  reader  should  never  confuse  the  wire  G,  Set  No.  i,  with  these 
levers.  Their  uses  are  as  different  as  the  material  of  which  they  are 
composed.  The  levers  are  used  only  in  rotation  (occasionally  in  ex- 
pansion), and  are  never  united  by  solder  in  forming  an  attachment ; 
while  the  wire  G,  Set  No.  i,  is  extremely  tough  and  malleable  and  has 
a  very  wide  range  of  application,  such  as  reinforcing  anchorage,  reten- 
tion, making  spurs,  staples,  etc. 

"The  elevation  of  a  tooth  in  its  socket  may  be  accomplished  as  shown 
in  Fig.  301,  wherein  a  superior  cuspid  is  being  drawn  out  or  erupted 
into  line.  The  clamp-band  No.  3,  Fig.  278,  was  fixed  on  the  lower 
second  bicuspid.  A  very  small  hole  was  drilled  into  the  cuspid,  and  a 
short  pin  was  set  with  thin  cement.  A  common  pin  answers  the  pur- 
pose very  well,  and  the  hole  need  not  be  deeper  than  the  enamel  if  the 
pin  is  accurately  fitted  to  it.  A  rubber  ligature  was  given  the  patient 
with  instructions  to  slip  it  over  the  pins,  as  shown  in  the  engraving. 
The  anchor-tooth  in  this  case  is  directly  opposed  by  the  superior  bi- 
cuspid. The  anchorage  is  simple  and  efficient.  The  ligature  may  be 
worn  at  night  only,  so  as  to  interfere  as  little  as  possible  with  speech 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


411 


and  mastication,  although  some  patients  wear  it  almost  continuously. 
Too  strong  a  ligature  should  not  be  worn,  as  it  might  endanger  the  life 
of  the  pulp,  but  gentle  traction  should  be  used,  gradually  directing  the 
tooth  into  its  proper  position.  The  direction  of  force  to  be  exerted 
upon  the  tooth  to  be  moved  will  of  course  indicate  which  tooth  in  the 
inferior  arch  should  be  selected  for  anchorage.  Should  the  anchorage 
fall  upon  a  tooth  with  no  antagonist,  there  would,  of  course,  be  danger 
of  loosening  it. 


Fig.  301. 

"Fig.  302  shows  a  case  in  which  the  anchorage  was  modified  to  suit 
the  conditions.  A  deciduous  cuspid  had  been  retained  too  long,  caus- 
ing the  permanent  cuspid  to  remain  in  the  alveolar  process  on  the 
palatal  side  of  the  lateral  incisor,  necessitating  a  complex  movement 
of  the  tooth  backward,  outward,  and  downward,  requiring  a  very  firm 
anchorage  and  a  strong  ligature.  On  the  inferior  cuspid  and  second 
bicuspid  were  fixed  bands,  having  pipes  R,  Set  No.  i,  attached  to  their 
labial  surfaces.  A  piece  of  the  wire  G  of  suitable  length  was  bent  at 
right  angles  and  hooked  into  the  pipes,  as  shown.  The  wire  fits  the 
bore  of  the  pipe  so  accurately  that  in  cutting  off  the  ends  which  emerge 
through  them,  each  end  spreads  sufficiently  to  prevent  its  coming  out. 
A  pin  was  soldered  to  the 
wire  about  midway  be- 
tween the  pipes.  The  liga- 
ture was  stretched  from 
pin  to  pin,  as  seen  in  the 
engraving. 

' '  Fig.  303  shows  a  modi- 
fication of  this  method  of 
anchorage.  The  anchor- 
wire  was  made  detachable 
and  the  pin  dispensed  with,  the  patient  slipping  the  wire  through  the 
ligature  and  into  the  pipes  upon  retiring,  and  removing  it  during  the 
day.  A  delicate  band  (made  of  F,  Set  No.  i),  to  which  was  soldered 
the  pin,  was  fixed  on  the  moving  tooth. 


Fig.  303. 


412 


DENTAL   SURGERY. 


Fig.  304. 


"Fig.  304  illustrates  a  case  in  which  the  appliances  used  were 
similar  to  those  before  described,  but  the  wire  anchorage  was  attached 
to  teeth  in  the  same  arch  in  which  was  located  the  malposed  tooth. 
The  first  bicuspid  was  banded  and  a  pipe  R,  Set  No.  i,  soldered  to 
the  labial  surface  of  the  band,  in  which  was  hooked  a  piece  of  the 
wire  G,  Set  No.  i,  the  other  end  of  the  wire  being  bent  so  as  to  rest 
on  the  cutting-edge  of  the  lateral  incisor.  A  pin  was  soldered  to  this 
wire,  as  in  the  case  before  described,  and  a  rubber  ligature  stretched 
from  pin  to  pin.  In  some  cases  where  more  force  was  necessary,  I 
have  used  the  combined  anchorage  described. 

"  A  tooth  may  be  elevated  in 
C\.  its  socket  by  employing  either 

of  the  wire  arches  E  or  B  as  an 
anchorage  ;  attaching  the  liga- 
ture to  the  tooth  to  be  moved 
in  any  of  the  ways  already 
described.  Fig.  305  shows  a 
case  where  all  of  the  upper  incis- 
ors are  being  elevated  by  this 
method.  Considerable  down- 
ward spring  was  given  to  the 
anterior  part  of  the  arch,  by 
spurs  attached  to  bands  oh  the  cuspids,  which  furnish  a  bearing  or  ful- 
crum for  the  wire  arch.  Force  is  exerted  in  this  case  by  the  down- 
ward spring  of  the  wire  arch  after  it  has  been  attached  to  the  moving 
teeth  by  wire  ligatures  or  bands  with  spurs. 

"There  are  several  modes  of  expanding  the  arch  by  this  system. 
First :  By  banding  and  tubing  the  first  and  last  teeth  of  those  to  h( 
moved  on  each  side,  and 
connecting  them  by  means 
of  wire  (G)  passing  through 
the  tubes.  The  jack-screw 
is  then  placed  in  position 
across  the  arch,  from  wire 
to  wire.  Collars  R,  Set 
No.  I,  are  soft-soldered  to 
the  wire  at  intervals  to  keep 
the  screw  in  proper  position. 
The  jack-screw  may  be 
moved  forward  or  backward, 

according  to  the  varying  requirements  of  the  case.  Before  placing  in 
position,  the  wires  which  pass  along  the  sides  of  the  arch  should  be 
bent  to  correspond  to  the  shape  of  the  sides  of  an  ideal  arch,  or 


^M.ix.-:ro^ 


Fig.  305. 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


413 


ged.      The 


Fig.  306. 


exactly  as  we   wish    the   teeth    to  be  when   finally  arran 
appliances  in  position  are  accurately  shown  in  Fig.  306 

"Fig.  307  shows  a  modifica- 
tion of  this  method  of  expan- 
sion, the  force  being  derived 
from  one  of  the  levers  L,  Set 
No.  I,  bent  in  the  form  of  the 
well-known  Coffin  spring,  afford- 
ing all  the  advantages  of  the 
Coffin  method  of  expansion, 
without  the  disagreeable  features 
of  the  rubber  plate.  Its  chief 
advantage  over  the  above  method 
is  that  it  may  be  also  used  in  ex- 
panding the  lower  arch,  without 
interfering  with  the  movement  of 
the  tongue,  as  would  jack-screws. 

"  The  appliance  for  double  rotation  shown  upon  the  central  inci- 
sors has  already  been  described,  and  is  repeated  only  to  illustrate  how 

it  may  be  used  with  advan- 
tage while  the  arch  is  being 
expanded  laterally ;  the  rub- 
ber ligature  is  used  at  the 
same  time  to  retract  the  in- 
cisors. 

"The  extra  tubes,  sol- 
dered at  right  angles  to  little 
collars  slipped  upon  the  bars 
on  each  side  of  the  arch,  are 
for  engaging  the  expanding 
spring,  should  it  be  found 
necessary  to  transfer  the 
pressure  to  that  part  of  the 
arch.  Should  it  be  found 
necessary  to  move  a  tooth  beyond  this  side  bar,  stretch  a  rubber 
wedge  between  the  tooth  and  bar,  as  shown  in  Fig.  324.  This  simple 
method  of  moving  a  tooth  beyond  the  limits  of  the  appliance  will  be 
found  valuable  in  connection  with  other  parts  of  this  system. 

"Another  method  of  expanding  the  arch  laterally,  as  well  as  ante- 
riorly, is  by  means  of  the  appliances  shown  in  Fig.  308,  wherein  the 
notched  ends  of  the  jack-screw  engage  a  piece  of  one  of  the  wire 
levers  L,  Set  No.  i,  held  in  position  by  notches  formed  in  the  united 
ends  of  the  bands  upon  the  lateral  incisors.    The  sheaths  of  the  screws 


Fig.  307. 


414 


DENTAL    SURGERY. 


Fig.  308. 


were  held  by  solder  to  anchor  clamp-bands  on  the  first  molars.  The 
incisors  were  moved  forward  by  turning  the  nuts  upon  the  jack- 
screws,  while  the  arch  was  be- 
ing expanded  laterally,  by 
means  of  one  of  the  spring 
levers  L,  Set  No.  i,  the  ends 
of  which  had  been  bent  sharply 
at  right  angles,  and  made  to 
engage  the  delicate  holes  bored 
into  the  sides  of  the  sheaths  of 
the  jack-screws,  all  as  clearly 
shown  in  the  engraving.  A 
modification  of  this  plan  is  to 
exert  pressure  laterally  by  means 
of  a  third  jack-screw  instead  of  the  spring,  this  screw  being  notched 
at  each  end  and  made  to  rest  in  contact  with  the  screws  upon  the  sides 
of  the  arch,  anterior  to  their  nuts. 

"  Another  excellent  method  of  expanding  the  arch  is  by  means  of 
lacing  the  teeth  to  the  expansion-arch  E,  shown  in  Figs.  274  and  276. 
The  wire  ligatures  are  occasionally  tightened  by  twisting,  until  the 
teeth  have  been  moved  outward  and  made  to  conform  to  the  shape  of 
the  wire  arch.  The  increasing  of  the  arch  is  provided  for  by  adjust- 
ing the  nuts  in  front  of  the  tubes  upon  the  anchor-bands.  By  this 
method,  one  or  both  of  the  lateral  sides  of  the  arch  may  be  expanded, 
or  the  anterior  part  of  the  arch  alone  may  be  moved  forward,  in  which 
case  the  teeth  are  laced  to 
the  arch  and  moved  forward 
collectively  by  turning  the 
nuts.     (See  Fig.  274.) 

"In  expanding  the  lateral 
halves  of  the  arch  by  this 
method,  the  wire  arch  should 
be  straightened  sufficiently 
to  give  all  possible  spring, 
which  in  most  instances 
exerts  sufficient  force.  In 
cases  where  the  teeth  are  ex- 
tremely firm,  the  expansion- 
arch  may  be  reinforced  by  the  spring  from  one  of  the  levers  L,  Set 
No.  I,  bent  to  conform  to  the  inside  of  the  arch,  and  made  to 
press  upon  the  anchor-bands  D.  The  ends  of  the  wire  are  held  in 
position  by  being  bent  at  right  angles,  and  slipped  into  pipes  R,  Set 
No.  I,  which  have  been  soldered  at  right  angles  to  tubes,  C,  slipped 


Fig.  309. 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA.  415 

over  the  ends  of  the  screw  upon  the  clamp-bands  D,  all  as  shown  in 
Fig.  309. 

"If  it  is  desirable  to  exert  pressure  only  upon  the  bicuspids,  the 
spring  of  L  alone  is  sufficient,  when  held  in  proper  position,  by  secur- 
ing the  ends  in  either  of  the  following  ways  :  By  resting  in  one  of  the 
pipes  R,  Set  No.  i,  soldered  to  the  clamp-band  (the  end  of  the  pipe 
being  closed  as  shown  on  the  left  of  Fig.  310),  the  arch  being  bent  so 
as  to  lie  in  contact  with  and  also  exert  pressure  upon  the  first  bicuspid ; 
or  the  end  may  be  secured,  as  on  the  right  of  Fig.  310,  by  being  bent 
to  engage  one  of  the  pipes  R,  Set  No.  i,  soldered  to  the  nut  upon  the 
clamp-band,  the  end  of  the  band-screw  resting  against  the  first  bicuspid. 
The  nut  must  be  removed  from  the  screw  while  soldering,  or  pieces  of 
the  anchor-wire  G  may  be  soldered  to  the  clamp-bands  encircling  the 
second  bicuspids,  the  front  ends  in  contact  with  the  lingual  surfaces  of 
the  first  bicuspids.     To  these  wires  are  soldered  at  right  angles  the 


Fig.  310.  Fig.  311. 

pipes  R,  which  engage  the  ends  of  the  spring,  as  in  Fig.  311.  Or  the 
same  attachment  to  the  clamp-bands  upon  the  bicuspids  may  be  made 
as  already  described  and  shown  in  Fig.  309. 

**  If  it  is  desirable  to  exert  pressure  upon  one  tooth  only,  a  pipe 
should  be  soldered  to  the  band  over  the  tooth  to  be  moved  ;  in  this 
pipe  rests  the  end  of  the  spring.  Bend  the  spring  so  that  all  the  force 
will  be  exerted  upon  the  one  tooth  to  be  moved,  while  two  or  more 
teeth  as  anchorage  on  the  opposite  side  of  the  arch  antagonize  this  force. 
This  latter  plan  will  be  found  useful  in  moving  outward  or  inward  a 
single  molar,  which  is  sometimes  desirable  in  order  to  establish  perfect 
occlusion." 

Dr.  W.  G.  A.  Bonwill  in  his  description  of  his  system  of  correctors 
for  irregularities  writes  as  follows  :  — 

"  ist.  To  commence  as  soon  as  possible  after  the  seventh  year,  or 
as  soon  as  there  is  evidence  of  decided  irregularity. 

"  2d.  To  watch  all  children's  teeth  from  the  third  year  and  deter- 
mine, by  an  exploring  needle  every  three  months,  the  exact  position 


41 6  DENTAL    SURGERY. 

of  the  coming  permanent  teeth  as  soon  as  the  first  permanent  molar 
has  appeared. 

"  3d.  To  preserve,  by  early  treatment,  the  first  and  second  molars — 
temporary — even  to  the  treatment  of  their  pulps,  if  they  were  not 
brought  in  time  to  obviate  it. 

"  4th.  To  be  sure  the  first  permanent  molars  are  preserved  with- 
out loss  of  pulp  and  allow  nothing  to  interfere  with  their  full  and  free 
development  in  the  arches,  as  upon  these  teeth  more  than  any  others 
are  due  the  irregularity,  by  coming  too  far  forward  in  the  arch  from 
decay  of  approximal  surfaces  of  temporary  molars,  or  from  the  tardy 
eruption  of  the  permanent  incisors.  The  sixth-year  molar  drives  the 
arch  into  smaller  space  when  the  incisors  have  appeared  out  of  or  in- 
side the  arch. 

"If  the  arch  is  once  interfered  with  the  area  is  not  so  great,  and 
consequently  there  will  be  a  deeper  underbite  and  the  permanent 
molars  will  move  forward  and  always  keep  them  so,  causing  the  per- 
manent teeth  which  are  yet  undeveloped  in  the  maxilla,  and  lying  over 
each  other  and  not  in  line,  to  roll  over  and  shorten  the  whole  maxilla 
in  front  of  the  permanent  molar.  Therefore,  keep  this  tooth  as  far 
back  toward  the  ramus  as  possible. 

*'5th.  That  all  apparatus  should  be  simple  and,  if  possible,  firmly 
fixed,  that  the  patient  can  have  no  control  over  it,  and  then  see  the 
case  every  few  days. 

"  6th.  That  constant  and  uninterrupted  pressure  is  preferable.  The 
antagonism  of  the  opposite  jaw  will  always  be  exerting  a  force  to  make 
them  move  back  and  forth  in  the  sockets,  which  makes  sufficient  in- 
termittent pressure. 

"  7th.  That  while  one  plan,  without  change  somewhat  to  each  case, 
will  not  do,  yet  the  infinite  number  of  such  apparatus  is  a  greater 
nuisance  to  patient  and  operator. 

"  8th.  Take  impressions  of  both  jaws  in  plaster  and  a  duplicate  from 
the  first ;  that  the  plaster  teeth  could  be  cut  off  and  rearranged  to  see 
the  effect,  and  these  models  placed  in  my  anatomical  articulator,  where 
they  could  be  studied  in  the  lateral  movements,  so  necessary.  That 
this  should  be  studied  carefully  ;  and,  before  action  is  taken,  have  the 
patient  call  and  study  the  case  in  relation  with  the  plaster  model; 
and  if  doubt  existed  as  to  the  extraction  of  a  tooth  or  teeth,  better 
postpone  a  few  days  and  send  for  patient  again  rather  than  make  so 
great  a  blunder. 

'*  9th.  That  a  tooth  should  be  held  as  sacred  as  an  eye;  and,  while 
extraction  is  sometimes  demanded,  when  the  greater  good  of  the  patient 
is  at  stake — when  of  weak  constitution — yet  do  not  too  hastily  resort 
to  it. 


IRREGULARITY    OF    THE    TEETH ORTHODONTIA.  417 

"  loth.  That  without  the  combined  assistance  of  parent  and  child, 
better  not  commence. 

"  nth.  That  nothing  should  be  withheld  from  the  child  or  parent, 
but  every  detail,  every  risk,  and  the  amount  of  patient  endurance 
needed,  the  long  time,  and,  when  all  is  corrected,  to  allow  of  stay 
plates,  that  the  work  gained  may  be  retained. 

"  12th.  Not  least  of  all  the  factors,  I  must  mention  (which  I  did  not 
at  first  see)  to  place  such  valuation  on  the  services  as  will  insure  your 
interest  and  will  drive  the  parties  concerned  up  to  their  duties. 

"  To  these  points  I  would  now  further  insist  on  the  great  importance 
of  utilizing  as  factors  or  fulcrums  the  temporary  molars. 

"  ist.  By  shaping  them  with  a  disc  on  all  their  sides  or  surfaces,  so 
that  a  gold  clasp  can  be  securely  placed  thereon.     Figs.  322  and  333. 

"2d.  Where  a  ligature  only  is  needed,  to  cut  a  groove  with  the  disc 
on  the  buccal  and  palatal  and  lingual  surfaces  near  the  cervix,  in 
which  to  place  the  silk  ligature  to  keep  it  from  working  down  under 
the  gum.     Fig.  332,  C  C. 

"  These  teeth  will  soon  be  lost,  and  no  injury  is  dofie  by  shaping  and 
grooving  thef?i. 

"3d.  By  the  use  of  gutta-percha  (Figs.  321  and  322),  warmed  and 
placed  on  the  palatal  or  lingual  side  of  the  tooth,  around  which  a  liga- 
ture is  to  be  placed  and  carried  slightly  up  over  the  grinding  surface 
to  prevent  the  ligature  from  pressing  down  under  the  gum.  This  I  use 
on  permanent  teeth. 

"4th.  Where  the  tooth  cannot  be  cut  or  gutta-percha  used,  then 
gum  sandarach  varnish  or  a  thin  solution  of  oxyphosphate  zinc  placed 
on  the  tooth  will  prevent  the  ligature  from  slipping  when  the  tooth  is 
being  rotated,  or  keep  it  from  pressing  up  under  the  gum. 

"  The  trouble  has  always  been  how  to  get  hold  of  any  of  the  tempo- 
rary teeth  as  a  fulcrum. 

"  It  has  been  my  practice  for  years  to  first  make  use  of  the  silk  liga- 
ture and  rubber  bands,  without  plates.  To  do  so,  how  shall  I  prevent 
the  ligature  from  slipping  off  the  permanent  tooth,  and  from  slipping 
down  over  the  temporary  tooth  used  as  the  fulcrum  ? 

"  I  argue  that  as  the  temporary  cuspids  and  first  molars  will  soon  be 
lost  after  the  permanent  lateral  incisors  have  come,  and  are  high  enough 
to  get  hold  of,  to  cut  a  slot  with  a  small  hard-rubber  disc  on  their 
buccal  and  palatal  surfaces  deep  enough  to  hold  the  ligature  which  keeps 
it  from  ever  passing  down  under  the  gum,  Fig.  332.  If  I  must  make 
a  plate  of  rubber  or  metal  for  the  inside  I  use  the  same  grooves  to  hold 
the  plate  in  position. 

"  If  I  must  have  a  clasp,  which  is  now  most  frequently  the  case  in 
the  use  of  this  new  appliance,  which  I  will  presently  show  you,  I  cut  the 
27 


41  8  DENTAL    SURGERY. 

first  temporary  molar  on  its  mesial  and  distal  surfaces  a  little  under 
parallel,  as  at  Fig.  333,  and  the  strain  is  so  slight  it  is  not  uplifted  be- 
fore the  lateral  incisor  has  been  drawn  into  the  circle.  If  there  is  any 
danger  from  the  ligature  wounding  the  gum,  I  place  underneath  gutta- 
percha. If  I  want  to  pass  a  ligature  around  a  permanent  tooth  (Figs. 
322  and  327),  as  a  fulcrum,  I  simply  warm  a  small  piece  of  gutta-percha 
and  press  it  on  the  palatal  or  lingual  side  of  the  tooth,  letting  it  extend 
slightly  down  on  the  gum,  and  when  cold  and  rigid  cut  two  holes 
through  it  to  let  the  ligature  pass,  and  then  between  the  teeth,  and  tied 
outside  to  the  rubber  band.  This  little  adjunct  cannot  be  overpraised, 
for  it  is  so  soon  adjusted,  is  pleasant  to  the  patient,  and  non-irritating 
to  the  tissues.  I  cannot  tell  you  how  much  I  love  gutta-percha,  and 
especially  just  here  to  save  me  so  much  plate  work  and  irritation,  and 
for  keeping  my  children  in  good  humor.  If  a  metal  wire  or  band  is 
pressing  into  the  gums,  and  a  hook  cannot  be  used  on  the  grinding 
surface,  the  gutta-percha  fills  the  need  ;  and  it  answers  well  as  a  fulcrum 


Fig.  312.  Fig.  313. 

by  letting  the  band  directly  into  the  gutta-percha  or  by  attaching  it  to 
the  wire  or  silk  ligature  that  holds  the  former. 

"  The  figures  from  312  to  333  show  all  the  appliances  and  their  ap- 
plications for  irregularities.  Fig.  312  to  317  show  the  spiral  spring 
in  various  phases. 

"  Fig.  312  is  a  silver  plate  to  fit  the  lower  incisors  tied  on  to  a  cen- 
tral to  correct  a  superior  central  from  the  inclined  projection  on  the 
right,  and  the  end  of  spring  acting  on  the  right  inferior  central  to 
throw  it  out  of  the  arch. 

"  Figs.  313,  314,  315  are  metal  bands  with  clasps,  with  the  spiral 
spring  soft-soldered  under  a  metal  loop  hard-soldered  to  the  band. 
This  retains  the  temper.  These  are  used  on  many  teeth  in  either 
jaw. 

"  ^^S-  3^5  is  a  metal  plate  with  half  clasps  fitted  to  the  bicuspids  to 
hold  it  in  position.  The  spiral  spring  is  soft-soldered  to  plate.  This 
can  be  changed  to  various  positions  on  i)late,  and  is  applicable  to  cases 
where  it  is  difficult  to  place  clasp  entirely  around  a  tooth. 


IRREGULARITY^    OF    THE    TEETH — ORTHODONTIA. 


419 


"  Fig.  316  was  made  for  drawing  backward  the  four  incisors  of  in- 
ferior jaw  with  spiral  springs,  adjusted  not  to  interfere  with  the  tongue 
or  superior  teeth.  The  piece  at  A  goes  over  the  incisors  and  is  held 
by  ligatures  tied  to  one  or  more  of  the  teeth. 


Fig.  314. 


Fig.  315. 


"  Fig.  317  is  a  jack-spring  for  constant  pressure.  It  may  be  made 
in  a  curve  to  conform  to  the  hard  palate.  It  is  very  powerful  and 
effective  and  superior  to  a  jack-screw. 

"  In  all  these  spiral-spring  appliances  the  spring  is  tied  to  the  tooth  to 
be  acted  upon  to  hold  it  from  slipping;  or,  in  some  cases,  a  hole 
drilled  into  the  tooth  is  better. 


Fig.  316. 


Fig.  319.— Applied  in  Fig. 


"  The  appliances  that  with  me  have  superseded  all  others  are  seen  in 
Figs.  318  to  T^T^-i)-  Fig-  318  is  a  curved  bar  of  platinized  gold  with 
four  holes  punched  therein  for  the  passage  of  silk  ligatures.  It  is 
another  way  of  applying  Fig.  319  without  band  and  used  mostly  for  a 
single  tooth  in  either  jaw.  The  principle  of  action  will  be  seen  in 
Fig.  326,  where  two  inferior  lateral  incisors  are  to  be  drawn  from 
within  out.  To  do  so  requires  expansion  of  the  jaws.  This  is  effected 
by  making  the  holes  in  the  end  of  the  plate  over  the  center  of  each 
cuspid  and  by  carrying  the  silk  ligature  from  the  mesial  side  of  the 
laterals  around  back  and  up  between  the  lateral  and  cusijid  and  through 


420  DENTAL    SURGERY. 

the  hole  in  plate  at  either  end,  and  attached  to  a  rubber  band  which  is 
stretched  between  the  holes.  This  pushes  the  cuspids  backward  or 
opens  the  arch,  and  the  centrals  move  forward  somewhat,  and  the 
laterals  easily  fill  the  breach.  Once  in  position  and  they  are  retained 
without  apparatus. 

"  If  the  holes  through  which  the  ligatures  pass  were  made  exactly 
opposite  the  laterals,  no  good  would  be  effected,  because  the  pressure 
would  be  as  much  down  as  out,  and  compressing  the  arch.  But  the 
ligatures  applied  as  directed  force  the  jaws  apart,  although  the 
band  is  resting  hard  on  the  cuspids.  The  ligature  is  a  loop  or  slip- 
knot, and  must  be  applied  so  as  to  come  out  between  the  lateral  and 
cuspid.  Gum  sandarach  varnish  will  keep  it  from  slipping  around  the 
tooth.  The  band,  as  heretofore  applied,  has  not  expanded  the  arches, 
because  the  holes  were  not  in  the  right  places — over  the  cuspids. 

"Fig.  319  is  this  same  bar  with  a  clasp  on  one  side  of  the  arch. 
The  bar  is  lengthened  beyond  the  clasp  to  allow  of  the  rubber  tubing 
tied  at  B  being  attached  far  enough  away  from  A  for  getting  power. 

"It  is  applied.  Fig.  330,  by  clasp- 
ing a  first  molar.  The  right  central 
has  to  be  twisted  and  the  lateral  also, 


B 

Fig.  320.— Bar  Shown  as  Applied,  Fig.  322.       Fig.  321.— Applied  in  Figs.  322  and  327. 

but  in  the  opposite  direction.  The  bar  rests  upon  the  mesial  buccal 
edge  of  the  lateral  while  the  silk  ligature  is  carried  twice  around  the 
central,  bringing  it  up  next  the  lateral  and  over  it  through  the  hole  in 
the  bar  in  the  point  where  it  rests  on  the  lateral  and  is  now  drawn 
through  the  rubber  band  which  has  been  tied  opposite  the  molar.  The 
rubber  is  stretched  to  the  full  length  of  the  bar.  The  cuspid  was  also 
drawn  outward  on  the  same  bar  by  boring  a  hole  directly  opposite, 
which  can  be  made  to  twist  the  cuspid  as  well  as  to  draw  it  outward. 

"  Fig.  320  is  the  same  bar  applied  to  Fig.  322  for  drawing  out  both 
superior  laterals  and  expanding  the  arch.  The  right  cuspid  is  just 
emerging  and  the  first  bicusj^id  is  clasped.  The  ligature  with  a  slip- 
loop  is  carried  over  the  right  lateral,  coming  up  from  its  distal  side 
and  through  the  hole  in  bar  at  A,  and  tied  to  the  rubber  band  near 
the  first  bicuspid.  The  left  lateral  is  ligated  the  same  way,  coming  up 
through  the  hole  at  B,  which  is  over  the  centre  of  cuspid.  The  liga- 
ture pressing  the  left  cuspid  backward  is  tied  to  the  rubber  band  at  C. 
Where  the  bar  is  too  short  to  stretch  the  rubber   band,  it  can  be 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


421 


lengthened  on   one  side  of  the  clasp  or   carried  back  to   the  right 
bicuspid. 

"  The  lower  jaw  partially  shows  the  application  of  the  gutta-percha 
itay-plate  (see  Fig.  321)  for  keeping  the  ligature  from  off  the  gum  at 
cervix,  on  the  first  molar.  The  lower  jaw  being  too  large  an  arch  for  the 
upper,  I  extracted  the  first  right  bicuspid,  and  as  the  right  lateral  infe- 
rior incisor  was  too  far  in  the  arch,  and  the  right  cuspid  very  far  out- 
side, I  simply  ligated  the  first  inferior  molar  on  the  same  side.  A 
piece  of  pink  base-plate  gutta-percha  was  warmed  and  pressed  up 
against  the  molar,  letting  it  rest  partially  on  the  adjoining  teeth  (see 
Fig.  321);  when  cold,  two  holes  were  made  in  it  for  the  passage  of 
the  ligature,  which  was  tied  on  the  buccal  surface  of  the  molar.  A 
rubber  band  was   tied   to  the  inside  before  adjusting.     A  ligature  is 


Fig.  322. 


now  cast  around  the  right  lateral,  carried  up  between  it  and  the  cus- 
pid, and  over  it  through  the  space  where  first  bicuspid  was  extracted, 
on  the  lingual  side  of  the  first  bicuspid,  and  tied  to  the  rubber  band 
attached  to  the  gutta-percha  stay  or  helmet  on  the  first  molar,  and 
stretched  over  the  buccal  surface  of  the  cuspid.  This  drew  the  lateral 
out  very  forcibly.  The  ligature  was  lastly  placed  on  the  cuspid  alone, 
and  remained  for  six  weeks  without  change. 

"Fig.  321  is  also  applied  in  Fig.  327.  This  was  a  very  contracted 
lower  arch  with  a  deep  underbite.  The  arch  was  first  expanded  by 
the  fixture  shown  in  Fig.  323,  made  of  piano  wire,  with  half  clasps 
of  platinized  gold  at  A  A,  made  with  small  ears  to  rest  on  the  grind- 
ing surfaces  of  the  first  bicuspids  to  prevent  slipping  down  upon  the 
gums.  These  clasps  are  soft-soldered  to  retain  the  full  temper  of  the 
piano  wire  as  a  spring.     It  is  a  very  cheap  and  easy  way  of  making 


422 


DENTAL    SURGERY. 


such  an  apparatus  and   with    a   powerful  spring,    which   such   cases 
demand. 

"  In  this  case  I  could  not  afford  to  extract  any  teeth,  because  the 
incisors  were  already  touching  the  gums  on  the  palatal  side  of  the  supe- 
rior centrals.  In  expanding  the  lower  arch  I  obviated  this  deep  over 
and  underbite.  The  left  lateral  was  very  far  inside  the  arch,  and  the 
cuspid  so  far  as  to  nearly  allow  the  bicus- 
pid to  touch  the  lateral.  The  silk  ligature 
was  now  placed  over  the  lateral  and  car- 


FiG.  323.— Applied  to  Fig.  327.— Expander 
OF  Bicuspids,  Lower. 


Fig.  324. — Shown  as  Applied, 
Fig.  325. 


ried  up  next  the  cuspid.  The  first  bicuspid  was  ligated  with  a  stay- 
plate  or  helmet  of  gutta-percha  on  its  lingual  side,  with  the  ligature 
running  through  both  holes  and  carried  around  the  first  bicuspid  and 
tied  on  buccal  side.  This  prevented  entirely  the  slipping  of  ligature 
upon  the  cervix.    A  rubber  band  was  now  stretched  between  the  lateral 


Fig.  325- 

and  bicuspid  and  secured.  This  expanded  the  arch  in  front  and  drew 
out  the  lateral  in  a  very  short  time.  Had  to  change  once  for  a  broken 
or  slipping  ligature.  These  little  gutta-percha  caps  or  helmets  work 
admirably  and  are  not  worn  or  displaced  in  mastication. 

"Fig.  324  is  another  modification  of  Fig.  320,  or  single  bar,  and  is 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


423 


Fig.  326. 


applied  in  Fig.  325,  where  the  four  superior  incisors  are  to  be  moved 
forward  from  one-fourth  to  three-eighths  of  an  inch  and  the  whole  arch 
expanded  to  meet  the  more  perfect  and  larger  arch  in  the  lower.  It  is 
made  of  two  flat  bars  of  platinized  gold  sliding  over  each  other  for  at 
least  two  (2)  inches.  A  loop 
is  soldered  to  the  end  of 
each  flat  bar  as  guides  to 
hold  them  in  place  while 
sliding  through.  A  rubber 
band  is  shown  attached  to 
the  end  of  each  bar  at  A  A, 
which,  in  contracting,  en- 
larges the  circle  and  conse- 
quently not  only  throws  out 
the  incisors,  but  the  bicus- 
pids and  cuspids  as  well. 

"The  attachments  are 
made  on  either  side  to  a  molar  or  bicuspid,  owing  to  the  ease  of  clasp- 
ing. I  have  utilized  the  decay  on  anterior  surface  of  a  molar  by  filling 
with  amalgam  and  cutting  a  hole  into  it  for  one  end  of  the  bar  to  rest, 
instead  of  a  clasp. 

"  The  apparatus  is  shown  applied  in  Fig.  325,  with  the  bars  some 
distance  away  from  the  incisors  to  be  attacked. 

"Before  the  apparatus  is  placed  permanently  in  position  the  four 
incisors  are  ligated  with  a  loop,  as  shown  in  Fig.  332,  using  gum 
sandarach  varnish  to  prevent  slipping  or  turning  on  the  tooth.  The 
ligature  should  be  so  adjusted  as  to  twist  the  tooth  if  needed  while 

drawing  it  forward.  These 
are  now  tied  to  the  sliding 
bars,  bringing  them  closely 
in  contact  with  all  the  teeth 
in  the  arch.  The  rubber 
band  is  now  tied  between 
the  two  points  A  A,  and 
the  application  is  complete. 
It  is  easy  to  see  not  only 
its  simplicity  but  its  great 
effectiveness.  It  can  be 
used  equally  well  for  con- 
tracting an  arch. 

"Fig.  328  shows  the 
worst  case  of  protrusion  of  the  upper  jaw  I  ever  saw.  It  was  not 
done   by  an    acquired   habit,   nor   did  -it   have   any   precedence   in 


Fig.  327. 


424 


DENTAL    SURGERY. 


heredity.  The  temporary  teeth  had  proper  arches.  No  cause  could 
be  assigned.  They  came  as  you  see  in  Fig.  328.  The  lower  incisors, 
when  I  first  saw  the  case,  were  three-eighths  of  an  inch  from  the 
superior  incisors  on  their  palatal  surface,  and  were  imbedded  into  the 
gums  on  the  hard  palate. 


Fig.  328. 


"Before  attempting  to  draw  in  the  incisors  I  made  a  rubber  plate 
(Fig,  329)  to  cover  the  hard  palate,  thickened  where  the  lower  teeth 
would  touch,  and  opened  the  jaws  at  the  bicuspids  at  least  one  eighth 
of  an  inch.  This  was  not  only  to  drive  the  inferior  incisors  up 
further  into  their  sockets,  but  to   allow  the  bicuspids  and  molars  to 

come  down  and  antagonize 
before  the  plate  was  removed. 
"  Two  }ears  were  con- 
sumed in  this.  To  this  plate 
I  now  attached  a  rubber  band 
carried  entirely  around  the 
arch,  with  a  silk  ligature,  and 
at  the  central  incisors  I  made 
a  metal  hook,  carried  over 
their  cutting  edge,  with  two 
holes  through  which  the  lig- 
ature passed.  This  kept  the 
ligature  down  on  the  incisors  near  the  cutting  edges,  and  while  it  was 
aiding  in  drawing  in  the  arch  it  did  another  important  thing  :  forced 
the  centrals  up  into  the  alveolus.  This  was  done  by  the  tendency  of 
the  rubber  band  to  work  up  toward  the  gums,  and  at  the  same  time  it 
pressed  them  up  and  made  them  shorter  without  grinding.  This  was 
a  parallel  case  with  the  one  delineated  by  Dr.  Kingsley  in  "  Oral 
Deformities,"   but  without  any  of  the  treatment  given  there.     The 


Fig.  329. 


IRREGULARITY    OF    THE    TEETH — ORTHODONTIA. 


425 


sliding  band  in  Fig.  324  would  have  done  well  here,  but  I  adopted  the 
simpler  one  of  ligature  and  rubber.     To  secure  it  a  gold  band  running 
over  the  arch  from  the  second  bicuspids,  which  was  soldered  to  clasps 
around  the  latter,  which  could  be  adjusted  or  removed  by  patient. 
' '  The  rubber  plate  was  removed   as  soon  as  I  commenced  to  draw 


Fig.  330. 

the  incisor  into  the  arch,  to  give  room  for  them  to  fill  a  smaller  arch. 
Fig.  331  shows  the  application  of  the  band  in  the  lower  jaw,  where 
the  temporary  molars  are  still  in  place.  The  permanent  laterals  are 
far  inside  the  arch.  The  temporary  cuspids  also  remained.  The  first 
molar  has  had  all  its  sides  squared  to  retain  a  clasp.  A  platinized 
gold  bar,  similar  to  Fig.  320,  with  clasps,  is  used,  with  a  hole  at  the 
end  of  bar  C ;  and  then  op- 
posite the  right  central  inci- 
sor, with  another  over  the 
centre  of  the  right  tempo- 
rary cuspid  at  G,  and  the 
fourth  hole  at  the  end  of 
bar  near  the  first  molar  at  B. 
"The  principal  feature 
about  this  is,  aside  from  the 
bar,  the  cutting  so  heroically 
the  temporary  molars  for 
retaining  the  plate.  This 
does  no  injury,  and  if  it 
was  likely  to,  they  would  soon  have  to  be  extracted  for  the  bicuspids. 


426 


DENTAL    SURGERY. 


"  The  ligatures  are  applied  as  in  all  former  cases  of  this  bar,  so  as 
to  press  backward  as  well  as  drawing  outward.  In  this  case  two  sepa- 
rate pieces  of  rubber  band  are  used. 

"  Fig.  332.  The  feature  about  this  case  which  makes  it  novel  and 
unique  is  the  utilization  of  the  superior  temporary  cuspids  for  holding 
the  ligature.  To  place  a  ligature  on  the  temporary  teeth  insures  their 
removal  or  extraction  without  this  plan.  To  keep  the  ligature  on 
the  body  of  the  tooth  I  take  a  small  hard-rubber  corundum  disc  and 


Fig.  332. 

make  a  groove  on  both  the  labial  and  palatal  sides  of  the  cuspid,  deep 
enough  for  the  ligature  to  rest  securely.  If  necessary,  I  should  do  it 
to  the  first  or  second  temporary  molars,  if  a  ligature  could  be  gotten 
around  the  incisor  to  be  turned  into  place. 

"The  rubber  band  is  drawn  through  and  between  the  centrals, 
which  gives  it  more  power  over  the  incisors.  The  left  superior  lateral 
was  soon  placed  in  the  arch. 

A 


Fig.  333. 

"  Fig.  333  shows  the  cut  surface  in  first  temporary  molar  on  the  left 
and  as  applied  on  the  right  with  the  clasp  around  it  attached  to  the 
bar.  The  ligature  passes  between  lateral,  over  central,  and  through 
hole  in  the  bar  at  A,  pressing  central  to  the  left  and  molar  to  right." 


TREATMENT   OF   DENTAL   CARIES.  427 

CHAPTER    II. 
TREATMENT  OF  DENTAL  CARIES. 

The  treatment  of  dental  caries  is  one  of  the  most  important  opera- 
tions in  dental  surgery,  because  of  the  usefulness  of  the  organs  to  be 
saved,  the  universality  of  the  disease,  also  the  complex  and  difficult 
nature  of  the  treatment  required.  The  caries  may  be  slight  and  super- 
ficial, or  it  may  be  more  or  less  deep-seated ;  lastly,  it  may  penetrate 
even  to  the  pulp-cavity.  The  difficulties  of  treatment  increase  in  the 
same  order,  and  in  this  order  they  will  be  taken  up.  Caries,  when 
superficial,  may  be  arrested  by  the  same  means  used  for  deeper  caries; 
but  in  a  large  number  of  cases  it  will  require  for  its  removal  only  the 
use  of  files,  enamel  chisels,  or  discs.  These  instruments  are  also  often 
used  preparatory  to  the  operations  necessary  for  the  arrest  of  deep- 
seated  caries ;  hence  their  use  demands  our  first  consideration. 

Such  instruments  as  enamel  chisels,  discs,  etc.,  have,  in  a  great 
measure,  however,  superseded  the  file  for  the  permanent  separation  of 
teeth  and  the  removal  of  superficial  caries. 

Treatment  of  Superficial  Caries. — There  is  no  operation  in 
dental  surgery  against  which  a  stronger  or  more  universal  prejudice 
prevails  than  that  of  filing  the  teeth,  yet,  when  judiciously  and  skill- 
fully performed,  it  often  proves  beneficial  in  arresting  the  progress  of 
caries.  Although  productive  of  much  good,  it  is,  in  the  hands  of 
unskillful  operators,  a  source  of  incalculable  injury. 

In  filing  the  front  teeth  and  those  on  the  right  side  of  the  mouth, 
the  operator  should  stand  to  the  right  and  a  little  behind  the  patient, 
in  order  to  steady  the  head,  as  it  rests  against  the  back  of  the  oper- 
ating chair,  with  his  left  arm,  while  with  the  fingers  of  the  left  hand 
the  lips  are  raised  and  the  teeth  properly  exposed  for  the  operation. 
In  filing  the  teeth  on  the  left  side  of  the  mouth  it  may  be  necessary 
for  the  operator  to  stand  upon  the  left  side  of  his  patient.  The  file, 
firmly  grasped  between  the  thumb  and  middle  finger  of  the  right  hand, 
with  the  end  of  the  forefinger  resting  upon  its  outer  end,  should  be 
moved  backward  and  forward  in  a  direct  line,  as  any  deviation  from 
this  would  immediately  snap  the  instrument.  The  first  opening 
between  the  teeth,  when  the  approximal  edges  of  the  two  are  carious, 
should  be  made  with  a  flat  file  about  one-fourth  of  a  line  in  thickness, 
cut  on  both  sides  and  both  edges ;  this  done,  a  file  cut  on  one  side 
and  both  edges  should  be  employed  for  the  completion  of  the  opera- 
tion. If  only  one  tooth  is  decayed  the  operation  may  be  commenced 
and  completed  with  a  safe-sided  file.     The  file,  during  the  operation, 


428 


DENTAL    SURGERY. 


should  be  frequently  dipped  in  tepid  water  to  prevent  it  becoming 
heated  or  clogged  while  in  use ;  especially  should  the  water  be  warm 

or  tepid  where  the  teeth 
are  sensitive.  When  the 
files  become  so  much 
clogged  that  the  water  or 
a  brush  will  not  cleanse 
them,  a  brass  or  steel 
scratch-brush  may  be  used, 
or  they  may  be  dipped  in 
sulphuric  or  chlorhydric 
acid,  and  then  washed  with 
the  greatest  care,  to  remove  every  trace  of  acid. 

Fig.  334  represents  various  forms  of  thin  separating  files. 
Fig.  335  represents  forms  of  flexible  separating  files. 
To  secure  the  success  of  the  operation  it  is  sometimes  necessary  to 
cut  away  a  considerable  portion  of  the  tooth ;  but  in  doing  this  the 
operator  should  be  careful  not  to  destroy  the  symmetry  of  the  labial 


Fig.  334- 


Fig.  335- 

surface.  The  aperture  anteriorly  should  only  be  wide  enough  to  admit 
of  a  free  oblique  or  diagonal  motion  of  a  safe-sided  file  of  about  one- 
fourth  of  a  line  in  thickness,  or  a  correspondingly  thin  corundum 
disc.  In  this  way  one-fourth  or  more  of  a  tooth  may  be  removed 
without  materially  altering  its  external  appearance.  But  a  tooth  should 


TREATMENT    OF    DENTAL    CARIES. 


429 


not  be  filed  entirely  to  the  gum  ;  a  shoulder  should  be  left,  to  prevent 
its  approximation  to  the  adjoining  tooth.  Sometimes  the  decay  is  of 
such  size  and  so  situated  that  it  may  be  removed  by  means  of  enamel 
chisels  with  less  alteration  in  the  external  or  labial  surface  of  the  tooth. 
These  very  valuable  instruments  will  also  be  found  useful  for  rapid 
cutting  preparatory  to  the  slower  action  of  the  file.     A  rounded  form 


Fig.  336. 


Fig.  337. 


can  be  given  by  them  to  the  inner  angles  of  the  teeth,  for  which  pur- 
pose they  may  either  follow  or  take  the  place  of  the  file. 

Fig.  336  represents  a  set  of  enamel  chisels,  straight  and  curved,  by 
which  the  operation  of  removing  a  portion  of  the  crown  of  a  tooth 
can  be  performed  much  more  rapidly  than  by  the  file,  and  also  with 
more  comfort  to  the  patient. 


43° 


DENTAL   SURGERY. 


Fig. 


337  represents  a  set  of  Dr.  Louis  Jack's  Double-end  Enamel 
Chisels. 

Fig.  339  represents  Dr.  W.  W.  Evans's  set  of  Enamel 
Chisels. 

When  operating  upon  the  front  teeth  with  the  enamel  chisel, 
the  instrument  should  be  firmly  grasped  in  the  hand,  near  to 
its  cutting  edge,  and  the  edge  applied  to  the  surface  of  the 
portion  to  be  removed,  while  at  the  same  time  the  point  of 
the  thumb  uses  as  a  fulcrum  the  cutting  edge  of  the  tooth  or 
the  one  adjoining. 

For  operating  upon  the  bicuspid  and  molar  teeth,  heavier 
enamel  chisels  are  required  than  in  the  case  of  the  front  teeth, 
and  with  either  straight  or  oblique  cutting  edges.  The 
curved  form  of  chisel  is  useful  when  the  mouth  is  small  and  it 
is  difficult  to  reach  the  point  desired  with  the  straight  form. 

Fig.  ;^^8  represents  Dr.  Gordon  White's  fixed  blade  sepa- 
rator for  immediately  separating  teeth  without  loss  of  sub- 
stance. It  is  manipulated  by  forcing  the  thin  portion  of  the 
blade  between  the  teeth  to  be  separated,  then  pulling  outward 
slowly  and  firmly,  with  a  little  swaying  motion,  until  the  proper 
space  is  obtained.  The  force  so  applied  tends  to  spread  the 
teeth  outwardly,  the  reverse  of  the  keystone  action  of  the  ordi- 
nary wedge,  and  thus  a  wider  space  is  very  easily  obtained. 

When  the  decay  occupies  a  large  portion  of  the  approxi- 
mal  surface  and  has  penetrated  into  the  tooth  to  a  considerable 
depth,  destroying  the  enamel  anteriorly  and  causing  it  to 
present  a  ragged  and  uneven  edge,  it  will  be  necessary  to  form 


Fig.  338. 


Fig.  339. 


a  wider  exterior  aperture  than  mere  regard  for  appearance  would  dic- 
tate.   When  the  approximal  surfaces  of  the  two  front  teeth  are  affected 


TREATMENT    OF    DENTAL    CARIES. 


431 


with  caries,  about  an  equal  portion  should,  if  circumstances  permit  and 
it  is  necessary  to  cut  away  tooth  substance,  be  filed  or  cut  from  each 
tooth.     In  the  case  of  delicate  front  teeth,  or  teeth  slightly  loose  in 


Fig.  340. 


Fig.  342- 


their  cavities,  it  will  be  well  before  filing  to  mold  a  small  piece  of 
gutta-percha  or  modeling  composition  around  or  against    the  inner 


432 


DENTAL    SURGERY. 


surfaces  of  the  tooth  to  be  filed  and  several  adjoining  ones.  It  gives 
support  to  frail  teeth,  and  greatly  lessens  the  danger  of  irritation  from 
the  motion  imparted  by  the  file  to  the  teeth  which  are  not  firmly  set 
in  their  sockets.  Some  use  for  this  purpose  plaster  ;  but  we  think  the 
gutta-percha  or  modeling  composition,  as  suggested  by  Prof.  Gorgas, 
will  be  found  altogether  more  conveniently  applied  and  more  agree 
able  to  the  patient. 

When  the  file  is  employed  for  separating  the  superior  incisors  and 
cuspids,  the  operation  may  be  completed  with  a  bevel-edged  file,  as  no 
sharp  angle  should  be  left  near  the  gum. 

In  separating  the  bicuspids  by  filing,  a  space  should  be  made  some- 
what in  the  form  of  the  letter  V;  it  should  not,  however,  form  an 
acute  angle  at  the  gum.  This  space  should  also  be  slightly  wider 
toward  the  palatal  and  lingual  surfaces.  For  its  formation  a  V-shaped 
file,  which  is  one  beveled  on  both  sides,  will  be  found  most  suitable. 
A  space  shaped  in  this  manner  will  prevent  the  approximation  of  the 


Fig.  343. 


sides  of  the  teeth,  and  if  filling  be  necessary,  it  will  enable  the  operator 
to  do  it  in  the  most  perfect  manner. 

Fig.  340  represents  knife-edge  or  bicuspid-pointed  and  blunt  files. 

Fig.  341  represents  a  file  designed  by  Dr.  E.  Family  Brown  for  con- 
touring the  approximal  surfaces  of  molars  and  bicuspids.  It  is  three- 
sided  and  cut  on  all  sides. 

When  the  separation  of  the  molar  teeth  in  this  manner  becomes 
necessary  the  same  shaped  space  should  be  formed.  But  as  these  teeth 
are  situated  far  back  in  the  mouth,  it  cannot  often  be  done  with  a 
straight  file ;  to  obviate  this  difficulty,  an  instrument  with  which 
every  dentist  is  acquainted,  denominated  a  file-carrier,  is  usually 
employed. 

Fig.  342  represents  Dr.  J.  E.  Line's  file-carrier,  which  is  simple  in 
its  construction  as  well  as  very  serviceable. 

Fig.  343  represents  Dr.  W.  B.  Miller's  file-carrier,  which  admits  of 
changing  direction  and  slant  very  quickly. 

Fig.  344  represents  a  cheap  and  simple  file-carrier,  the  device  of 


TREATMENT    OF    DENTAL    CARIES. 


433 


Dr.  D.  M.  Clapp,  either  straight  or  curved,  which  will  carry  a  thin 
separating  file,  and  also  finer  ones  for  cutting  metal. 

A  file-carrier  attachment  for  use  with  the  dental  engine  has  also  been 
devised,  but  it  is  not  so  readily  controlled  as  the  hand  instrument. 


Fig.  344. 

A  great  variety  of  V-shaped  separating  files  are  now  to  be  found  in 
the  dental  depots,  from  English,  French,  and  American  manufac- 
turers.    Fig.  345  will  give  a  correct  idea  of  some  of  these  shapes. 

Discs  composed  of  different  substances,  and  attached  to  mandrels, 
for  use  with  the  dental  engine,  are  employed  for  separating  teeth  that 


Fig.  345. 

are  aflFected  with  superficial  caries  on  their  proximate  surfaces,  and  also 
for  removing  superficial  caries  from  such  surfaces.  Figs.  346  and  347 
represent  the  diamond  disc,  composed  of  a  thin  plate  of  metal,  such 
as  nickel,  in  which  diamond  powder  is  thoroughly  incorporated.  The 
corundum  discs,  Fig.  348,  introduced  by  the  late  Dr.  Robert  Arthur, 
of  Baltimore,  are  now  used,  to  the  almost  entire  exclusion  of  files,  in 
separating  teeth,  especially  molars  and  bicuspids.  Although  often 
28 


434 


DENTAL   SURGERY. 


employed  for  separating  the  incisor  teeth,  they  require  careful  manipu- 
lation for  such  delicate  operations,  on  account  of  being  less  readily  con- 
trolled than  the  chisel  or  file.  The  incisor  teeth,  being  much  smaller 
than  the  posterior  teeth,  should  never  be  cut  in  the  same  proportion. 
When  the  disc  is  used  for  separating  the  an- 
terior teeth  the  greatest  care  should  be  ex- 
ercised to  avoid  too  much  cutting,  especially 
of  the  labial  angles. 


Fig.  346. 


Fig.  347. 


These  discs  are  similar  in  composition  to  the  ordinary  corundum 
wheels  used  for  grinding  porcelain  teeth,  being  composed  of  emery 
powder  and  gum  shellac,  which,  being  softened  by  heat,  is  rolled  into 


Fig.  348. 


a  great  variety  of  shapes  to  suit  the  different  operations  to  be  per- 
formed by  them.     The  discs  thus  formed   are  mounted  on  mandrels 


Fig.  349. 


(Fig.  350)  for  use  with  the   dental  engine,  an  instrument  which  will 
hereafter  be  described. 

Fig.  349  represents  a  few  forms  of  Dr.  A.  L.  Northrop's  corundum 
points  for  cutting  and  polishing. 


TREATMENT    OF    DENTAL    CARIES. 


435 


Fig.  350  represents  different  forms  of  mandrels,  with  and  without 
shoulders,  for  mounting  corundum,  diamond,  rubber,  celluloid,  box- 
wood, emery-paper,  sand-paper,  and  cuttle-fish  paper  discs  and  points. 

After  a  sufficient  portion  of  the  tooth  has  been  cut  away  the  surface 


should  be  made  as  smooth  as  possible,  with  a  very  fine  or  half-worn 
file,  or  with  Arkansas,  Hindostan,  or  Scotch  stones,  wood  polishing 
points,  discs  of  soft  or  hard  rubber,  boxwood,  felt,  emery,  sand  or 
cuttle-fish  paper,  carrying  powders  such  as  pumice,  silex,  emery,  buck- 


FlG.  351. 


Fig.  352. 


horn,  corundum  flour,  Hindostan,  Arkansas,  etc.,   etc.,  or  with  tape 
charged  with  such  powders. 

Fig.    351   represents   hard  rubber  discs   for   carrying   powders   for 
polishing  the  natural  teeth  and  finishing  fillings. 


Fig-  353- 


Fig.  35  2  represents  boxwood  discs. 

Fig.   353  represents  corrugated   soft   rubber  discs  and    points   for 
carrying  powders  for  polishing. 


,36 


DENTAL    SURGERY. 


Fig.  354  represents  emery,  sand,  and  cuttle-fish  paper  discs. 

Fig.    355    represents  points    of    Arkansas,   Hindostan,  and  Scotch 


Fig.  354. 


stoncrb,   mounted   on   mandrels,   for  polishing  the  natural  teeth  and 
fillings. 

Fig,  356  represents  wood  polishing  points,  which  are  screwed  into  a 
mandrel  for  use  with  the  dental  engine.     These  points  are  alsoservice- 


FiG.  356. 


able   for   removing  discoloration  from  the  teeth,  such  as  results  from 
depositions  of  calculus. 

Dr.  George  H.  Cushing's  Changeable  Angle  Disc  Carrier,  Fig.  357, 
is  easily  attached  and  removed  from  the  dental  engine  hand-piece,  its 
angular  range  being  indicated  by  the  dotted  lines. 


TREATMENT    OF    DENTAL    CARIES. 


437 


A  fountain  mouth  protector  (Fig.  358),  while  protecting  the  tongue 
and  cheek  from  injury,  serves  also  to  keep  the  disc  wet.  A  supply  of 
water  is  stored  in  the  rubber  bulb  of  reservoir  B,  by  compressing  and 
immersing  it  in  water,  and  is  fed  as  required  through  the  small  aper- 
ture seen  in  the  cuts  by  a  touch  of  the  finger  on  the  bulb.     The  tube 


Fig.  357. 

A  is  sprung  over  the  hand-piece,  and  may  be  turned  for  use  in  any  part 
of  the  mouth. 

Fig.  359  represents  Dr.  F.  Herrick's  fountain  drip-point,  intended 
for  keeping  up  a  continuous  dripping  of  water  upon  corundum  points, 
engine  burrs,  and  other  rapidly  revolving  instruments. 

When  removing  superficial  caries  all  edges  and  sharp  corners  should 
be  rounded  and  made  smooth,  and  when  the  operation  is  completed 
the  patient  should  be  directed  to  keep  the  excised  surfaces  of  tooth- 
structure  perfectly  clean,  for  if  the  secretions  of  the 
mouth  or  extraneous  matter  be  permitted  to  adhere 
to  such  surfaces  a  recurrence  of  the  disease  will 
take  place.  Prior  to  removing  superficial  caries 
from  the  approximal  surfaces,  and  especially  of  the 
front  teeth,  such  teeth  may  be  separated  by  pres- 
sure  made  with  wood,   cotton,   tape,  or  rubber, 


Fig.  358. 


Fig.  359- 


SO  that  unnecessary  cutting  of  enamel  may  be  avoided,  and  but  little 
more  of  the  tooth-structure  be  removed  than  the  decalcified  part. 
When  a  portion  of  the  approximal  surface  of  a  tooth  is  cut  away,  the 
excised  surface  should  be  left  free  and  exposed  to  the  friction  of  the 
tongue  and  lips,  which  will  prevent  food  and  other  extraneous  matters, 
as  well  as  the  secretions  of  the  mouth,  from  lodging  and  remaining  in 
contact  with  it.  The  portion  cut  away  should  be  as  much  as  is  pos- 
sible from  the  posterior  part  of  the  approximal  surface,  especially  in 


438  DENTAL    SURGERY. 

the  case  of  the  front  teeth,  so  as  to  prevent  any  noticeable  disfigure- 
ment. When  superficial  caries  is  located  on  the  approximal  surfaces 
of  the  bicuspids  and  molars,  and  near  to  the  grinding  surfaces,  it  may 
be  removed  by  cutting  out  a  V-shaped  space  between  such  teeth. 
When  enamel  chisels  are  employed  for  removing  superficial  caries, 
the  instrument  should  be  grasped  near  its  cutting  edge,  which  should 
be  applied  in  the  line  of  the  enamel  fibres,  using  the  adjoining 
tooth  as  a  fulcrum  for  the  thumb,  in  order  to  prevent  the  instrument 
from  slipping  and  wounding  the  soft  part  adjacent.  Having  in  such 
a  manner  removed  the  overhanging  enamel,  the  softened  or  decalcified 
dentine  should  be  cut  away  with  a  scoop-shaped  excavator,  the  use  of 
which  will  also  determine  the  depth  to  which  the  caries  has  pene- 
trated, and  if  not  too  extensive,  the  enamel  chisel  can  again  be 
employed  until  the  surface  is  made  level  or  uniform.  All  edges  and 
sharp  corners  should  be  rounded  and  made  smooth,  and  it  may  be 
necessary,  in  order  to  complete  the  cutting  process,  to  use  a  curved 
fine-cut  file.  Corundum  discs  operated  with  the  dental  engine  may 
be  found  more  convenient  for  the  removal  of  superficial  caries,  and 
especially  in  the  case  of  the  bicuspids  and  molars,  to  be  followed  by 
strips  of  emery  cloth  or  paper  of  the  fine  grades ;  also  discs  of  fine 
sand-paper.  When  a  perfectly  smooth  and  normal  surface  is  obtained, 
it  should  be  highly  polished  with  pulverized  pumice  or  silex  applied  on 
linen  tape,  or  on  discs  of  flexible  rubber,  boxwood,  or  celluloid,  com- 
pleting the  operation  with  polishing  putty  (peroxid  of  tin).  The 
corundum  and  Arkansas  or  Hindostan  stone  points,  followed  by  the 
use  of  wood  points  for  the  application  of  the  polishing  putty,  will  be 
found  useful  for  removing  superficial  caries  from  exposed  surfaces. 
When  the  operation  of  removing  superficial  caries  is  completed,  the 
patient  should  be  directed  to  keep  the  excised  surface  of  tooth-structure 
perfectly  clean.  Caries  upon  the  approximal  surfaces  of  the  teeth 
may  be  prevented  by  occasionally  polishing  such  surfaces  and  passing 
floss  silk  between  the  teeth  in  connection  with  the  use  of  the  tooth- 
brush. 

Since  the  introduction  of  the  dental  engine  the  removal  of  super- 
ficial caries  and  the  preparation  of  the  excised  surface  can  be  very 
effectively  performed  ;  and  it  should  be  remembered  that  such  a  surface 
should  be  left  self-cleansing,  so  that  deleterious  substances  may  not 
lodge  and  remain  in  contact  with  it. 

For  separating  the  teeth  to  obtain  space  for  the  free  use  of  the 
instruments  employed  in  preparing  and  filling  cavities  on  the  approx- 
imal surfaces,  the  reader  is  referred  to  the  "  Treatment  of  Deep-seated 
Caries." 

Separation  of  the  Teeth. — Before  a  cavity  can  be  prepared  in  the 


TREATMENT    OF    DENTAL    CARIES.  439 

approximal  surface  of  a  tooth,  it  is  usually  necessary  to  separate  it 
from  the  adjoining  one.  This  may  be  done  either  with  a  file,  enamel 
chisel,  corundum  disc,  or  by  the  pressure  of  some  interposed  elastic 
substance,  or  by  wedges  of  wood  driven  between  the  teeth,  or  by 
metallic  wedges  or  separators.  Each  of  these  methods  has  its  advan- 
tages. When  caries  has  extended  over  nearly  the  whole  approximal 
surface,  so  that  after  the  removal  of  the  diseased  part  the  orifice  of  the 
cavity  will  be  surrounded  by  a  thin,  brittle,  and  irregular  wall,  the 
former  is  the  preferable  method,  especially  in  individuals  having  a 
decided  scorbutic  tendency,  or  who  have  suffered  from  the  use  of  mer- 
curial medicines  or  syphilitic  disease,  and  in  aged  persons.  But  when 
the  caries  has  spread  over  only  a  small  portion  of  the  surface  of  the 
tooth,  and  is  surrounded  by  sound,  healthy  enamel,  the  latter  method 
should  be  adopted,  especially  in  individuals  in  whom  there  is  no  mani- 
fest tendency  to  inflammation  or  sponginess  of  the  gums  and  in  young 
subjects.  The  manner  of  separating  teeth  with  cutting  instruments 
has  been  already  described  ;  it  will  only  be  necessary,  therefore,  in 
this  place,  to  offer  a  few  remarks  on  separating  by  pressure,  which  was 
first  adopted  by  Dr.  Eleazer  Parmly. 

The  following  are  its  advantages,  where  it  can  be  resorted  to  with 
safety :  after  the  removal  of  the  pressure  the  teeth  almost  immediately 
come  together,  leaving  no  space  to  injure  their  beauty ;  what  is  of  still 
greater  importance,  the  dentine  around  the  external  surface  of  the  fill- 
ing is  not  exposed  to  the  action  of  the  secretions  of  the  mouth,  or 
other  agents  capable  of  exerting  upon  it  a  deleterious  action.  On  the 
other  hand,  some  are  of  opinion  that  when  the  teeth  come  together 
again  a  lodgment  is  afforded  to  corrosive  agents,  upon  the  presence 
of  which  the  disease  was,  in  the  first  instance,  produced,  and  which 
would  soon  cause  a  recurrence  of  it.  In  replying  to  this  objection  it 
is  only  necessary  to  observe  that  the  parts  of  teeth  first  attacked  by 
caries  were  the  points  in  contact  with  each  other,  where  the  enamel 
may  be  supposed  to  have  sustained  some  injury  by  pressure,  thus  ren- 
dering them  more  vulnerable  at  these  points  to  the  action  of  the  causes 
that  produced  the  disease.  By  properly  replacing  the  diseased  parts 
with  gold,  the  external  surfaces  of  the  fillings  will  be  the  only  parts 
that  come  in  contact  with  each  other,  and  if  of  gold  will  not  be  liable 
to  injury  from  the  above-mentioned  mechanical  causes.  The  enamel 
around  the  fillings,  if  proper  attention  to  cleanliness  be  observed,  is 
not  so  liable  to  be  acted  on  by  chemical  agents  as  the  dentine  which 
the  cutting  instrument  would  expose. 

But  teeth  cannot  always  with  impunity  be  separated  by  pressure  ;  it 
can  only  be  done  with  safety  in  certain  cases.  As  a  general  rule,  the 
writer  is  of  the  opinion   that   it  ought  not  to  be  attempted  after  the 


440  DENTAL    SURGERY. 

thirtieth  or  fortieth  year  of  age,  though  it  may  sometimes  be  done 
with  safety  at  even  a  later  period.  The  diseased  action  excited  for  the 
time  in  the  sockets  of  the  teeth  does  not  so  readily  subside  at  a  later 
age;  and  it  has  in  some  instances  been  known  to  result  in  the  loosen- 
ing and  ultimate  loss  of  the  organs.  In  one  case  which  came  under 
the  observation  of  the  author  the  inflammation  extended  to  the  pulp, 
causing  its  disorganization  and  the  consequent  death  of  the  tooth. 

The  pressure  ought  never  to  be  too  actively  exerted  ;  it  should  be 
gradual  and  constant.  From  three  to  five  days  are  usually  required 
for  the  separation  of  two  teeth  sufficiently  for  the  removal  of  the 
decayed  part  and  the  introduction  of  a  filling.  After  they  have  been 
separated  in  this  way,  they  should  be  kept  apart,  without  any  increase 
of  pressure,  until  the  soreness  in  the  cavities  shall  have  subsided,  before 
any  further  steps  are  taken  in  the  operation.  Cotton  saturated  with 
sandarach  varnish,  or  white  gutta-percha,  or  zinc  filling  materials,  may 
be  used  to  retain  teeth  after  being  separated  with  other  substances,  or 
by  the  rapid  method.  Only  two  teeth  should  be  separated  in  the  front 
part  of  the  mouth  in  the  same  jaw  at  the  same  time.  As  soon  as  the 
cotton  or  tape,  or  other  substance  used  to  separate  teeth,  has  afforded 
the  desired  space  it  should  be  removed,  and  the  space  retained  for  one 
or  two  days  by  cotton  saturated  with  sandarach  varnish,  or  white 
gutta-percha,  or  one  of  the  zinc  filling  materials  pressed  between  them, 
when  the  teeth  may  be  well  enough  to  permit  of  being  operated  on. 

The  pressure  is  usually  made  by  introducing  between  the  crowns  of 
two  teeth  a  thin  wedge  of  soft  wood,  a  piece  of  India-rubber,  tape,  a 
little  raw  cotton  or  ligatures,  replacing  the  first-named  substances 
every  day  or  two  with  thicker  pieces.  While  some  prefer  India-rubber 
to  any  other  substance  employed  for  the  purpose,  the  object  may  be 
readily  attained  with  other  substances.  Cotton  or  tape  pressed  firmly 
between  the  teeth  and  renewed  daily,  also  gutta-percha,  will  in  the 
course  of  a  (ew  days  separate  teeth,  and  with  less  soreness  than  India- 
rubber,  to  the  use  of  which  many  object  on  account  of  the  irritation 
it  causes.  Many  operators  prefer  gradual  pressure  in  separating  teeth, 
but  others,  on  account  of  economy  of  time,  consider  it  better  for  the 
separation  to  be  made  at  once,  and  not  prolonged  through  several 
days.  It  is  also  urged  that  the  patient  suffers  less  and  that  there  is  also 
less  danger  to  the  teeth,  in  rapid  separation  than  where  this  process  is 
gradual.  The  degree  of  pressure  and  the  method  by  which  the  sepa- 
ration is  to  be  accomplished  should,  however,  be  determined  by  the 
susceptibility  of  the  parts  to  inflammation.  The  operation  of  rapidly 
separating  the  teeth  consists  in  the  use  of  two  wedges  of  fine-grained 
wood,  either  orange  or  boxwood.  The  first  wedge  is  forced  between 
the  necks  of  the  teeth,  care  being  taken  not  to  lacerate  the  gum,  while 


TREATMENT    OF    DENTAL    CARIES.  44I 

the  second  wedge,  which  tapers  more  than  the  first,  is  inserted  be- 
tween the  points  of  the  teeth,  the  wedges  being  driven  alternately  by 
mallet  force,  until  sufficient  space  is  obtained,  when  the  second  wedge 
is  removed.  Very  great  care  should  be  exercised  in  driving  the  second 
wedge  between  the  points  of  the  teeth,  on  account  of  the  force  exerted 


Fig.  360. 

by  it.     This  description  applies  to  the  front  teeth,  as  it  is  not  advisable 
to  attempt  the  separation  of  the  molar  teeth  in  this  manner. 

Fig.  360  represents  a  set  of  the  Jarvis  Separators,  by  means  of  which 
adjacent  teeth  can  be  forced  apart  without  delay  or  appreciable  pain 
to  the  patient.  This  separator  consists  of  a  piece  of  steel,  nickel- 
plated,  bent  upon  itself,  having  the  two  ends  formed  to  fit  the  outer 


442 


DENTAL    SURGERY. 


portions  of  the  approximal  surfaces  of  the  two  adjoining  crowns. 
These  jaws  are  forced  apart  by  the  action  of  the  screw  which  passes 
through  one  and  against  the  other.  The  compound  forms  consist  of 
two  wedges  approaching  or  passing  each  other,  and  are  applicable  to 
the  incisor  teeth,  the  first  forms  being  applicable  to  the  bicuspid  and 
molar  teeth. 

Figs.  361,  362,  and  363  represent  Dr.  S.  G.  Perry's  two-bar  separa- 


FiG.  361. 


Fig.  363 


tors,  which  are  operated  by  a  wrench  with  a  double  end,  one  straight 
and  the  other  bent  at  an  angle,  to  give  greater  facility  for  turning 
the  bars  in  different  directions.  The  shape  of  these  separators  per- 
mits the  teeth  to  which  they  are  applied  to  be  approached  readily 
from  either  side.  The  arrows  on  the  bars  indicate  the  direction 
they  are  to  be  turned  to  spread   the   separator.     Fig.  364,  365,  and 


Fig.  366. 


366  represent  Dr.  W.  A.  Woodward's  separators,  the  blades  of  which 
act  independently,  which  is  an  advantage  when  the  teeth  are  irregular. 

Fig-  367  represents  Chase's  Dental  Wedge  Forceps,  by  which 
wooden  wedges  can  be  forced  between  adjacent  teeth  for  the  purpose 
of  separating  them,  and  by  the  use  of  this  appliance  it  is  claimed  that 
there  is  less  danger  of  irritation  and  subsequent  inflammation  than  by 
the  method  of  driving  a  wedge  with  a  hand-mallet. 

Dr.  Corydon  Palmer  recommends  the  following  method  of  rapid 
wedging:  A  wedge  made  from  a  thin  piece  of  wood  or  quill  is  first 


TREATMKNT    OF    DENTAL   CARIES. 


443 


introduced  between  the  teeth  to  protect  the  gum.  Next  to  the  first 
wedge,  a  square,  tapering  one,  of  orange  or  boxwood,  is  introduced 
at  the  gum  in  such  a  manner  as  not  to  interfere  with  the  view  of  the 
wall  of  the  cavity,  and  which  is  permitted  to 
remain  during  the  operation  of  filling,  being 
driven  to  hold  the  space  gained  by  a  broad 
wedge  introduced  by  hand  pressure  or  mallet 
force  between  the  cutting  edges  of  the  teeth, 
its  point  being  directed  toward  the  gum.  The 
separation  is  gradually  accomplished,  in  order 
to  allow  the  tissues  to  accommodate  them- 
selves to  the  pressure  to  which  they  are  sub- 
jected. It  is  recommended  that  the  rapid 
process  for  separating  teeth  be  restricted  to 
cases  where  but  little  space  is  required,  and 
where  the  structures  are  soft  and  spongy. 
Fig.  368  represents  a  wedge- cutter  for  remov- 
ing the  projecting  portions  of  the  wooden 
wedges. 

After  separating  teeth  by  rapid  wedging, 
the  wooden  wedges  should  not  be  permitted 
to  remain  between  the  teeth,  when  more  than 
one  sitting  is  necessary  to  complete  the  opera- 
tion of  filling,  but  removed,  and  the  space 

maintained  by  cotton  saturated  with  sandarach  varnish,  or  by  gutta- 
percha, until  the  next  sitting. 

There  is  a  difference  of  opinion  among  many  prominent  and  skillful 


Fig.  367, 


Fig.  368. 


operators  in  regard  to  the  permanent  separation  of  the  teeth,  the  advo- 
cates of  contour  fillings  objecting  to  the  removal  of  so  much  tooth- 


444 


DENTAL    SURGERY. 


substance  without  substituting  for  it  a  non-destructible  substance,  such 
as  gold,  while  the  advocates  of  the  permanent  separation  method  con- 
tend that  self-cleansing  surfaces,  properly  prepared,  are  preferable  to 
the  labor,  pain,  time,  expense,  and  general  strain  for  both  patient  and 
operator  in  perfecting  contour  work. 

Dr.  T.  F.  Chupein,  an  advocate  of  the  permanent  separation  of  the 
teeth,  describes  his  method  as  follows  :  — 

"The  mode  of  treating  the  upper  incisors  and  cuspids  is  indicated 
by  the  following  diagram,  Fig.  369. 


Fig.  369. 

"  It  will  be  noticed  that  there  are  semilunar  spaces  cut  from  the 
palatal  surfaces  of  each  tooth.  These  spaces  are  cut  for  the  removal 
of  incipient  decay,  for  its  anticipation,  as  well  as  to  obtain  room  to 
fill  when  decay  is  deep-seated.  To  make  these  spaces  without  muti- 
lating   the   outer  faces  of    the  teeth,  we  proceed  as    follows  :     Two 


Fig.  370. 

teeth  are  well  wedged  apart  by  the  introduction  of  wooden  wedges, 

floss  cotton,  or  rubber,  whichever  seems  best  to  the  operator.     When 

separated  about  the  thirty-second  of  an  inch  or  more,  a  thin  disc  is 

used  on  the  dental  engine.     The  Arthur  disc,  D,  is  about  the  proper 

size,  and  this  is  used  on  the  palato-mesial  and  distal  aspects  of  the 

teeth  being  operated  on,  and  the  cutting  so 

■         shaped  that  the  outer  faces  of  the  teeth  are 

not  encroached  upon.     After  the  enamel  from 

— m — ■  these  surfaces  is  removed,  a  curved  file,  (see 

1^  Fig.    370),    may   be   used  to   curve    out    the 

^m  surface    begun    by  the  disc,  or,  what  is  still 

Fig.  371.  better,  a  small  corundum  point,  mounted  on 

the    right-angle    attachment    of    the    dental 

engine,  and  applied  between  the  two  teeth  to  be  operated  on,  the  head 

of  the  patient  being  well  thrown  back,  so  that  these  surfaces  may  be 


TREATMENT    OF    DENTAL    CARIES. 


445 


readily  reached.  Should  either  of  the  teeth  thus  separated  need  filling, 
the  filling  should  be  done  at  once,  as  more  room  is  had  now  than  if 
the  teeth  are  permitted  to  fall  back  into  their  old  places.  When  two 
are  thus  separated  (and  filled,  if  they  need  filling),  two  more  are 
wedged  apart  and  the  spaces  cut,  as  has  been  described." 

Concerning  the  treatment  of  the  bicuspids  and  molars.  Dr.  Chupein 
says : — 

"These  teeth  are  so  concealed  by  the  lips  that  even  when  pretty 
wide  separations  are  made  between  them  they  present  no  revelation 
of  their  having  been  operated  upon  at  all.  To  separate  the  molars 
and  bicuspids  we  do  not  wedge  them  apart,  as  we  recommend  the  in- 
cisors and  bicuspids  to  be  done  (although  it  would  be  no  detriment 
to  do  so),  but  we  leave  the  teeth  in  the  relation,  one  to  the  other,  that 
we  find  them,  and  separate  them,  so  as  to  leave  a  small  point  of  con- 
tact near  the  gum  margin.  This  point  of  contact,  though  minute,  is 
sufficient  to  keep  the  surfaces  that  have  been  deprived  of  the  enamel 
by  the  disc  or  file  from  again  approaching  each  other,  and  also  serves 
to  protect  the  gum  from  being  irritated  by  the  impaction  of  food. 
Fig.  372  will  illustrate  this  idea. 


''>S^^^^ 


Fig.  372. 


Fig.  373- 


"It  will  be  seen  that  the  filed  surfaces  are  entirely  kept  apart,  and 
that  though  the  tooth  may  change  its  position  or  turn  in  its  socket 
(which  is  not  likely)  the  cut  surfaces  would  be  still  kept  from  close 
proximity.  It  also  permits  a  free  space,  which  is  readily  kept  clean 
by  simply  rinsing  the  mouth.  We  fear  that  it  is  the  careless  manner 
in  which  this  operation  has  been  performed  that  has  brought  it  into 
disrepute,  and  which,  from  this  carelessness,  has  made  many  who  tried 
the  system  abandon  it  as  being  ineffectual,  when  the  fault  lay  more 
in  the  manner  of  its  performance  than  in  the  integrity  of  the  opera- 
tion. Particular  stress  must  be  laid  on  the  non-removal  of  this  point 
of  contact,  otherwise  the  operation  becomes  ineffective.  Indeed,  if 
it  is  removed  we  consider  that  the  operation  would  be  worse  than  if 
nothing  at  all  had  been  done.  To  make  it  entirely  effective  it  should 
be  done  in  anticipation  of  decay  or  when  decay  is  in  its  first  stages — 
when  it  has  not,  or  scarcely  has,  pierced  the  enamel.  If  attempted 
later  the  very  point  of  contact  we  wish  to  preserve  will  be  encroached 
on  by  decay  or  completely  destroyed  by  it.     If  in  anticipation  of 


446  DENTAL    SURGERY. 

decay,  the  cutting  need  be  done  only  from  one  tooth,  and  that  trom 
the  mesial  surface  of  the  furthest  back  tooth.  Fig.  373  will  illustrate 
this. 

"We  would  recommend  that  after  the  teeth  are  separated  a  waxed 
thread  be  passed  through  the  separations  down  to  the  gum,  and  that 
this  should  pass  the  point  of  contact  easily  and  with  a  snap,  to  indi- 
cate that  the  teeth  are  just  held  apart,  but  yet  touch  sufficiently  that 
their  relation  one  to  the  other  should  not  have  been  changed.  The 
thread  or  silk  thus  used  should  not  be  frayed.  This  would  indicate 
roughened  edges  of  enamel  or  too  close  contact.  If  the  former,  it 
should  be  polished  or  cut  smooth  ;  if  the  latter,  the  point  of  contact 
should  be  lessened  so  that  the  string  will  pass  through  readily  and  with 
a  snap.  We  recommend,  too,  that  the  rubber  dam  be  applied  on  these 
teeth  after  these  separations  are  made.  It  will  often  appear  that  all 
decay  has  been  removed.  This  deception  is  caused  by  the  gloss  left 
on  the  cut  surfaces  by  the  saliva,  but  when  the  dam  is  applied  and  the 
surfaces  dried  and  critically  examined,  we  can  know  for  certain  if  all 
the  disorganized  tissue  has  been  removed  or  not. 

"  We  proceed  to  make  these  separations  by  arming  the  dental  engine 
with  a  disc  like  that  represented  at  Fig.  369  d.  We  cut  the  teeth 
through  from  their  buccal  to  their  palatal  asjiect,  if  in  the  upper,  and 
from  their  buccal  to  their  lingual  aspect  if  in  the  lower  jaw.  We  stop 
from  time  to  time  as  we  proceed,  to  see  if  we  have  not  gone  too  far. 
When  nearly  down  to  the  point  of  contact,  near  the  gum,  we  stop  with 
the  engine  and  finish  with  a  file  having  a  round  edge,  like  Fig.  374  ; 
or,  in  case  of  molar  teeth,  with  a  file  like  Fig.  375.  When  finished, 
the  buccal  aspects  of  the  teeth  have  the  appearance  represented  by 
Fig.  376,  while  the  teeth  viewed  from  their  masticating  surfaces  are 
represented  by  Fig.  377. 

"  Should  it  be  found  necessary  to  fill  the  teeth  thus  separated,  an  easy 
approach  to  the  cavity  is  had,  and  the  fillings  as  well  as  the  filed  sur- 
faces can  be  left  highly  polished. 

"The  class  of  teeth  shown  at  Fig.  378  are  such  as  we  recommend  to 
be  treated  as  we  have  described,  for  they  present  broad  surfaces  of 
cintact  on  their  buccal,  masticating,  and  palatal  aspects,  and  are  thus 
rendered  more  prone  to  decay  from  the  ready  lodgment  of  particles  of 
food  between  them. 

"The  other  class  of  teeth,  represented  by  Fig.  379,  rarely  decay, 
because,  as  will  be  seen,  they  touch  only  by  minute  points  of  contact, 
and  are  thus  not  liable  to  decay.  We  do  not  recommend  teeth  of 
this  form  to  be  separated.  If  they  decay  they  should  be  wedged  apart 
and  filled,  and  allowed  to  fall  back  in  their  old  position.  Decay  in 
teeth  of  this  class  will  generally  be  found  above  the  point  of  contact, 


TREATMENT    OF    DENTAL    CARIES.  447 

toward  the  gum.    Should  permanent  separation  be  attempted  with  teeth 


Fig.  376. 


Fig.  377. 


Fig.  378. 


Fig.  374. 


Fig.  375. 


Fig.  379. 


of  this  class  it  might  prove  ruinous,  or  if  effective  the  teeth  must,  from 
their  shape,  be  considerably  mutilated  and  cut  away,  to  prevent  the 


448  DENTAL    SURGERY. 

cut  surfaces  from  again  falling  in  close  ajjposition.  Judgment,  there- 
fore, must  be  used  in  the  separation  of  the  teeth,  although,  as  we  have 
said,  the  operation  is  comparatively  simple. 

"  But  whether  the  teeth  be  separated  with  cutting 'instruments  or  by 
pressure,  the  space  should  be  sufficiently  wide  to  enable  the  dentist  to 
operate  with  ease,  otherwise  it  will  be  impossible  to  remove  the  caries 
and  fill  the  teeth  in  a  proper  manner." 

TREATMENT    OF    DEEP-SEATED    CARIES. 

Filling  teeth  is  one  of  the  most  difficult  operations  the  dentist  is 
called  upon  to  perform  ;  it  often  baffles  the  skill  of  operators  who  have 
been  in  practice  many  years.  It  is  advisable  only  under  certain  cir- 
cumstances, and  when  the  operation  is  performed  without  due  regard 
to  these  it  must  be  productive  of  injury  rather  than  benefit.  It  is  the 
only  certain  remedy  that  can  be  applied  for  arresting  the  progress  of 
deep-seated  caries ;  but  to  be  effective  it  must  be  executed  in  the  most 
thorough  and  perfect  manner.  The  preservation  of  a  tooth  may  be 
regarded  as  comparatively  certain  when  well  filled,  and  with  a  suitable 
material,  if  it  be  afterward  kept  constantly  clean.  At  any  rate,  it  is 
not  likely  ever  again  to  be  attacked  by  caries  in  the  same  place.   .  _ 

On  this  highly  important  operation  Dr.  E.  Family  thus  remarks : 
"  If  preservation  is  as  good  as  a  cure,  this  is  as  good  as  both  ;  for  the 
operation  of  filling,  when  thoroughly  performed,  is  both  preservation 
and  cure.  And  yet  it  must  never  be  forgotten  that  this  assertion  is 
true  only  in  those  instances  in  which  the  operation  is  well  and  properly 
done ;  and  perhaps  it  is  imperfectly  and  improperly  performed  more 
frequently  than  any  other  operation  on  the  teeth. 

"There  are  reasons  for  this  fact,  into  which  every  ambitious  and 
honorable  practitioner  will  carefully  inquire.  Although  the  books  are 
explicit  on  this  point,  I  deem  it  sufficiently  important  to  deserve  a  few 
additional  remarks.  The  following  considerations  are  essential,  and, 
therefore,  indispensable  to  success  in  this  department  of  practice. 
Firstly.  The  instruments  used  must  be  of  the  proper  construction  and 
variety.  Secondly.  The  material  employed  must  be  properly  prepared 
as  well  as  properly  introduced.  Thirdly.  The  cavity  which  receives 
the  filling  must  be  so  shaped  as  to  retain  it  in  such  a  manner  as  to 
exclude  not  only  solids,  but  all  fluids,  and  even  the  atmosphere  itself. 
Fourthly.  The  surface  of  the  filling  must  be  left  in  such  condition  as 
to  place  it  beyond  the  reach  of  injury  from  food  and  other  mechanical 
agents  with  which  it  necessarily  comes  in  contact.  Fifthly.  The  tooth 
thus  filled  should  be  free  from  pain  and  every  known  cause  of  internal 
inflammation." 

It  is  important  that  the  operation  be  performed  before  the  disease 


TREATMENT    OF    DENTAL    CARIES.  449 

has  reached  the  pulp-cavity ;  after  this,  the  permanent  preservation  of 
the  tooth  may  be  regarded  as  more  or  less  questionable.  Still,  under 
favorable  circumstances  the  author  believes  it  may,  in  the  majority  of 
cases,  be  performed  with  success.  But,  as  the  propriety  and  manner 
of  filling  a  tooth  after  the  pulp  has  become  exposed  will  hereafter  come 
up  for  special  consideration,  as  well,  also,  as  the  operation  of  filling  the 
pulp-cavity  after  the  destruction  of  the  pulp,  it  will  not  be  necessary 
to  enlarge  upon  these  subjects  at  this  time. 

Materials  Employed  for  Filling  Teeth. — Among  the  articles 
which  have  been  employed  for  filling  teeth  are  gold,  platina,  silver, 
tin,  lead  ;  fusible  alloys  of  tin,  lead,  bismuth,  and  cadmium  ;  amal- 
gams, gutta-percha,  oxychlorid  of  zinc,  oxyphosphate  of  zinc,  and 
various  preparations  of  the  gum  resins.  Of  these  no  single  one  can  be 
said  to  unite  all  the  requirements  of  a  perfect  material  for  filling, 
which  may  be  enumerated  :  i.  Resistance  to  the  mechanical  action 
of  mastication.  2.  Resistance  to  the  chemical  action  of  the  mouth. 
3.  Facility  of  introduction  and  consolidation.  4.  Harmony  of  color. 
5.  Absence  of  all  galvanic,  chemical,  or  vital  action  upon  the  teeth 
or  the  general  system.  6.  Absence  of  all  heat-conducting  property. 
7.  Absence  of  shrinkage. 

Gold  Foil. — To  the  use  of  this  material,  when  properly  prepared, 
there  is  the  least  possible  objection,  perfectly  answering  the  first, 
second,  fifth,  and  seventh  requirements,  to  a  great  extent  the  third, 
if  in  skillful  hands,  but  deficient  in  the  fourth  and  sixth.  No  better 
material  is  wanted  for  the  operation.  A  tooth  may  be  so  filled  with 
it  as  to  secure,  in  almost  every  case,  its  permanent  preservation.  It 
should,  however,  be  perfectly  pure,  be  beaten  into  thin  leaves,  and 
well  annealed  by  the  manufacturer  before  it  is  used.  When  prepared 
in  this  manner,  it  may  be  pressed  into  all  the  inequalities  of  the  cavity, 
and  rendered  so  firm  and  solid  as  to  be  impermeable  to  the  fluids  of 
the  mouth. 

Although  there  may  be  no  difference  in  the  purity  of  the  gold  and  the 
thickness  of  the  leaves,  yet  a  marked  difference  will  be  found  to  exist 
in  the  malleability  and  toughness  of  the  foil  of  different  beaters. 

The  art  of  preparing  gold  for  filling  teeth  is  an  exceedingly  nice 
and  difficult  one,  and  is  believed  to  have  attained  greater  perfection  in 
the  United  States  than  in  any  other  country  ;  at  least,  this  fact  is  so 
generally  admitted  that  many  of  the  most  eminent  European  practi- 
tioners procure  nearly  all  they  use  from  America.  (See  process  of 
manufacture  in  "Harris'  Med.  and  Dent.  Dictionary.") 

The  principal  preparations  of  gold  used  for  filling  teeth  are  the  non- 
cohesive,  the  cohesive,  and  the  sponge  or  crystal  gold. 

Nofi-cohesive  or  Soft  Gold  Foil. — This  is  a  preparation  of  leaf  gold 
29 


45©  DENTAL    SURGERY. 

which  does  not  possess  the  property  of  cohesion  to  such  a  degree  that 
the  leaves  can  be  firmly  united  on  being  pressed  together  with  moder- 
ate force,  and  is  introduced  on  the  wedging  principle,  the  cavity  for 
its  reception  being  made  of  such  a  form  or  shape  as  will  retain  the 
mass  after  it  has  been  properly  introduced  and  consolidated. 

Non-cohesive  gold  foil  is  employed  in  different  forms,  such  as  the 
rope,  the  tape  or  ribbon,  the  cylinder,  the  pellet,  and  the  mat  or 
block. 

The  thickness  of  the  leaves  is  determined  by  the  number  of  grains 
each  contains,  and  is  designated  by  numbers  on  the  books  between  the 
leaves  of  which  they  are  placed  after  having  been  properly  annealed. 
These  numbers  range  from  3  to  240.  A  book  containing  a  quarter  of 
an  ounce  of  No.  4  will  have  thirty  leaves  in  it.  Some  dentists  use  foil 
varying  in  numbers  from  4  up  to  20,  and  even,  of  late,  to  120, 
while  others  confine  themselves  to  a  single  number.  If  but  one 
number  of  the  non-cohesive  be  used,  5  will  perhaps  be  found  better 
than  any  other.  The  author  has  used  Nos.  4,  5,  6,  8,  10,  and  15,  but 
he  prefers  4  and  5,  and  is  decidedly  of  opinion  that,  in  a  large  major- 
ity of  cases,  a  better  filling  can  be  made  with  the  first  two  numbeis 
than  any  of  the  others.  There  may  be  cases  in  which  higher  numbers 
can  be  more  advantageously  employed;  as,  for  instance,  in  cavities 
which  are  very  large,  and  where  the  operation  of  filling  has  extended 
beyond  the  walls  of  the  cavity,  owing  to  the  difficulty  of  securing  a 
perfect  adaptation. 

Cohesive  Gold  Foil. — This  is  a  preparation  of  leaf  gold  which  ])os- 
sesses  the  property  of  cohesion  to  such  a  degree  that  the  leaves  readily 
and  firmly  unite  on  being  pressed  together  with  moderate  force. 

Although  one  or  two  others  claim  priority  in  the  discovery  of  the 
advantages  now  derived  from  the  use  of  cohesive  gold  foil,  yet  the 
credit  is  certainly  due  to  Dr.  Robert  Arthur,  as  he  was  not  only  the 
first  to  demonstrate  the  applicability  of  this  form  of  gold  in  filling 
teeth,  but  in  a  series  of  well-written  articles*  he  overcame  the  objec- 
tions which  were  at  first  urged  against  it,  and  proved  that  its  great 
cohesive  property  rendered  it  a  valuable  adjunct  in  the  preservation 
oi  the  teeth.  This  form  of  foil  is  so  cohesive  that  any  number  of 
pieces  may  be  welded  one  to  another  ;  thus  a  part,  or  even  the  whole 
of  the  crown  of  a  tooth  may  be  built  up  with  it.  The  same  property 
may  to  a  limited  extent  also  be  imparted  to  foil  manufactured  in  the 
ordinary  way  of  reannealing.  This  property  is  peculiarly  valuable 
in  many  cases  where  it  becomes  necessary  to  build  up  a  large  portion 
of  the  crown  of  a  tooth;  but  when  it  is  used,  instruments  having  ser- 

*"  A  Treatise  on  the  Use  of  Adhesive  Gold  Foil,"  1857. 


TREATMENT    OF    DENTAL    CARIES.  45 1 

rated  points  are  required,  like  those  employed  in  the  use  of  crystal  or 
sponge  gold. 

Crystal  or  Sponge  Gold  has  been  employed  by  dentists  for  filling 
teeth  for  a  number  of  years.  The  author  has  used  it  in  a  number  of 
cases  with  very  satisfactory  results.  Since  the  publication  of  the 
fifth  edition  of  this  work,  the  properties  of  crystal  or  sponge  gold 
have  been  more  thoroughly  and  extensively  tested,  and  the  result 
has  fully  confirmed  the  favorable  opinion  entertained  by  us  with 
regard  to  its  value.  The  author  was  acquainted  with  several  of  the 
most  skillful  operators  in  the  United  States  who  used  it  almost 
exclusively  in  their  practice  for  several  years,  and  saw  fillings  made 
by  some  of  these  gentlemen  which,  for  beauty  and  solidity,  he 
does  not  think  could  be  surpassed.  This  form  of  gold  has  a  spongy 
texture,  being  composed  of  crystals,  and  widely  differs  from  foil  or 
leaf  gold.  The  crystals  possess  the  property,  when  pressed  firmly 
against  each  other,  of  welding  and  becoming  as  solid  and  almost  as 
incapable  of  disintegration  or  crumbling  as  a  piece  of  bullion  or  coin. 
This  property  enables  a  skillful  manipulator  to  supply  almost  any  loss 
which  a  tooth  may  have  sustained,  even  to  the  building  up  of  an  entire 
crown.  Still,  it  will  never  supersede  the  use  of  cohesive  and  non- 
cohesive  gold  foils,  as  there  are  many  cases  in  which  leaf  gold  can  be 
used  more  advantageously  and  with  more  facility.  Nor  will  the 
employment  of  it,  in  the  opinion  of  the  author,  ever  become  universal, 
for  the  reason  that  more  care  and  skill  are  required  to  make  a  good 
filling  with  it  than  with  leaf  gold,  especially  when  the  cavity  in  the 
tooth  is  difficult  of  access.  Filling  with  crystal  gold  is  more  tedious 
than  the  same  operation  with  ordinary  foil. 

Experiments  have  been  made  with  silver,  platinum,  and  aluminium, 
but  with  unsatisfactory  results.  They  are  less  malleable  than  gold, 
and  therefore  cannot  be  made  so  thin ;  at  the  same  time  they  have  not 
the  softness  of  tin,  hence  they  work  harshly  under  the  plugger.  An 
additional  objection  to  silver  is  its  liability  to  undergo  chemical  change, 
being  in  this  respect  greatly  inferior  to  pure  tin.  Platinum,  while 
it  possesses  indestructibility,  in  this  respect  beiiig  even  superior  to 
gold,  is  deficient  in  other  properties  as  a  filling  material,  as  it  cannot 
be  welded  with  facility,  is  difficult  to  manipulate  in  the  form  of  foil 
on  account  of  its  stiffness  and  harshness,  and  hence  cannot  be  adapted 
and  condensed  in  such  form  to  the  surface  of  a  cavity.  A  form  of 
platinum  known  as  platinum  sponge  has  been  employed  with  greater 
facility  than  platinum  in  leaf  form,  but  it  requires  skillful  manipula- 
tion, and  its  cohesive  property  is  readily  destroyed  by  the  slightest 
degree  of  moisture.  Platinum  has  also  been  used  in  the  form  of  foil 
coated  with  a  considerable  thickness  of  pure  gold,  and  it  is  claimed 


452  DENTAL    SURGERY. 

that  by  such  a  combination  a  denser  filling  can  be  made,  and  also  one 
conforming  to  the  color  of  the  tooth  in  which  it  is  placed.  The 
peculiarity  of  aluminium,  in  this  relation,  is  the  impossibility  of  weld- 
ing its  leaves  by  pressure;  even  under  the  gold-beater's  hammer  it 
forms  loose  scales,  which  no  annealing  can  make  adherent. 

Tin  Foil. — This,  when  chemically  pure  and  properly  prepared,  is 
less  objectionable  for  filling  teeth  than  most  of  the  articles  hereafte?^ 
enumerated.  Under  favorable  circumstances,  if  skillfully  introduced 
it  will  prevent  the  recurrence  of  caries.  The  greatest  objection,  per 
haps,  to  the  use  of  tin  foil  as  a  filling  material  is  its  softness  and  con 
sequent  inability  to  withstand  the  friction  of  mastication  for  manj 
years.  When  used  in  cavities  not  so  exposed  it  answers  a  good  pur^ 
pose  as  a  filling  material,  as  it  is  unalterable  by  reagents.  Being  an 
inferior  conductor  of  heat  it  is  tolerated  in  sensitive  teeth  in  cases 
where  a  better  conductor,  such  as  gold,  would  not  be.  It  is  also 
regarded  as  valuable  in  soft  teeth,  and  some  regard  it  as  possessing 
advantages  over  gold  for  filling  in  such  teeth,  and  also  in  the  tempor- 
ary teeth,  being  easy  of  introduction  and  in  accord  with  the  tooth- 
structure.  On  account  of  the  qualities  referred  to,  tin  foil  is  some- 
times employed  for  lining  cavities  to  be  filled  with  gold.  It  is 
prepared  as  a  filling  material  in  the  form  of  foil,  the  leaves  varying  in 
thickness  from  No.  4  to  No.  20.  The  numbers  from  4  to  10  are  mostly 
used,  and  it  is  manipulated  in  the  same  manner  as  non-cohesive  gold 
foil. 

Lead  is  far  more  objectionable  than  tin,  as  it  is  more  easily  decom- 
posed by  the  secretions  of  the  mouth  ;  its  introduction  into  the  stomach 
might  be  productive  of  serious  injury  to  the  general  health  of  the 
patient.     But,  happily,  the  article  is  now  seldom,  if  ever,  used. 

Amalgam,  formerly  known  by  the  name  of  mineral  cement,  or  litho- 
deon,  is  usually  composed  of  about  equal  parts,  by  weight,  of  pure  tin, 
silver,  and  varying  proportions  of  zinc  and  platinum — and  sometimes 
gold  and  copper — the  zinc,  about  one  to  three  percent.,  constituting 
a  most  important  element  in  controlling  shrinkage  and  preventing 
oxidation.  The  gold  is  not  especially  valuable,  and  when  used  in  an 
amalgam  from  one  to  four  per  cent,  is  sufficient.  These  metals  are 
melted  in  a  crucible  and  poured  into  ingots,  which  are  then  cut  up 
with  a  file  into  filings.  These  filings  are  mixed,  after  the  cavity  in 
the  tooth  is  prepared  for  the  filling,  with  about  thirty-three  and  one-third 
per  cent,  of  distilled  mercury,  and  incorporated  to  the  consistency  of 
a  thick  paste.  The  mass  is  then  thoroughly  washed  with  alcohol,  to 
which  is  added  a  few  drops  of  a  strong  solution  of  chloride  of  zinc. 
The  excess  of  mercury  is  then  removed  by  twisting  the  mass  in  a  piece 
of  chamois  skin  or  strong  muslin.     It  is  also  recommended  to  press 


TREATMENT    OF    DENTAL   CARIES.  453 

the  mass  quite  thin,  after  it  is  removed  from  the  chamois  skin,  with  a 
strong  i^air  of  flat  pliers,  in  order  to  remove  still  more  of  the  mercury. 
Caution  should,  however,  be  used  to  avoid  pressing  out  too  much  mer- 
cury. The  mass,  when  introduced,  should  be  about  the  consistency 
of  ordinary  putty.  The  cavity  should  be  prepared  with  as  much  care 
as  for  a  gold  filling,  and  moisture  prevented  from  coming  in  contact 
with  it.  When  the  cavity  approaches  near  to  the  pulp,  some  non- 
conducting substance,  as  Hill's  Stopping,  should  be  applied  between 
the  amalgam  and  the  bottom  of  the  cavity.  After  the  filling  has 
become  sufficiently  hard,  its  surface  should  be  carefully  finished  by 
filing  and  burnishing. 

Dr.  Bonwill  gives  the  following  directions  for  working  amalgam 
composed  of  silver,  tin,  and  gold  ;  from  five  to  seven  per  cent,  of  the 
latter  he  considers  sufficient : — 

"As  soon  as  the  first  piece  of  alloy  is  inserted,  a  wad  of  bibulous 
paper  (Japanese)  as  large  as  the  cavity  is  placed  thereon,  and  an  oval- 
pointed  steel  instrument  is  pressed  upon  it  with  great  force,  to  crowd 
out  the  superabundant  mercury.  Go  on  adding  alloy  and  more  paper 
until  the  cavities  are  crowded  full  from  cuspid  to  molar,  leaving  no 
intervening  space.  Direct  pressure  is  not  as  efficacious  as  rubbing  the 
amalgam  in  with  a  burnisher  over  the  paper,  which  drives  the  mercury 
out  at  all  points.  No  rough-faced  instrument  should  be  used  ;  smooth 
burnishers  and  oval-faced  only,  on  the  same  principle  as  in  rubbing  in 
gold  by  the  action  of  the  mechanical  mallet.  When  you  have  reached 
nearly  the  proper  fullness,  use  the  flatter  burnishers  entirely,  to  not 
only  add  the  alloy,  but  to  be  sure  that  the  mercury  is  carried  to  the 
edges.  To  do  this  you  must  not  lose  a  moment ;  and  the  alloy  should 
not  have  too  much  gold  in  it,  or  you  cannot  undertake  so  much  at  one 
sitting." 

Describing  the  operation  of  filling  with  amalgam  the  superior  cuspid 
decayed  on  its  distal  surface,  with  the  first  and  second  bicuspids  on 
the  anterior  distal,  and  grinding  surfaces  gone  so  far  as  to  leave  noth- 
ing standing  but  the  buccal  and  palatal  walls,  and  to  this  add  the  first 
molar  with  its  anterior  wall,  crown,  and  distal  surfaces  as  seriously 
involved,  the  same  writer  continues  : — 

"By  the  time  you  have  gotten  all  the  cavities  full,  you  must  com- 
mence at  once  to  divide  between  each  and  contour. 

"  It  will  be  found  that  when  the  opposite  teeth  are  made  to  antag- 
onize with  it,  great  care  must  be  used  to  keep  from  dislodging  any 
portion  of  this  large  mass ;  therefore,  before  the  division  on  the 
approximal  surfaces  is  made,  see  that  the  articulation  is  absolutely  cor- 
rect. Then  with  a  broach  with  small  point  turned,  scratch  away  all 
the  cervix  until  the  tool  reaches  from  both  buccal  and  palatal  surfaces. 


454 


DENTAL    SURGERY. 


and  the  divisions  are  clear  to  nearly  the  grinding  surface.     Now,  with 
a  very  thin  knife  or  saw  you  can  carefully  divide  the  fillings,  to  make 

Fig.  380. 


each   tooth   distinct.      In    this    proceeding 
great  care  must  be  exerted  or   the  contour 
will  be  broken.     When  this  has  been  done, 
shape  with  proper   instruments,  leaving   all 
the  grinding  surface  in  contact  as  broadly  as 
possible,   so  that  when    the   teeth  go  back 
again    to   their   positions    from   which   the 
gutta-percha  had  moved  them,  the  food  can- 
not  wedge   down     between   them.      Where 
cavities  are  obscure  on  approximal  surfaces, 
get  the  alloy  as  nearly  in  place  as  you  can, 
and  a  wad  of  paper  will  be  sure  to  force  it 
down.     Besides  those  cases  with  more  or  less 
walls  for  support,  in  those  where  much  of  the  cusps  of  either 
wall  is  gone  the  alloy  can  be  added  and  compressed  easily  and 
surely.     Entire  or  partial  crowns  can  be  secured  in  a  few 
minutes.      Be  sure  that  the  alloy  is  not  allowed  to  remain 
projecting   over   the  free  margin  of  the  contour  before  the 
patient  leaves.     Then  but   little  dressing  of  the  contour  is 
necessary  when  the  operations  are  filed  and  finished." 

Fig.  380  represents  a  set  of  what  are  known  as  Arrington's 
amalgam  instruments.  Amalgam  becomes  hard  by  the  crys- 
tallization of  the  mass  and  the  evaporation  of  the  mercury ; 
hence,  without  a  well-prepared  form  is  used,  and  great  care 
exercised  in  its  amalgamation  and  introduction,  a  filling  of 
this  material  may  either  contract  or  become  porous  ;  and  when 
the  latter  is  the  case  the  oxidation  extends  to  the  tooth-struc- 
ture, which  becomes,  as  a  consequence,  discolored. 
Amalgams,  unlike  the  plastic  gutta-percha  and  zinc  preparations,  do 


TREATMENT    OF    DENTAL    CARIES.  455 

not  adhere  to  the  walls  of  the  tooth-cavity;  hence,  in  their  use  it  is 
necessary  that  attention  should  be  paid  to  the  form  of  cavity  into 
which  they  are  to  be  introduced;  and  as  they  are  often  employed  for 
filling  cavities  of  a  shallow  form,  and  with  frail  walls,  under-cuts  and 
dovetails  are  required  for  the  retention  of  such  fillings.  From  the 
tendency  of  the  amalgams  of  mercury  to  assume  a  spheroidal  shape 
and  separate  from  the  margins  of  a  cavity,  sharp  angles  and  pits  are 
objectionable.  The  addition  of  palladium  to  an  amalgam  may  prevent 
such  shrinkage,  but  adds  to  the  discoloration,  and  the  rapidity  of  its 
setting  is  such  as  to  evolve  a  sufficient  amount  of  gas  to  cause  an  ex- 
plosion with  emission  of  light.  Such  an  accident  may  be  avoided  by 
gradually  adding  the  palladium  powder  to  the  compound  and  using 
very  small  pieces  for  introduction,  and  their  rapid  insertion,  each 
piece  being  well  compounded  as  it  is  added  to  the  mass.  It  is  claimed 
that  while  the  surface  of  a  palladium  amalgam  changes  to  a  black  color, 
it  does  not  stain  the  tooth-structure,  and  that  it  is  the  most  durable  of 
the  amalgams.  An  excess  of  silver  will  also  cause  an  amalgam  to 
blacken  and  stain  the  tooth-structure.  Silver  and  copper  control  the 
change  in  form,  as  the  solid  particles  of  copper  which  remain  have  an 
amalgamated  surface  only,  which  prevents  the  change  in  form  common 
to  a  homogeneous  mass.  Platinum  imparts  toughness  and  edge- 
strength  to  an  amalgam.  Gold  makes  an  amalgam  composed  of  tin, 
silver,  and  mercury  unclean,  although  an  amalgam  of  pure  gold  and 
mercury  alone  is  white  and  clean,  but  is  not  adapted  for  a  filling 
material. 

A  better  class  of  amalgamis  now  in  use  appears  to  change  bulk  to  a 
less  degree  and  to  preserve  their  light,  silvery  color  much  better  than 
the  older  forms  ;  hence,  the  former  objections  to  this  filling  material 
appear  to  have,  in  a  great  measure,  been  overcome.  The  ease  with 
which  amalgam  fillings  can  be  introduced  no  doubt  often  leads  to  care- 
lessness in  the  manipulation  of  this  material,  but  it  should  be  remem- 
bered that  to  obtain  the  best  results  from  it  the  cavity  in  which  it  is 
placed  should  be  as  carefully  prepared  as  for  a  gold  filling,  and  also 
that  perfect  dryness  is  essential  to  its  adaptation  and  durability. 

There  exist  some  differences  of  opinion  concerning  the  necessity 
for  washing  amalgam,  prior  to  its  introduction,  with  alcohol  and  other 
fluids,  some  contending  that  by  so  doing  it  is  impossible  to  remove 
all  the  moisture  in  time  for  its  insertion.  Sufficient  mercury  should 
be  allowed  to  remain  in  the  mass  as  will  permit  of  its  being  manipu- 
lated without  crumbling,  and  when  it  is  inserted  over  a  sensitive  sur- 
face or  in  proximity  to  the  pulp  of  a  tooth,  some  intervening  sub- 
stance, such  as  Hill's  Stopping  or  oxyphosphate  of  zinc,  should  be 
placed  between  the  sensitive  surface  and  the  filling. 


456  DENTAL    SURGERY. 

It  is  claimed  that  continuous  pressure  with  the  burnisher  upon  the 
surface  of  an  amalgam  filling  during  its  setting  will  prevent  its  tendency 
to  separate  from  the  walls  of  the  cavity,  and  insure  better  results  from 
its  use.  It  is  also  very  necessary  that  the  margins  of  amalgam  fillings 
should  be  well  defined,  as,  owing  to  its  brittle  nature,  thin,  overhang- 
ing portions  are  liable  to  break  away,  leaving  imperfections  which  may 
soon  prove  injurious  to  the  filling.  After  an  amalgam  filling  has 
become  hard  (and  during  this  hardening  process  the  patient  should 
be  warned  against  masticating  upon  it)  the  surface  should  be  as  care- 
fully prepared  and  polished  as  that  of  gold  filling. 

The  objections,  therefore,  urged  against  amalgam  are,  that  it  oxid- 
izes and  blackens ;  that  the  tooth-structure  with  which  it  remains  in 
contact  becomes  discolored  ;  that  it  contracts  in  hardening,  allowing 
the  secretions  to  make  their  way  around  the  filling.  Of  late  years  it 
has  been  urged  that  it  is  incompatible  with  tooth-structure,  and  that 
the  mercury  might  act  injuriously  on  the  system.  These  objections 
are  characteristic  of  most  of  the  amalgams  now  on  the  market, 
although  in  a  k\v  notable  exceptions  they  have  been  almost  entirely 
overcome  ;  but  there  is  no  good  reason  why  amalgam  should  be  in- 
compatible with  tooth-structure,  or  that  the  small  amount  of  mercury 
imprisoned  in  this  alloyed  mass  should  possibly  produce  any  mercurial 
effects.  There  is  good  reason,  therefore,  for  believing  it  to  be,  in 
these  respects,  perfectly  inert.  The  use  of  amalgam  is  contraiiuUcated 
in  all  teeth  which  can  be  filled  with  gold — in  the  front  teeth  on 
account  of  its  color,  and  in  pulp-cavities  on  account  of  the  difficulty 
of  introduction  into  small  canals.  Various  opinions  are  held  as  to  the 
indications  for  the  use  of  amalgam.  In  our  own  opinion  it  is  one  of 
the  most  valuable  materials  for  some  operations,  as,  for  instance,  in 
cavities  so  difficult  of  access  as  to  render  the  introduction  of  a  perfect 
gold  filling  doubtful,  and  where  the  operation  would  be  long,  tedious, 
and  difficult  to  both  patient  and  operator,  were  gold  used.  Amalgam 
is  also  employed  by  some  for  filling  roots,  on  account  of  the  ease  and 
facility  with  which  it  can  be  carried  to  the  end  of  the  root-canal. 

Fig.  381  represents  some  forms  of  amalgam  Carriers  and  Fillers. 

Several  of  these  instruments  are  constructed  with  fixed  points,  cov- 
ered by  a  tube,  which  projects  to  form  a  cup  for  the  amalgam,  and 
recedes  so  that  the  points  work  through  as  Pluggers  to  force  it  into  the 
cavity,  one  being  half-curve,  another  double-end,  giving  two  angles, 
and  another  straight.  One  has  a  fixed  tul)e  with  spring  plunger  to 
force  in  the  amalgam.  A  Loadstone  Carrier  and  Plugger  has  a  double 
end,  one  point  of  which  is  so  prepared  as  to  attract  amalgam,  which 
will  adhere  to  it  while  being  conveyed  to  the  cavity  in  the  tooth;  the 
reverse  end  is  made  as  a  Filler. 


TREATMENT    OF    DENTAL    CARIES. 


457 


P  *V 


Fig.  382  represents  a  Mercury  Holder 
for  convenient  preparation  of  amalgam. 

Fig.  383  represents  a  set  of  Weston's 
Amalgam  Pluggers. 

Gutta-percha  and  HilV s  Stopping. — 
Gutta-percha  is  an  excellent  material  for 
temporary  fillings.  It  may  be  made 
harder,  whiter,  and  less  contractile  by 
incorporating  with  it  some  very  fine 
powder  of  feldspar,  silex,  lime,  or  mag- 
nesia. A  very  excellent  preparation 
known  as  HiW  s  Stopping  is  made  by 
mixing  gutta-percha  with  as  much  of  the 
following  powder  as  it  will  hold  without 


Fig.  382. 


I 

'1 


Fig.  3S1. 


becoming  brittle  \  quicklime,  two  parts, 
very  fine  quartz  and  feldspar,  one  part 
each.  Prepared  gutta-percha  and  Hill's 
Stopping  are  introduced  in  small  pieces 
by  first  warming  on  a  porcelain  or  metal- 
slab,  over  an  alcohol  lamp,  until  they 
become  plastic  enough  to  be  readily 
pressed  into  the  cavity  and  to  adhere  to 
its  walls.  As  soon  as  the  cavity  is  filled, 
an  instrument  having  a  condensing  point 
large  enough  to  cover  the  entire  surface 
of  the  filling  should  be  applied  and 
kept  in  position  until  the  mass  has  be- 
come cool. 


45  S 


DENTAL    SURGERY. 


Fig.  384  represents  Dr.  Howe's  Thermoscopic  heater  for  scientific- 
ally softening  gutta-percha,  which  is  described  as  follows: — 

''  The  Heater  (illustrated  natural  size)  is  made  of  steatite,  which 
absorbs  heat  slowly  and  retains  it  a   long  while.     A  non-conducting 


Fig.  383. 


handle  of  wood  allows  the  Heater  to  be  held  over  the  flame,  as  shown. 
In  a  small  recess  a  quantity  of  metal.  A,  fusible  at  212°  F. ,  is  placed. 
When  this  melts,  the  Heater  may  be  set  on  the  bracket-table,  and 
gutta-percha  pellets,  1,1,  will  be  found  to  be  safely  and  suitably  soft- 
ened for  use.     Low-heat  pellets,  as   2,   3,  or  4,  are  placed  at  various 

distances      from 
A,  according  to 
their     softening 
points,  to  insure 
their  being  heat- 
ed    to     exactly 
suitable  temper- 
atures. For  high- 
heated  pellets,  A 
is  melted,  poured 
out,  and  the  230°  F.  button  B  substituted.     The 
Thermoscopic  Heater  thus  enables  the  dentist  to 
heat  gutta-percha  of  whatever  grade  to  its  proper 
softening   point  with  the  scientific  certainty  of 
imiformly  producing   suitable    plasticity   without 
danger  of  injuring  the  sensitive  material,  which 
is  so   frequently  burned,   smoked,    or   otherwise 
impaired  by  the  crude  methods  in  common  use,  meeting  every  need." 
The    preparations    uf  gutta-percha    now  used   for   filling    materials 
possess  different  grades  uf  plasticity,  so   that  a  filling  may  be  com- 
menced with  one  that  softens  at  a  low  temperature,  and  finished  with 


TREATMENT    OF    DENTAL   CARIES. 


459 


another  which  requires  more  heat  to  render  it  plastic,  and  hence 
becomes  harder.  For  cavities  situated  on  the  approximal  surfaces 
of  the  teeth  and  extending  below  the  margin  of  the  gum,  gutta-percha 
preparations  appear  to  answer  a  good  purpose  in  resisting  the  dissolving 
action  of  the  acid  from  the  inflamed  gum.  When  the  gutta-percha 
preparation  is  made  plastic  enough  to  adhere  to  the  walls  of  a  cavity, 
by  passing  it  through  the  flame  of  a  spirit-lamp,  care  is  required  that 
it  should  be  evenly  heated  and  not  burnt.  By  using  the  lower  grade 
over  sensitive  portions  of  a  cavity  less  pain  is  experienced  from  the 
heat,  and  after  the  cavity  is  filled  with  the  higher-grade  material  the 
surplus  can  be  removed  with  thin  steel  or  platinum  spatulas  heated  to 
the  required  degree,  and  the  surface  made  smooth  by  passing  over  it  a 
burnisher.  Chloroform  applied  to  the  surface  of  a  gutta  percha  filling 
will  give  a  smooth  finish,  but  may  render  such  a  surface  less  durable  on 
account  of  its  dissolving  action. 

Fig.  385  represents  a  set   of  Dr.  W.  A,  Bronson's  gutta-percha  in- 
struments. 


0 


I  I 


Fig.  385. 


Zinc  Preparations. — A  mixture  of  chlorid  of  zinc  and  oxid  of  zinc 
has  been  much  used  under  the  various  names  of  oxychlorid  of  zinc,  os- 
artificial,  osteo- dentine,  osteo-plastic,  mineral  paste,  etc.  Quackery 
has  seized  it  with  eagerness,  and  plastered  up  many  teeth  with  a  mortar 
even  more  conveniently  used  than  amalgam.  Although  in  some  few 
cases  it  may  resist  the  action  of  the  secretions  of  the  mouth,  it  will 
not  answer  for  a  permanent  filling.  The  friction  of  mastication  soon 
destroys  it,  and  in  approximal  cavities  it  frequently  crumbles  away  in 
a  few  weeks  or  months.  Still,  as  a  temporary  filling,  it  may,  if  em- 
ployed with  caution  and  judgment,  be  found  useful,  and  for  certain 
cases  very  valuable.  It  has  been  used  with  success  for  filling  the  pulp- 
cavities  of  the  teeth.  It  has  also  been  applied  to  partially  exposed 
nerves,  and  in  some  favorable  cases  successfully,  but  its  use  for  such 
a  purpose  is  very  uncertain,  as  the  escharotic  action  of  the  zinc 
chlorid  may  produce  death  of  the  pulp.     In  the  combination  of  the 


460  DENTAL   SURGERY. 

oxychlorid  ingredients  the  oxid  of  zinc  is  usually  mixed  with  some 
siliceous  substance,  to  increase  the  hardness,  and  the  chlorid  of  zinc 
is  diluted  Avith  water.  When  the  powder  and  liquid  are  combined  a 
cement  results,  which  forms  hydrated  oxychlorid  of  zinc  by  the  taking 
up  of  some  of  the  water  as  a  base.  Some  prefer  mixing  the  oxy- 
chlorid in  the  form  of  a  thin  paste,  and  after  adapting  it  carefully  to 
the  bottom  and  sides  of  the  cavity,  or  over  a  sensitive  surface,  to 
complete  the  operation  with  a  paste  of  thicker  consistency.  A  warm 
burnisher  will  hasten  the  setting  of  the  oxychlorid  and  apparently 
increase  its  hardness.  The  application  of  talc  (soapstone)  in  the 
form  of  a  properly-shaped  point,  which  may  be  heated,  or  in  the  form 
of  powder,  appears  to  improve  the  surface  of  such  a  filling  by  render- 
ing it  less  permeable  to  moisture.  On  account  of  the  oxychlorid  pre- 
paration being  acted  on  by  weak  acid  and  even  alkaline  solutions,  it 
cannot  be  depended  upon  for  a  permanent  filling  material,  and  will 
frequently  dissolve  away  in  a  few  weeks  or  months,  especially  if 
introduced  near  to  or  beneath  the  margin  of  the  gum.  It  often  answers 
a  good  purpose  when  applied  to  sensitive  dentine,  but,  like  the  chlorid 
of  zinc,  one  of  its  ingredients,  its  application  causes  considerable  pain 
for  a  short  time.  It  has  also  been  employed  for  bleaching  discolored 
dentine,  and  as  an  interposing  substance  between  a  thin  wall  of  cavity 
and  darker,  but  more  durable,  filling  material,  such  as  amalgam. 

Of  late  years  various  preparations,  known  as  oxyphosphates  of  zinc, 
have  been  introduced,  composed  of  the  basic  oxid  of  zinc  and  glacial 
phosphoric  acid.  One  of  the  zinc  preparations  is  composed  of  the 
nitrate  of  zinc  and  phosphoric  acid.  The  oxyphosphate  prepara- 
tions are  preferable  to  the  oxychlorids  on  account  of  their  being  less 
irritant  to  the  pulp  and  more  durable,  especially  when  placed  about 
the  necks  of  the  teeth.  They  have  also  the  advantage  over  the  oxy- 
chlorids of  greater  hardness,  but  it  should  be  remembered  that  all  of 
the  zinc  preparations  are  liable  to  be  dissolved  by  the  fluids  of  the 
mouth,  and  hence  are  not  so  reliable  for  temporary  fillings  as  gutta- 
percha, especially  the  form  known  as  Hill's  Stopping,  particularly  where 
such  fillings  extend  beneath  the  margin  of  the  gum  to  the  cementum. 

The  oxyphosphates  mix  less  readily  than  the  oxychlorids,  and 
require  more  care  in  the  combination  of  the  powder  and  liquid.  If 
mixed  too  thin,  a  sticky,  unmanageable  mass  results,  and  if  too  thick 
the  mass  will  crumble  in  pieces ;  it  is  therefore  recommended  to 
so  prepare  it  that  it  may  be  rolled  between  the  thumb  and  finger 
without  adhering  to  them,  or,  on  the  other  hand,  crumbling  to 
pieces.  On  account  of  the  oxyphosphate  setting  very  rapidly,  the 
cavity  should  be  ready  to  receive  it  before  it  is  mixed,  by  being  free 
and  protected   from  moisture  by  the  application  of  the  rubber-dam. 


TREATiMENT    OF    DENTAL    CARIES. 


461 


Like  the  oxychlorid,  it  is  necessary  that  the  surface 
of  a  filling  of  this  material  should  be  protected  from 
moisture  for  some  minutes  after  its  introduction,  and 
the  same  substances  may  be  used  to  coat  over  the  sur- 
face, as  in  the  case  of  the  oxychlorid.  Unlike  the 
oxychlorid,  however,  a  warm  instrument  cannot  be 
employed  to  hasten  its  setting.  A  number  of  forms 
of  these  cements  are  in  use  under  the  names  of  those 
originating  them.  One  form,  known  as  Poulson's,  is 
the  pyrophosphate  of  zinc,  the  pyrophosphoric  acid 
being  in  crystals,  which  require  to  be  melted  in  a 
platinum  or  porcelain  spoon  held  over  a  spirit  lamp, 
care  being  taken  that  ebullition  does  not  occur. 
When  reduced  by  heat  to  the  consistency  of  glycerin, 
it  is  dropped  upon  a  warm  porcelain  slab,  and  is  ready 
for  introduction  into  the  cavity.  Exposure  of  this 
preparation  to  the  air  causes  its  deterioration,  hence 
it  should  be  kept  in  hermetically  sealed  vessels.  Some 
of  these  plastic  zinc  preparations  appear  to  be  much 
less  soluble  in  some  mouths  than  in  others,  and  con- 
siderable importance  is  attached  to  the  manner  in 
which  they  are  mixed  and  inserted  into  the  cavity. 

In  using  any  of  these  preparations  the  cavity  is  pre- 
pared as  usual ;  then  a  small  quantity  of  the  liquid 
(either  the  chlorid  of  zinc  or  the  phosphoric  acid)  is 
dropped  upon  a  piece  of  glass  or  porcelain,  and  enough 
of  the  powder  (oxid  of  zinc)  added  to  make  a  paste  so 
thick  that  the  surface  will  not  appear  watery.  The 
cavity  having  been  perfectly  dried  and  protected 
from  saliva,  the  material  is  quickly  introduced,  after 
which  it  is  kept  free  from  moisture  for  ten  or  twenty 
minutes.  When  sufficiently  hard,  the  surface  is  fin- 
ished by  scraping  and  polishing.  The  longer  the  sur- 
face is  kept  dry,  the  harder  these  materials  become. 
Coating  the  surface  with  sandarach  varnish  (or  gutta- 
percha dissolved  in  chloroform,  or  melted  wax)  will 
afford  protection  for  some  time. 

In  all  cases  where  these  preparations  are  introduced 
near  a  pulp,  or  as  a  capping  over  exposed  pulps,  the 
cavity  should  always  be  previously  wiped  out  with  a 
solution  of  gutta-percha  and  chloroform,  to  prevent 
the  escharotic  and  irritant  effect. 

Fig.  386  represents  platinum  points  for  oxychlorid 
and  oxyphosphate  filling. 


Fig.  386. 


462 


DENTAL   SURGERY, 


Fig-  387  represents  the  agate  burnisher, 
which  is  considered  by  some  to  be  superior  to 
any  other  burnisher  for  surface  finishing  of 
oxychlorid  and  oxyphosphate  fillings. 

Fig.  388  represents  the  points  of  different 


Fig.  387. 

forms  of  spatulas  for  mixing  the  zinc  prepara- 
tions, which  is  conveniently  done  on  a  porcelain 
palette,  such  as  is  used  by  artists. 

Fig.  389  represents  a  common  form  of  mouth 
mirror,  of  which  both  plain  and  magnifying 


\ 


Fig.  388. 


are  used  in  examining  the  teeth.  Dr.  May- 
nard,  of  Washington,  made  an  improvement 
in  mouth  mirrors,  by  substituting  pebbles  for 
glass,  which  more  clearly  reflect  the  objects 
they  picture. 


Fig.  389. 


TREATMENT    OF    DENTAL    CARIES.  463 

Fig.  390  represents  reflectors  for  attachment  to  rubber-dam  clamps, 
so  that  while  providing  a  strong  light,  both  hands  of  the  operator  are 
left  free  for  manipulation.  They  are  useful  in  operations  upon  poste- 
rior cavities  in  molars.  By  means  of  a  ball-joint  the  mirror  can  be 
adjusted  to  concentrate  the  light  upon  the  cavity  or  any  portion  of  the 
mouth  required. 

Instruments  known  as  stomatoscopes  have  been  devised  for  the  pur- 
pose of  obtaining  a  perfect  light  for  operations  on  the  distal  surfaces 
of  molars  and  bicuspids,  and  are  found  to  be  especially  useful  when  the 
sky  is  cloudy  and  for  night  work.  Such  instruments  as  the  Grohnwald 
and  Beseler  stomatoscopes,  which  are  capable  of  being  so  adjusted  as 
to  throw  light  to  any  part  of  the  mouth  necessary  in  filling  teeth  may 
be  used.  Dr.  C.  F.  W.  Bodecker  asserts  that  by  aid  of  a  stomatoscope 
he  was  enabled  to  see  up  to  near 
the  apex  of  the  pulp-canal  of  a 
palatal  root  of  a  first  upper  molar, 
the  cavity  being  on  the  distal  and 
grinding  surface. 

The  electric  light  has  also  been  „ 

55  Fig.  390. 

Utilized  for  the  same  purpose,  and 

also  for  examinations  of  the  throat,  and  even  of  the  stomach. 
Mr.  E.  T.  Starr,  of  the  S.  S.  White  dental  establishment,  suc- 
ceeded in  obtaining  highly  satisfactory  results  in  this  direction. 
His  instrument  consists  of  a  lamp  formed  of  a  delicate  glass  bulb, 
from  which  the  air  has  been  withdrawn  and  as  nearly  a  perfect 
vacuum  created  as  possible.  The  bulb  varies  in  shape,  being 
spheroidal,  flat,  and  compass-shaped,  and  also  cylindrical,  with  a 
conical  termination.  Through  the  thin  wall  of  the  lamp  run  the 
conducting  wires,  connected  by  a  carbon  arc,  on  which  the  elec- 
tricity centers,  and  which  thus  becomes  the  place  of  light.  The 
glass  lamp  is  very  small,  the  cylindrical-shaped  being  scarcely  half  an 
inch  in  length,  and  with  a  diameter  much  less  than  that  of  an  ordinary 
lead-pencil.  The  compass-shaped  lamp  is  about  one-quarter  of  an 
inch  thick,  and  has  a  diameter  of  three-quarters  of  an  inch  to  an  inch, 
while  the  spheroidal  is  scarcely  larger  than  a  good-sized  pea.  The 
lamp  is  attached  to  a  handle  from  seven  to  nine  inches  long  and  about 
half  an  inch  thick,  through  which  run  the  wires  connecting  with  the 
battery.  The  intensity  of  the  power  and  the  brilliancy  of  the  arc  of 
light  can  be  regulated  by  moving  along  the  handle  a  ring  which  con- 
nects with  the  wires.  The  handle  has  several  joints,  and  its  position 
can  be  arranged  so  as  to  adapt  it  to  the  shape  of  the  cavity  it  is  to  illu- 
minate. Mirrors  can  also  be  fastened  to  the  lamp,  and  light  reflected 
to  places  where  the  lamp  cannot  be  introduced.     To  prevent  the  too 


464  DENTAL   SURGERY. 

great  radiation  of  heat  and  the  diffusion  of  light,  the  lamp  may  be 
partially  covered  with  a  hard  rubber  or  gutta-percha  case.  When  the 
lamp  is  placed  in  the  mouth  of  a  patient,  every  portion  of  the  throat, 
even  to  the  lowest  parts,  and  every  recess  of  the  upper  places  can  be 
plainly  seen.  Placed  behind  the  teeth,  the  intense  light  renders  not 
only  the  teeth,  but  even  the  gums  above,  highly  transparent.  If  the 
teeth  are  good  and  free  from  caries,  no  lines  will  be  visible,  but  the 
presence  of  a  filling  or  the  beginning  of  caries  may  at  once  be  seen. 
When  the  lamp  is  placed  within  the  mouth,  and  the  lips  are  closed, 
the  entire  front  structure  of  the  mouth  is  brought  to  view.  No  un- 
pleasant sensations  are  experienced,  even  in  cases  of  protracted  use. 

Fig.  391  represents  the  "Electric  Mouth  Lamp,"  or  "  Stomato- 
scope." 

The  electric  mouth  lamp  will  be  found  an  invaluable  assistant  to  the 
dentist  in  diagnosing  lesions  of  the  teeth  and  associate  parts,  especially 
in  those  obscure  cases  where,  although  tliere  are  unmistakable  symp- 
toms of  serious  pathological  disturbance,  careful  examination  with  the 
appliances  heretofore  in  vogue  fails  to  discover  the  exact  location  of 
the  trouble.  Sound  teeth  are  sometimes  needlessly  sacrificed  in  fruit- 
less endeavors  to  find  the  seat  of  neuralgic  pains  for  which,  owing  to 
the  insufficiency  of  the  means  of  diagnosis,  no  satisfactory  cause  can  be 
established.  The  electric  mouth  lamp  illuminates  the  oral  cavity  so 
brilliantly  that  any  departure  from  normality,  whether  it  be  a  hidden 
cavity  of  decay,  an  unsuspected  dead  pulp,  or  even  the  slight  thick- 
ening of  the  tissues  which  is  the  precursor  of  decay,  is  unerringly 
detected. 

This  apparatus  will  also  be  found  very  useful  in  the  operating  room 
in  other  directions.  In  the  preparation  of  inaccessible  cavities  it  is 
often  difficult  to  tell  when  the  excavation  has  proceeded  far  enough, 
but  the  electric  mouth  lamp  will  show  at  once  whether  all  the  disinte- 
grated tooth-substance  has  been  removed. 

In  use  the  lamp  is  placed  behind  the  object  to  be  illuminated — that 
is,  so  that  the  object  is  interposed  between  the  lamp  and  the  eye  of 
the  observer.  Thus,  in  examining  the  teeth  the  lamp  is  placed  within 
th&arch,  so  that  its  light  falls  upon  the  lingual  or  palatal  surfaces  of 
the  teeth,  while  the  eye  of  the  operator  is  directed  to  the  labial  or 
buccal  surfaces.  So  lighted,  every  portion  of  the  teeth  and  gums  is 
thrown  into  strong  relief;  the  sound  teeth  will  appear  translucent  and 
with  no  variations  in  texture,  but  a  dead  tooth  will  be  at  once  detected 
by  its  opaque  or  dark  appearance,  even  although  to  ordinary  obser- 
vation its  color  would  indicate  vitality.  A  cavity  of  decay,  or  any 
foreign  substance  about  the  teeth,  will  show  as  plainly  as  a  spot  upon  a 
window-pane.     A  healthy  root  will   not  be  distinguishable  Irom  the 


TREATMENT   OF   DENTAL   CARIES. 


465 


30 


Fig.  391. 


466 


DENTAL    SURGERY. 


membrane  surrounding  it ;  but  caries  of  the  pulp-canal  or  any  thick- 
ening of  the  tissues  will  be  brought  out  by  the  illumination. 

For  the  examination  of  posterior  cavities  in  teeth  a  mirror  is 
attached  to  the  guard  in  front  of  the  lamp  globe,  forming  a  perfect 
apparatus  for  the  purpose. 

It  has  been  found  impossible,  so  far,  to  make  the  lamps  of  exactly 
equal  power,  but  the  variation  is  not  great.  To  develop  their  full 
capacity  requires  about  3^  to  4)4  volts — say  the  current  from  two  to 
three  cells  of  a  Bunsen  battery.  The  cells  of  the  battery  supplied  with 
the  electro-magnetic  mallet  are  excellent  for  the  purpose,  or  three  or 
four  cells  of  any  bichromate  battery  will  answer. 

The  circuit  should  be  broken  occasionally  during  a  prolonged  exam- 
ination, and  also  whenever  the  lamp  is  not  in  use,  to  prevent  its 
becoming  so  hot  as  to  be  unbearable  in  the  mouth. 

For  the  examination  of  posterior  cavities  a  mirror,  set  at  an  angle 


r7\^ 


(( 


>iv 


Fig.  392. 


of  45  degrees,  is  attached  to  the  end  of  the  guard.  With  the  mirror 
attachment  the  electric  mouth  lamp  forms  a  perfect  laryngoscope. 

Instruments  for  Forming  the  Cavity. — Fig.  392  represents  a  set 
of  instruments  called  "Explorers,"  useful  for  examining  the  teeth  to 
determine  the  presence  of  caries.  For  the  removal  of  the  diseased 
part  of  the  tooth  and  the  formation  of  a  cavity  for  the  proper  recep- 
tion and  retention  of  a  filling,  a  variety  of  instruments  are  recjuired, 
which  should  be  constructed  of  the  best  steel  and  so  tempered  as  to 
prevent  them  from  either  breaking  or  bending.  Their  points  should 
be  so  shaped  that  they  may  be  conveniently  applied  to  any  part  of  a 
tooth,  and  made  to  act  readily  upon  the  portion  which  it  is  necessary 
to  remove. 

The  instruments  employed  for  this  purpose  are  chisels,  excavators  and 
burs.  Fig.  393  represents  some  of  the  many  forms  of  excavators  in  use. 
They  may  be  formed  either  with  handle  and  point  in  one  piece  or  fitted 
to  separate  handles  made  of  wood,  ivory,  pearl,  or  cameo,  or  be  made  to 


TREATMENT    OF    DENTAL    CARIES. 


467 


fit  into  one  common  socket  handle,  or  for  use  in  the  engine.     The 
introduction  of  cone-socket  handles  has  supplanted  all  other  styles  of 


A  1 


n  J  I 


1     If     U     \  f   sf 


11  I  I  I  I  I  I 

^\  1 )  1 


'^,    '^ 


Fig.  393- 


socket-handle  instruments.     These  handles  are  made  of  steel,  nicely 
engraved  and  nickel-plated.     Fig.  394  represents  such  instruments. 


46: 


DENTAL    SURGERY. 


Fig.  395  represents  the  form  of  plyers  for  screwing  the  points  into 
the  cone-socket  handles. 

Fig.  396  represents  Dr.  W.  C.  Head's  approximal  surface  excava- 
tors, intended  chiefly  for  use  in  preparing  cavities  between  the  upper 


Fig.  394. 


Fig.  395. 


Fig.  396. 


g 


Fig.  397. 


front  teeth,  working  from  underneath,  but  are  also  useful  on  bicuspids 
where  compound  cavities  are  to  be  formed  for  contour  fillings. 

The  flat    and  bur-headed  drills  represented  in  Fig.   397  are   very 
useful  for   enlarging  the  orifice  of  a  cavity.     Fig.   398  represents  a 


TREATMENT    OF    DENTAL    CARIES. 


409 


revolving  head  bur  and  drill  socket,  which  carries  burs  and  drills  of 
all  sizes.  The  clutch  is  operated  by  throwing  forward  or  backward 
the  section  of  the  socket  at  A. 

The  use  of  excavating  burs,  by  means  of  the  dental  engine,  has 


\J 


Fig.  398. 


Flat, Spear  Square.        Flat, Square        Spade. 

Point.  Point. 


Forbes's. 


Round. 


Five-sided.  "  Flexible  "  Burs  and  Drills. 

Fig.  399- 


almost  supplanted  the  separate-handle  drills.     Fig.  399  represents  a 
variety  of  forms  of  excavating  burs  and  drills  for  use  with  the  dental 

engine. 

The  Dental  Engine  is  a  valuable  invention,  for  which  tne  profession 
is  indebted  to    Dr.  Morrison,  of  St.  Louis,  and  by  means  of  which 


4^9 


DENTAL   SURCxERY. 


Fig.  400. 


TREATMENT    OF    DENTAL    CARIES. 


471 


instruments,  such  as  burs,  drills,  discs,  condensing  points,  burnishers, 

wood-points,  etc.,  can  be  rapidly  revolved  and  effectively  employed 

Figs.  400  and  402  repre- 


sent two  dental  engines, 
a  number  of  which  are  now 
in  use. 

Hand- Pieces,  straight 
and  angle,  of  various  de- 
signs, and  which  hold 
burs,  discs,  points,  etc., 
are  attached  to  the  cable 
or  arm  of  the  dental 
engine.  Some  of  these 
hand  -  pieces  are  repre- 
sented by  Fig.  401.  The 
cable  of  a  dental  engine 
can  be  attached  to  a  water- 
motor  or  to  an  electric 
Avire,  both  of  which  make 
efficient  motive  power. 

Fig.  403  represents  a 
rubber  bulb  chip  syringe, 
for  blowing  the  cuttings 
and  dust  from  cavities  in 
teeth  by  means  of  cold  air. 

Fig.  404  represents  an 
elastic  bulb  syringe  for 
cleansing  cavities.  The 
bulb  is  first  compressed, 
and  the  point  is  then  in- 
serted under  water,  when 
it  fills  itself. 

Enamel  chisels  of  dif- 
ferent shapes,  and  gouges, 
are  also  very  valuable  in- 
struments for  the  prelimi- 
nary operation  of  opening 
large  cavities  or  cutting  off 
sound  enamel  or  dentine 
whenever  necessary. 

But  the  cavity  can   seldom    be  completed  with  such  instruments. 
After  it  has  been  opened   and   the  orifice   made  sufficiently  large, 


Fig.  401. 


472 


DENTAL   SURGERY. 


Fig.  403.  Fig.  404. 


Fig.  402. 


TREATMENT    OF    DENTAL    CARIES.  473 

it  should  be  finished  with  excavators  (Fig.  393)  and  burs  (Fig.  399) 
properly  adapted  to  the  purpose;  in  fact,  in  the  majority  of  cases  it 
should  be  wholly  formed  with  instruments  of  this  sort. 

Excavators,  shaped  like  those  represented  in  Fig.  393,  have  been 
found  by  the  author  to  be  as  well  adapted  for  the  removal  of  caries  as 
any  which  he  has  ever  employed.  There  should  be  several  sizes  of 
each  shape ;  also  duplicates  of  each  instrument,  to  prevent  delay  in 
case  of  accident  while  operating.  As  the  proper  formation  of  the 
cavity  greatly  depends  on  having  suitable  instruments,  every  operator 
should  be  provided  with  a  large  supply  of  bur  drills  and  excavators,  so 
that  he  may  never  be  at  a  loss  for  such  as  the  peculiarity  of  any  case 
may  require.  He  should  also  have  the  material,  and  know  how,  in  an 
emergency,  to  point  his  own  excavators.  For  this  purpose  he  will 
need  a  lamp,  a  small  anvil  and  hammer,  a  set  of  fine-cut  files,  such  as 
are  used  by  watchmakers,  and  an  assortment  of  steel  rods  of  various 
sizes  and  of  the  best  quality.  It  is  not  our  purpose  to  give  specific 
directions  for  working  steel,  but  we  would  offer  two  cautions :  first, 
small  points  quickly  become  brittle  by  hammering  and  need  frequent 
annealing  ;  second,  steel  is  greatly  injured  by  raising  it  to  a  full  red 
or  white  heat.  A  very  fine  temper  may  be  given,  after  shaping  the 
point,  by  heating  to  redness  and  suddenly  plunging  it  in  wax  or 
tallow. 

As  excavators  must  be  kept  very  sharp,  an  oil-stone  should  be  con- 
stantly at  hand.  The  Arkansas,  Hindostan,  or  Superior  stones  are 
superior,  for  this  purpose,  to  all  other  varieties,  on  account  of  their 
hardness,  fineness,  and  sharpness  of  grit. 

Manned'  of  Forming  the  Cavity. — The  preparation  of  the  cavity  in  a 
tooth  for  the  reception  of  a  filling  is  a  very  essential  part  of  the 
operation,  and,  though  usually  the  easiest,  is  sometimes  attended  with 
much  difficulty.  The  removal  of  the  diseased  part  is  sometimes  all 
that  is  necessary  preparatory  to  the  introduction  of  the  gold,  but  in 
the  majority  of  cases  the  cavity  must  be  so  shaped  as,  when  properly 
filled,  to  retain  the  filling  in  place. 

Where  the  orifice  to  a  cavity  is  small  and  contracted  it  should  be 
enlarged,  by  means  of  a  bur  drill,  sufficiently  to  allow  the  use  of 
excavators  to  remove  the  softened  dentine.  Small  cavities  may  not 
only  be  enlarged,  but  cleaned  and  formed,  by  the  drills. 

Some  prefer  excavators  in  the  form  of  scoops,  for  the  removal  of  the 
softened  dentine,  which  should  be  completely  removed,  and  a  dense, 
normal  surface  reached,  due  regard  being  had  to  avoid  injury  to  the 
pulp  of  the  tooth.  A  knowledge  of  the  anatomical  structure  of  the 
teeth  will  enable  the  operator  to  avoid  penetrating  to  dangerous  points 
when  excavating  cavities.     Burs  operated  by  the  dental  engine  can 


474  DENTAL    SURGERY. 

be  applied  at  almost  any  angle,  and  prove  very  serviceable  in  prepar- 
ing cavities  for  fillings. 

The  part  of  the  tooth  surrounding  the  orifice  should  present  no 
rough  or  brittle  edges.  The  size  of  the  bottom  of  the  cavity  should 
be  as  near  that  of  the  orifice  as  is  possible,  even  a  little  larger,  rather 
than  any  smaller.  But  the  difference  between  the  size  of  the  one  and 
the  other  should  never  be  very  great;  for  if  the  interior  of  the  cavity 
is  much  larger  than  the  orifice,  it  will  be  difficult  to  make  the  filling 
sufficiently  firm  and  solid  to  render  it  absolutely  impermeable  to  the 
fluids  of  the  mouth.*  If,  on  the  other  hand,  the  orifice  is  larger  than 
the  bottom  of  the  cavity,  it  will  be  difficult  to  obtain  sufficient  stabil- 
ity for  the  filling,  so  as  to  prevent  it  from  ultimately  loosening  and 
coming  out.  It  often  happens,  however,  that  the  situation  and  extent 
of  the  decay  is  such  as  to  render  it  impossible  to  make  the  cavity  so 
large  at  the  bottom  as  at  the  orifice  ;  when  this  is  the  case,  several  pits 
or  circular  grooves  should  be  cut  in  the  inner  walls,  for  the  purpose 
of  obtaining  as  much  security  for  the  filling  as  possible ;  being  careful 
to  make  these  in  the  dentine  rather  than  in  the  enamel,  which  is  so 
much  more  brittle.  By  proper  attention  to  this  precaution,  a  filling 
may  be  so  inserted  in  this  difficult  class  of  cases  as  to  preverit  it  from 
coming  out. 

As  a  general  rule  it  is  easier  to  form  a  cavity  in  the  grinding  surface 
of  a  molar  or  bicuspid  than  in  any  other  position  ;  though  it  sometimes 
happens  that  even  here  it  is  attended  with  difficulty,  and  especially 
when  the  decay,  commencing  in  the  center,  follows  the  several  depres- 
sions which  run  out  from  it.  In  such  cases  the  edges  bordering  on 
and  covering  the  affected  parts,  which  are  often  thick  and  very  hard, 
should  be  cut  away,  together  with  the  subjacent  decayed  dentine  ;  the 
radiating  depressions  should  open  fully  into  the  central  cavity,  and 
be  made  sufficiently  wide  and  deep  to  admit  of  being  filled  to  their 
extremities  in  the  most  perfect  and  substantial  manner.  The  surface 
of  a  filling  occupying  a  cavity  of  this  kind  presents  a  sort  of  stellated 
appearance.  When  two  or  more  decayed  places  are  separated  only 
by  very  thin  walls  of  tooth-substance,  these  should  be  cut  away,  and  a 
cavity  formed  large  enough  to  include  all  the  diseased  points  ;  as  one 

*  Place  a  lump  of  cotton  in  the  hollow  of  the  hand  formed  by  bringing  the  ends 
of  the  fingers  against  the  palm.  Then  press  with  an  instrument  upon  the  center  of 
the  cotton,  and  it  will  leave  the  sides  of  the  cavity.  This  simple  illustration,  sug- 
gested by  Dr.  Edward  Maynard,  will  explain  the  cause  of  failure,  in  certain  cases 
which  have  come  under  his  notice,  from  the  hands  of  operators  of  deservedly  high 
reputation.  The  cavity,  smallest  at  the  orifice,  had  been  well  filled ;  but  the  final 
compression  upon  the  center  had  drawn  the  gold  from  the  sides,  thus  permitting  the 
access  of  fluids,  and  ultimately  decaying  the  tooth  around  the  filling. 


TREATMENT    OF    DENTAL    CARIES.  475 

large  filling  will  secure  the  preservation  of  the  tooth  more  effectually 
than  by  filling  each  cavity  separately. 

Sharp  angles  should  be  avoided,  as  far  as  possible,  in  the  outline  of 
the  orifice  of  the  cavity,  because  of  the  extreme  difficulty  of  filling 
them  compactly.  The  orifice  must  also  have  a  firm,  decided  margin, 
with  no  thin  projecting  edges  of  enamel  on  the  one  hand ;  with  no 
countersunk  depressions  on  the  other.  In  the  first  case  the  thin  enamel 
is  apt  to  break  off  either  during  the  operation  or  subsequently ;  in  the 
second  case  the  thin  scale  on  the  edge  of  such  fillings  breaks  away  in 
the  course  of  time ;  in  both  cases  the  filling  fails  perfectly  to  answer 
its  purpose  in  the  preservation  of  the  tooth. 

The  enamel  edges  of  every  cavity,  in  preparing  it  for  the  introduc- 
tion of  a  filling,  should  be  smoothed  by  means  of  enamel  chisels  or 
the  margin  chisels,  or  the  stone  wheels  and  points,  so  that  it  may  be 
somewhat  countersunk.  Too  much  care  cannot  be  taken  to  properly 
prepare  the  enamel  edges,  as  the  perfection  of  the  filling  depends  in  a 
great  measure  upon  the  adaptation  of  the  gold  to  such  edges  or  margins. 

It  is  preferable,  in  many  cases  of  front  approximal  fillings,  to  cut 
away  the  inner  angles  of  the  tooth,  thus  avoiding  the  injury  to  the 
external  appearance  of  the  tooth  caused  by  the  file,  etc.  Upon  com- 
pletion of  the  operation,  the  surface  thus  cut  is  perfectly  polished,  as 
every  filled  or  cut  surface  upon  the  teeth  should  be,  and  so  shaped  as 
to  be  kept  readily  cleansed  with  the  brush  or  with  floss  silk.  It  is  also 
very  important  that  all  parts  of  the  cavity  should  be  accessible  and 
free  from  moisture  before  the  introduction  of  the  filling. 

All  debris  accumulating  during  the  cutting  away  of  softened  dentine 
and  the  formation  of  the  cavity  should  be  removed,  either  by  the 
syringe  with  tepid  water,  or  blasts  of  air,  the  latter  being  preferable 
where  it  is  desirable  to  keep  the  cavity  dry  during  the  entire  excava- 
tion. 

In  forming  a  cavity  for  the  reception  of  cohesive  gold  foil,  it  is  very 
necessary  that  it  should  be  of  such  a  shape  as  to  retain  securely  the 
first  gold  introduced,  and  to  accomplish  this  one  or  more  small  cavities, 
called  retaining  points,  can  be  made  within  the  larger  cavity.  These 
retaining  points  in  many  cases  afford  anchorage  for  the  entire  mass  of 
gold  composing  the  filling,  and  in  every  case  where  cohesive  forms  of 
gold  are  used,  they  are  the  support  in  the  building  up  from  the  bottom 
to  the  orifice  of  the  cavity. 

These  retaining  points  are  formed  in  the  dentine  by  means  of  a 
small,  square,  chisel-edged  spear,  or  spear-shaped  drills,  and  can  very 
often  be  made  of  one  sixteenth  of  an  inch  in  depth  ;  a  less  depth, 
however,  will  answer  in  many  cases.,  One  of  these  retaining  points 
in  connection  with  one  or  two  under-cuttings  on  the  opposite  wall 


476  DENTAL   SURGERY. 

will  be  sufficient  in  some  cavities,  while  in  others  two  or  three  are 


;!■!: 


I       \ 


Fig.  40s  Fig.  406. 

required.     The  gold  should  be  introduced  into  these  retaining  points 
in  such  a  manner  as  to  form,  when  they  are  filled,  solid  masses  of 


TREATMENT    OF    DENTAL   CARIES.  477 

metal,  which  would  require  considerable  force  to  dislodge  them. 
Upon  these  solid  masses  the  gold  filling  the  cavity  is  built. 

Fig.  405  represents  a  set  of  Dr.  E.  S.  Talbot's  Margin  Chisels  and 
Pluggers,  for  cutting,  rounding,  and  smoothing  the  edges  of  cavities, 
leaving  them  in  a  condition  to  receive  the  gold,  which  should  be 
adapted  accurately  to  the  margins. 

Protecting  Cavities  from  Moisture. — The  first  step  in  this  operation 
is  to  wipe  the  mucous  membrane  covering  the  parts  about  the  tooth  to 
be  filled  perfectly  dry,  as  well  as  the  mouth  of  the  duct  of  the  nearest 
salivary  gland,  from  which  saliva  may  flow  in  such  a  manner  as  to 
interfere  with  the  operation  of  filling  the  cavity.  Before  the  intro- 
duction of  the  rubber-dam  the  following  method  was  pursued  to 
protect  cavities  from  moisture  :  Over  the  mouth  of  the  duct  a  roll  of 
bibulous  paper  was  placed,  upon  which  rested  one  part  of  a  napkin, 
which  was  so  arranged  about  the  tooth  as  to  prevent  the  mucous  secre- 
tions from  reaching  the  cavity.  The  napkin  was  held  in  place  by  the 
thumb  and  fingers  of  the  left  hand.  The  remaining  portion  of  the 
napkin  could  be  used  to  prevent  the  breath  from  coming  in  contact 
with  the  material  used  for  filling,  as  well  as  the  cavity.  When  this 
was  accomplished,  the  cavity  was  dried,  as  hereafter  described,  and 
was  then  ready  for  the  filling.  Much  more  difficulty  was  met  with 
in  protecting  cavities  in  the  inferior  teeth  from  moisture  than  in 
the  case  of  the  superior,  and  various  appliances  were  devised  to 
overcome  it. 

The  common  saliva  pump  (Fig.  407)  is  used  to  remove  the  saliva  as 
it  accumulates  in  the  lower  part  of  the  mouth,  and  consists  of  a  glass 
tube  with  an  elastic  bulb. 

Fig.  406  represents  a  very  superior  saliva  pump.  A,  bottle  or 
reservoir.  C,  clamp,  furnished  at  its  upper  and  lower  ends  with  two 
steel  pins,  E,  F,  to  secure  it  to  the  upholstery  of  a  chair,  so  that  it 
cannot  be  detached  by  accidental  force.  When  used,  the  hard-rubber 
mouth-tube,  /,  is  held  in  the  mouth  by  one  hand  of  the  patient,  and 
the  bulb,  A",  in  the  other.  Whenever  saliva  accumulates,  the  patient 
presses  the  bulb,  and  the  saliva  flows  into  the  reservoir.  The  reser- 
voir is  emptied  by  unscrewing  the  cap,  B.  A  very  ingenious  improve- 
ment on  this  instrument  has  been  recently  made  for  attachment  to  the 
"fountain  spittoon,"  the  current  of  the  water  causing  a  constant 
automatic  suction,  by  which  the  instrument  is  operated  and  the  mouth 
kept  free  from  saliva. 

Fig.  408  represents  the  Adjustable  Fountain  Spittoon  with  the 
Saliva  Pump  attachment. 

The  Rubber  Dam. — For  one  of  the  most  simple,  yet  effective,  appli- 
ances for  controlling  the  flow  of  saliva  and  protecting  cavities  from 


478 


DENTAL  SURGERY. 


moisture  we  are  indebted  to  the  late 
Dr.  S.  C.  Barnum.  It  consists  of 
nothing  more  than  a  thin  sheet  of 
India-rubber,  of  good  quality  that  it 
may  possess  sufficient  strength  and  not 


tear  easily,  and  of  a  thickness 
double  that  of  letter  paper. 

Some  distance  from  the  edge 
of  the  sheet,  which  is  from  four 


TREATMENT    OF    ]JEN  lAL    CARIES. 


•479 


tc  eight  inches  square,  one,  two,  or  more  holes  are  made,  through  which 
the  crowns  of  the  teeth  are  passed  when  it  is  applied  to  the  mouth. 

The  holes  made  in  the  rubber  should 
be  about  one-tenth  smaller  in  diameter 
than  the  necks  of  the  teeth  they  are  tc 
embrace. 

Fig.  409  represents  the  Rubber  Dan) 
in  position,  and  Fig.  410  represents  a 
"dam  holder  "  in  connection  with  th€ 
rubber  dam. 


Fig.  411. 


Fig.  41a. 


480  DENTAL    SURGERY. 

It  is  better  in  all  cases  to  make  several  of  these  holes  in  the  sheet,  in 
order  to  include  within  the  coffer-dam  formed  when  the  sheet  is  in 
position  the  crowns  of  the  teeth  adjoining  the  one  in  which  the  cavity 
to  be  filled  is  situated.  When  the  crowns  of  the  teeth  approximate 
closely,  the  holes  should  be  made  about  one-eighth  of  an  inch  apart ; 
if  some  space  exists  between  the  crowns  the  holes  maybe  made  at  a 
greater  distance  from  each  other.  These  holes  may  be  formed  in  the 
rubber  by  means  of  a  small  chisel-edged  punch,  Fig.  412,  or  by  the 
Ainsworth  punch.  Fig.  411. 

The  rubber,  thus  prepared,  is  carried  between  the  teeth  by  either  a 
thin,  flat  burnisher,  or,  which  is  better,  by  waxed  floss  silk,  and  the 
margins  of  the  holes  pressed  gently  under  the  free  edges  of  the  gums 
in  the  direction  of  the  roots  of  the  teeth. 

These  margins  should  be  secured  to  the  necks  of  the  teeth  by  means 
of  waxed  floss  silk  tied  around  them,  or  by  the  use  of  suitable  clamps, 
such  as  are  now  manufactured  for  that  purpose. 

Fig.  413  represents  an  "  Applier  "  for  the  use  of  waxed  floss  silk  in 
adjusting  the  Rubber  Dam. 


p-JG.  413. 

Fig.  414  represents  some  of  the  many  forms  of  Rubber-Dam  Clamps, 
used  for  securing  the  rubber  dam  to  the  necks  of  teeth.  Forms  of  these 
clamps  are  made  with  tongue-guards. 

Fig.  415  represents  the  Rubber- Dam  Clamp  Forceps,  by  means  of 
which  the  clamp,  in  connection  with  the  rubber  dam,  is  placed  in 
position  on  the  tooth. 

Figs.  416,  417,  and  418  represent  the  How,  Johnson,  Climax,  and 
Ivory  cervix  screw-clamps,  and  the  T.  A.  Long  clamp. 

Several  other  simple  appliances  are  in  use  to  protect  cavities  from 
moisture,  such  as  wooden  wedges  forced  between  the  necks  of  the 
teeth,  and  waxed  cord  surrounding  the  tooth  in  which  the  cavity  is 
situated,  and  passing  to  an  adjoining  tooth  ;  also  a  band  of  rubber  cut 
from  tubing,  which  is  placed  high  up  on  the  neck  of  the  tooth  and 
then  carried  around  an  adjoining  one.  Two  of  these  bands,  acting  in 
opposite  directions,  answer  better  than  a  single  one,  and  in  many  cases 
effectually  protect  this  cavity  from  moisture. 

Drying  Cavities. — After  every  particle  of  decomposed  dentine  has 
been  removed,  the  cavity  should  be  thoroughly  cleansed  before  the 
filling  is  introduced.     This  may  be  done  by  first  injecting  tepid  water 


TREATMENT    OF    DENTAL    CARIKJ. 


Fig.  414. 


31 


DENTAL   SURGERY. 


into  it  with  a  properly  constructed  syringe,  and  afterward  wiping  it 
dry  with  a  small  lock  of  absorbent  cotton   fixed  upon  the  point  of  a 


Fig.  415. 


TREATMENT    OF    DENTAL    CARIES. 


483 


probe  or  excavator ;  or  the  cavity  may,  in  the  first  place,  be  wiped 
with  a  little  raw  cotton  moistened  with  water  and  afterward  with 
absorbent  cotton.  The  application  of  the  cotton  should  be  followed 
by  that  of  Japanese  bibulous  paper,  which  has  a  very  loose,  absorbent 
texture,  and  may  be  folded,  for  convenience,  in  the  form  of  a  rope, 

from  which  the  moistened  end  can 
be  torn  after  each  insertion.  Tissue 
or  bibulous  paper  absorbs  moisture 
more  perfectly  than  cotton.  The 
absorbing  qualities  of  cotton,  how- 
ever, may  be  increased  by  boiling  it 


Fig.  41S. 


Fig.  420. 


for  fifteen  or  twenty  minutes  in  a  tolerably  strong  alkaline  solution ; 
this  done,  it  should  be  thoroughly  dried  before  using  ;  or  by  saturating 
it  with  sulphuric  ether  to  remove  the  natural  oil.  Several  materials 
have  been  of  late  years  used  in  drying  cavities,  such  as  prepared  flax, 
fine  and  white,  with  a  long,  absorbent  fibre,  prepared  spunk,  absorbent 


484  DENTAL    SURGERY. 

cotton.  Fig.  421  represents  a  Hot-air  Syringe  for  drying  cavities, 
the  heating  chamber  being  filled  with  carbon,  the  best  known  retainer 
of  heat.  To  fill  this  syringe  with  heated  air,  the  turret  of  the  air- 
chamber  is  held  in  the  flame  of  a  spirit-lamp ;  the  turret,  being  pro- 


FlG.  421. 

vided  with  a  metallic  valve,  recedes  as  the  bulb,  after  being  compressed, 
fills  with  air  and  allows  the  flame  to  be  drawn  into  the  chamber.  It  is 
desirable  that  the  cavity  should  be  perfectly  dry  before  the  filling  is 
introduced. 

INSTRUMENTS    FOR   INTRODUCING    AND    CONSOLIDATING    GOLD. 

For  introducing  and  consolidating  non-cohesive  gold  foil,  a  number 
of  instruments  are  required,  which  should  be  sufficiently  strong  to 
resist  any  amount  of  pressure'  the  dentist  can  safely  exert  in  the  oper- 
ation. Hand  instruments  should  have  round  or  octagonal  handles, 
large  enough  to  prevent  the  liability  of  being  broken  and  to  enable 
him  to  grasp  them  firmly.  Their  points  should  vary  in  size,  though 
none  should  be  very  large.  Several  should  be  straight,  but  for  the 
most  part  they  require  to  be  curved — some  very  slightly,  others  form- 
ing with  the  shaft  of  the  instrument  an  angle  of  90°.  Fig  422  repre- 
sents a  set  of  small-pointed  hand  pluggers.  For  other  forms  the  reader 
is  referred  to  the  chapter  on  "  Filling  Individual  Cavities." 

Plugging  instruments,  as  received  from  the  instrument  makers,  have 
usually  a  temper  which  will  not  permit  them  to  be  bent.  It  will  add, 
we  think,  greatly  to  the  value  of  the  instrument  if  the  practice  of  Dr. 
Maynard  were  more  generally  adopted.  He  gives  to  the  extreme 
point  a  hard  temper  (straw  color)  to  prevent  it  from  wearing;  for  a 
little  distance,  say  one  to  three-quarters  of  an  inch,  a  spring  temper  is 
given  (purple  or  blue  color)  to  insure  strength  when  the  shape  is  deli- 
cate ;  the  rest  of  the  instrument  is  left  soft,  so  as  to  admit  of  being 
bent  (with  pliers)  in  the  direction  best  suited  for  that  particular  point 
in  any  given  operation. 

Most  of  them  should  have  a  slim  wedge  shape  ;  some,  however,  both 
of  the  straight  and  curved  instruments,  should   have  blunt  serrated 


INSTRUMENTS    FOR    INTRODUCING    AND    CONSOLIDATING    GOLD.     485 

points,  and  a  few  should  have  highly  polished  oval  points,  for  finishing 
the  surface  of  fillings.  Formerly,  most  dentists  employed,  for  intro- 
ducing and  consolidating  the  gold,  simple  blunt-pointed  pluggers ; 
but  it  is  impossible  with  such  instruments  to  make  a  filling  as  firm  and 
solid  as  it  should  be  for  the  perfect  preservation  of  a  tooth,  especially 
if  the  cavity  is  large.     From  one-fourth  to  one-half  more  gold  can  be 


^     /f 


Fig.  422. 


introduced  into  a  tolerably  large  cavity  with  a  wedge-pointed  than 
with  a  blunt-pointed  -instrument. 

Fig.  423  represents  an  excellent  set  of  points  designed  by  Professor 
James  H.  Harris  for  use  in  solid  or  socket  handles,  and  also  with  the 
automatic  or  hand  mallet,  and  although  intended  for  cohesive  gold, 
can  also  be  used  for  the  non-cohesive. 

This  general  description  will  serve  to  convey  a  tolerably  correct  idea 
of  the  kind  of  instruments  required  for  the  operation. 

Instruments  having  serrated  points  are  required  for  filling  teeth  with 
crystal  or  sponge  gold  and  with  cohesive  gold  foil. 


4S6 


DENTAL    SURGERY. 


Fig.  424  represents  some  knurled  handles  for  cone  socket  plugger 
points. 

Fig.  425  represents  Dr.  R.  W.  Varney's  set  of  Pluggers  for  the 
cohesive  form  of  gold  foil. 


Fig.  423- 


Fig.  426  represents  Dr.  Marshall  H.  Webb's  set  of  pluggers,  also  for 
the  cohesive  form  of  gold  foil. 


Fig.  424. 


Fig.  427  represents  Dr.  Chapelle's  malleting  siiaft  ])luggers,  for  the 
use  of  cohesive  gold,  especially  No.  30  rolled  cohesive  gold,  cut  in 
strips  Jg,  i,  y^g  inch  wide  and  one  inch  long. 


INSTRUMENTS    FOR    TNTRODUCING    AND    CONSOLIDATING    GOLD.      /S7 

I 

"  C53     "SO       -S25    —  ej3  ~E5n3"llml 


B 


Fig.  425. 


Fig.  426. 


488 


DENTAL   SURGERY. 


Fig.  427. 


u 


f  I  sro  "^ 


r\ 


Fig.  428. 


Fig.  429. 


PREPARING,    INTRODUCING,    AND    CONSOLIDATING    GOLD.  489 

Fig.  428  represents  a  combined  foil  carrier  and  plugger,  for  taking 
up  pieces  of  gold  and  placing  them  in  the  cavity  and  partially  con- 
densing them. 

MANNER  OF  PREPARING,  INTRODUCING,  AND  CONSOLIDATING  GOLD,  ANP 
FINISHING    THE    SURFACE    OF    THE    FILLING. 

Nofi- Cohesive  Gold  Foil. — The  operator,  being  provided  with  the 
necessary  instruments,  should  cut  this  form  of  gold  with  a  pair  of  foil- 
scissors  into  strips  containing  from  one-fourth  of  a  sheet  to  one  whole 
sheet.  Each  of  these  should  be  loosely  rolled  or  folded  together 
lengthwise,  by  the  aid  of  a  foil-holder  or  spatula  (Fig.  429),  on  a 
piece  of  soft  spunk,  covered  with  chamois  skin  or  white  kid — the  foil- 
scissors  and  spatula  have  recently  been  combined  into  one  instrument 
— and  after  the  cavity  has  been  properly  cleansed  and  dried,  the  end 
of  one  fold  should  be  introduced  and  carried  to  the  bottom  of  the 
cavity,  with  a  straight  or  curved  wedge-pointed  instrument ;  the  roll 
on  the  outside  should  then  be  folded  on  the  part  first  inserted.  The 
folding  should  be  commenced  on  one  side  of  the  cavity,  and  the 
inner  end  of  each  fold  taken  to  the  bottom,  the  outer  extending 
nearly  a  twelfth  or  an  eighth  of  an  inch  on  the  outside  of  the 
orifice;  thus,  fold  after  fold  is  introduced,  until  no  more  can,  in 
this  manner,  be  forced  into  the  cavity.  Having  proceeded  thus  far  in 
the  operation,  the  instrument  should  be  forced  through  the  center  of 
the  filling  and  the  gold  firmly  pressed  against  the  walls  of  the  cavity. 
The  opening  thus  made  should  be  filled  in  the  manner  as  first  described, 
and  this  time  it  should  be  packed  in  as  tightly  as  possible.  This  done, 
the  operator  should  endeavor  to  force  a  small,  wedge-pointed  instru- 
ment in  the  center  of  the  filling,  until  he  has  tried  every  part  of  the 
plug,  filling,  as  he  proceeds,  every  opening  which  he  makes,  and  exert- 
ing, in  the  packing  of  the  gold,  all  the  pressure  which  he  can  apply 
without  endangering  the  tooth.  If  one  roll  or  fold  of  gold  is  not 
enough,  he  should  take  another  and  another,  until  the  cavity  is 
thoroughly  filled.  When  the  walls  of  the  cavity  are  frail  it  is  the 
practice  of  some  operators  to  introduce  the  gold  rather  loosely,  and  to 
depend  upon  surface  condensing  to  obtain  the  necessary  solidity. 
But  it  is  better  to  well  condense  every  fold  immediately  after  it  is 
carried  to  its  proper  place  in  the  cavity ;  such  condensing  will  often 
render  the  use  of  the  wedge-shaped  instrument  unnecessary. 

The  advantage  to  be  derived  from  introducing  the  gold  in  this  man- 
ner is  obvious.  By  extending  the  folds  from  the  orifice  to  the  bottom 
of  the  cavity  the  liability  of  the  gold  to  crumble  and  come  out  if 
effectually  prevented,  and  by  introducing  it  with  a  wedge-pointed 
instrument  it  may  be  carried  into  all  the  depressions  of  the  walls  of  the 


490  DENTAL    SURGERY. 

cavity,  and  rendered  altogether  more  solid  than  i-t  could  otherwise  be 
made.  The  cohesiveness  of  the  gold  may  be  increased  by  slightly 
warming  in  the  flame  of  a  spirit  lamp,  after  it  has  been  made  into  rolls 
or  folds. 

After  the  cavity  has  been  completely  filled,  every  portion  of  the 
projecting  part  of  the  gold  must  be  thoroughly  consolidated  before  it 
is  allowed  to  become  wet,  with  a  small,  blunt-pointed  instrument, 
straight  or  curved,  as  may  be  most  convenient;  or,  if  the  filling  is  in 
the  approximal  side  of  a  tooth,  it  may  be  compressed  with  the  angle 
of  the  point  of  fhe  plugger,  making  the  adjoining  organ,  to  a  slight 
extent,  a  kind  of  fulcrum  for  the  instrument.  After  the  filling  has 
been  thus  consolidated  as  long  as  it  can  be  made  to  yield  in  the  least 
to  the  pressure  of  the  instrument,  the  protruding  parts  may  be  scraped 
or  filed  off,  down  to  the  tooth,  so  as  to  form  a  smooth,  uniform,  gently 
swelling,  or  perfectly  flat  surface.  Fig.  444  represents  a  number 
of  finishing  files.  If  in  this  part  of  the  operation  any  portion  of 
the  gold  should  crumble  or  be  dislodged,  which  it  will  not  do  if  it 
has  been  properly  introduced  and  consolidated,  the  injury  may  be 
repaired  by  making,  in  the  part  of  the  plug  where  it  has  occurred,  an 
opening,  and  filling  it,  or  by  the  removal  of  the  whole  of  the  filling 
and  the  introduction  of  another.  If  any  portions  of  gold  have  been 
forced  over  the  edge  of  the  orifice  of  the  cavity  they  should  be  care- 
fully removed,  either  with  a  file  or  sharp-pointed  cutting  instrument 
suited  to  the  purpose.  This  precaution  should  never  be  neglected, 
especially  when  the  filling  is  in  the  approximal  surface  of  a  tooth, 
where  a  portion  of  the  gold  is  very  liable  to  be  forced  up  or  down 
upon  the  neck  and  under  the  gum.  If  the  filling  is  located  on  a  mas- 
ticating surface,  a  flat  and  level  gold  surface  will  answer  the  best  pur- 
pose in  preserving  the  tooth-structure;  if  upon  an  approximal  surface, 
the  filling  should  be  contour,  as  a  general  rule.  Soft  or  non-cohesive 
gold  foil,  in  the  form  of  the  ribbon  or  loosely-rolled  cylinders,  is  fre- 
quently used  in  connection  with  cohesive  gold  foil  as  a  base  upon 
which  to  build  the  latter  form  of  gold.  This  combination  is  especially 
applicable  in  the  case  of  cavities  upon  the  approximal  surfaces  of  the 
teeth  and  which  extend  to  the  gum.  The  soft  or  non-cohesive  gold 
in  such  cases  is  employed  to  cover  over  the  cervical  walls,  being  first 
introduced  into  one  of  the  angles  of  the  cavity,  until  this  wall  is  com- 
pletely covered,  when  mallet  force  is  employed  to  condense  the  mass 
which  has  been  introduced,  with  a  fine  foot-plugger.  On  this  base  of 
non-cohesive  gold,  pieces  or  pellets  or  the  ribbon  of  cohesive  gold  are 
condensed,  and  the  filling  completed  with  the  latter  form  of  gold. 
The  non-cohesive  gold,  owing  to  its  quality  of  adaptability,  is  capable 
of  being  closely  packed  against  the  most  vulnerable  walls  of  cavities, 


PREPARING,    INTRODUCING,    AND    CONSOLIDATING    GOLD.  49 1 

where  it  may,  in  some  cases,  answer  a  better  purpose  in  the  preservation 
of  the  teeth  than  the  cohesive  forms  would  do  in  the  same  location. 

Cylinder  Filling. — The  method  of  filling  cavities  with  non-cohesive 
gold  foil  in  the  form  of  cylinders  is  a  favorite  one  with  many  oper- 
ators, and  is  in  some  cases,  especially  grinding  surface  cavities  with 
firm  walls,  preferable  to  that  of  the  fold  or  rope.  A  common  method 
of  preparing  these  cylinders  is  to  fold  lengthwise,  in  the  form  of  a 
ribbon,  either  the  third,  half,  or  whole  of  a  leaf  of  No.  4  or  6  gold 
foil ;  the  width  of  the  ribbon  determines  the  length  of  the  cylinders. 


Fig.  430. 

One  end  of  this  ribbon  is  then  held  between  the  thumb  and  index 
finger  of  the  left  hand,  and  wound  upon  a  three-  or  four  sided  broach 
until  the  cylinder  thus  formed  is  of  the  size  desired,  when  the  remain- 
ing portion  of  the  ribbon  is  torn  off. 

The  cylinders  should  be  a  little  longer  than  the  cavity  is  deep  in 
order  to  allow  for  surface  condensing.  The  density  of  the  cylinders 
depends  upon  the  tightness  with  which  the  ribbon  is  wound  upon  the 
broach ;  by  winding  it  loosely  upon  the  broach  soft  cylinders  are 
formed,  to  be  placed  in  contact  with  the  walls  of  the  cavity,  while  the 
hard  cylinders  made  by  tighter  winding  are  introduced  inside  of  the 
soft  and  form  the  center  of  the  filling.     Different  forms  as  well  as  sizes 


Size  I.  Size  2,  Size  3.  Size  4. 

Fig.  431. 


□  □  □ 


of  cylinders  are  necessary  in  every  case,  cone-shaped  as  well  as  the 
true  cylindrical.  The  cone-shaped  cylinders  are  useful  where  there  is 
an  under-cutting,  and  also  for  completing  the  introduction  of  the  gold. 

These  cone-shaped  cylinders  are  formed  by  winding  the  ribbon  back 
from  the  point  of  the  broach,  which  should  taper  slightly,  in  order 
that  the  cylinder  when  completed  may  be  easily  detached. 

Loosely  rolled  cylinders,  prepared  ready  for  use,  can  be  obtained 
of  manufacturers  (Fig.  430). 

These  loose  cylinders  are  useful,  applied  to  the  cervical  walls  of 
approximal  cavities,  as  a  base  upon  which  to  build  cohesive  gold  foil. 

Also  the  blocks  or  mats  represented  in  Fig.  431. 

For  placing  the  cylinders  in  their  proper  places  in  the  cavity  the 
introducing  pliers  are   necessary,  which  have  smooth  points  bent  at 


492  DENTAL    SURGERY. 

such  an  angle  as  will  permit  of  their  being  used  when  closed  as  a 
condensing  point.     See  Fig.  428. 

The  cavity  being  prepared  for  the  gold  and  properly  protected  from 
moisture,  one  of  the  soft  cylinders  is  carried  into  it  with  the  pliers  and 
placed  in  such  a  position  that  one  end  rests  on  the  bottom  and  the 
other  protrudes  from  the  orifice.  Pressure  in  the  direction  of  the 
wall  against  which  the  cylinder  rests  is  then  made  with  the  closed  points 
of  the  pliers,  and  afterward  with  a  condensing  instrument  having  either 
a  smooth,  wedge-shaped  point,  or,  with  what  is  better,  a  serrated  point. 
When  the  first  cylinder  introduced  has  been  well  condensed  against  one 
of  the  walls  of  the  cavity,  others  are  introduced  and  condensed  in  suc- 
cession, until  these  walls  are  covered  by  the  soft  cylinders.  The  hard 
cylinders  are  then  disposed  round  the  cavity  in  the  same  manner  as  the 
soft  ones,  until  it  diminishes  so  much  as  to  render  it  necessary  to  form 
a  cavity  in  the  center  of  the  gold  already  introduced,  by  means  of  a 
smooth,  wedge-shaped  instrument,  such  as  is  represented  in  Fig.  432. 
The  cavity  formed  by  this  instrument  is  then  filled  with  a  small,  dense 


Fig.  432. 

cylinder,  and  successive  openings  are  thus  made  and  filled  until  no 
more  gold  can  be  introduced,  when  the  protruding  ends  of  the  cylin- 
ders are  condensed  by  pressure  applied  in  the  direction  of  the  bottom 
of  the  cavity.  The  surface  of  the  filling  is  then  finished  in  the  manner 
to  be  described  hereafter.  To  obtain  an  extremely  dense  surface,  crys- 
tal or  sponge  gold  may  be  added  to  the  surface  of  a  cylinder  filling, 
before  such  a  surface  is  condensed,  by  introducing  it  into  the  inter- 
stices between  the  cylinders  projecting  above  the  margin  of  the  cavity 
and  then  applying  mallet  force. 

When  the  cavity  is  of  considerable  depth  and  small  in  diameter,  or 
the  bottom  is  uneven,  pellets  of  gold  may  be  introduced  and  condensed 
upon  the  bottom  until  the  cavity  is  about  one-third  filled.  By  this 
method  the  gold  is  better  adapted  to  the  bottom  of  the  cavity  than  by 
placing  the  ends  of  the  cylinders  upon  an  uneven  surface.  The  sur- 
face-condensing of  cylinder  fillings  should  be  made  with  small-pointed 
condensing  instruments,  and  any  opening  it  is  possible  to  make  with 
them  be  filled  with  small,  dense  cylinders. 

The  Herbst  Method. — Dr.  Herbst,  of  Germany,  has  recently  intro- 


PREPARING,    INTRODUCING,    AND    CONSOLIDATING    GOLD. 


493 


duced  a  method  of  manipulatiug  a  quality  of  soft  or  non-cohesive 
gold,  in  the  form  of  cylinders,  made  by  Wollrab,  of  Bremen,  to  which 
the  name  "  rotation  gold  filling  "  has  been  given. 

Fig.  433  represents  the  instruments  used  in  the  Herbst  method, 
which  are  smooth,  but  not  polished,  and  some  of  the  points  are 
quite  fine.  As  these  instruments,  when  made  of  steel,  become  coated 
with  gold  by  its  adhesion,  they  can  be  cleansed  during  their  use  by 
rubbing  their  points  on  a  piece  of  block-tin  or  upon  fine  crocus-cloth  ; 
it  has  also  been  suggested  to  plate  the  points  with  gold.  This  German 
gold  appears  to  become  cohesive  by  rubbing  it  with  the  instruments, 
which  have  points  like  burnishers  and  are  rotated  in  the  introduction 
and  consolidation  of  the  gold.  By  slightly  annealing  the  cylinders 
they  can  be  united,  and  even  hammered,  without  crumbling  in  pieces. 
The  cavities  into  which  this  form  of  gold  is  introduced  are  prepared 
in  the  usual  manner,  with  their  edges  smooth  and  slightly  rounded  off; 
deep  retaining  points  are  unnecessary,  and  but  few  pits  are  required. 

I         23         4         5         6         7         8         9        10       II       12        13        14       15       16        17       18 


Fig.  433. 


For  filling  an  ordinary  cavity  in  a  grinding  surface,  the  quantity  of 
gold  first  introduced  should  be  large  enough  to  be  retained  when  con- 
•densed,  without  support  from  an  instrument,  which  is  accomplished  by 
packing  the  cavity  loosely,  but  quite  full  of  the  cylinders,  when  the 
instruments  numbered  2,  3,  or  4  (Fig.  433),  by  a  slow  rotation,  burnish 
the  gold  against  the  walls.  A  second  layer  of  gold  is  made  to  adhere 
to  the  surface  of  the  first  gold  introduced,  by  the  use  of  the  form  of 
instrument  represented  by  numbers  5,  6,  7,  or  8,  by  rotating  it  quickly 
until  the  polished  surface  of  the  first  gold  introduced  has  been  destroyed, 
when  the  second  layer  of  gold  will  adhere  to  it.  The  filling  of  the 
cavity  is  continued  in  this  manner  mitil  all  of  the  gold  necessary  is 
introduced  and  consolidated. 

For  filling  two  superior  incisor  cavities  in  opposite  approximal  sur- 
faces, after  being  prepared  in  the  usual  manner,  they  are  treated  as  one 
cavity  by  introducing  the  gold  into  both  at  the  same  time  (bringing 
over),  first  securing  it  in  the  four  corners  or  angles  by  rotation  with 


494  DENTAL    SURGERY. 

the  instruments  represented  by  numbers  5,  6,  7,  8,  according  to  the 
size  required,  so  that  a  common  mass  of  gold  appears.  The  fine- 
pointed  instrument,  No.  18,  is  then  inserted,  with  regular  rotation, 
into  this  mass,  between  the  two  teeth,  until  it  is  separated,  when  thin 
files  or  discs  and  tape  are  employed  to  finish  the  surfaces  of  each 
filling. 

For  filling  two  similar  cavities  in  the  approximal  surfaces  of  bicus- 
pids and  molars  a  matrix  is  used,  which  is  secured  in  place  between  the 
teeth  with  shellac,  one  cavity  being  first  filled  by  commencing  the  in- 
troduction of  the  gold  against  the  cervical  wall  or  border,  and  con- 
densing against  the  matrix  at  that  point,  and  then  toward  the  center 
of  the  crown.  The  first  cavity  being  filled,  the  shellac  is  removed  and 
the  remaining  cavity  filled  in  the  same  manner.  The  rotation  and 
pressure  of  the  instruments  appear  to  produce  sufficient  heat  to  render 
the  gold  cohesive,  and  it  is  claimed  that  a  filling  by  this  method  and 
with  this  quantity  of  gold  can  be  inserted  very  quickly,  and  that  it  is 
impermeable  to  all  fluids. 

Pellets. — Another  form  in  which  non-cohesive  gold  foil  is  used  is 
that  of  pellets,  which  are  formed  by  lightly  rolling  a  portion  of  a 
sheet  between  the  thumb  and  fingers.  They  are  made  of  different 
sizes,  and  when  placed  in  a  cavity  are  welded  together  by  means  of 
pointed  or  serrated  instruments.  It  is  necessary  that  the  first  pellets 
introduced  should  be  securely  anchored,  in  order  that  the  successive 
ones  may  be  built  upon  them  ;  these  last  should  be  small  enough  to 
allow  the  welding  instrument  to  pass  through  them  to  the  gold  beneath. 

COHESIVE    GOLD    FOIL. 

Cohesive  gold  foil  is  well  adapted  for  all  shallow  cavities  and  for 
restoring  lost  portions  of  the  crowns  of  teeth.  While  non-cohesive 
gold  is  retained  by  the  general  form  of  the  cavity,  cohesive  gold  is 
anchored  by  means  of  retaining  points  or  pits,  on  the  principle  of 
welding  one  piece  or  fold  to  another  until  the  required  quantity  is 
introduced.  The  number  of  retaining  pits  will  depend  upon  the  form 
of  cavity  to  be  filled,  varying  from  three  to  six.  The  depth  of  these 
retaining  points  will  also  depend  upon  the  strength  of  the  walls  of  the 
cavity,  as  will  also,  in  a  great  measure,  their  diameter;  as  a  general 
rule,  a  greater  number  of  small  pits  if  the  wall  is  weak,  and  a  {q.\\  large 
pits  where  the  wall  is  strong,  or  where  a  portion  of  the  filling  has  to 
withstand  great  force.  These  retaining  pits  are  made  with  small, 
square-edged  drills,  to  a  depth  corresponding  with  the  diameter  of  the 
drill,  and  in  a  direction  opposite  to  each  other,  and  in  a  line  with  the 
force  to  be  resisted.  Each  of  these  retaining  pits  is  solidly  filled  with 
pellets  of  a  suitable  size,  the  pieces  of  gold  being  conveyed  to  the  cavity 


COHESIVE    GOLD    FOIL.  495 

by  means  of  the  introducing  pliers,  and  thoroughly  condensed  by 
mallet  force.  The  retaining  pits  being  filled,  the  gold  is  built  over 
from  one  to  the  other,  until  the  surface  upon  which  they  are  located  is 
covered,  which  secures  a  base  for  the  entire  filling.  Larger  pellets  are 
then  built  upon  this  base,  care  being  taken  to  adapt  the  gold  perfectly 
to  the  walls  of  the  cavity  by  gradually  building  it  somewhat  higher 
against  the  walls  than  in  the  center.  The  operation  is  continued  in 
this  manner  until  the  edge  of  the  cavity  is  reached,  when  the  gold  is 
built  up  in  the  center  and  above  and  over  the  margins,  to  permit  of 
its  being  so  cut  away  as  to  conform  to  the  original  contour  of  the 
surface  which  it  is  to  restore. 

The  cutting  away  of  the  surplus  gold  is  accomplished  by  means  of 
suitable  plug-finishing  files,  or  plug-finishing  burs,  corundum  disks 
or  points,  Hindostan  or  Arkansas  stone  points,  etc.,  after  which 
smoothing  process  a  high  polish  is  given  to  the  entire  surface. 

In  manipulating  with  cohesive  foil,  a  preliminary  step  in  the 
operation  is  to  attend  to  the  quality  of  the  gold.  It  must  possess 
sufficient  cohesiveness  to  cohere  under  moderate  pressure ;  and  as  this 
property  deteriorates  on  the  exposure  of  the  foil  to  the  atmosphere, 
it  is  often  necessary  to  restore  it  by  the  application  of  heat,  as  the 
welding  principle,  and  not  mechanical  force,  is  relied  upon.  To  ac- 
complish this,  the  gold,  either  in  the  sheet,  ribbon,  or  pellet  form, 
is  subjected  to  the  flame  of  an  alcohol  lamp  until  it  becomes  a 
bright  red. 

Fig.  396  represents  a  gold-foil  annealing  lamp.  A  wire-gauze  frame 
is  very  convenient  for  re-annealing  the  entire  sheet,  and  a  mica  plate 
or  platinum  pan  for  the  pieces  or  pellets.  Many  prefer  to  pass  the 
roll  and  pellets  directly  through  the  flame  at  the  moment  they  are 
being  carried  to  the  cavity  with  the  introducing  pliers.  Another 
method  is  to  boil  the  gold  for  a  few  minutes  in  a  solution  composed 
of  forty  drops  of  sulphuric  acid  and  two  gills  of  rain-water.  This 
diluted  acid  removes  all  extraneous  matter  from  the  surface  of  the 
gold,  which  soon  dries,  and  is  found  to  be  very  cohesive. 

There  are  a  number  of  methods  by  which  this  form  of  gold  foil 
is  prepared  for  introduction  into  the  cavity.  .One  consists  in  tearing 
fragments  from  a  sheet,  previously  annealed,  and  condensing  a  single 
thickness  at  a  time  with  a  fine  serrated  point.  Another  method  con- 
sists in  lightly  rolling  up  the  whole  or  part  of  a  sheet  in  the  form  of  a 
rope  and  cutting  this  up  into  pellets  of  different  sizes.  In  forming 
the  pellets,  the  sheet  should  be  very  lightly  rolled  up  between  the 
thumb  and  fingers,  or,  what  is  better,  lightly  folded  by  means  of  a  foil 
folder,  and  chamois  skin.     It  may  also  be  folded  within  the  leaves  of 


496 


DENTAL    SURGERY. 


the  book  containing  it,  into  two,  three,  four,  or  more  ribbons,  accord- 
ing to  the  size  of  the 
cavity  to  be  filled,  and 
then  cut  with  the  scissors. 
Some,  instead  of  form- 
ing pellets,  prefer  to  in- 
troduce this  quality  of 
gold  in  a  long  rope,  or, 
better  still,  a  ribbon  con- 
taining from  one-tenth  to 
one-half  sheet  of  No.  4 
foil,  which  is  annealed  by 
holding  it  in  the  center 
with  the  pliers  and  rapid- 
ly passing  it  through  the 
flame.  When  the  gold  is 
ready  to  introduce  and 
the  cavity  is  carefully 
dried  and  protected 
against  moisture — abso- 
lute dryness  being  very 
essential  in  the  use  of  all 
the  cohesive  forms  of 
gold — the  first  pellet,  or  the  end  of  the  rope  or  ribbon,  when  such 
forms  are  used,  is  carried  from  the  flame  to  a  retaining  point  in  the 
cavity,  where  it  is  securely  anchored  by  being  thoroughly  consolidated 
by  means  of  instruments  having  fine  serrated  points.  As  soon  as  the 
retaining  points  are  solidly  filled,  the  gold  is  built  up  from  these  over 
the  bottom  and  sides  of  the  cavity,  care  being  taken  to  condense  it 
well  against  the  walls  as  it  approaches  the  orifice.  Every  pellet  or  fold 
must  be  consolidated  as  it  is  introduced,  and  the  gold  built  up  higher 
against  the  walls  of  the  cavity  than  in  the  center,  until  the  orifice  is 
reached,  when  the  depression  left  in  the  center  can  be  filled  up.  Very 
lightly  rolled  or  folded  gold  should  be  applied  to  the  walls  of  the  cavity, 
else  it  may  clog,  and  cannot  be  consolidated  to  such  a  degree  as  is 
necessary  to  give  solidity  to  the  filling.  It  is  beyond  question  that  to 
the  introduction  of  the  rubber  dam  is  due  the  splendid  achievements 
with  cohesive  gold  of  the  present  time,  as  it  is  absolutely  necessary  that 
such  gold,  during  its  manipulation,  should  be  kept  perfectly  dry.  The 
rubber  dam  has,  therefore,  become  an  indispensable  aid  in  all  manipu- 
lations with  gold  as  a  filling  material.  Should  moisture  interfere  with 
the  introduction  of  gold  in  filling  a  tooth,  it  is  far  preferable  to  re- 


FiG.  434. 


COHESIVE    GOLD    FOIL. 


^97 


move  all  that  has  been  introduced  and  commence  anew  than 
to  depend  upon  any  attempt  to  dry  the  surface  by  means  of 
heated  air  from  the  hot-air  syringe. 

Figs.  423,  425,  426  and  427  (pages  486,  487  and  488) 
represent  the  forms  of  instruments  for  introducing  and  con- 
solidating cohesive  gold  foil. 

Heavy  Foil. — A  number  of  years  ago  attention  was  directed 
by  Dr.  Robert  Arthur  to  the  use  of  the  heavy  numbers  of  gold 
foil  for  filling  teeth  ;  and  later  the  interest  in  this  form  of  gold 
revived  to  such  a  degree  that  very  many  advocated  its  claims. 

Nos.  15,  20,  30,  60,  120,  and  even  higher  numbers  have 
been  used.  Nos.  15  and  20  can  be  consolidated  by  hand 
force,  if  such  is  desired,  while  the  heavier  numbers  require 
mallet  force.     The  method  of  manipulating  this  foil  is  to  cut 


Fig.  435. 


it — without  allowing  it  to  come  in  contact  with  the  fingers — 
into  pieces  varying  from  one-fourth  to  three-fourths  of  an  inch 
square,  or  into  strips  of  a  proper  width  and  length  to  suit  the 
cavity  to  be  filled.  The  gold  is  then  annealed  by  heating 
each  piece  or  strip,  held  by  the  pliers  in  the  flame  of  an  alco- 
hol lamp,  to  a  red  heat.  For  filling  the  front  teeth  the  strip 
is  preferable,  condensing  each  layer  across  the  entire  surface 
of  the  cavity  and  folding  the  strip  upon  itself.  Retaining 
points  are  solidly  filled  and  the  gold  built  from  one  to  the 
other,  presenting  as  uniform  a  surface  as  possible,  and  not 
allowing  the  foil  to  become  crumpled  or  folded  irregularly 
upon  itself.  For  filling  the  posterior  teeth  the  small  pieces 
are  preferable,  introduced,  like  the  strip,  with  the  pliers,  and 
each  one  thoroughly  consolidated.  The  gold  should  be 
32 


498 


DENTAL    SURGERY. 


carefully  condensed  at  and  over  the  margins  of  the  cavity,  layer  by 
layer. 

The  manufacture  of  these  heavy  foils  by  rolling  instead  of  beating  is 
said  to  render  them  softer  and  more  cohesive ;  but,  in  the  editor's 
opinion,  this  form  of  gold  offers  no  advantages  over  the  lighter  num- 
bers, such  as  No.  4.  On  the  contrary,  it  is  decidedly  more  difficult 
of  manipulation  and  f9.r  less  easily  adapted  to  the  walls  of  the  cavity. 
Some  have  found  it  useful  for  finishing  out  the  surfaces  of  large  fillings. 

Fig.  435  represents  a  set  of  Dr.  C.  R.  Butler's  instruments  for 
manipulating  the  heavy  foils  with  mallet  force. 

CRYSTAL   OR   SPONGE   GOLD. 

In  the  use  of  crystal  or  sponge  gold  a  different  method  of  procedure 
is  required  from  that  employed  with  foil. 

The  chief  difference  between  the  instruments  employed  for  intro- 
ducing and  consolidating  crystal  gold  in  the  cavity  of  a  tooth  and 


Fig.  436. 

those  used  for  gold  foil,  consists  mainly  in  having  the  working  ex- 
tremity blunt,  varying  in  diameter  from  a  line  to  almost  a  mere  point, 
with  shallow  serrations  upon  the  surface. 

Fig.  436  represents  a  set  of  instruments  well  adapted  for  the  manipu- 
lation of  crystal  gold. 

In  filling  teeth  with  crystal  gold  the  cavity  is  prepared  in  the  same 
manner  as  when  leaf  gold  is  employed.  This  done,  the  gold  is  cut,  or 
rather  torn,  from  the  block  with  the-point  of  an  instrument,  into  small 
pieces,  varying  in  size  according  to  the  dimensions  of  the  cavity  and 
the  particular  stage  of  the  operation  in  which  it  is  to  be  used.  It 
being  important  that  the  crystals  or  particles  composing  the  mass 
should  be  as  little  separated  or  displaced  as  possible  before  the 
piece  is  carried  to  its  place  in  the  tooth,  this  form  of  gold  should 
be  used  in  pellets  as  large  as  can  be  introduced  into  the  cavity  with- 


CRYSTAL    OR    SPONGE    GOLD.  499 

otit  crumbling.  The  gold  being  divided  into  pieces  of  the  proper 
size,  the  cavity  is  washed,  and  then  wiped  dry  with  prepared  cotton, 
or  flax  and  bibulous  paper  ;  a  piece  of  gold,  as  large  as  the  orifice  of 
the  cavity  will  receive,  is  taken  up  with  suitable  pliers  or  one  of  the 
sharp-pointed  instruments,  as  may  be  most  convenient. 

The  spongy  mass  readily  adheres  to  the  serrated  surface  of  the  work- 
ing extremity  when  pressed  gently  upon  it,  and  with  this  it  may,  in 
most  cases,  be  carried  to  the  bottom  of  the  cavity.  Every  part  must 
now  be  thoroughly  consolidated,  first  with  a  large,  and  next  with  a 
smaller,  and  lastly  with  a  very  delicately-pointed  instrument,  so  bent 
that  it  may  be  readily  applied  to  all  the  depressions  and  inequalities 
of  the  walls  and  floor  of  the  cavity ;  for  unless  the  fold  is  made  abso- 
lutely solid  in  these  places,  as  well  as  throughout  all  the  parts  of  the 
filling,  the  success  of  the  operation  will  be  more  or  less  uncertain. 
Thus,  piece  after  piece  is  applied,  consolidating  each  one  as  the  oper- 
ation progresses,  until  the  gold  protrudes  sufficiently  from  the  orifice 
of  the  cavity  to  admit  of  a  good  finish,  leaving  the  surface  flush  with 
that  of  the  tooth. 

If,  during  any  part  of  the  operation,  the  smaller-pointed  instruments 
can  be  forced  between  the  gold  and  the  walls  of  the  cavity,  such  open- 
ing or  openings  should  be  filled  with  smaller  masses  of  the  material 
before  another  large  piece  is  introduced.  This  precaution  ought  never 
to  be  neglected  ;  for  should  any  soft  places  exist  after  the  completion 
of  the  operation,  the  iilling  will  be  apt  to  absorb  moisture,  and  ulti- 
mately to  crumble  and  come  out.  It  is  also  indispensably  necessary 
that  the  gold,  during  its  introduction  into  the  tooth,  be  kept  absolutely 
free  from  moisture,  as  this  destroys  the  cohesive  or  welding  property  of 
the  crystals. 

The  gold  having  been  introduced  and  consolidated  as  directed,  the 
exposed  surface  is  scraped  or  filed  down  to  a  level  with  the  orifice 
of  the  cavity,  then  made  smooth  by  rubbing  it  with  Arkansas  stone 
or  with  finely-powdered  pumice,  and  burnished  or  polished  with 
crocus,  in  the  manner  as  described  when  gold  foil  is  used. 

In  finishing  a  filling  made  with  these  preparations  of  gold  the 
operator  should  see  that  there  are  no  thin,  overlapping  portions  upon 
the  teeth  outside  of  the  orifice  of  the  cavity.  They  are  liable,  in 
biting  hard  substances  or  in  ordinary  mastication,  to  be  broken  off, 
leaving  a  depression  for  the  lodgment  of  extraneous  matter  and 
clammy  secretions.  Sooner  or  later  this  will  give  rise  to  a  soften- 
ing of  the  dentine  thus  exposed,  which,  if  it  does  not  cause  the 
filling  to  loosen,  will  ultimately  render  its  removal  and  replacement 
necessary.  In  short,  the  precautions  necessary  to  be  observed  in 
making   a    filling   with   gold    foil    are   equally   necessary   when    the 


500 


DENTAL    SURGERY. 


operation  is   made  with  either  of  the  preparations  now  under  con- 
sideration. 

Mallei  Force  in  Consolidating  Gold. — A  number  of  years  ago  Dr.  W. 
H.  Atkinson  introduced  a  method  of  consolidating  gold  by  means  of 
mallet  force,  which  has  now  become  a  favorite  one  with  many  of  the 
best  operators  in  the  profession.  He  claimed  for  this  method  the 
following  advantages  over  hand  pressure :  A 
more  perfect  condensation  of  the  gold  and  a 
more  thorough  welding  than  can  be  made  by 
hand  pressure  ;  that  the  gold  will  be  anchored 
in  its  position  with  much  more  facility;  that  the 
instrument  always  acts  under  the  mallet  upon  the 
designed  point,  does  not  slip  from  its  position, 
and,  consequently,  there  is  no  liability  of  abrading 
or  wounding  the  soft  parts ;  that  mallet  force  is  not 
more  unpleasant  to  the  patient  than  the  ordinary 
method  of  condensing,  and  that  it  is  far  less  fatigu- 
ing than  hand  pressure  in  protracted  operations. 

That  mallet  force  is  an  effective  method  of 
condensing  the  cohesive  forms  of  gold  there  can 
be  no  question. 

Mallets  of  almost  every  description  have  been 

used,  such  as  wood,  lead,  tin,  copper,  brass,  steel, 

ivory,  and  vulcanized  rubber. 

The  steel  mallet,  however,  is  considered  by  many  to  produce  the 

best  results,  while  the  lead  mallet  gives  a  dead  blow  and  may  be  more 

agreeable  to  the  patient. 

Heavy  lead  and  tin  mallets,  weighing  from  four  and  a  half  to  six 
and  a  half  and  even  eight  ounces,  are  preferred  by  many  of  the 
advocates  of  the  hand  mallet. 

In  using  the  hand  mallet,  which  is  represented  in  Fig.  437,  the  aid 
of  an  assistant  is  necessary,  who  taps  the  end  of  the  plugger  squarely 
with  sharp,  springing  strokes,  while  the  principal  operator  directs  its 
condensing  point  over  the  gold  as  it  is  introduced  into  the  cavity. 

With  instruments  called  automatic  mallet  pluggers — Figs.  438  and 
439  represent  Snow  and  Lewis's,  Fig.  440  Abbott's — the  aid  of  an 
assistant  is  unnecessary. 

All  of  these  forms  operate  by  the  action  of  a  spiral  spring,  and  some 
of  them  have  a  back  action. 

Automatic  pluggers  for  use  with  the  dental  engine  are  also  employed 
for  the  condensation  of  gold  in  filling  teeth. 

Fig.  441  represents  an  engine  mallet  invented  by  Dr.  W.  G.  A.  Bon- 
will,  having  his  hand-piece  attached.     This  engine  mallet  gives  a  very 


MALLET   FORCE    IN    CONSOLIDATING   GOLD. 


501 


e-D 


vp'A  I  k'i  .'l  l.^  I'l 


Fig.  458 


Fig.  439. — Double  Action. 


Fig.  440. 


502 


DENTAL    SURGERY. 


satisfactory  blow,  and  requires  but  little  foot  power,  and  can  be  worked 

by  either  foot  and  on  either  side  of  the  chair. 

Fig.  442  represents  the  electro-magnetic  mallet  invented  by  Dr.  W. 

G.  A.  Bonwill,  which  is  used  by  many  of  the  most  skillful  operators. 

The  blow  is  delivered 
upon  the  packing  instru- 
ment, just  at  the  point 
where  its  force  is  great- 
est, as  the  attraction  of 
the  magnets  constantly 
increases  as  the  mallet 
approaches  them  until  the 
circuit  is  broken.  By 
combining  the  stem  and 
holder  of  the  Electric 
Mallet  with  the  striking 
mechanism  of  the  Me- 
chanical Mallet  No.  i, 
an  appliance  is  formed  in 
which  the  operator  can 
use  effectively  the  long- 
handle  pluggers  made  for 
the  electric  mallet.  Ordi- 
nary socket-points  can 
also  be  used  in  it  with 
equal  facility  by  means 
of  the  proper  socket- 
handles. 

Fig.  443  represents  a 
set  of  instruments  devised 
by  the  late  Dr.  Marshall 
H.  Webb,  for  use  with  the 
electro-magnetic  mallet. 

Finishing  the  Surface 
of  the  Filling.  — After  hav- 

JjPJIfjj  \nf  ing    thoroughly   consoli- 

if  \\  dated  the  surface  of  the 

filling,  finishing  files, 
such  as  are  represented 
in  Fig.  444,  are  used  to  remove  the  protruding  portions  of  gold  and 
to  form  a  smooth,  uniform  surface,  free  from  the  slightest  indentations 
which  may  afford  lodgment  to  extraneous  matter.  This  is  a  point 
never  to  be  lost  sight  of;  for,  however  excellent  the  filling  may  be  in 


Fig.  441. 


Fig.  442. 


FINISHING    FILLINGS. 


503 


Fig.  443- 


Fig.  444' 


504 


DENTAL   SURGERY. 


W 


II     A  other  respects,   if  the  surface  is  not    smooth, 

/       I  uniform,  and  flush  with  the  orifice  of  the  cavity, 

I        I  the  object  intended  to  be  accomplished  by  it 

I         n  J   will  be  partially,  if  not  wholly,  defeated. 

'ijl  //         It  is  better,  however,  to  cut  off  but  a  portion 

of  the  protruding  gold  at  first,  and  then  to 
burnish,  condense,  and  to  cut  a  second  time, 
with  a  fine  file  or  bur  or  an  emery  strip,  all  it 
is  necessary  to  remove.  After  each  filing,  and 
before  applying  the  burnisher,  the  surface 
should  be  cleansed  of  all  loose  pieces  of  gold. 
After  a  second  burnishing,  the  Arkansas, 
Hindostan,  or  Scotch 
stone,  or  finely-pow- 
dered pumice,  may  be 
applied  to  the  surface, 
to  remove  all  the  file 
scratches  and  other  as- 
perities. For  a  filling 
in  the  approximal  sur- 
face of  a  tooth  the  stone 
may  be  shaped  like  a 
pinion  file ;  it  should 
be  frequently  dipped  in 
water,  and  when  its 
pores  become  filled  with 
gold  the  surface  may  be 
ground  off  by  rubbing 
it  on  a  corundum  slab. 
If  the  filling  is  finished 
with  pumice,  it  may  be 
applied  with  floss  silk 
or  tape  moistened  with 
water,  by  drawing  it 
backward  and  forward 
across  the  surface  of  the 
filling. 

Fig.  445  represents 
plug-finishing  files,  for 
finishing  contour  com- 
pound gold  operations  in  the  approximal  surfaces  of  teeth.  With  them 
the  gold  can  be  so  finished  as  to  restore  the  natural  contour,  thereby 
preventing  the  surfaces  of  the  teeth  from  assuming  an  unnatural  contact. 


Fig.  445. 


FINISHING    FILUNGS. 


505 


Fig.    446  represents    different  forms  of  plug-finishing  burs  for  use 
with  the  dental  engine. 


Knife.  Edge. 


Fig.  447  represents  an  excellent  file-carrier,  contrived  by  Dr.  Forbes, 
for  files  for  finishing  fillings  on  the  approximal  surfaces  of  the  front 
teeth,  and  Fig.  448  a  tape-carrier. 


Fig.  447- 


Fig.  448. 


;o6 


DENTAL    SURGERY. 


Fig.  449  represents  a  small  split  tape  arbor  for  carrying  a  short  piece 
of  polishing  tape  (Fig.  44ga),  which  by  the  turning  of  the  bit  in  the 
,;  /,  hand-piece  is  rolled  on  to  the  arbor  and  becomes  a  small 
polishing-point  that  will  reach  fissures  and  depressions 
between  cusps  to  finish  fillings  or  gold  contour  work  in  a 
quick  and  superior  manner.  Fig.  449  i  shows  the  small 
size  of  the  polishing  point  thus  obtained,  but  by  rolling 
on  a  longer  piece  of  tape  a  correspondingly  larger  point 
will  be  made.     Sand-paper  discs  are  also  useful. 

If  the  filling  is  in  the  grinding,  buccal,  or  palatine 
surface  of  a  molar  or  bicuspid,  a  long  piece  of  stone, 
having  a  small,  triangular,  and  slj^ghtly  oval  point,  may  be 
used  ;  if  powdered  pumice-stone  be  employed,  it  may  be 
used  on  the  point  of  a  similarly-shaped  piece  of  soft  wood,  previously 
softened  in  water.  After  all  the  asperities  have  been  cut  down,  the 
surface   should   be  washed  until  every  particle  of  grit   is  removed. 


Fig.  450. 


This  done,  it  may  be  polished  with  a  suitable  burnisher,  dipped  from 
time  to  time  in  a  solution  of  pure  Castile  soap,  until  the  filling  is  ren- 
dered as  brilliant  as  a  mirror.  Fig.  450  represents  various  forms  of 
burnishers. 


Fig.  451. 


Fig.    451    represents   a  set  of  burnishers  for  use  with  the  dental 
engine.     Also,  Dr.  Brown's  metal  tape,  used  with  wet  polishing  pow- 


FINISHING    FILLINGS. 


507 


der,  will  be  found  very  effective,  especially  in  spaces  too  small  for  the 
entrance  of  silk  (Fig.  452). 

Various  instruments  are  used  in  the  process  of  finishing  the  surface 
of  metallic  fillings,  such  as  coarse  and  fine 
burs,  corundum  points,  wood  points,  emery 
strips,  sand-paper  discs,  all  rotated  by  the 
dental  engine. 
f'^31  I' J  Fig.  453  represents  finishing  strips  with 
crimped  finger-holds,  for  proximate  surface- 
fillings. 

Fig.  454  represents  Dr.  J.  W.  Smith's 
mandrels  for  carrying  paper,  felt,  or  rubber 
discs. 

Having  proceeded  thus  far,  the  surface  may 

be  again  washed  and  the  operation  completed 

nil    III     by  rubbing  it  from  three  to  six  minutes  with 

dry  floss  silk.     Rouge  or  rotten  stone  applied 

to  the  surface  on    tape,  or   finely-powdered 


mm' 

m 


Fig.  452- 


Fig.  4;3- 


silex  or  pumice-stone  on  a  piece  of  orange-wood  after  it  is  prepared 
by  the  method  just  described,  will  remove  the  bright  metallic  lustre— 
when  this  is  objectionable  on  account  of  the  exposure  of  the  filling— 


5o8  DENTAL    SURGERY. 

and  leave  a  fine  finish.  Holly  strips  in  the  form  of  thin  shavings 
answer  admirably  for  applying  levigated  pumice,  rouge,  etc.,  in  the 
polishing  process. 

Non- Conductors. — When  the  caries  has  penetrated  nearly  to  the  pulp 
cavity,  the  presence  of  a  gold  or  any  other  metallic  filling  is  sometimes 
productive  of  considerable  pain  and  irritation,  especially  when  hot  or 
cold  fluids  are  taken  into  the  mouth  or  during  the  inspiration  of  cold 
air.  In  some  cases  inflammation  and  suppuration  of  the  pulp  super- 
vene. To  prevent  these  disagreeable  results  a  variety  of  means  have 
been  proposed.  Dr.  Solyman  Brown  recommended  placing  asbestos, 
this  being  a  non-conductor  of  caloric,  on  the  bottom  of  the  cavity 
previously  to  the  introduction  of  the  gold.  The  author  prefers  chloro- 
percha,  which  may  be  used  in  the  form  of  a  thick  solution,  or  a  layer 
of  thin  gutta-percha  may  be  placed  at  once  in  the  bottom  of  the 
cavity.  When  the  solution  is  used  a  drop  may  be  placed  in  the 
cavity,  and  a  sufficient  time  allowed  for  the  chloroform  to  evaporate 
before  introducing  the  filling.  A  thin  layer  of  "Hill's  stopping," 
of  which  gutta-percha  forms  the  principal  ingredient,  may  be  used 
with  equal  advantage.  Oxychlorids  and  oxyphosphates  of  zinc  have 
also  been  used  for  the  same  purpose,  but  the  latter  are  less  irritating 
than  the  former,  and  neither  possesses  any  advantages  over  gutta- 
percha. 

The  time  required  by  an  expert  operator  to  fill  a  tooth  well  may  be 
said  to  vary  from  thirty  minutes  to  two  hours  and  a  half,  or  even  longer, 
according  to  the  size,  shape,  and  situation  of  the  cavity,  and  in  some 
cases  a  much  longer  time  will  be  required.  Less  time  and  skill  are 
usually  required  to  fill  a  cavity  in  the  grinding  than  in  the  approximal 
surface  of  a  tooth  ;  but  the  operation  in  either  place,  to  be  beneficial 
to  the  patient,  must  be  performed  in  the  most  thorough  manner.  The 
dentist  who  does  not  feel  the  importance  of  making  all  his  operations 
as  perfect  as  possible  should  never  be  intrusted  with  the  management 
of  these  important  organs.  Want  of  attention  to  two  points  in  the 
consolidation  of  a  filling  often  causes  the  ultimate  failure  of  operations 
in  all  other  respects  well  performed.  First,  by  not  making  sufficient 
lateral  compression  whilst  introducing  the  gold  the  surface  is  apt  to 
be  more  solid  than  the  interior.  Consequently  the  filling  may  drop 
out  for  want  of  a  firm  contact  against  the  sides  ;  or,  if  retained,  it  is 
apt  on  grinding  surfaces  to  be  pressed  inward,  leaving  a  space  around 
the  orifice  for  the  penetration  of  fluids.  Second,  want  of  care  in  con- 
densing around  the  edges  of  the  filling  will,  by  the  crumbling  away  or 
scaling  off  of  portions  of  the  gold,  expose  the  edges  of  the  cavity  to 
decay. 

In  every  part  of  the  operation  the  dentist  should  so  guard  his  instru- 


KILLING    THE    SUPERIOR    INCISORS    AND    CUSPIDS.  509 

ments  as  to  prevent  them  from  slipping,  which  he  will  usually  be  better 
able  to  do  by  standing  a  little  to  the  right  and  behind  his  patient  than 
in  any  other  position.  In  filling  the  lower  teeth  he  should  stand 
several  inches  higher  than  while  filling  the  upper,  and  for  this  purpose 
he  should  have  a  stool  or  movable  platform  on  which  to  stand.  When 
it  can  be  done,  he  should  grasp  the  tooth  with  the  thumb  and  fore- 
finger of  his  left  hand,  not  only  to  prevent  it  from  being  moved  by 
the  pressure  he  applies,  but  also  to  catch  the  point  of  the  instrument 
in  case  it  should  slip  ;  if  he  is  always  careful  to  press  in  a  direction 
toward  the  orifice  of  the  cavity  this  need  not  happen  ;  nevertheless,  he 
should  always  take  the  precaution  to  guard  against  possible  accident. 
When  he  cannot  shield  the  mouth  with  the  thumb  and  finger  of  his 
left  hand,  he  should  let  the  thumb  or  one  of  the  fingers  of  his  right 
rest  either  upon  the  tooth  he  is  operating  on  or  upon  some  other. 

For  the  special  application  and  modification  of  these  general  direc- 
tions the  reader  is  referred  to  the  filling  of  individual  cavities  in  teeth. 

FILLING    INDIVIDUAL    CAVITIES    IN    TEETH. 

To  describe  the  method  of  filling  each  individual  cavity  in  every 
locality  in  which  a  tooth  is  liable  to  be  attacked  by  caries  would  be 
unnecessarily  tedious.  But  as  this  is  one  of  the  most  important  and, 
at  the  same  time,  one  of  the  most  difficult  operations  in  dental  sur- 
gery, it  may  be  well  to  enter  a  little  more  into  detail  upon  the  subject 
than  we  have  as  yet  done.  In  doing  this  the  writer  will  confine  him- 
self, for  the  most  part,  to  the  manner  of  filling  a  cavity  in  each  of  the 
following  localities,  which  are  the  parts  of  teeth  most  liable  to  caries. 

First.  In  the  approximal  and  labial  surfaces  of  the  superior  inci- 
sors, and  cuspids  and  the  palatine  surfaces  of  the  incisors,  the  anterior 
surfaces  of  the  cuspids  and  the  posterior  surfaces  of  cuspids  and  inci- 
sors being  rarely  attacked  by  caries. 

Second.  In  the  grinding,  approximal,  buccal,  and  palatine  surfaces 
of  the  molars  and  bicuspids  of  the  u])per  jaw. 

Third.  In  the  approximal  surfaces  of  the  inferior  incisors  and 
cuspids. 

Fourth.  In  the  grinding,  approximal,  and  buccal  surfaces  of  the 
molars  and  bicuspids  of  the  lower  jaw. 

Other  parts  of  the  teeth  sometimes  become  the  seat  of  caries,  but 
the  foregoing  are  the  localities  most  liable  to  be  attacked  by  the 
disease. 

FILLING    THE    SUPERIOR    INCISORS    AND    CUSPIDS. 

I.  With  Non-cohesive  Gold  Foil.— In  describing  the  manner  of 
introducing  a  filling  in  one  of  the  first-named  teeth,  we  shall  com- 
mence with   the  right  approximal  surface  of  the  left  central  incisor. 


5iO  DENTAL    SURGERY. 

The  directions  we  propose  giving  for  the  performance  of  the  operation 
here  will  be  applicable,  with  a  few  exceptions,  to  the  same  surface  on 
all  the  upper  incisors.  As  a  general  rule,  the  gold  should  be  intro- 
duced from  behind  the  teeth  forward  and  upward,  and  for  the  following 
reasons :  i .  When  the  aperture  between  the  teeth  has  been  formed 
with  a  cutting  instrument  it  should,  when  circumstances  of  the  case 
will  permit,  and  for  reasons  stated  in  another  place,  be  made  wider 
behind  than  before  ;  consequently  the  diseased  part  can  be  most  easily 
approached  from  this  direction.  2.  The  gold,  in  the  majority  of  cases, 
can  be  more  conveniently  introduced  from  the  palatine  side,  and  the 
force  required  for  condensing  it  can  be  more  advantageously  applied. 

The  exceptions  to  the  above  rule  are  when  the  approximal  side  of  the 
tooth  is  turned  slightly  forward  toward  the  lip,  and  when  the  caries  is 
situated  nearer  the  labial  than  the  palatine  angle  ;  also,  when  the  teeth, 
instead  of  occupying  a  vertical  position  in  the  alveolar  border,  or  pro- 
jecting slightly,  as  they  usually  do,  incline  backward  toward  the  roof 
of  the  mouth.  It  sometimes  happens,  too,  when  they  are  separated  by 
pressure,  that  the  diseased  part  can  be  most  conveniently  reached  from 
the  front  surface. 

The  instrument  which  the  author  has  found  best  adapted  for  the  in- 
troduction of  the  gold  into  a  cavity  in  the  right  approximal  surface  of 


Fig.  455. 

an  incisor  or  cuspid  tooth  is  represented  in  Fig.  455.  The  width  and 
length,  as  well  as  the  curvature  or  angle  of  the  point,  should  vary 
according  to  the  size  of  the  cavity  and  the  width  of  the  space  between 
the  teeth. 

The  stem  of  the  instrument,  as  well  as  the  shank,  should  be  strong 
enough  to  sustain  any  amount  of  pressure  which  it  may  be  necessary  to 

apply  in  forcing  the  folds  of 
gold  tightly  against  each  other. 
The  point  should  be  wedge 
shape  and  the  extremity  ser- 
rated. 

The  decay  having  been  removed,  the  cavity,  properly  shaped, 
cleansed,  dried,  and  protected,  is  ready  for  the  reception  of  the  gold. 
The  patient  should  be  seated  in  a  chair  sufficiently  high  to  bring  the 
head  on  a  level  with  the  breast  of  the  operator  and  resting  on  the  head- 
piece of  the  chair,  with  the  face  upward.  The  operator,  standing 
upon  the  right  side,  should  support  the  ]>atient's  head  firmly  with  his 


==\ 


Fig.  456. 


FILLING    THE    SUPERIOR    INCISORS    AND    CUSPIDS. 


Fig.  457. 


left  arm  during  the  operation,  while  with  the  forefinger  of  the  same 
hand  the  upper  lip  is  held  out  of  the  way.  The  middle  finger  of  the 
same  hand  ought  to  rest  on  the  end  of  a  tooth  to  the  left  of  the  one  on 
which  the  operation  is  being  performed,  while  with  the  little  finger  the 
lower  lip  may  be  gently  depressed.  The  roll  or  strip  of  gold  is  first 
introduced  with  the  foil  pliers. 

During  the  introduction  of  the  gold  the  instrument  should  be  held 
in  the  right  hand  of  the  operator  (Fig.  457),  and  grasped  with  suffi- 
cient firmness  to  prevent  it  from  slipping  or  rotating. 

In  introducing  the  gold  the  first  fold  should  be  applied  against  the 
upper  wall  of  the  cavity, 
that  the  pressure  may  always 
be  exerted  in  a  direction 
toward  the  extremity  of  the 
root,  applying  each  addi- 
tional fold  as  closely  to  the 
preceding  one  as  possible. 
The  folds  should  also,  in 
their  introduction,  be  ap- 
plied as  closely  to  the  labial 
and  palatine  walls  of  the  cavity  as  possible,  but  always  directing  the 
pressure,  when  these  are  thin  and  brittle,  in  the  direction  of  the  axis 
of  the  root. 

When  the  lower  part  of  the  cavity  is  very  narrow,  as  is  often  the 
case,  especially  where  it  extends  nearly  to  the  labial  angle  of  the  tooth, 
it  is  often  necessary  to  change  the  instrument  for  one  having  a  smaller 
point. 

To  carry  a  fold  of  gold  to  the  bottom  of  a  cavity  upon  the  point 
of  the  instrument,  without  breaking  or  cutting  it,  requires  some  tact. 
The  point  should  never  be  carried  directly  toward  the  bottom ;  on 
entering  the  orifice,  it  should  be  inclined  toward  the  wall  of  the 
cavity  opposite  the  one  against  which  the  folds  are  first  laid.  Equally 
as  much  tact  is  required  to  prevent  displacing  the  gold  before  a  suffi- 
cient quantity  has  been  introduced  to  procure  support  for  it  from  the 
surrounding  walls,  which  is  an  accident  particularly  apt  to  occur  with 
young  practitioners,  when  the  cavity  is  superficial  and  has  a  large 
orifice.  To  prevent  this,  the  folds  of  gold  should  be  long  enough  to 
project  some  distance  from  the  orifice,  that  they  may  receive  support 
from  the  adjoining  tooth,  and  from  the  thumb  and  forefinger  of  the 
left  hand  of  the  operator,  until  the  operation  has  reached  that  stage 
when  sufficient  stability  shall  have  been  obtained  from  the  walls  of  the 
cavity. 

There  are  cases  in  which  an  instrument  like  the  one  represented 


512  ■  DENTAL   SURGERY. 

in  Fig.  458  can  be  very  advantageously  employed  in  the  introduction 
of  the  gold ;  but  in  the  majority  of  cases  the  instrument  represented 
in  Fig.  455  will  be  found  more  convenient. 

After  having  filled  the  cavity  so  thoroughly  that  a  small  wedge- 
pointed  instrument  cannot  be  made  to  penetrate  the  gold  at  any 
point,  the  extruding  portion  of  the  filling  should  be  consolidated, 
beginning  with  the  portions  overlapping  the  lower  part  of  the  tooth 
and  the  edge  of  the  posterior  wall.  These  should  be  carefully  and 
firmly  pressed  toward  the  cavity  with  an  instrument  having  a  flat 
point,  like  the  one  represented  in  Fig.  459.  This  done,  it  may  be 
firmly  applied  to  every  part  of  the  surface  of  the  filling,  continuing 


Fig.  458.  Fig.  459. 

the  pressure  as  long  as  the  point  of  the  instrument  can  be  made  to 
indent  the  gold. 

When  the  space  between  the  teeth  is  very  narrow,  an  instrument 
shaped  as  in  Fig.  460  may  be  used.  The  operator  should  be  provided 
with  two  or  three  instruments  like  each  of  the  two  last,  varying  in  the 
size,  length,  and  curvature  of  their  points. 

During  the  process  of  consolidating  the  gold,  the  tooth  should  be 
firmly  grasped  between  the  thumb  and  forefinger  of  the  left  hand ; 
this  prevents  it  from  being  pressed  too  forcibly  against  the  opposite 
side  of  the  socket,  while,  at  the  same  time,  the  end  of  the  forefinger, 
by  being  placed  above  the  instrument,  assists  in  directing  its  point 


Fig.  460. 

and  serves  to  keep  it  from  slipping.  When  the  labial  and  palatine 
walls  of  the  cavity  are  very  thin,  great  care  is  necessary  to  prevent 
fracturing  them  in  introducing  and  consolidating  the  gold.  The 
consolidation  should  be  commenced  around  the  edges,  and  the  pressure 
applied  toward  the  centre  of  the  cavity. 

It  sometimes  happens  that  the  caries  extends  forward  to  the  labial 
angle  of  the  tooth,  and  upward,  at  the  same  time,  under  the  edge  of 
the  gum.  Great  difficulty  is  often  felt  in  thoroughly  filling  this 
portion  of  the  cavity,  and  it  cannot  always  be  done  from  behind  the 
tooth.  In  this  case,  after  having  filled  the  cavity  in  the  manner  as 
already  described,  the  operator  may,  standing  on  the  left  side  of  the 
patient,  and  with  an  instrument  having  a  wedge-shaped  point  (Fig. 


FILLING   THE   SUPERIOR   INCISORS   AND    CUSPIDS.  513 

461),  make  as  large  'an  opening  as  possible  in  the  gold.  This  done, 
he  may  grasp  the  left  lateral  incisor  or  cuspid  tooth  with  the  thumb 
and  middle  finger  of  his  left  hand,  elevating  the  upper  lip  with  the 
forefinger  of  the  same  ;  then,  with  the  instrument  held  as  in  Fig.  462, 
he  may  proceed  to  introduce  the  gold,  filling  the  upper  part  of  the 
opening  first.  After  introducing  fold  after  fold,  until  the  cavity  is 
completely  and  compactly  filled,  the  extruding  portion  should  be  con- 
solidated with  a  similarly-shaped  instrument,  having  a  flat,  serrated 
point,  this  style  of  point  being  preferable  to  the  round  point  for  intro- 
ducing and  consolidating  non-cohesive  gold. 

The  size  of  the  roll  of  gold  must  be  varied  to  suit  the  size  of  the 
cavity,  though  it  should  seldom  have  in  it  more  than  a  fourth  of  a  leaf 
of  No.  4.  If  more  than  this  is  employed  at  one  time,  it  will  be 
difficult  to  apply  the  folds  sufficiently  near  each  other. 

The  method  of  filling  the  right  central  incisor  in  the  left  approximal 


Fig.  462. 


surface  is  so  very  similar  to  that  of  filling  the  left  in  the  right  side 
that  it  will  not  be  necessary  to  enter  so  minutely  into  detail.  In  this, 
as  in  the  other  case,  the  gold,  as  a  general  rule,  should  be  introduced 
from  behind  the  tooth,  forward  and  upward  ;  but  if  introduced  from  the 
front,  the  operator  should  still  stand  on  the  right  side  of  the  patient. 
The  head  should  have  the  same  elevation  and  inclination  backward 
but  the  face  should  be  turned  more  toward  the  operator,  to  give  him  a 
better  view  of  the  cavity  in  the  tooth,  and  to  enable  him  to  reach  it 
more  readily  with  the  instrument. 

The  cavity  being  formed,  cleansed,  and  dried,  the  operator  may 
proceed  to  introduce  the  gold  as  already  directed,  with  an  instrument 
like  the  one  represented  in  Fig.  455.  In  many  cases,  however,  he 
will  require  one  having  a  somewhat  longer  point,  and  curved  at  nearly 
a  right  angle  with  the  stem.  The  instrument  should  be  held  some- 
what differently  in  the  hand  (Fig.  463),  and  grasped  firmly  with  the 
thumb  and  fore  and  middle  finger,  so  as  to  prevent  it  from  rotating. 
33 


5^4 


DENTAL   SURGERY. 


The  head  should  be  securely  confined  with  the  left  arm,  the  upper  lip 
raised  with  the  left  thumb,  pressing  it  at  the  same  time  firmly  against 
the   anterior  surface   of  the   tooth.      The   middle   or   forefinger   of 

the  same  hand  may  be 
placed  against  the  gum 
just  inside  the  tooth,  to 
direct  the  application 
of  the  point  of  the  in- 
strument, prevent  the 
liability  of  its  slipping, 
and  control  the  free  end 
of  the  roll  of  foil.  The 
lower  lip  may  be  de- 
])ressed  either  with  the  middle  joint  of  this  or  with  one  of  the  other 
fingers. 

After  having  placed  one  end  of  the  fold  in  the  cavity,  fold  after 
fold  should  be  introduced  until  it  is  compactly  filled,  except  in  those 
cases  where  the  lower  part  is  very  small,  when  a  smaller-pointed  in- 
strument should  be  employed  for  the  completion  of  the  operation  and, 
indeed,  for  the  introduction  of  all  the  gold,  if  the  cavity  is  not  large, 
or  the  aperture  between  the  teeth  very  narrow. 

For  consolidating  the  extruding  gold,  the  instrument  represented  in 
Fig.  459  "^^'^^  ^11  many  cases,  be  all  that  is  required.  But  the  one 
represented  in  Fig.  464  can  sometimes  be  used  very  advantageously; 


Fig.  463. 


Fig.  465. 


and  the  one  in  Fig.  465  will  be  found  a  useful  condenser  for  the  right 
as  well  as  the  left  approximal  surface  of  an  incisor  or  cuspid  tooth  ; 
and  both  the  last  mentioned  instruments  may  often  be  used  to  great 
advantage  on  the  approximal  surfaces  of  other  teeth.  Some  of  the 
instruments  employed  in  filling  teeth  with  cohesive  and  crystal  or 
sponge  gold  may  also  be  advantageously  employed  in  consolidating  the 
ordinary  gold  in  the  approximal  surfaces  of  the  incisors  and  other 
teeth. 

In  completing  the  operation,  it  is  important  that  every  particle  of 
gold  overlapping  the  orifice,  and  frequently  extending  under  the  free 
edge  of  the  gum,  should  be  removed  before  finishing  the  surface  of  the 
filling  ;  but  the  operator  ought,  at  the  same  time,  to  avoid  as  much  as 
possible  wounding  the  gum  and  peridental  membrane.  As  the  cavity 
frequently  extends  a  little  above  the  gum,  great  care  is  necessary  to 


FILLING    THE    SUPERIOR    INCISORS    AND    CUSPIDS. 


515 


prevent  wounding  it ;  indeed,  there  are  many  cases  in  which  it  cannot 
be  avoided,  imless  the  point  of  the  gum  is  pressed  up  between  the 
teeth  by  the  introduction  of  a  piece  of  raw  cotton,  band  of  rubber  or 
wedge  of  wood,  or  Hill's  stopping,  a  day  or  two  before  the  operation 
of  filling  is  performed. 

In  filling  an  incisor  or  cuspid  tooth  on  the  labial  surface  the  opera- 
tion is  often  very  simple  and  easy,  but  there  are  many  cases  in  which 
it  is  both  difficult  and  tedious.  The  head  of  the  patient  should  rest 
with  the  face  upward,  as  already  described,  and  sustained  in  the  same 
way,  with  the  left  arm  of  the  operator,  while,  with  the  thumb  of  the 
left  hand  placed  on  the  gum  above  the  tooth,  the  upper  lip  should  be 
elevated. 

The  forefinger  should  be  pressed  firmly  against  the  palatine  surface 
of  the  tooth  and  the  left  side  of  the  chin  gently  grasped  with  the 
other  three  fingers.  Then,  with  an  instrument  (Fig.  466)  having  a 
wedge-shaped  point, 
grasped  with  the  right 
hand,  as  in  Fig.  463 
or  467,  the  operator 
should  proceed  to 
introduce  the  gold, 
standing  at   the  right 


x>^" 


^y^' 


Fig.  466. 


Fig.  467. 


side  of  the  patient,  with  the  thumb  of  the  right  hand  resting  on 
a  tooth  to  the  left  of  the  one  he  is  about  to  fill  or  against  the 
cheek.  He  should  commence  by  laying  the  first  fold  against  the  walls 
of  the  cavity  nearest  to  him,  and  thus  introduce  fold  after  fold,  until 
it  is  compactly  filled.  The  extruding  portion  may  be  consolidated 
with  a  round  or  square-pointed  instrument,  or  with  a  sharp-pointed 
one,  as  represented  in  Fig.  468.  Great  care  is  necessary  to  prevent 
the  instrumeut  from  slipping  and  wounding  the  gums.  After  having 
partially  consolidated  the  gold,  the  overlapping  portion  must  be 
firmly  pressed  toward  the  centre  of  the  cavity,  and  the  point  of  the 
instrument  repeatedly  applied  to  every  part  of  the  surface  of  the  filling, 
until  it  can  no  longer  be  made  to  yield  to  pressure.  This  done,  the 
gold  may  be  filed  down  to  the  level  of  the  tooth,  smoothed  with 
Arkansas  stone,  and  burnished  or  polished. 

When  the  cavity  is  shallow  and  the  orifice  broad,  the  gold,  as  it  is 
introduced,  must  be  held  in  its  place  with  the  thumb  of  the  left  hand 


5l6  DENTAL   SURGERY. 

until  a  sufficient  quantity  has  been  placed  in  the  cavity  to  obtain  for 
it  the  necessary  support  from  the  surrounding  walls.  But  in  over- 
coming difficulties  of  this  sort,  the  peculiar  circumstances  of  the  case 
can  alone  suggest  the  proper  means  to  be  employed  by  the  operator. 

The  decay  sometimes  extends  entirely  across  the  labial  surface  of 
the  tooth,  leaving  after  its  removal  a  horizontal  groove  open  at  both 
ends.  In  this  case  the  walls  should  be  made  rough,  wider  at  the 
bottom  than  at  the  opening,  and  the  operation  of  filling  commenced 
at  one  end  by  applying  the  folds  of  foil  alternately  against  the  upper 
and  lower  wall,  and  consolidating  them  so  thoroughly  as  to  prevent 
the  liability  of  their  being  displaced  during  any  subsequent  part  of  the 
operation.  Successive  folds  are  introduced  in  the  same  manner,  each 
in  close  contact  with  the  preceding  series,  until  the  groove  is  com- 
pletely filled,  applying  the  pressure,  during  the  whole  of  the  operation, 
against  the  two  walls.  In  condensing  the  extruding  gold,  the  operator 
should  commence  first  at  one  end  of  the  groove,  then  at  the  other, 
and  afterward  consolidate  the  whole  surface  of  the  filling.  In  finish- 
ing the  operation,  the  same  precaution  with  regard  to  wounding  the 


Fig.  468.  Fig.  469.  Fig.  470. 

gum  and  peridental  membrane  should  be  observed  here  as  recom- 
mended for  the  approximal  surface  of  the  tooth. 

Although  it  rarely  happens  that  the  palatine  surfaces  of  the  upper 
incisors  are  attacked  by  caries,  yet  the  disease  does  sometimes  develop 
itself  there,  in  the  indentations  occasionally  found  a  little  below  the 
free  edge  of  the  gum.  The  removal  of  the  diseased  part,  the  forma- 
tion of  a  cavity,  and  the  introduction  of  a  filling  can,  in  the  majority 
of  cases,  be  more  easily  accomplished  in  this  than  in  any  other  part  of 
an  incisor  tooth. 

The  cavity  being  properly  prepared  for  filling,  the  head  should  be 
placed  as  before  directed,  except  that  the  chin  may  be  a  little  more 
elevated,  to  enable  the  operator  to  obtain  a  more  convenient  view  of 
the  locality  of  his  operation  :  the  thumb  of  the  left  hand  may  be 
placed  on  the  labial  surface  of  the  tooth  and  the  forefinger  on  the 
gum  immediately  above  the  palatine  surface.  He  should  now,  with 
a  wedge-pointed  instrument,  shaped  as  in  Fig.  469,  proceed  to  intro- 
duce the  gold,  applying  the  first  fold  against  the  palatine  wall  or  the 
palato-approximal  angle  of  the  cavity,  as  may  be  most  convenient. 
Having  filled  the  cavity,  the  extruding  gold  may  be  condensed  with 
an  instrument  like  the  one  represented  in  Fig.  470. 


FILLING   THE   SUPERIOR   INCISORS   AND   CUSPIDS.  517 

Sometimes  straight  instruments,  and  at  other  times  instruments 
curved  at  the  points  more  than  those  represented  in  Figs.  469  and 
470,  can  be  more  conveniently  employed,  depending  altogether  upon 
the  size  of  the  mouth  and  the  forward  or  backward  deviation  of  the 
teeth  from  a  vertical  position.  This  is  a  matter,  therefore,  which  the 
judgment  of  the  operator  must  determine. 

II.  JVi'f/i  Cohesive  Gold  Foil. — For  filling  cavities  in  the  approximal 
surfaces  of  the  superior  incisors  and  cuspidati,  the  most  effectual 
means  should  be  adopted  to  retain  the  filling.  In  some  i&'N  cases  it 
may  not  be  possible  to  do  more  than  form  small  undercuttings  at  each 
approximal  angle  of  the  cavity,  and  another  similar  one  at  the  cutting- 
edge,  which  would  be  sufficient  for  the  retention  of  a  non-cohesive 
gold  filling ;  but  in  the  majority  of  cases  one  of  cohesive  gold  can  be 
so  securely  anchored  that  the  cervical  wall  is  perfectly  protected,  and  a 
fracture  at  any  point  along  the  edges  of  the  cavity  will  not  dislodge 
the  filling. 

To  effect  this,  retaining-points,  made  by  a  small,  square-edged  drill, 
are  necessary,  which  can  be  formed  in  approximal  surface  cavities  of 
the  incisors  and  cuspidati,  in  that  portion  of  the  dentine  near  the 
labial  surface  where  it  unites  with  the  cementum,  and  in  the  same 
position  in  the  palatine  surface.  These  retaining-points  can  be  made 
from  the  one-twentieth  to  the  one-sixteenth  of  an  inch  in  depth,  and 
in  addition  a  small  undercutting  on  the  wall  next  to  the  cutting-edge. 
In  drilling  the  retaining-points  in  the  cervical  wall  near  the  labial  and 
palatine  surfaces,  the  drill  should  be  directed  in  a  line  with  the  long 
axis  of  the  root,  in  order  that  the  cavity  made  by  it  is  sufficiently 
distant  from  the  pulp  of  the  tooth.  The  cavity  being  properly  formed, 
dried,  and  protected  from  all  moisture,  the  gold  foil,  prepared  in  the 
manner  before  described,  is  carried  into  the  cavity  with  the  introduc- 
ing pliers  or  on  the  point  of  an  instrument,  and  packed  into  the  re- 
taining-points until  these  are  solidly  filled. 

The  gold  is  then  compactly  built  from  one  of  these  retaining-points 
to  the  other,  and  over  the  floor  of  the  cavity,  until  a  base  is  formed 
extending  over  the  whole  of  the  floor. 

From  this  base  the  gold  is  then  built  to  the  orifice  ;  and  during  the 
entire  process  it  is  packed  a  little  higher  about  the  walls  than  in 
the  centre,  in  order  to  obtain  a  more  thorough  contact.  When  the 
gold  has  reached  the  orifice,  the  centre  is  then  built  up  and  the  sur- 
face condensed  and  finished  as  before  described. 

Crystal  gold  is  preferred  by  some  for  filling  the  retaining  points  and 
forming  the  base  covering  the  floor  of  the  cavity,  on  account  of  its 
retaining  its  position  better  than  foil.  This  description  of  the  method 
of  introducing  cohesive  foil  will  apply  to  all  cavities  wherever  situated. 


5r8  DENTAL   SURGERY. 

and  need  not  be  repeated  hereafter.  For  crystal  gold  the  cavity  may 
be  formed  in  the  same  manner  as  for  cohesive  gold  foil,  although 
many  depend  upon  under-cuttings  instead  of  retaining  points  for  its 
retention. 

The  margin  of  the  cavity  to  be  filled  should  be  uniformly  shaped,  to 
permit  of  the  easy  introduction  of  the  gold  over  them  when  it  is  carried 
into  the  cavity,  and  the  edges  should  be  slightly  countersunk,  to  pro- 
tect them  from  fractures  and  to  permit  of  a  more  perfect  adaptation 
of  the  gold  to  the  margins,  and  also  to  properly  define  the  margins 
of  the  filling  in  the  process  of  finishing  the  surface.  Such 'directions 
will  apply  to  all  cavities  in  teeth  during  their  preparation  for  filling. 

FILLING   THE   SUPERIOR   MOLARS   AND    BICUSPIDS. 

I.  With  Non-cohesive  Gold  Foil. — In  describing  the  manner  of  fill- 
ing a  cavity  in  each  of  the  principal  localities  liable  to  be  attacked  by 
caries  in  the  above-mentioned  teeth,  the  writer  will  begin  with  the 
grinding  surface  of  the  first  molar  on  the  right  side.  The  directions 
given  for  filling  a  cavity  here  will,  with  a  few  exceptions,  be  applicable 
to  the  introduction  of  a  filling  in  the  grinding  surface  of  any  of  the 
upper  molars  or  bicuspids. 

When  the  cavity  is  very  deep  and  its  circumference  not  large,  it  is 
difficult,  if  not  impossible,  to  make  a  filling  sufficiently  firm  and  solid 
in  every  part  by  the  introduction  of  folds  of  gold  long  enough  to 
extend  from  the  bottom  to  the  orifice.  The  operation,  therefore, 
should  be  divided  into  two  parts;  two-thirds  of  the  cavity  should  be 
first  thoroughly  filled  with  vertical  folds,  and  afterward  the  remaining 
third  in  the  same  manner. 

In  filling  a  molar  or  bicuspid  on  any  part  of  its  surfaces  the  head  of  the 
patient  should,  for  the  most  part,  occupy  very  nearly  the  same  position 
and  have  the  same  elevation  as  required  for  an  operation  on  an  incisor 
or  cuspid.  The  cavity  being  prepared  for  the  filling,  and  one  end  of 
the  roll  or  ribbon  of  foil  placed  in  it,  the  tooth  may  be  grasped  with 
the  thumb  and  forefinger  of  the  left  hand  of  the  operator — the  former 
placed  on  the  buccal  surface  in  such  a  manner  as  to  press  back  the 
commissure  of  the  lips,  and  the  latter  on  the  palatine  surface ;  then 
fold  after  fold  may  be  introduced  and  forcibly  i)ressed  against  the 
posterior  wall  until  the  cavity  is  filled.  For  this  purpose  an  instru- 
ment may  be  used  like  the  one  represented  in  Figs.  466  or  469.  If 
the  former  is  used,  it  is  to  be  held  as  shown  in  Fig.  463.  The  extrud- 
ing portion  should  then  be  condensed  with  the  same  instrument  as 
the  one  used  for  introducing,  and  still  more  condensed,  if  necessary, 
with  pluggers  similar  to  Figs.  470  and  471. 

As  a  general  rule,  filling  a  cavity  in  the  grinding  surface  of  an  upper 


FILLING    THE    SUPERIOR    MOLARS    AND    BICUSPIDS.  519 

molar  or  bicuspid  is  an  exceedingly  simple  operation,  requiring  less 
skill  than  the  introduction  of  a  filling  in  any  other  locality  in  these 
teeth ;  but  there  are  cases  in  which  it  is  rendered  very  difficult,  as,  for 
example,  when  there  are  one  or  more  fissures  or  carious  depressions 
radiating  from  the  main  cavity.  After  the  caries  has  been  removed 
and  the  fissure  enlarged,  which  was  often  a  very  tedious  operation 
before  the  use  of  fissure  burs  with  the  dental  engine,  it  requires  con- 
siderable time  and  skill  to  fill  these  thoroughly.  When  it  is  not 
properly  done,  as  is  too  often  the  case,  a  recurrence  of  the  disease  will 
soon  take  place,  and  thus  defeat  the  object  for  which  the  operation 
was  performed. 

The  introduction  of  a  filling  in  the  grinding  surface  of  the  second 
or  third  molar  of  a  person   having  a  very  small  mouth  is  sometimes 
attended  with  great  difficulty ;    in  some  cases  it 
can   only  be  done  with  an  instrument  having  a 
point  bent  nearly  at  right  angles  with  the  stem, 
like   the   one   represented  in   Fig.    471  ;    conse- 
quently, the  power  required  for  introducing  and 
consolidating  the  gold  is  applied  to  great  disad- 
vantage.    But  the  instrument  represented  in  this 
cut  is  only  intended  for  the  first  part  of  the  operation  of  consolidating 
the  metal ;  for  its  completion  smaller  points  are  required. 

In  filling  a  cavity  in  the  grinding  surface  of  a  first  upper  molar  on 
the  left  side  of  the  mouth,  the  thumb  of  the  left  hand  may  be  placed 
against  the  left  cuspid  or  first  or  second  bicuspid,  as  may  be  most 
convenient  to  the  operator,  while  the  forefinger  is  placed  behind  the 
point  of  the  instrument  and  at  the  same  time  made  to  push  back  the 
commissure  of  the  lips.  To  obtain  a  good  view  of  the  cavity  in  a 
second  or  third  molar  during  the  operation,  the  cheek  should  be 
pressed  from  the  tooth  with  the  forefinger  of  the  left  hand  ;  but  this 
finger  can  seldom  be  carried  far  enough  back  on  this  side  of  the  mouth 
to  be  placed  behind  the  point  of  the  instrument.  During  the  intro- 
duction of  gold  the  instrument  should  be  grasped  as  in  Fig  463,  or, 
better  still,  as  in  Fig.  467. 

In  filling  a  cavity  in  the  anterior  approximal  surface  of  a  right  superior 
molar  or  bicuspid,  the  operation  may  be  commenced  by  placing  the 
gold  against  the  palatine  wall  and  ending  at  the  buccal.  But  before 
the  process  of  condensing  is  commenced  every  portion  of  the  surface 
ought  to  be  thoroughly  tested  with  a  wedge  pointed  instrument,  and 
wherever  the  point  can  be  forced  into  the  gold  the  cavity  thus  formed 
should  be  filled.  The  instrument  employed  for  the  introduction  of 
the  gold  may  be  like  the  one  represented  in  Fig.  466,  but  having  a 
rather  longer  point  and  grasped  as  in  Fig.  463.     For  condensing  the 


520 


DENTAL   SURGERY. 


extruding  portions,  either  or  both  of  the  instruments  represented  in 
Figs,  460  and  464  may  be  used,  as  also  the  one  employed  for  the 
introduction  of  the  gold.  During  this  part  of  the  operation  the  instru- 
ment may  be  held  as  before,  or  as  seen  in  Fig.  473,  which  permits  a 
much  greater  amount  of  force  to  be  applied  than  when  held  in  any 

other  manner. 

Nearly  the  same  method  and  the 
same  instruments  are  required  for  fill- 
ing a  corresponding  cavity  on  the 
opposite  side  of  the  jaw.  When  prac- 
ticable, the  forefinger  of  the  left  hand 
should  be  placed  on  the  palatine  sur- 
face of  the  tooth,  and  the  thumb 
against  the  buccal  surface,  and  in 
addition  to  the  instruments'  recom- 
mended for  the  right  side  of  the 
mouth  the  one  shown  in  Fig.  458 
may  be  very  conveniently  employed 
to  introduce  the  gold ;  also  Fig.  460 
or  474  in  condensing  the  surface  of  the 
filling.  The  writer  finds  this  last  par- 
ticularly valuable  in  very  many  cases. 
A  cavity  in  the  posterior  approxi- 
mal  surface  of  a  superior  bicuspid  on 
either  side  of  the  mouth  can,  in  the 
majority  of  cases,  be  as  easily  filled 
as  one  in  the  anterior  approximal  surface.  The  position  of  the  left 
hand  is  very  nearly  the  same,  and  in  the  introduction  of  the  gold 
the  first  folds  are  placed  against  the  palatine  wall  of  the  cavity.  By 
commencing  on  this  side  the  operator  is  enabled  to  lay  the  folds  more 
compactly  than  he  could  were  he  to  commence  at  any  other  point.  He 
also  has  a  more  perfect  control  over  the  instrument  in  this  part  of  the 
operation,  and  has  a  better  view  of  the  cavity  during  the  introduction 
of  the  gold.  For  consolidating  the  filling,  the  instruments  represented 
in  Figs.  459,  460,  and  465  are  as  well  adapted  to  the  purpose  as  any 
that  can  be  employed. 

When  the  mouth  of  a  patient  is  large,  a  filling  can  often  be  intro- 
duced with  nearly  as  much  ease  in  the  posterior  approximal  surface  of 
a  first  or  even  a  second  upper  molar  as  in  that  of  a  bicuspid  ;  but  when 
the  mouth  is  small  and  the  cheeks  fleshy,  it  often  becomes  a  difficult 
and  perplexing  operation,  although  the  same  method  is  used ;  yet,  as 
it  is  absolutely  necessary  to  the  introduction  of  a  good  filling  that  the 
operator  should  see  the  cavity  and  witness  every  part  of  the  operation, 


Fig.  474. 


FILLING    THE    SUPERIOR    MOLARS    AND    BICUSPIDS.  52I 

his  ingenuity  is  often  taxed  to  the  utmost  in  contriving  the  most  suit- 
able means  to  enable  him  to  do  it.  A  number  of  instruments  for 
drawing  back  the  corner  of  the  mouth  have  been  invented,  but  the 
writer  believes  there  are  none  so  well  suited  to  the  purpose  as  the  thumb 
or  forefinger  of  the  left  hand  of  the  operator.  If  the  operator  will 
accustom  himself  to  the  use  of  a  small  mouth-glass  held  in  the  left 
hand  whilst  operating,  he  will  be  spared  many  back-breaking  efforts  to 
keep  in  view  fillings  on  posterior  surfaces.  It  is  necessary  to  become 
familiar  with  the  apparently  reverse  motion  of  the  instrument  as  seen 
in  the  glass ;  also  to  accustom  the  three  fingers  of  the  left  hand  to  act 
independently  of  the  thumb  and  forefinger.  But  one  of  the  most 
careful  and  skillful  operators  of  this  or  any  other  country,  Dr.  Maynard, 
assured  us  that  he  worked  from  a  reflected  view  in  the  glass  with  the 
same  ease  as  where  he  had  a  direct  view  of  the  cavity,  and  obtained,  in 
very  many  cases  where  he  used  the  glass,  an  accuracy  of  view  which 
direct  vision  could  not  give  him. 

Before  dismissing  this  part  of  the  subject  there  is  one  point  to  w^hich 
the  attention  of  the  young  practitioner  should  be  particularly  directed. 
Many,  in  other  respects  tolerably  good,  operators  are  most  likely  to 
fail  in  not  introducing  a  sufficient  quantity  of  gold  in  the  upper  pala- 
tine portion  of  the  cavity.  The  author  frequently  meets  with  cases  in 
which  the  walls  of  the  cavity  are  perfectly  sound  and  every  other  part 
of  the  filling  well  consolidated ;  but  here,  upon  the  application  of  a 
wedge-pointed  instrument,  the  gold  is  easily  perforated.  He  would 
therefore  advise  the  inexperienced  operator  to  test  this  by  severe 
pressure  with  a  sharp,  wedge-pointed  instrument,  as  well,  indeed,  as 
every  part  of  the  filling,  before  leaving  the  operation.  There  is  also 
one  other  precaution  applicable  to  fillings  in  the  approximal  surfaces 
of  the  incisors  and  cuspids,  as  well  as  of  the  molars  and  bicuspids  ;  it 
relates  to  overlapping  portions  of  gold  under  the  free  edge  of  the  gum, 
which  must  be  carefully  and  completely  removed  before  the  operation 
can  be  regarded  as  complete. 

In  filling  a  cavity  in  the  buccal  surface  of  an  upper  bicuspid  or 
molar,  on  either  side  of  the  mouth,  the  gold  may  be  introduced 
with  the  instruments  represented  in  Figs.  456  and  466.  The  latter 
is  better  adapted  for  the  left  side,  but  may  also  be  used  on  the  right. 
The  straight,  wedge-pointed  instrument  may  also  be  advantageously 
employed  on  this  side.  The  first  folds  of  gold  should  be  placed 
against  the  posterior  wall,  proceeding  from  behind  forward,  and 
pressing  the  folds  against  each  other  as  compactly  as  possible.  When 
the  cavity  has  a  large  orifice  and  is  rather  shallow,  or  in  other  re- 
spects badly  shaped  for  the  retention  of  the  gold,  the  operation  is 
often  tedious,  difficult,  and  perplexing.     But  under  favorable  circum- 


522  DENTAL   SURGERY. 

Stances  a  filling  may  be  almost  as  readily  introduced  here  as  in  any 
other  part. 

The  palatine  surface  of  a  bicuspid  or  of  a  molar  is  rarely  attacked 
by  caries ;  on  the  latter  it  is  usually  seated  in  a  depression  at  the 
termination  of  a  fissure  leading  from  the  posterior  depression  in  the 
grinding  surface.  It  is  usually  situated  near  the  posterior  palato- 
approximal  angle  of  the  crown,  about  half  way  between  the  gum 
and  the  coronal  extremity  of  the  tooth.  It  sometimes  happens  that 
the  walls  of  these  fissures  are  affected  with  caries  throughout  their 
whole  extent,  requiring  to  be  filled  from  the  depression  in  the  grinding 
to  its  termination  on  the  palatine  surface.  In  this  case  the  portion  of 
the  cavity  on  the  grinding  surface  may  be  first  filled  ;  then  the  ope- 
rator may  proceed  to  fill  the  palatine  portion  in  the  same  manner  as 
if  it  were  a  simple  cavity,  placing  the  first  folds  of  foil,  in  the  case  of  a 
right  molar,  against  the  upper  and  posterior  side  of  the  opening  with 
an  instrument  like  the  one  represented  in  Fig.  466.  Great  care  is 
necessary  to  prevent  the  instrument  from  slipping.  It  often  happens, 
too,  that  the  orifice  becomes  choked  with  foil  before  the  cavity  is 
half  filled.  This,  indeed,  is  liable  to  occur  in  filling  any  cavity  in 
any  tooth;  and  when  it  does  happen,  unless  a  sufficient  amount  of 
pressure  is  applied  to  make  a  free  opening  into  it,  the  filling  will  be 
imperfect  and  the  object  of  the  operation  wholly  defeated.  When  the 
cavity  is  situated  in  a  left  molar,  the  gold  may  be  introduced  with  the 
instruments  represented  in  Figs.  456  and  469,  placing  the  first  folds 
against  the  upper  wall  of  the  cavity  and  proceeding  downward. 

A  tubercle  of  greater  or  less  size  is  sometimes  found  on  the  anterior 
palatine  surface  of  a  molar,  near  the  crown.  Between  this  and  the 
body  of  the  crown  a  deep  impression  is  often  seen,  which  becomes  the 
seat  of  caries  ;  but  the  removal  of  the  diseased  part  and  the  introduc- 
tion of  a  filling  is  so  simple  that  a  special  description  of  the  operation 
is  not  deemed  necessary. 

II.  lVi//i  Cohesive  Gold  Foil. — In  forming  cavities  in  the  approxi- 
mal  surfaces  of  the  bicuspids  and  molars  it  is  essential,  in  the  majority 
of  cases,  to  separate  the  teeth  either  by  means  of  pressure  or  by  cutting 
away  a  portion  of  the  crown. 

When  they  are  very  close  together  it  is  often  impossible  to  gain 
sufficient  space  by  pressure,  and  it  then  becomes  necessary  to  resort 
to  the  enamel  chisel,  file,  or  disc,  cutting  away  a  portion  from 
each  tooth  when  both  are  decayed,  and  from  one  only  if  the  other 
is  in  a  sound  condition.  The  former  practice  in  separating  these 
teeth  was  to  cut  away  so  much  of  the  entire  approximal  surface  as 
to  form  a  V-shaped  space  of  sufficient  extent  to  enable  the  operator  to 
reach  the  cavity  easily.     But  by  this  method  the  crown  of  the  tooth 


FILLING    THE    SUPERIOR   MOLARS   AND    BICUSPIDS. 


523 


was  disfigured  and  a  space  formed  in  which  food  readily  collected 
and  became  a  source  of  considerable  annoyance.  To  avoid  this, 
the  practice  now  is  to  cut  through  the  grinding  surface  to  the  ap- 
proximal  cavity,  mortising  this  opening,  and  thus  preserve  the  palato- 
and  bucco-approximal  angles,  while  at  the  same  time  the  shape  of  the 
opening  through  the  grinding  surface  materially  assists  in  the  retention 
of  the  filling.  In  preparing  these  cavities  for  cohesive  gold  foil,  at 
least  two  good  retaining  points  should  be  made  at  the  cervical  wall 
and  two  under  cuttings  at  the  cusps,  which  have  been  preserved  by 
the  method  of  gaining  space  just  described.  But  one  of  these 
retaining  points,  in  connection  with  the  two  under-cuttings  at  the 
cusps,  will  often  secure  the  filling  when  the  nature  of  the  case  will 
not  allow  of  more  being  made. 

In  preparing  a  cavity  on  the  posterior  approximal  surface  of  a 
molar  tooth,  access  is  obtained  by  cutting  through  the  grinding  sur- 
face in  the  manner  before  referred  to ;   then,  by  means  of  instruments 


Fig.  475- 


more  or  less  curved,  the  buccal  and  palatine  walls  are  made  parallel 
with  each  other,  under-cuttings  formed  at  the  cusps,  and  retaining 
points  drilled  in  the  cervical  wall  at  different  angles.  Advantage  is 
also  gained  from  having  the  cervical  wall  slightly  undercut.  In  in- 
troducing the  gold  into  a  cavity  of  this  nature  many  prefer  placing 
a  polished  plate  of  metal  or  a  matrix  back  of  the  cavity,  in  the  space 
between  the  teeth,  and  condensing  the  gold  firmly  against  it  in 
building  up  this  portion  of  the  crown.  By  this  method  a  good 
support  is  obtained,  and  after  all  the  gold  necessary  is  introduced  and 
consolidated  the  metal  plate  is  removed. 

Fig.  475  represents  a  set  of  loop  matrices,  consisting  of  thin,  flex- 
ible steel  bars  and  a  milled  thumb-screw.  To  use  them,  one  of  the 
proper  size  is  selected,  the  head  with  the  smooth  hole  being  passed 
over  the  thumb-screw ;  the  screwed  head  is  then  bent  around  and  the 
loop  screwed  to  its  place  on  the  tooth. 


524 


DENTAL   SURGERY. 


Fig.  476  represents  an  ingenious  matrix  inventq^d  by  Dr.  Louis 
Jack,  a  shows  the  concave  and  wedging  sides  of  the  matrix,  and 
b  shows  a  matrix  placed  between  two  teeth  ready  to  wedge  and  fill. 
c  represents  the  form  of  pliers  for  placing  a  matrix  in  position. 

The  points  especially  notable  in  the  use  of  a  matrix  are,  to  cut 
away  the  masticating  surface  of  enamel  to  the  depth  of  the  cavity ; 
to  prepare  the  edges  flat  and  smooth ;  to  cut  down  to  sound  structure  in 


Fig.  476. 

the  neck  of  the  tooth,  forming  the  base  of  the  cavity,  and  shaping  it 
so  that  the  matrix  will  fit  accurately  on  the  cervical  wall.  Having 
excavated  the  cavity  and  cut  a  retaining  groove  along  the  buccal  and 
palatal  walls  (terminating  at  the  very  surface  of  the  masticating  walls 
of  the  enamel),  select  a  matrix  the  concaved  surface  of  which  matches 
the  cavity.  Then,  after  applying  the  rubber  dam,  finish  and  dry  the 
cavity,  place  the  matrix,  and  secure  it  with  wedges  of  boxwood, 
which,  being   hard  and  dry,  require  very  little  forcing.     The  filling 


Fig.  477. 


Fig.  47S. 


Fig.  479. 


may  be  then  done  with  the  ease  and  certainty  of  a  crown  cavity  with 
strong  walls. 

Figs.  477  and  478  represent  the  double  screw  matrices  designed  by 
Dr.  W.  A.  Woodward,  which,  like  those  of  Dr.  Jack,  occupy  a  single 
interdental  space. 

Figs.  479,  480,  481,  482,  and  483  represent  Dr.  T.  W.  Brophy's 
matrices  and  their  use  in  the  forms  of  bands  and  screws. 

Soft  or  non-cohesive  foil  should  be  used  for  the  cervical  margins 
and  for  the  first  half  of  the  filling,  because  of  the  ease  with  which  it 


FILLING    THE    SUPERIOR    MOLARS    AND    BICUSPIDS. 


525 


may  be  adapted  to  the  cavity  walls  and  the  rapidity  with  which  it  may 
be  inserted ;  the  masticating  surface  to  be  finished  with  cohesive  gold. 
Wedge-shaped  pluggers  are  the  most  desirable  forms  with  which  to 
condense  the  soft  foil.     If  amalgam  or   cement  be  used    the   band 


Fig.  4S0. 


Fig.  481. 


Fig.  482. 


Fig.  483. 


should  be  oiled  on  the  inner  surface,  to  prevent  the  filling  from  adher- 
ing to  it. 

Figs.  484  and  485  represent  Dr.  W.  B.  Miller's  matrices  and  their  use. 

This  matrix  is  commonly  held  firmly  in  place  by  reason  of  its  duplex 


Fig.  484. 


Fig.  485. 


spring  expansibility,  but  it  may  be  additionally  supported  by  a  wedge 
of  wood  driven  between  the  springs.  Either  the  concave  or  convex 
edges  go  next  to  the  gum,  according  as  the  cervical  margin  of  the 
cavity  is  upon  or  beneath  the  gum,  and  a  thick  or  thin  matrix  will  be 
indicated  by  the  width  of  the  space  between  the  teeth. 


Fig.  4S6. 


Dr.  Guilford's  band  matrices  and  clamps  are  represented  by  Figs. 
486,  487,  and  488. 

The  Herbst  matrix  consists  of  a  band  of  soft  German  silver,  of  the 
thickness  32  Am.  gauge,  about  one  inch  and  a  half  in  length,  and  as 


526 


DENTAL   SURGERY. 


wide  as  is  necessary  to  cover  the  cavity  in  the  proximate  surface  of  the 
tooth.  It  is  iirst  fitted  to  the  crown  by  bending  it  around,  bringing 
both  ends  of  the  band  to  the  buccal  surface,  and  drawing  them  tightly 
together  by  the  pliers.  When  the  band  is  thus  made  to  fit  perfectly  to 
the  crown  of  the  tooth  to  be  filled,  it  is  carefully  removed  and  the 
joint  soldered  with  soft  solder,  using  muriate  of  zinc  solu- 
tion as  a  flux.  This  matrix  is  prepared  before  excavating 
the  cavity. 

For  the  use  of  gold  by  the  Herbst  method,  matrices  are 

also  employed  made  of  gum  shellac,  which  is  molded  to  the 

tooth  crown  in  a  plastic  condition,  and  then  trimmed  to 

the  proper  shape  so  as  to  form  a  supporting 

wall  and  not  interfere  with  the  introduction 

of  the  gold. 

"  Dr.  Perry's  matrix  consists  of  a  strip  of 
metal  to  go  about  halfway  around  the  tooth 
and  having  a  hole  drilled  through  each  end 
(Fig.  489).  It  is  fastened  around  the  tooth  by  means  of  a  threading 
cord  of  floss  silk,  which  is  passed  through  the  holes  and  tied  fast  with  a 
double  or  treble  knot  (Fig.  490J.  The  knot  can  be  pushed  out  of  the 
way  upon  one  side  of  the  tooth.  The  usual  fault  with  matrices  of  this 
character  is  that  they  are  made  in  different  parts,  one  or  more  of 
which  is  liable  to  fall  upon  the  floor,  and  they  are  in  other  respects 
difficult  to  manage.  This  one  is  very  simple.  You  pass  the  threads 
through  the  holes  in  the  ends,  place  the  matrix  where  you  wish  to  have 
it,  wrap  the  thread  around  the  tooth,  and  tie  it    (Fig.   491).     If  it 


Fig.  4S7. 


6;-^.,^-© 


Fig.  490. 


Fig.  491. 


stretches  a  trifle  there  is  no  harm  done,  because  in  packing  gold  there 
is  a  greater  certainty  of  a  close  fit  at  the  margins  if  the  matrix  yields 
a  little.  The  matrix  is  made  of  very  thin  steel,  and  to  prevent  it  from 
cutting  the  thread  with  which  it  is  tied  small  pieces  of  metal  are  sold- 
ered to  the  ends,  and  the  holes  for  the  thread  are  drilled  through  those 
extra  pieces  of  metal.  This  makes  it  so  thick  and  firm  that  the  thread 
can  be  drawn  tight  without  danger  of  cutting  it.  The  matrix  is  not 
universal  in  its  application,  and  it  is  well  to  have  others;  but  it 
is,   in  certain   cases,  a  very  good  device.     The  holes  are  drilled   in 


FILLING    THE    SUPERIOR    MOLARS    AND    BICUSPIDS. 


527 


such  a  manner  that  the  thread  comes  near  the  cervical  wall,  and  the 
matrix  is  made  to  hug  the  tooth  at  that  point.  If  it  does  not,  a 
wedge  of  wood  dipped  in  sandarac  varnish  and  pushed  between  it 
and  the  adjoining  tooth  will  cause  it  to  fit  well  at  the  cervical  border. 
This  matrix  is  equally  suited  for  gold  or  other  plastics.  It  is  particu- 
larly neat  when  amalgam  is  used,  and  it  is  often  desirable  to  leave  it 
on  the  tooth  for  a  day  or  night.     To  avoid  obstruction  many  narrow 


Fig.  492. 

forms  of  this  matrix  may  be  kept  on  hand,  some  of  which  do  not 
cover  more  than  one-third  or  one-half  the  length  of  the  tooth. 

"There  is  another  use  to  which  the  same  matrix  may  be  applied. 
It  is  that  of  adapting  it  by  a  simple  method  of  binding  and  tying  to 
any  of  the  other  teeth.  Reference  to  the  cuts  will  show  how  it  can 
be  easily  applied  to  the  incisors,  which  almost  always  should  be  filled 
from  the  lingual  side  (Fig.  492),  and  to  the  bicuspids  and  molars  (Fig. 
493),  which  can   be  sometimes  filled  from  the  buccal  or  lingual  side 


Fig.  494. 

without  cutting  down  from  the  grinding  surface.  To  one  who  reveres 
the  shapes  of  the  teeth  this  is  an  operation  that  is  most  satisfactory, 
and  by  the  aid  of  this  simple  matrix  it  is  more  easily  performed." 

Fig.  494  represents  the  Weirich  single  band  metal  alloy  matrix  with 
a  loop  at  the  end. 

To  apply  the  matrix,  place  the  band  between  the  teeth,  bringing  the 
loop  to  the  buccal  side  of  the  tooth  to  be  operated  upon  ;  pass  the  other 
end  through  the  loop,  drawing  the  band  close  around  the  tooth,  then 
bend  it  sharply  back  on  the  loop  and  it  will  remain  firmly  in  place. 


528  DENTAL   SURGERY. 

To  remove  the  matrix,  merely  reverse  the  movement,  straighten  the 
band,  and  slip  it  off. 

Split  teeth  may  be  secured  by  gold  bands  or  collars  used  in  connec- 
tion with  oxychlorid  or  oxyphosphate  of  zinc  between  the  fractured 
surfaces. 

"  Large  contour  restorations  may  be  expeditiously  made  by  means 
of  the  collars  set  tightly  on  the  thoroughly  prepared  and  dried  tooth, 
which  can  then  be  filled  with  gold  or  gutta-percha  or  cement.  For 
cutting  the  collars  to  conform  to  the  cervical  curves,  an  engine  corun- 
dum point  or  Herbst  rotary  file  will  serve  the  purpose,  and  a  collar  so 
cut  is  shown  by  Fig.  495.  To  keep  the  gold  as  much  as  possible  out 
of  view,  the  collar  should  be  cut  as  seen  in  Fig.  496.  Platinum  collars 
will  be  required  when  the  filling  is  to  be  of  amalgam,  but  a  gold  collar 
may  be  varnished  with  a  mere  film  of  collodion,  copal,  sandarac,  or 
shellac  varnish,  at  the  part  which  is  to  come  in  contact  with  the 
amalgam,  and  then  with  proper  care  a  dry  amalgam  will  not  combine 
with  the  gold  of  the  collar.  A  thin  collar,  somewhat  larger  than  the 
tooth,  can  be  put  in  place,  and  a  wedge  of  wood  driven  between  the 
remaining  portion  of  the  tooth  and  the  collar,  to  form  a  matrix,  which, 


Fig.  495.  Fig.  496.  Fig.  497. 

after  the  filling  has  been  built  in  it,  can  be  removed  by  first  with- 
drawing the  wedge.  Such  a  matrix  is  illustrated  in  Fig.  497,  and  by 
this  means  many  large  and  complex  fillings  may  be  rapidly  and  per- 
fectly constructed." 

In  filling  grinding  surface  cavities  in  the  molar  teeth,  where  the 
decay  has  extended  along  one  or  more  of  the  crown  fissures,  with 
cohesive  gold  foil  or  crystal  gold,  the  gold  is  first  introduced  into  the 
bottoms  of  the  crown  fissures  and  built  up  to  their  orifices,  thus  com- 
pleting the  filling  of  these  fissures  before  the  central  cavity  is  filled. 
The  fissures  or  sulci  should  be  opened  to  their  extreme  limits  and  the 
ends  be  made  round.  Small  curved  chisels  and  fissure-drills  are  well 
adapted  for  preparing  sulci,  and  the  excavation  should  be  commenced 
at  the  central  part.  In  preparing  cavities  extending  in  the  form  of 
sulci  or  fissures  over  the  buccal  and  palatine  surfaces  of  the  bicuspids 
and  molars,  all  projecting  portions  of  enamel  should  be  cut  away,  so 
as  to  allow  these  cavities  to  be  but  little  larger  within  than  at  their 
orifices ;  and  the  ends  of  the  groove,  which  are  usually  shallow,  should 
be  made  as  deep  as  the  center.     One  retaining-point  may  then  be 


F   i.LING    THE    INFERIOR    INCISORS    AND    CUSPIDS.  529 

made  in  each  of  the  two  walls  forming  the  ends  of  the  groove-like 
cavity,  or  one  retaining-point  in  the  posterior  wall,  in  connection  with 
an  under-cutting  in  the  anterior  one,  will  answer  for  the  retention  of 
the  filling.  In  introducing  the  gold  into  a  cavity  of  this  form  the 
retaining-points  are  first  filled  and  the  gold  built  across  the  floor  of 
the  cavity  from  one  to  the  other,  and  from  the  base  thus  formed  to 
the  orifice.  When  a  cavity  upon  the  buccal  or  palatine  surface  extends 
under  the  free  margin  of  the  gum,  it  is  necessary  to  either  force  the 
gum  away  by  pressure  with  pledgets  of  cotton  saturated  with  chlorid 
of  zinc,  when  the  cavity  is  not  too  near  the  pulp,  or  to  remove  the 
portion  overlapping  the  cavity.  The  hemorrhage  which  follows  this 
latter  method  may  be  checked  by  any  of  the  hemostatic  agents  in  use, 
such  as  tannin,  phenol  sodique,  creasote,  powdered  subsulphate  of 
iron,  etc. 

The  application  of  chlorid  of  zinc  will  prove  very  effectual  in  such 
cases  ;  also  nitrate  of  silver,  but  the  latter  agent  has  a  tendency  to 
discolor  the  dentine. 

FILLING    THE     INFERIOR    INCISORS   AND   CUSPIDS. 

The  operation  of  filling  a  lower  incisor  or  cuspid  is  far  more  diffi- 
cult than  filling  an  upper. 

The  constant  tendency  of  the  lower  jaw  to  change  its  position  is 
embarrassing  to  the  dentist  in  operating  on  any  of  the  teeth  in  it,  and 
in  case  of  the  incisors  and  cuspids  it  is  sometimes  peculiarly  perplex- 
ing. To  prevent  this  all  the  effort  the  operator  can  make  with  his  left 
hand  is  frequently  required.  From  the  backward  inclination,  too,  of 
these  teeth,  it  rarely  happens  that  the  gold  can  be  introduced  from  the 
lingual  side  of  the  arch  ;  consequently  it  is  necessary  to  make  the 
space  as  wide  anteriorly  as  posteriorly.  But  as  the  teeth  are  compara- 
tively small,  the  separation,  when  made  with  a  file,  chisel,  disc,  etc., 
should  be  no  wider  than  absolutely  necessary  for  the  removal  of  the 
diseased  part  and  the  introduction  of  the  gold.  When,  however,  it 
can  be  done  with  safety,  the  separation  should  be  made  with  a  piece 
of  rubber  or  other  substance  between  the  teeth,  in  the  manner  before 
described,  or  by  rapid  separation. 

While  operating  on  the  lower  teeth  the  head  of  the  patient  should 
occupy  a  more  perpendicular  position  than  while  operating  on  the 
upper ;  this  may  be  done  either  by  lowering  the  seat  or  raising  the 
head-piece  of  the  chair.  When  by  the  latter  it  will  be  occasionally 
necessary  for  the  operator  to  stand  upon  a  stool  five  or  six  inches  in 
height. 

In  filling  a  cavity  in  the  right  approximal  surface  of  a  lower  incisor 
or  cuspid  with  non-adhesive  gold  foil  the  following  method  is  recom- 
34 


DENTAL    SURGERY, 


mended.  The  cavity  being  prepared  and  a  sufficient  quantity  of  gold 
foil  made  into  a  small  roll  or  folded  lengthwise,  as  the  operator  may 
prefer,  with  the  left  arm  over  the  patient's  head,  the  chin  is  gently 
grasped  with  the  left  hand,  while  the  thumb  is  placed  against  the  lin- 
gual surface  of  the  tooth,  the  forefinger  serving  to  direct  the  gold  and 
point  of  the  instrument  and  also  to  depress  the  lower  lip.  The  folds 
of  gold,  in  their  introduction,  are  pressed  firmly  against  the  lower 
wall  of  the  cavity.  The  instrument  employed  for  this  purpose  may  be 
shaped  like  the  one  represented  in  Fig.  498,  with  a  very  small,  wedge- 
shaped  point,  and  held  as  in  Fig.  467.  The  consolidation  of  the  gold 
may  be  effected  partly  with  the  same  instrument,  partly  with  a  round- 
pointed  one  shaped  as  shown  in  Fig.  499,  and  partly  with  an  instru- 
ment shaped  as  in  Fig.  465.  The  tooth  should  be  firmly  held  between 
the  thumb  and  forefinger  of  the  left  hand,  to  prevent  it  from  being 
moved  in  its  socket  by  the  pressure  of  the  instrument. 

When  the  incisors  are  very  small  and  the  caries  has  spread  over  a 
large  portion  of  the  side  of  the  tooth,  it  is  often  difficult  to  form  a 
suitable  cavity  for  the  retention  of  the  filling  without  penetrating  to 
the  pulp-cavity.     In  such  cases  the  patience  and  skill  of  the  operator 


Fig.  498.  Fig.  499. 

are  frequently  taxed  severely  in  obtaining  a  sufficiently  secure  support 
for  the  gold.  But  this  he  can  usually  do  if  he  can  make  the  bottom 
of  the  cavity  as  large  as  the  orifice,  even  though  it  have  but  little 
depth. 

The  manner  of  in-troducing  a  filling  in  the  left  approximal  surface 
is  very  similar.  The  left  arm  and  hand,  as  well  as  the  thumb  and 
forefinger,  are  all  disposed  of  in  the  manner  just  described.  The 
same  instruments,  too,  may  be  employed  for  introducing  and  consoli- 
dating the  gold,  though  in  the  first  part  of  the  operation  the  instru- 
ment. Fig.  461,  may  often  be  advantageously  substituted  for  the  one 
in  Fig.  498.  The  instruments  known  as  "  rights  and  lefts,"  of  differ- 
ent sizes,  are  very  serviceable  for  filling  all  approximal  cavities. 

Nothing  has  been  said  with  regard  to  fillings  in  the  labial  or  lingual 
surfaces  of  lower  incisors  and  cuspids.  Although  caries  rarely  attacks 
either  of  these  surfaces  of  a  lower  incisor,  it  does  sometimes  develop 
itself  in  the  labial  surface  of  a  cuspid  ;  but  the  operation  of  intro- 
ducing a  filling  here  is  so  simple  that  a  separate  description  of  the 
manner  of  it  is  not  deemed  necessary. 

The  operation  of  forming  cavities  in  the  inferior  teeth  and  intro- 
ducing cohesive  gold  foil  and  crystal  gold  is  the  same  as  that  described 


FILLING    THE    INFERIOR    MOLARS    AND    BICUSPIDS.  53 1 

for  the  superior  teeth,  and  a  second  description  is  therefore  not  con- 
sidered necessary.  As  absolute  dryness  is  essential  in  manipulating 
the  cohesive  forms  of  gold,  the  reader  is  referred  to  the  various 
methods  and  appliances  before  described  for  drying  cavities  and 
protecting  them  from  moisture.  In  filling  the  inferior  teeth,  the 
rubber  coffer-dam  will  be  found  to  be  a  valuable  appliance  for  ex- 
cluding all  moisture  from  both  the  gold  and  cavity,  and  the  saliva- 
pump  an  efficient  adjunct  to  this  dam  for  relieving  the  mouth  of 
the  saliva  as  it  accumulates  in  prolonged  operations.  For  control- 
ling the  movements  of  the  tongue,  a  tongue  and  duct  compressor 
has  been  used  in  connection  with  pads  of  bibulous  paper  placed  upon 
the  mouths  of  the  ducts  beneath  the  tongue.  Prepared  spunk  has  also 
been  used  successfully  on  the  mouths  of  the  sublingual  and  submaxil- 
lary ducts  for  controlling  the  flow  of  saliva.  The  rubber  dam,  how- 
ever, will  answer  all  requirements  when  used  in  connection  with 
clamps. 

FILLING    THE    INFERIOR    MOLARS    AND    BICUSPIDS. 

In  filling  a  cavity  in  the  grinding  surface  of  a  right  lower  molar  or 
bicuspid,  the  operator  may  stand  on  the  same  side  of  his  patient  and 
a  few  inches  higher  than  while  operating  on  an  incisor  or  cuspid. 
With  his  left  arm  placed  over  his  patient's  head,  the  tooth  may  be 
grasped  with  the  thumb  and  forefinger  of  the  left  hand,  while  the 
middle  finger  is  placed  by  the  side  of  the  chin ;  the  other  two  should 
be  placed  beneath  it.  After  preparing  the  cavity,  non-cohesive  gold 
foil  radiY  be  introduced  with  an  instrument  like  the  one  represented  in 
Fig.  469,  and  held  as  shown  in  Fig.  463,  pressing  the  folds  against 
the  posterior  walls  of  the  cavity. 

In  condensing  the  gold  after  the  cavity  is  filled,  use  the  instrument 
represented  in  Fig.  470.  Sometimes,  however,  a  greater  amount  of 
force  can  be  exerted  when  this  instrument  is  held  in  the  manner  shown 
in  Fig.  473,  previously  wrapping  it  with  the  corner  of  a  napkin  to 
prevent  the  small  part  of  the  instrument  from  hurting  the  little  finger. 
The  kind  of  instrument  and  the  manner  of  holding  it  will,  after  all, 
have  to  be  determined  by  the  operator.  During  the  introduction  and 
consolidation  of  the  gold  the  lower  jaw  should  be  firmly  held  with  the 
left  hand,  to  prevent  it  from  moving  and  from  being  too  much 
depressed.  This  precaution  is  the  more  necessary,  as  the  muscles  of 
the  lower  jaw  and  the  articular  ligaments  are  seldom  strong  enough  to 
resist  the  amount  of  force  required  in  the  operation. 

In  filling  a  cavity  in  the  grinding  surface  of  a  tooth  on  the  left 
side  the  dentist  may  sometimes  operate  to  greater  advantage  by  stand- 
ing on  the  same  side.  In  this  case  the  commissure  of  the  lips  should 
be  pressed  back  with  the  thumb  of  the  left  hand,  placing  it  on  or 


532  DENTAL   SURGERY. 

against  the  tooth  to  be  filled,  while  the  forefinger  passes  in  front  of 
the  chin  and  the  other  three  beneath  it.  As  a  general  rule,  however, 
he  will  be  able  to  operate  more  conveniently  by  standing  on  the  right 
side  of  his  patient  and  holding  the  tooth  and  the  chin  in  the  manner 
before  directed.  In  either  case,  the  gold,  in  its  introduction,  should 
be  pressed  against  the  posterior  wall  of  the  cavity. 

The  foregoing  general  directions  will  be  found,  for  the  most  part, 
applicable  to  the  introduction  of  a  filling  in  the  approximal  surfaces. 
When  the  crowns  of  the  teeth  are  long  and  the  cavity  situated  near 
the  gum,  the  operation  is  sometimes  very  difficult  and  tedious,  requir- 
ing all  the  patience  and  skill  the  dentist  can  exercise  to  accomplish  it 
securely.  This  difficulty  is  increased  when  the  shape  of  the  cavity  is 
unfavorable  for  the  retention  of  the  gold ;  or,  in  other  words,  when 
the  cavity  is  shallow  and  has  a  large  orifice.  There  is  also  another  very 
serious  difficulty  which  the  operator  encounters  in  the  introduction 
of  a  filling  in  the  approximal  and  also  in  the  buccal  surface  of  a  lower 
molar  or  bicuspid.  The  flow  of  saliva  is  often  so  profuse  that  the 
whole  of  the  lower  part  of  the  mouth  is  completely  filled,  and  the 
tooth  is  inundated  before  it  is  possible  to  introduce  a  sufficient  quantity 
of  gold  to  fill  the  cavity.  This  not  only  retards  the  operation,  but 
it  also  renders  it  more  difficult  and  perplexing;  for  it  is  necessary  to 
force  out  every  particle  of  moisture  from  the  cavity  and  from  between 
the  different  layers  of  gold  before  the  necessary  cohesive  attraction 
between  them  can  be  secured.  If  this  is  not  done  or,  at  any  rate,  if 
all  the  moisture  is  not  forced  from  the  cavity,  and  the  gold  sufficiently 
consolidated  to  render  it  impermeable  to  the  fluids  of  the  mouth,  the 
operation  will  be  unsuccessful  to  a  great  extent ;  hence  the  rubber 
dam  is  a  valuable  adjunct. 

Ordinary  foil  (non-cohesive),  when  introduced  in  folds  lying  par- 
allel with  the  sides  of  the  cavity,  keeps  its  place  by  the  close  lateral 
contact  of  the  folds  against  each  other  and  the  Avails  of  the  cavity. 
Hence  such  fillings  may  prove  successful,  although  done  "  under 
water,"  provided  the  lateral  pressure  is  sufficient  to  force  out  the 
saliva  from  between  the  layers  of  foil.  But  if  the  folds  are  laid  in 
parallel  with  the  bottom  of  the  cavity,  the  operation  will  fail,  in 
consequence  of  the  scaling  off  of  the  successive  layers  which  have  no 
cohesion.  Crystal  gold  and  cohesive  foil  fillings  depend  for  their 
success  upon  the  perfect  cohesion  of  their  component  pieces  ;  there- 
fore the  slightest  moisture,  or  even  dampness,  while  being  introduced 
is  fatal  to  their  durability. 

For  the  purpose  of  obviating  this  difficulty  a  variety  of  means  have 
been  proposed,  the  most  important  of  which  have  already  been  described 
and  need  not  be  again  referred  to. 


FILLING    THE    INFERIOR   MOLARS   AND    BICUSPIDS.  533 

In  the  introduction  of  non-cohesive  gold  on  the  right  side,  it  may 
be  pressed  against  the  buccal  wall  of  the  cavity  on  the  left  side,  or 
against  the  lingual  wall.  Either  of  the  instruments  represented  in  Figs. 
455  and  456  may  be  employed  for  the  introduction  of  the  gold, 
whether  the  cavity  be  situated  in  the  anterior  or  posterior  approximal 
surface  of  the  tooth,  and  may  be  held  in  the  hand  in  the  manner  shown 
in  Figs.  463  and  467. 

In  filling  a  cavity  in  the  lingual  and  posterior  approximal  angle  of  a 
first  or  second  bicuspid,  and  especially  from  the  loss  of  the  tooth  behind 
it,  when  there  is  a  backward  inclination  of  the  organ,  great  care  is 
necessary  to  prevent  the  instrument  from  slipping  and  wounding  the 
lower  lip.  The  most  convenient  position  for  the  operator  in  this  case 
is  on  the  left  side  and  partly  in  front  of  the  patient.  The  tooth  may 
then  be  firmly  grasped  between  the  thumb  and  forefinger  of  the  left 
hand,  or  the  thumb  alone  pressed  against  the  outside  of  the  tooth ;  in 
either  case  it  is  to  be  used  as  a  rest  for  the  ring  finger  of  the  right  hand 
during  the  introduction  and  consolidation  of  the  gold.  But  the  locality 
of  the  cavity  is  such,  especially  when  the  mouth  of  the  patient  is  small, 
that  it  can  only  be  seen  with  great  difficulty.  Hence  the  operator  is 
constantly  liable  to  place  the  point  of  the  instrument  on  one  side  of 
the  orifice  against  an  overlapping  portion  of  gold,  which,  when  pres- 
sure is  applied,  is  cut  through  or  detached.  The  instrument  thus  comes 
in  contact  with  the  hard,  smooth  enamel,  and  unless  the  hand  is  so 
guarded  as  to  control  its  motions  it  is  liable  to  slip  and  wound  some 
part  of  the  mouth,  especially  the  lower  lip,  which  accident,  unless 
proper  precaution  is  observed,  may  occur  in  filling  any  tooth. 

Among  the  principal  difficulties  which  the  dentist  encounters  in  fill- 
ing a  cavity  in  the  buccal  surface  of  a  lower  molar,  apart  from  that  of 
keeping  the  cavity  dry  until  the  gold  is  introduced,  is  the  contact  of 
the  lower  and  inner  part  of  the  cheek  with  the  tooth.  This  may,  to 
a  considerable  extent,  be  prevented,  and  the  commissure  of  the  lips  at 
the  same  time  pushed  back  with  the  forefinger  of  the  left  hand  of  the 
operator,  which  also  will  serve,  when  the  cavity  is  shallow  and  the 
orifice  large,  to  hold  the  gold  in  place  until  a  sufficient  quantity  is 
introduced  to  obtain  support  from  the  surrounding  walls.  In  operating 
upon  the  bicuspids  it  is  only  necessary  to  depress  the  corner  of  the 
mouth  to  obtain  free  access  to  the  cavity. 

For  the  introduction  of  the  gold  on  the  right  _^     t^  1   1   ■ 

side,  either  of  the    instruments  represented    in  fig  soo  ^ 

Figs.  456  and  466  may  be  employed,  but  on  the 

left  side  the  latter  will  generally  be  found  most  convenient.  A  straight, 
wedge-pointed  instrument  (Fig.  500)  can  often  be  advantageously  used 
in  introducing  the  foil  in  either  of  the  right  bicuspids,  and  sometimes 


534 


DENTAL   SURGERY. 


even  in  the  first  molar.  This  instrument  can  also  often  be  used  in 
filling  a  cavity  in  the  grinding  surface  of  a  molar  of  either  jaw,  but 
oftener  in  the  upper  than  the  lower.  It  is  scarcely  necessary  to  say 
that  the  introduction  of  the  gold  should  commence  behind  and  pro- 
ceed forward.  The  instruments  represented  in  Figs.  459,  468,  and 
472  may  be  used  in  consolidating  the  foil. 

It  may  be  well  to  mention  here  that  in  filling  a  molar  or  bicuspid 
on  the  left  side  in  the  lower  jaw,  whether  in  the  grinding,  approximal, 
or  buccal  surface,  the  back  of  the  chair,  if  so  constructed  as  to  admit 
of  being  moved,  should  be  thrown  five  or  six  inches  further  back,  to 
lower  the  head  of  the  patient  and  give  the  face  a  more  horizontal  in- 
clination. By  this  means  the  operator  is  enabled  to  approach  the 
locality  of  his  manipulations  with  greater  ease,  thus  enabling  him  to 
exercise  a  more  perfect  control  over  his  instrument,  as  well  as  over  the 
mouth.  But  if  the  back  of  his  operating-chair  is  stationary,  he  should 
stand  upon  a  stool  of  five  or  six  inches  in  height. 

The  precaution  of  removing  all  the  overlapping  portions  of  gold 
should  never  be  omitted,  and  this  sometimes  constitutes  a  difficult  part 
of  the  operation,  especially  when  the  cavity  extends  under  the  margin 
of  the  gum.  For  this  purpose  some  of  the  files  represented  in  Fig.  444 
may  be  very  advantageously  used.  Some  are  made  straight  at  each 
end,  others  are  curved.  The  cutting-burs  operated  by  the  dental 
engine,  and  also  the  corundum  and  sand-paper  discs,  are  useful  instru- 
ments for  removing  surplus  gold. 

The  manner  of  building  up  the  whole  or  a  part  of  the  crown  of  a 
tooth  will  now  be  described. 

CONTOUR   FILLINGS. 

The  term  "contour"  signifies  "the  line  that  bounds,  defines,  or 
terminates  a  figure  ;  hence  a  "contour  filling"  is  one  that  is  made 
to  conform  to  the  line  that  defined  the  contour  of  the  lost  tooth 
tissue ;  in  other  words,  the  filling  material  is  built  up  to  such  a  degree 
as  is  necessary  to  restore  the  original  form  of  the  crown  of  the  tooth. 

It  is  scarcely  to  be  expected  that  any  one  who  has  not  had  consider- 
able experience  in  filling  teeth,  and  acquired  a  high  degree  of  dexterity 
in  the  use  of  instruments  and  the  working  of  some  one  or  more  of  the 
preparations  of  gold  employed  for  the  purpose,  such  as  cohesive  gold, 
will,  simply  from  any  directions  that  can  be  laid  down  upon  the  sub- 
ject, be  able  at  once  to  perform  the  operation  of  building  on  the 
whole  or  part  of  the  crown  of  a  tooth.  But  it  is  hoped  that  the 
following  description  may  serve  as  a  guide  to  those  who  have  never 
attempted  it,  and  may  wish  to  exercise  their  mechanical  and  artistic 
abilities  on    this,    the   most   difficult   of  all  operations  in  dentistry. 


CONTOUR    FILLINGS.  535 

Those  only  who  are  aiming  at  high  excellence  in  this  department  of 
practice  will  be  likely  to  undertake  it ;  and  should  their  first  efforts 
prove  unsuccessful,  the  increase  of  skill  they  will  have  thus  acquired 
in  the  use  of  instruments  will  inspire  new  confidence,  and  ultimately, 
by  perseverance,  enable  them  to  achieve  the  object  of  their  wishes. 

The  operation,  to  be  successful,  must  not  only  be  performed  in  the 
most  perfect  manner,  but  the  tooth  itself  must  be  situated  in  a  healthy 
cavity  and  firmly  articulated.  Under  other  circumstances  it  would  be 
useless  to  attempt  the  restoration  of  the  organ.  The  general  system, 
too,  should  be  free  from  any  preternatural  susceptibility  to  morbid 
impressions. 

A  tooth  on  which  this  operation  is  called  for  has,  in  nearly  every 
case,  suffered  so  much  loss  of  substance  as  to  render  it  necessary,  in 
cases  where  the  pulp  of  the  tooth  is  not  exposed,  that  great  care 
should  be  exercised  in  preparing  the  cavity  for  such  a  large  mass  of 
filling  material,  especially  gold,  and  securely  anchoring  it.  Where 
the  exposure  of  the  pulp  of  the  tooth  necessitates  the  destruction  and 
removal  of  this  organ  the  operation  of  "contouring"  is  much  less 
difficult,  as  the  pulp-chamber  affords  secure  anchorage  for  the  filling. 
Where  the  pulp  has  previously  perished  from  inflammation  and  suppur- 
ation, the  permanent  preservation  of  the  organ  cannot  be  counted  on 
with  as  much  certainty  as  when  it  is  destroyed  by  extirpation  or  by 
the  application  of  an  escharotic  two  or  three  days  before  the  perform- 
ance of  the  operation.  Its  destruction  by  the  suppurative  process  is 
more  apt  to  be  followed  by  alveolar  abscess  :  and  this,  having  once 
established  itself,  must  be  completely  cured,  to  prevent  the  liability 
to  its  recurrence.  Hence,  if  the  operation  is  determined  on,  the 
parts  of  the  extremity  of  the  root  must  first  be  restored  to  health  ;  for 
without  this  it  should  never  be  attempted.  The  preparatory  treatment 
in  cases  of  this  sort,  as  well  as  in  cases  of  simple  morbid  secretion 
escaping  from  the  root,  is  given  in  another  chapter. 

In  describing  the  operation  we  will  commence  with  the  first  molar  of 
the  left  side  of  the  superior  maxilla.  We  will  suppose  that  about 
three-fourths  of  the  crown  has  been  destroyed  by  caries  and  that  the 
buccal  wall  is  the  only  portion  remaining,  the  pulp  being  more  or  less 
exposed.  This  is  to  be  destroyed  and  extirpated  to  the  extremity  of 
each  root ;  the  decayed  portions  of  the  tooth  are  then  to  be  removed, 
and  the  central  chamber  enlarged  until  the  wall  of  dentine  on  the 
palatine,  anterior,  and  posterior  approximal  sides  are  only  about  one  line 
in  thickness.  On  the  inside  of  this  wall  a  shallow  groove  or  undercut 
is  made  and  also  retaining  points,  to  give  additional  security  to  the 
gold. 

The  tooth  as  now  prepared   is  represented  in  Fig.  501,  and,  after 


536  DENTAL   SURGERY. 

the  application  of  the  rubber  dam,  is  ready  for  the  introduction  and 
building  on  of  the  gold.  But  before  describing  the  manner  of  doing 
this  it  may  be  well  to  say  a  few  words  with  regard  to 
the  preparation  of  gold  most  proper  to  be  employed. 
For  filling  the  roots,  non-cohesive  gold  foil  is  the  best. 
If  the  leaves  are  thick,  weighing  from  fifteen  to  twenty 
grains,  it  should  be  introduced  in  very  narrow  strips, 
without  folding,  in  the  manner  described  in  another 
chapter  ;  if  leaves  of  four  or  six  grains  are  preferred,  it 
may  be  cut  in  strips  varying  from  an  eighth  to  a  quarter 
of  an  inch  in  width,  according  to  the  size  of  the  canal 

Fig.  501.  ^ 

in  the  root,  and  then  rolled  or  made  into  very  narrow 
folds.  For  the  central  chamber  and  crown,  gold  possessing  cohesive 
properties  should  be  employed  ;  although  this  property  may,  to  a  de- 
gree, be  imparted  to  common  gold  foil  by  slightly  annealing  immedi- 
ately before  using,  cohesive  gold  foil  possesses  it  in  a  higher  degree, 
and  this  also  requires  to  be  annealed.  Either  kind  of  foil,  therefore, 
or  crystal  gold  may  be  employed.  The  operation,  however,  can  be 
better  performed  with  the  cohesive  foil  or  crystal  gold  than  with  the 
non-cohesive  foil.  Crystal  gold  is  often  used  to  fill  the  central  cham- 
ber and  act  as  a  base  upon  which  to  build  the  cohesive  gold  foil. 

As  the  manner  of  filling  roots  is  described  in  another  place,  we 
shall  commence  with  the  pulp  cavity.  The  gold,  supposing  it  to  be 
cohesive  foil,  is  loosely  rolled  into  a  fold  or  rope,  from  which  pellets 
are  cut.  A  sufficient  number  of  these  having  been  prepared,  the  sur- 
faces against  which  the  gold  is  to  be  placed  are  made  perfectly  dry  by 
wiping  with  Japanese  bibulous  paper  or  absorbent  cotton.  This  done, 
one  of  the  pellets  is  placed  in  the  central  chamber  with  pliers,  pressed 
into  a  retaining  point,  where  the  formation  of  such  points  is  necessary, 
and  consolidated  with  a  small-pointed  condensing  instrument ;  another 
and  another  is  added,  each  being  consolidated  as  the  first,  until  a 
sufficient  number  have  been  introduced  to  fill  this  chamber.  The 
process  of  consolidation  is  now  to  be  repeated  and  continued  until  no 
part  of  the  gold  can  be  made  to  yield  to  the  pressure  of  the  instru- 
ment ;  then  additional  pellets  are  applied  and  condensed  as  in  the 
first  instance,  forcing  those  placed  against  the  surrounding  wall  firmly 
and  compactly  into  the  groove  or  undercut  made  in  it,  thus  securing 
for  the  entire  mass  the  greatest  possible  stability.  Again,  pellet  after 
pellet  is  applied,  pressing  those  placed  along  the  outer  edge  firmly 
against  the  enclosed  margin  of  dentine  and  against  the  buccal  wall  of 
the  tooth,  until  a  solid  mass  considerably  larger  than  the  portion  of 
the  crown  to  be  supplied  shall  have  been  thus  formed.  The  same 
result  may  be   obtained  much  more  rapidly  by  using  the  gold  in  the 


CONTOUR    FILLINGS.  537 

form  of  a  ribbon.  In  this  case  fold  after  fold  of  the  gold  is  intro- 
duced, each  fold  being  thoroughly  welded  and  consolidated  as  in- 
troduced. 

For  the  complete  solidification  of  every  part  of  the  gold  and  the 
welding  of  every  piece  to  the  adjoining  ones,  a  number  of  instruments 
are  required,  with  serrated  points,  which  are  represented  in  the  figures 
illustrating  the  instruments  employed  in  the  use  of  the  cohesive  forms 
of  gold.  For  some  parts  of  the  operation  a  straight  instrument  can  be 
employed  most  advantageously  ;  for  other  parts,  one  slightly  bent  near 
the  point ;  and  for  others,  one  bent  at  right  angles  with  the  stem. 
The  kind  most  suitable  for  each  case  must  be  determined  by  the  judg- 
ment of  the  operator.  One,  perhaps,  may  use  very  efficiently  an 
instrument  in  a  particular  locality  and  for  a  certain  purpose,  that 
another,  for  the  same  purpose,  would  handle  very  awkwardly.  But 
for  completing  the  work  of  consolidation,  all  agree  that  very  small- 
pointed  instruments  are  indispensable.  The  consolidating  or  building 
instruments  may  consist  of  Varney's  hand-mallet  pluggers,  or  the 
points  of  the  automatic  or  engine  mallets. 

As  the  cohesiveness  of  the  gold  is  destroyed  by  the  contact  of  liquids, 
it  must  be  kept  absolutely  free  from  moisture  during  the  entire  process 
of  introducing  and  consolidating  the  metal.  But  if,  notwithstanding 
every  precaution,  the  saliva  should  come  in  contact  with  the  gold 
before  its  complete  introduction,  the  unfinished  surface  must  be 
thoroughly  consolidated,  then  dried  with  some  good  absorbing  sub- 
stance, scraped,  burnished,  dried  again,  and  made  rough  with  a  sharp- 
pointed  instrument.  To  this  surface  fresh  portions  of  gold  can  now 
be  united,  and  sometimes  made  to  adhere  quite  firmly,  but  often  it  is 
necessary  to  drill  retaining  points  into  the  gold  and  continue  the  opera- 
tion from  these  points.  The  use  of  the  rubber  dam  and  other  appli- 
ances now  enables  the  operator  to  perform  prolonged  operations  with- 
out the  danger  from  moisture  which  formerly  existed. 

The  next  step  is  to  consolidate  thoroughly  every  part  of  the  surface. 
This  may  be  commenced  with  the  larger-pointed  instruments.  After 
going  over  it  ten  or  a  dozen  times  with  these,  smaller  points  may  be 
used,  and  these  again  changed  for  still  smaller,  until  no  more  impres- 
sion can  be  made  upon  it  than  upon  a  solid  ingot  of  pure  gold. 

it  now  remains  to  cut  the  surface  until  the  gold  is  made  to  assume 
very  nearly  the  shape  of  that  portion  of  the  original  tooth  the  loss  of 
which  it  supplies.  The  plug-finishing  burs  operated  by  the  dental 
engine,  the  files  for  finishing  the  surface  of  fillings,  and  the  corundum 
and  sand-paper  and  stone  discs  and  points,  will  be  found  serviceable 
for  such  operations.  In  doing  this  an  opportunity  is  afforded  to  the 
operator  for  the  display  of  much  artistic  skill  and  ingenuity.     While 


5  3^  DENTAL    SURGERY. 

shaping  the  grinding  surface  the  patient  should  be  requested,  from 
time  to  time,  to  close  the  mouth,  that  the  depression  in  it  may  be 
made  to  correspond  to  the  cusps  of  the  tooth  with  which  it  antagonizes, 
so  that  these  two  may  touch  simultaneously  with  the  other  teeth  of  the 
upper  and  lower  jaw^s.  This  part  of  the  operation  is  ahvays  tedious, 
usually  requiring  more  time  than  for  the  consolidation  of  the  gold. 
The  use  of  articulation  paper  may  facilitate  this  part  of  the  operation. 
The  surface  of  the  gold  may  now  be  rubbed  with  properly  shaped 
pieces  of  Arkansas  or  Hindostan  stone  or  with  pulver- 
ized pumice  until  all  the  scratches  left  by  the  files  are 
removed  ;  then  polish  with  crocus  and  a  burnisher.  The 
appearance  of  the  tooth  as  thus  restored   is  shown  in 

As  it  is  impossible  to  perform  the  entire  operation  at 
one  time,  it  may  readily  be  divided  into  three  parts, 
Xht.  first  consisting  in  the  extirpation  of  the  pulp  (when 
necessary)  and  the  preparation  of  the  tooth,  the  second 
in  the  introduction  and  solidification  of  the  gold,  the 
third  in  giving  to  the  metal  the  proper  conformation  and  in  finishing 
the  surface.  The  time  required  for  the  first,  supposing  the  operation 
to  be  like  the  one  just  described,  may  vary  from  one  and  a  half  to  two 
and  a  half  hours  ;  for  the  second,  from  two  to  three  and  a  half  hours  ; 
and  for  the  third,  from  two  to  six  hours,  according  to  the  difficulties  to 
be  encountered,  the  ability  of  the  dentist,  and  the  completeness  of  his 
preparation  for  the  operation.  Some,  perhaps,  may  prefer  crystalline 
or  sponge  gold,  supposing  it  to  be  more  easily  welded  than  cohesive  foil ; 
but  as  the  manner  of  working  this  variety  of  gold  has  already  been 
described,  it  will  not  be  necessary  to  give  additional  directions  for  its 
use. 

The  late  Dr.  M.  H.  Webb,  an  expert  operator  in  contour  work,  gave 
the  following  directions  for  completing  such  an  operation  :  — 

"When  the  foil  has  been  prepared  and  impacted  as  described,  and 
so  that  the  substitution  for  the  lost  tissue  is  complete,  a  fine  saw  or 
suitable  file  should  be  used  to  cut  away  the  surjjlus  material  and  to  aid 
in  making  the  filling  conform  to  the  original  contour  of  the  part,  after 
which  narrow  strips  (a  line  or  ^-inch  wide)  cut  from  fine  emery  cloth 
should  be  so  manipulated  as  to  properly  form  and  finish  the  surface  ©f 
the  gold.  When  this  has  been  done  and  the  rubber  dam  removed,  the 
finishing  should  be  completed  by  the  use  of  fine  pumice  and  silex  upon 
linen  tape,  as  before  suggested.  The  gold  at  the  masticating  surface 
should  be  finished  with  fine  burs,  and  by  their  use  made  concave  or 
to  conform  to  the  original  type  of  the  part  operated  upon.  The  gold 
should   be  so  impacted   as  to   be  flush  with  the  prepared  margin  of 


CONTOUR    FILLINGS.  539 

enamel,  yet  even  then  made  concave  when  such  concavity  is  indicated. 
Fine  burs  should  be  used  for  the  purpose  of  trimming  and  shaping 
such  fillings,  because  the  form  of  the  remaining  part  or  parts  of  the 
cusps  and  prepared  edges  of  enamel  against  which  the  gold  is  placed 
may  be  changed  and  the  teeth  made  less  useful  when  corundum  cones 
are  used.  The  polishing  of  the  gold  upon  the  surface  referred  to  may 
be  done  with  pumice  and  silex,  mounted  upon  suitably  shaped  points 
of  wood,  leather,  or  rubber. 

"Whether  the  cavity  is  large  or  small,  the  gold  ought  to  be  built 
out  to  the  original  contour  of  the  part  and  at  its  periphery,  a  little 
beyond  the  margin,  then  finished  down  to  the  surface  of  the  enamel, 
and  the  whole  filling  made  to  conform  to  the  line  that  defined  the 
contour  of  the  lost  tissue.  If  the  gold  be  not  impacted  against,  and 
be  not  flush  with,  the  edges  of  the  enamel,  the  operation  is  not  such  as 
is  demanded  for  the  preservation  of  remaining  tissues.  A  plain  sur- 
face of  gold  should  not  be  made,  because  the  tooth  thus  operated  upon 
and  the  one  adjoining  may  approximate  closely  and  disintegration  of 
enamel  take  place  near  or  at  the  part  in  contact.  Restoration  of  con- 
tour prevents  such  contact,  and  this  prevention  is  necessary,  especially 
when  the  tissues  of  the  organ  operated  upon  are  not  fully  calcified. 
When  operations  have  been  so  performed  as  to  entirely  prevent  fluids 
or  semi-solids  from  entering  between  gold  and  the  tissue  against  which 
it  has  been  placed,  the  gold  tint  may  be  seen  through  the  light  walls 
or  edges  of  translucent  enamel  soon  after  the  removal  of  the  rubber 
dam  and  completion  of  the  operation.  If  an  opaque  or  dark  line  or 
spot  be  visible  at  or  near  the  parts  where  gold  ought  to  be  in  contact 
with  dentine  and  enamel,  the  operation  has  been  imperfectly  per- 
formed, and  chemical  action  may  soon  follow  and  the  entire  filling 
prove  a  failure." 

The  operation  of  building  on  the  entire  crown  of  a  tooth  should  be 
proceeded  with  much  in  the  same  way  as  just  described  for  part  of 
the  crown.  If  too  large  pieces  of  either  crystal  gold  or  foil  are  used 
at  one  time,  the  surface  will  become  crusted  over  by  the  pressure  of 
the  point  of  the  instrument,  and  this  will  prevent,  by  any  subsequent 
force  that  can  be  safely  applied,  its  thorough  consolidation.  In  this 
case  the  general  mass  will  be  more  or  less  spongy  and  the  operation 
imperfect.  The  dentist  should  be  well  assured,  therefore,  as  he  pro- 
gresses with  his  work,  that  every  successive  layer  is  firmly  adherent  to 
the  preceding  one.  To  build  up  an  entire  crown  requires  more  time  ; 
perhaps,  also,  more  skill,  as  there  is  no  wall  of  tooth  substance  to  give 
partial  support.     In  other  repects  it  resembles  the  previous  operation. 

It  was  suggested  by  the  late  Prof.  Austen,  as  a  plan  to  avoid  much 
of  the  tediousness  of  the  second  stage  of  this  operation,  to  fill  the 


540  DENTAL   SURGERY. 

pulp  cavity,  inclosing  in  the  center  a  screw-cut,  notched,  or  double- 
headed  pin,  and  carrying  the  gold  over  the  edges  of  the  cavity  ;  make 
this  surface  somewhat  irregular  in  shape,  but  finish  it  smoothly,  and 
trim  the  circumference  to  the  exact  size  of  the  tooth ;  take  a  wax  or 
plaster  impression  of  the  surface,  and  fit  to  the  plaster  model  a  lump 
of  gold,  having  in  the  center  a  hole  larger  than  the  pin  projecting 
from  the  root ;  shape  and  polish  it  oict  of  the  mouth,  then  set  it  in 
place  and  secure  it  by  filling  with  gold  around  the  pin.  If  the  color 
is  not  objected  to  a  vulcanite  crown  could  be  very  perfectly  adapted  in 
this  manner ;  or  a  porcelain  tooth  could  be  made,  hollow  in  the  cen- 
ter, with  pins  or  a  dovetail  to  hold  a  thin  layer  of  vulcanite,  by  means 
of  which  it  could  be  fitted  with  perfect  accuracy  to  the  prepared  root. 
Prof.  Austen  thought  that  in  this  way  the  root  will  be  less  injured,  and 
the  union  between  the  gold  and  the  root  less  disturbed  than  by  the 
long-continued  and  severe  pressure  of  the  ordinary  operation.  While 
the  artificial  crown  is  being  made  he  suggests  a  temporary  gutta-percha 
crown  to  prevent  any  irritation  from  the  projecting  pin. 

A  large  portion  of  the  crown  of  a  tooth  may  be  built  up  with  ordi- 
nary gold  foil  if  it  be  of  the  best  quality,  but  the  cohesive  prepara- 
tions, either  foil  or  crystal  gold,  are  preferable.  The  manufacture, 
however,  of  porcelain  crowns  well  adapted  to  all  forms  of  teeth,  as  well 
as  the  introduction  of  porcelain  facings,  or  sections  of  crowns,  for 
attachment  to  remaining  natural  portions,  afford  many  advantages  in 
restoring  the  lost  portions  of  the  teeth  over  that  of  building  up  with 
solid  gold.     See  Fig.  506. 

We  have  endeavored  in  the  foregoing  description  to  point  out  the 
general  method  of  procedure  in  the  operation  of  which  we  have  been 
treating.  We  have  also  noticed  some  of  the  precautions  necessary  to 
be  observed;  but  unexpected  difficulties  are  sometimes  encountered, 
the  peculiar  nature  of  which  it  is  impossible  to  anticipate.  Few,  how- 
ever, are  of  so  formidable  a  character  that  they  cannot  be  overcome. 

During  the  operation  of  building  up  a  portion  or  the  whole  of  a 
crown  with  cohesive  gold,  if,  in  condensing  it,  any  part  becomes  dis- 
placed or  fails  to  unite  with  that  already  introduced,  it  should  be 
removed,  otherwise  the  filling  will  prove  defective  ;  and  this  rule  will 
apply  to  all  fillings  of  this  form  of  gold.  Each  piece,  as  it  is  intro- 
duced, must  be  firmly  attached  to  that  already  in  position,  and  no 
doubt  should  exist  concerning  secure  anchorage.  When  a  contour 
filling,  which  includes  a  portion  or  the  whole  of  the  masticating  sur- 
face of  a  bicuspid  or  molar,  has  been  properly  inserted,  and  the  gold 
built  up  flush  with  the  margins  of  enamel,  such  a  surface  should  be 
made  to  correspond  to  the  original  surface  in  form,  by  making  it  con- 
cave by  means  of  the  fine  finishing  burs  or  corundum  points  used  with 


CONTOUR   FILLINGS. 


541 


the  dental  engine,  when  it  may  be  polished  with  pumice  and  silex, 
applied  by  properly-shaped  points  of  wood,  rubber,  or  leather.  In  all 
such  building  up  the  gold  should  be  carried  beyond  the  margin  and 
then  cut  down  to  the  surface  of  the  enamel,  preserving  the  original 
contour  of  the  part  as  much  as  is  possible.  By  the  aid  of  matrices  the 
contouring  of  approximal  surface  cavities,  especially  posterior  ones,  is 
greatly  facilitated,  as  they  enable  the  operator  to  adapt  and  impact  the 
gold  in  a  perfect  manner. 

To  retain  the  gold  of  contour  fillings  in  large,  saucer-shaped,  and 
other  forms  of  cavities,  screws  made  of  fine  gold,  securely  anchored  in 
the  dentine,  with  free  ends  projecting  above  the  surface  around  which 
the  gold  is  built,  are  available. 

Fig.  503  represents  Dr.  How's  retaining  screws  and  instruments  for 
their  introduction.  A  shows  a  cone-socket  screw-driver  with  a  sliding 
split  tube  which  serves  as  an  adjustable 
holder  for  the  screw,  in  the  end  of  which 
is  a  slot,  such  as  the  operator  may  readily 
cut  with  a  No.  5  separating  file.  On 
placing  the  screw  in  the  holder,  the 
driver  blade  will  enter  the  slot,  as  shown 
in  partial  section  by  B.  C  shows  in  its 
palatal  aspect  an  incisor  wherein  the 
apical  portion  of  the  pulp  chamber  has 
been  properly  filled  and  the  main  por- 
tion drilled  and  tapped  with  an  A  tap 
and  drill.  The  tap  is  so  set  in  the  tap- 
chuck  as  to  be  a  gauge  by  which  the 
screw- post  may  be  cut  as  much  shorter 
than  the  gauge  as  will  let  the  screw,  after 
it  has  been  placed  in  the  holder  (see  B) 

and  carried  to  its  place  in  the  root,  project  as  shown  in  C.  D  shows 
a  molar  in  the  palatal  root  of  which  a  B  screw  has  been  likewise 
inserted.  It  is  obvious  that  large  contour  fillings  may  be  securely 
built  around  screw-posts  thus  firmly  fixed  in  the  roots  of  such  teeth. 

Fig.  504  represents  Dr.  E.  Osmond's  screws  for  securing  gold  fill- 
ings, with  the  instruments  necessary  for  their  introduction. 

A  A  are  screws  made  of  20-carat  gold  wire,  annealed,  split  about 
half-way,  once  or  twice,  so  as  to  form  two  or  four  arms  when  opened. 
B  is  a  screw-driver,  surrounded  by  a  tube  for  the  purpose  of  holding 
the  screw  and  carrying  it  to  its  place  in  the  tooth.  C  is  a  drill,  for 
the  purpose  of  drilling  a  hole,  which  is  afterward  tapped  by  the  tap- 
screw  D. 

Figs.  I  and  2  are  teeth  with  large  saucer-shaped  cavities,  such  as 


Fig.  503. 


542 


DENTAL    SURGERY. 


we  very  frequently  find ;  but  other  cases  in  which  these  screws  are 
available  will  readily  suggest  themselves  to  the  mind  of  the  experi- 
enced operator. 


^       A 


Fig.  504. 


Fig.  505  represents  the  instruments  for  manipulating  what  is  known 
as  the  St.  Louis  system  of  retaining  screws. 

In  this  set  of  instruments  the  drills,  taps,  and  wire  fitted  for  each 
other  bear  corresponding  numbers,  as  i,  2,  3. 


The  wire-holder  is  made  adjustable  to  take  either  size  of  wire. 
The  cutting  edges  of  the  cutting  pliers  are  formed  with  two  round 
openings,  as  shown  in  the  cut.     The  long  wire  to  be  used,  if  put  in 


CONTOUR   FILLINGS. 


543 


one  of  the  openings,  can  be  "  nicked  "  at  the  proper 
distance  to  form  the  screw  while  in  the  wire-holder, 
so  that  after  having  been  screwed  into  place  it  may 
readily  be  broken  off  without  the  use  of  file  or  plier? 
in  the  mouth. 

Fig.  507  represents  anchor  screws,  drills,  and  taps 
Cut  No.   I   shows  the  size  of  the   i8-carat  goW 
anchor  screw. 

No.  2.  Iridio-platinum  anchor  screw,  same  diame- 
ter, but  longer  than  No.  i. 

A.  Anchor  screw  magnified  to  show  thread  and 
slot. 

No.  3.  The  starting  or  center  drill  will  form  a  pit 
at  the  exact  point  desired ;  but  if  this  point  be  not 
at  first  obtained,  the  pit  center  may  be  moved  later- 
ally while  the  drill  is  revolving. 

B.  Point  of  center  drill  magnified. 

No.  4.  Limit  or  anchor  drill ;  will  bore  only  to  the 
depth  determined  by  the  limit  shoulder, — half  thrf 
length  of  screw  No.  i. 

C.  Point  of  limit  or  anchor  drill  magnified. 


Class  A. 


00000000 

Class  B. 

0000000 


Class  C. 


Class  D. 


Class  E. 


Class  F. 


Fig.  506. 


544 


DENTAL    SURGERY. 


No.  5.  Screw-tap,  its  diameter  being  only  thirty  one-thousandths 
(.030)  of  an  inch. 

No.  6.  Screw-driver  and  sleeve  which  holds  the  screw  for  insertion 
or  removal,  as  shown  magnified  at  D. 

No.  1.     No.  3. 
I 


No.  2. 


B        No.  4.  0  No.  5. 


No.  6. 


Fig.  507. 

E  and  F  exemplify  the  anchor  screw  in  gold  contouring  operations. 
A  drilled  and  tapped  hole  to  be  filled  with  gold  foil  serves  as  a  supe- 
rior retaining  point. 

Under  the  head  of  "  Contour  Work  "  reference  may  be  made  to 

the  use  of  forms  or  facings  of 
porcelain,  as  shown  in  Fig.  506, 
for  filling  cavities  of  decay. 

These  are  to  be  used  in  conjunc- 
tion with  oxychlorid  or  oxyphos- 
phate  of  zinc,  gutta-percha,  or  they 
may  be  set  in  amalgam.  Used  on 
an  articulating  surface,  they  have 
the  advantage  of  a  hardness  at  least 
equal  to  the  most  solid  metal  filling. 
They  may  also  be  used  to  avoid  the 
display  of  more  noticeable  filling 
material. 

For  what  is  commonly  called 
"bridge-work"  the  reader  is  re- 
ferred to  the  article  on  ' '  Prepara- 
tion of  a  Natural  Root  and  Attach- 
ment of  an  Artificial  Crown." 
Fig.  508  represents  Dr.  B.  J. 
Bing's  method  of  capping  a  carious  or  broken  tooth.     It  consists  in 


Fig.  508. 


FILLING    TEETH    OVER    EXPOSED    PULPS.  545 

properly  preparing  the  walls  of  the  cavity,  and  taking  an  impression 
of  it  with  wax  or  modeling  composition.  Dies  are  thus  obtained, 
upon  which  gold  caps  are  struck.  Small  loops  or  rings  are  soldered 
to  the  bottom  of  the  caps,  which  are  secured  in  the  cavities  by  gutta- 
percha or  oxyphosphate  of  zinc. 

Outfit  of  Operative  Instruments. — A  student's  set  of  operative  in- 
struments may  consist  of  a  limited  number  of  instruments,  such  as 
pluggers,  chisels,  scalers,  foil  carrier  and  plugger  combined,  excava- 
tors, dental  engine  instruments,  pulp  cavity  pluggers,  drills  and  ex' 
tractors,  files,  syringe,  Arkansas  stone,  foil  shears,  foil  folder,  mouth 
mirror,  rubber  dam,  rubber-dam  holder,  rubber-dam  clamps,  rubber- 
dam  clamp  forceps,  the  hand  or  automatic  mallet,  chamois  skin,  orange 
wood,  linen  tape,  burnisher.  The  heavy  and  expensive  instruments, 
such  as  the  dental  engine,  extracting  forceps,  and  dental  chair,  are 
usually  furnished  by  the  dental  schools.  A  number  of  dental  chairs 
are  in  use  at  the  present  time,  which  combine  all  of  the  different 
movements  required  by  the  dental  practitioner. 


CHAPTER  III. 
FILLING  TEETH  OVER  EXPOSED  PULPS. 

The  pulps  of  the  teeth  may  be  exposed  by  mechanical  injuries  and 
by  caries ;  the  first  may  occur  from  falls,  blows,  the  careless  excava- 
tion of  carious  cavities  by  means  of  the  engine-bur  or  the  excavator, 
while  the  latter  is  the  result  of  the  destruction  and  disintegration  of 
the  tooth-structure  to  such  a  degree  as  to  expose  the  organ,  which  be- 
comes irritated  as  a  consequence,  and,  if  the  irritation  is  continued, 
leads  to  its  suppuration,  ulceration,  and  death.  The  propriety  of 
filling  a  tooth  after  the  invasion  of  the  pulp  cavity  by  caries  without 
first  destroying  the  pulp  was  for  a  long  time  doubted  by  many  prac- 
titioners. It  was  thought  that  inflammation  and  suppuration  of  the 
pulp  must  necessarily  result  from  the  operation.  But  Dr.  Koecker, 
who  was  the  first  to  recommend  filling  a  tooth  under  such  circum- 
stances, cited  a  number  of  cases  in  which  he  performed  the  operation 
successfully. 

The  earlier  attempts  at  capping  exposed  pulps  were  for  the  purpose 

of  preserving  the  organ  from  the  contact  of  air  and  from  pressure 

during  the  introduction  of  the  crown-cavity  filling,  and  consisted  in 

the  medication  of  the  pulp  with  creasote  or  a  combination  of  creasote 

35 


S4(>  DENTAL   SURGERY. 

and  tannic  acid,  and  later  with  carbolic  acid,  and  its  further  protec- 
tion by  means  of  some  form  of  cap. 

The  results,  however,  were  unsatisfactory,  and  a  correct  method  of 
treatment  was  first  suggested  by  Dr.  Keep,  who  employed  a  paste  of 
chlorid  of  zinc,  which  was  applied  to  the  exposed  pulp,  which  com- 
pletely filled  the  space  around  the  point  of  exposure,  and  thus  pre- 
vented any  receptacle  in  which  effused  serum  or  lymph  could 
accumulate.  The  irritating  effects  of  the  chlorid  of  zinc,  however, 
were  such  that  this  method  was  modified  by  substituting  for  the 
stronger  zinc  chlorid  a  weaker  solution,  which  permitted  its  neutral- 
ization and  thus  diminished  its  power  to  irritate  the  pulp.  Later,  the 
oxyphosphate  of  zinc  was  substituted  for  the  oxychlorid,  the  surface 
of  the  pulp  being  dressed  with  either  pure  or  diluted  carbolic  acid. 

The  method  of  Dr.  King,  that  of  combining  pure  oxid  of  zinc  with 
pure  wood  creasote,  or  carbolic  acid,  as  a  pulp-capping  paste,  which  is 
flowed  over  or  carefully  applied  to  the  pulp,  has  received  a  wide 
acceptance  and  given  satisfactory  results.  This  paste  is  covered  with 
a  layer  of  either  the  oxychlorid  or  the  oxyphosphate  of  zinc,  and  the 
crown  cavity  filled  temporarily  with  either  of  the  zinc  preparations, 
or  gutta-percha,  or  Hill's  stopping.  A  modification  of  Dr.  King's 
method. consists  in  first  applying  pure  carbolic  acid  to  the  exposed  sur- 
face of  the  pulp  to  produce  a  superficial  coagulation,  and  thSn  to  cover 
it  with  a  concave  cap  of  platinum  filled  with  the  paste  composed  of 
oxid  of  zinc  and  equal  parts  of  carbolic  acid  and  oil  of  cloves,  and 
then  filling  the  remaining  portion  of  the  cavity  with  any  of  the  plastic 
materials. 

It  is  the  practice  of  some  to  coat  the  surface  of  such  concave  caps 
in  contact  with  the  pulp  with  a  solution  of  gutta-percha  and  chloro- 
form, which  acts  as  a  non-conducting  substance  and  is  tolerated  by 
the  sensitive  organ,  owing  to  its  anodyne  and  protective  properties. 
The  interposing  substance  may  be  held  in  place  within  the  cavity  by 
a  delicate  excavator  or  nerve  instrument,  and  the  oxychlorid,  of  thin 
consistency,  flowed  over  it,  when  the  remaining  portion  of  the  cavity 
can  be  filled  with  the  same  material  in  the  form  of  a  thicker  paste. 
A  portion  of  this  material  is  afterward  removed  for  the  accommoda- 
tion of  a  more  permanent  filling.  Caps  of  tin  of  a  thickness  of  No. 
28,  and  of  platinum  No.  30,  the  concave  surfaces  filled  with  the  paste 
of  oxid  of  zinc,  carbolic  acid,  and  oil  of  cloves,  or  with  a  solution  of 
gutta  percha'and  chloroform,  and  carefully  applied  over  the  point 
of  exposure,  will  often  prove  serviceable  in  restoring  the  pulp  to  a  nor- 
mal condition.  It  is  suggested  that  such  caps  be  inserted  edgewise, 
in  order  to  prevent  the  direct  pressure  of  the  air  or  the  paste  on  the 
sensitive  organ.     Over  the  metal  caj)  a  temporary  filling  is  introduced 


FILLING   TEETH    OVER    EXPOSED    PULPS.  547 

— one  which  requires  little  force  for  its  introduction  and  of  low  con- 
ductivity. For  such  purposes  the  zinc  preparations  are  commonly- 
employed,  although  some  prefer  gutta-percha,  tin,  or  amalgam.  The 
zinc  preparations  when  employed  for  such  temporary  fillings  should 
not  be  neglected,  owing  to  their  liability  to  disintegrate  near  the 
margin  of  the  gum.  Asbestos,  either  alone  or  enclosed  between 
layers  of  gold  or  tin  foil,  has  also  been  employed  as  a  capping,  concave 
discs  being  formed  when  metal  is  used  in  combination  with  the  asbes- 
tos, the  inner  surfaces  of  which  are  coated  with  the  solution  of 
gutta-percha  and  chloroform.  Thin  card-board  paper,  in  the  form 
of  caps  saturated  with  carbolic  acid,  has  also  been  employed  as  an 
interposing  substance  between  the  point  of  exposure  and  a  filling  of 
the  zinc  preparation.  Dr.  W.  C.  Barrett  has  been  successful  in  cap- 
ping exposed  pulps  with  the  lactophosphate  of  lime,  which  is  applied 
as  an  immediate  cover  to  the  exposed  tissue,  and  which  is  prepared  as 
follows  :  on  a  piece  of  glass  or  porcelain  is  placed  a  drop  of  Merck's 
lactic  acid,  to  which  as  much  magma  phosphate  is  added  as  it  will 
digest;  it  is  then  reduced  to  the  proper  consistency  by  adding  the 
dry  precipitated  phosphate.  The  magma  phosphate  must  be  kept 
under  water.  It  has  been  found  that  the  lactophosphate  of  lime, 
prepared  as  above,  is  very  congenial  to  the  pulp. 

Although  bathing  the  exposed  surface  of  the  pulp  with  pure  car- 
bolic acid  is  practiced  by  many  prominent  dental  practitioners,  some 
contend  that  the  escharotic  action  of  the  agent  may  prove  injurious, 
and  hence  use  either  a  diluted  form,  or  the  pure  crystallized  carbolic 
acid  rendered  fluid  by  a  small  quantity  of  chloroform  ;  others  assert  that 
the  results  desired  cannot  be  effected  by  a  dilute  solution  of  carbolic 
acid,  owing  to  its  greater  affinity  for  water  allowing  it  to  be  absorbed 
to  a  much  greater  degree,  and  causing  more  irritation  and  less  coagula- 
tion than  the  pure  form.  It  is  very  essential,  in  the  treatment  of  cases 
of  exposure  of  the  pulp,  that  a  due  regard  be  paid  to  the  condition  of 
the  organ,  and  the  difference  between  normal  and  abnormal  sensitive- 
ness determined.  If  it  is  a  case  of  simple  exposure,  after  carefully  pre- 
paring the  crown  cavity  and  the  margin  of  the  opening  leading  to  the 
pulp,  after  syringing  with  tepid  water,  all  moisture  should  be  carefully 
removed,  and  a  drop  of  the  solution  of  gutta-percha  dissolved  in  chloro- 
form applied  on  the  point  of  a  delicate  instrument  (some  prefer  dilute 
tincture  of  aconite  or  a  thin  coating  of  glycerin  or  collodion),  and 
the  cavity  filled  temporarily  with  wax  or  cotton,  the  tooth  remaining  at 
rest  for  a  few  days  and  protected  from  irritation. 

When  everything  has  progressed  favorably  for  such  a  period  the 
operation  of  capping  maybe  performed.  Should  the  pulp  be  irritable 
or  the  seat  of  acute  pain  when  first  examined,  the  cavity  should  be 


548  DENTAL    SURGERY. 

syringed  out  with  tepid  water  containing  a  sufficient  quantity  of  car- 
bonate of  soda  to  render  the  solution  slightly  alkaline.  Such  an  appli- 
cation will  relieve  the  pain,  even  if  it  is  acute.  The  application  of 
lead  water  is  often  useful  for  the  same  purpose,  or  the  dilute  tincture 
of  aconite,  or  a  solution  of  the  sulphate  of  atropin. 

Professor  James  H.  Harris  recommends  the  following  method  of 
treating  teeth  with  exposed  pulps  :  "  First  remove  all  decomposed 
dentine,  for  if  any  dentine  in  such  a  condition  is  allowed  to  remain, 
the  progress  of  decay  will  continue  and  causeinflammationof  the  pulp, 
finally  resulting  in  its  destruction.  Even  if  the  carious  portion  is  en- 
tirely removed  and  the  pulp  not  directly  exposed,  we  still  need  not  be 
too  confident  of  the  ultimate  preservation  of  the  vitality  of  the  tooth, 
for  \\it probability  is  that  the  dentinal  fibrillse  die  in  advance  of  the 
actual  decomposition  of  the  tooth  substance,  and  hence,  before  the 
decay  has  actually  reached  the  pulp,  this  organ  may  have  assumed  a 
condition  from  which  recovery  is  impossible.  Still,  however,  every 
attempt  should  be  made  to  preserve  the  vitality  of  the  pulps  of  the  teeth, 
and  with  this  object  in  view,  having  removed  all  of  the  decay,  should 
any  hemorrhage  occur  it  may  be  arrested  with  spirits  of  camphor  or 
with  camphor  and  tincture  of  opium.  The  entire  crown  cavity  should 
now  be  carefully  filled  with  a  ternporary filling  oi  Hill's  stopping,  avoid- 
ing undue  pressure  upon  the  pulp.  The  first  piece  of  the  Hill's  stop- 
ping may  be  more  safely  adapted  by  first  moistening  it  with  chloro- 
form. 

"  This  temporary  filling  should  be  removed  from  time  to  time,  as 
may  be  necessary,  during  a  period  of  from  one  to  five  years,  according 
to  the  health  of  the  patient,  extent  of  exposure,  etc.  With  this  treat- 
ment the  reparative  process  will  more  readily  go  on,  and  when  the  pulp 
is  found  to  have  become  protected  by  a  layer  of  osteo-dentine  a  per- 
manent metallic  filling  may  be  inserted. 

"  As  a  further  precaution  against  danger  to  the  pulp,  a  layer  of  Hill's 
stopping  or  of  oxyphosphate  of  zinc  may  be  placed  in  the  bottom  of  the 
cavity  and  the  permanent  filling  inserted  over  this.  Sometimes,  when 
the  exposure  is  quite  large,  it  will  be  found  well  to  cap  the  pulp  with  a 
thin  mixture  of  oxyphosphate  of  zinc,  as  this  material  can  be  more 
readily  adapted  to  the  exposed  pulp  without  danger  of  producing 
undue  pressure.  But  even  when  this  method  is  pursued  it  is  best  to 
first  coat  the  exposed  surface  of  the  pulp  with  a  solution  of  gutta-percha 
and  chloroform,  in  order  to  protect  it  from  the  slightly  irritant  effect 
of  the  oxyphosphate.  The  oxyphosphate  first  introduced  should  be 
mixed  thin  and  allowed  to  harden,  when  the  remainder  of  the  cavity 
should  be  filled  with  the  same  material  mixed  stiffer,  especially  when 
the  cavity  involves  the  grinding  surface,  where  a  portion  of  the  filling 


FILLING    TEETH    OVER    EXPOSED    PULPS.  549 

is  subjected  to  the  friction  of  mastication.  Sometimes,  in  large  grind- 
ing surface  cavities,  after  capping  and  filling  the  cavity  two-thirds  full 
of  Hill's  stopping  or  oxyphosphate,  the  filling  may  be  finished  with 
amalgam,  which  is  permitted  to  remain  as  a  test-filling  for  from  three 
to  six  months,  when,  if  no  symptoms  of  pulpitis  manifest  themselves, 
such  as  paroxysms  of  pain  caused  by  heat  and  cold,  and  gradually  be- 
coming constant,  a  portion  of  the  temporary  filling  (about  one-third) 
may  be  removed  and  the  cavity  filled  with  amalgam,  which  is  allowed 
to  remain,  as  before  stated,  from  one  to  five  years.  Then  the  amalgam 
may  be  removed,  and,  if  necessary  for  the  support  of  the  gold  to  be 
substituted,  a  small  portion  of  the  Hill's  stopping  or  the  oxyphosphate, 
and  a  gold  filling  inserted.  In  removing  the  temporary  filling,  pre- 
paratory to  inserting  a  gold  filling,  the  condition  of  the  dentine  should 
be  carefully  noted — whether  it  is  normally  sensitive  or  not,  as  the  pulps 
of  teeth  often  die  from  chronic  inflammation  without  pain  to  the 
patient,  in  which  case  the  dentine  would  be  devoid  of  sen.sitiveness. 
Ossification  of  a  pulp  renders  the  dentine  painless.  During  the  re- 
moval of  a  portion  of  the  temporary  filling,  should  the  dentine  be 
found  not  sensitive,  the  operation  of  removing  the  temporary  filling 
should  be  continued  until  the  cause  of  such  want  of  sensation  be  ascer- 
tained, whether  due  to  the  death  of  the  pulp  or  its  ossification. 

"In  performing  the  operation  of  '  capping'  the  rubber  dam  should 
be  applied  if  possible. 

"  In  the  treatment  of  cases  of  exposure  of  the  pulp  a  careful  record 
should  always  be  kept,  as  it  is  impossible  to  remember  the  peculiarities 
of  each  case  extending  through  a  long  period  of  treatment." 

Traumatic  exposures  of  the  pulp,  or  those  which  occur  from  acci- 
dents, such  as  fracture  of  the  teeth  or  careless  use  of  dental  instru- 
ments, should  be  treated  by  the  application  of  diluted  tincture  of 
calendula  to  the  exposed  surface,  and  the  pulp  then  capped  by  a  gold 
or  platinum  concave  cap  filled  with  the  oxid  of  zinc,  carbolic  acid, 
and  oil  of  cloves  paste,  and  a  permanent  filling  in  the  cavity.  Cases 
of  accidental  exposure  of  healthy  pulps  admit  of  immediate  treatment, 
as  a  general  rule,  without  unfavorable  results. 

In  cases  of  long  exposure  it  has  been  recommended  to  wash  out  the 
cavity  with  a  warm  solution  of  salt  and  water,  for  its  sedative  effect, 
or  of  carbonate  of  soda ;  then  to  apply  creasote  on  a  pledget  of 
cotton,  over  which  the  paste  of  oxid  of  zinc  and  a  temporary  filling 
of  Hill's  stopping  are  placed,  to  remain  for  one  or  two  days;  then  to 
remove  the  temporary  filling  and,  if  no  pain  has  been  experienced,  to 
permanently  fill  the  cavity. 

Where  it  is  desirable  to  cap  the  pulps  of  the  temporary  teeth,  a  con- 
vex cap  of  platinum,  the  concavity  of  which  is  filled  with  the  sola- 


55°  DENTAL    SURGERY. 

tion  of  gutta-percha  and  chloroform,  may  be  applied  in  such  a  manner 
as  to  avoid  pressure,  and  a  Hill's  stopping  filling  inserted  over  the  cap. 
The  treatment  just  described  refers  to  pulps  free  from  disease,  the 
condition  being  primary  irritation  from  exposure  and  not  inflammation 
from  long-continued  irritation.  In  the  great  majority  of  the  latter 
cases  attempts  at  preservation  prove  failures,  and  when  persisted  in  may 
prevent  any  successful  subsequent  treatment  following  the  extirpation  of 
the  pulp.  Hence  it  is  necessary  to  accurately  determine  the  condition 
of  the  pulp,  when  exposed,  by  a  careful  examination  before  treatment 
is  commenced.  When  the  patient  possesses  a  healthy  constitution  and 
correct  local  conditions  are  present,  efforts  for  the  preservation  of 
pulps  in  more  or  less  unhealthy  conditions  may  be  instituted.  For 
example,  if  effusion  of  serum  or  lymph  is  present  the  tincture  of 
aconite  should  be  applied  to  the  pulp  and  also  to  the  gum  about  the 
neck  and  root  of  the  tooth,  after  which  the  application  of  pure  car- 
bolic acid  to  the  exposed  surface  of  the  pulp,  to  produce  coagulation, 
is  indicated.  If  such  treatment  arrests  the  exudation,  which  may  be 
determined  by  drying  the  parts,  then  the  treatment  for  a  simple  expo- 
sure of  the  pulp  may  be  at  once  instituted,  or  oxid  of  zinc  made  into  a 
paste  with  water  may  be  applied  and  the  cavity  in  the  crown  of  the 
tooth  filled  with  a  temporary  material.  Should  the  exudation  con- 
tinue, the  oxid  of  zinc,  carbolic  acid,  and  oil  of  cloves  paste  may  be 
applied  to  the  exposed  surface  of  the  pulp,  but  a  loosely  introduced 
pellet  of  cotton  saturated  with  sandarac  should  be  substituted  for  the 
temporary  filling,  so  that  the  fluids  of  the  mouth  may  be  excluded, 
but  the  cavity  should  not  be  closed  so  tightly  as  to  cause  trouble  by 
the  retention  and  accumulation  of  the  effusion.  When  the  vessels  of 
the  pulp  are  engorged,  depletion  by  means  of  an  incision,  after  the 
application  of  equal  parts  of  oil  of  cloves  and  chloroform,  may  be 
made  and  the  pulp  be  capped  by  the  paste  before  referred  to,  over 
which  a  pellet  of  cotton  saturated  with  sandarac  maybe  placed.  Such 
a  dressing  is  allowed  to  remain  for  several  days,  when,  if  everything 
is  favorable,  the  permanent  capping  of  the  pulp  may  be  made.  For 
purulent  discharges  from  the  pulp,  after  the  removal  of  the  irritation, 
the  treatment  consists  in  the  application  of  a  mild  escharotic  in  the 
form  of  a  solution  of  chlorid  of  zinc,  grs.  xxx,  water  3J,  for  several 
minutes,  after  which  repeated  injections  of  tepid  water  should  be  made 
and  the  cavity  exposed  to  the  saliva  to  free  the  eschar  from  the  chlorid 
of  zinc.  The  subsequent  treatment  is  the  same  as  that  described  for  effu- 
sions of  serum  and  lymph.  After  capping  an  exposed  pulp  the  case 
should  be  carefully  watched,  and  if  there  is  undue  sensitiveness 
to  cold,  which  is  usually  the  indication  of  further  trouble,  the  gum 
about  the  affected  tooth  should  be  bathed  with  a  solution  composed 


FILLING    PULP    CHAMBERS    AND    CANALS    OF    TEETH.  55: 

of  tincture  of  aconite,  5ij,  and  chloroform,  3J.  Several  applications 
may  be  required,  although  frequently  but  one  is  necessary.  Another 
application  for  the  same  condition,  or  in  case  the  former  one  is  not 
effective,  consists  of  tincture  of  iodin,  fsij ;  tincture  of  aconite,  fgj, 
and  chloroform,  f3J. 


CHAPTER  IV. 
FILLING  PULP  CHAMBERS  AND  CANALS  OF  TEETH. 

This  operation  has  now  become  very  common,  and  is  practiced  by 
the  most  skillful  dentists  in  America  and  Europe. 

Drs.  Maynard  and  Baker  were  the  first  to  show  that  most  of  the 
morbid  phenomena  resulting  from  the  presence  of  a  tooth  in  the  mouth 
after  the  destruction  of  the  pulp  arose  from  the  irritation  produced 
by  the  matter  contained  in  the  pulp  chamber  and  canal  of  the  root. 
To  prevent  their  occurrence,  therefore,  they  proposed  filling  both 
chamber  and  canal  in  such  a  manner  as  completely  to  exclude  every- 
thing else.  The  accumulation  of  purulent  matter  being  prevented 
here,  its  secretion  at  the  extremity  of  the  root  will,  in  a  majority  of 
cases,  either  cease  altogether  or  go  on  faster  than  it  is  reabsorbed,  as 
has  been  shown  by  repeated  experiments.  Thus  it  would  seem  that 
the  amount  of  vitality  which  a  tooth  derives  from  the  investing  mem- 
brane is  sufficient,  ordinarily,  to  prevent  it  from  exerting  any  apparent 
morbid  action  upon  the  surrounding  parts. 

Although  it  is  desirable  that  the  operation  should  be  performed 
before  any  diseased  action  has  been  set  up  at  the  extremity  of  the 
root,  much  advantage  may  also  be  derived  from  it,  even  after  alveolar 
abscess  has  actually  occurred,  as  great  benefit  often  results  from  cleans- 
ing, disinfecting,  and  filling  the  root-canals  of  teeth  which  are  af- 
fected with  abscess. 

The  application  of  disinfectant  and  antiseptic  agents  to  the  inner 
walls  of  the  sac,  introduced  through  the  canal  in  the  root  previously 
to  filling,  is  one  of  the  most  certain  means  of  cure.  All  root-canals 
do  not  require  to  be  drilled  out  or  enlarged,  and  filled  solidly  to  the 
apex  in  order  to  ensure  comfort  to  the  tooth ;  yet  all  canals  should  be 
sterilized  that,  owing  to  their  small  size  and  tortuous  direction,  cannot 
be  filled.  Very  small  and  abnormally  situated  canals  can  have  their 
openings  into  the  pulp-chamber  exposed  by  flooding  this  chamber  with 
absolute  alcohol  and  drying  it  with  hot-air.  Alcohol  will  also  absorb 
the  moisture  from  the  pulp-tissue  remaining  in  the  canals  and  facili- 


552  DENTAL   SURGERY. 

tate  its  removal.  When  the  openings  of  the  canals  have  been  located, 
their  orifices  should  be  reamed  out  to  such  a  degree  as  will  indicate 
the  size  and  direction  of  the  canals.  A  small,  stiff  broach  should  then 
be  employed  to  explore  each  canal  as  far  as  possible,  and  when  the 
broach  cannot  pass  beyond  a  certain  point,  it  may  be  regarded  as  con- 
clusive that  the  caliber  of  the  canal  thus  explored  is  so  small  that  no 
trouble  will  result  from  failure  to  proceed  further.  An  antiseptic 
should  then  be  pumped  well  into  the  canal  by  flooding  the  pulp-cham- 
ber and  forcing  on  the  medicine  a  piece  of  soft  vulcanite  or  cotton. 

A  favorite  method  of  filling  root-canals  is  to  first  introduce  chloro- 
percha,  and  after  thus  lubricating  the  canal,  to  force  into  it,  with  gentle 
but  constant  pressure,  a  cone  of  gutta-percha,  which  the  lubricant  will 
soften  and  thus  permit  of  its  easy  introduction  into  and  adaptation  to 
the  canal.  Some  prefer  a  solution  of  eucalyptol  and  gutta-percha  to 
the  chlora-percha,  on  account  of  the  eucalyptol  being  less  irritating 
than  the  chloroform  in  the  chloro-percha. 

Treat7nent  Preparatory  to  Filling  the  Canals  of  Teeth. — The  fol- 
lowing is  a  method  of  treatment,  preparatory  to  filling  root- canals, 
which  has  for  some  time  been  pursued  :  Carefully  remove  all  disorgan- 
ized pulp  and  decomposed  dentine  ;  also  all  softened  dentine.  Then 
syringe  out  all  loose  particles  of  the  debris  with  tepid  water,  and  dry 
the  canal  to  the  apex  of  the  root  with  floss  silk,  being  careful  to  leave 
an  end  projecting,  so  as  to  permit  its  easy  removal.  Several  such 
pieces  being  used,  a  shorter  piece  is  then  saturated  with  pure  wood 
creasote  or  carbolic  acid,  and  passed  to  the  end  of  the  canal,  leaving 
a  slight  projecting  piece  in  the  crown-cavity,  so  that  it  may  be  seized 
with  pliers  when  it  is  to  be  removed. 

Then  introduce  into  the  crown-cavity  a  temporary  filling  of  Hill's 
stopping,  gutta-percha,  or  the  zinc  preparations.  In  some  cases  where 
the  effusion  is  considerable,  and  its  retention  causes  discomfort,  the 
temporary  filling  should  consist  of  cotton,  loosely  introduced,  so  that 
it  may  be  readily  removed  by  the  patient  if  necessary.  In  twenty-four 
hours  the  canal  is  examined,  and  the  antiseptic  agent  renewed  if  neces- 
sary. When  not  the  slightest  odor  of  purulent  secretion  is  perceptible, 
then  apply  on  the  floss  silk  carbolic  acid  mixed  with  a  little  chloro- 
form, replace  the  filling,  and  wait  for  several  days. 

If  at  the  end  of  this  time  there  is  no  trace  of  diseased  action,  fill 
the  canal;  then  wait  a  few  days  until  all  chance  of  irritation  from  the 
pressure  used  in  the  operation  has  passed  away,  and  then  complete  the 
filling.  But  not  unfrequently  it  is  necessary  to  repeat  this  course  of 
treatment  several  times. 

In  some  cases  it  may  be  prudent  to  insert  a  filling  of  "  Hill's 
stopping"  for  several  months,  especially  when  there  is  the  slightest 


FILLING    PULP    CHAMBERS    AND    CANALS    OF    TEETH.  553 

doubt  of  the  arrest  of  the  disease;  for  the  gold  once  introduced  into 
the  canal,  it  is  exceedingly  tedious  and  difficult  to  remove  it.  Dis- 
ease on  the  outside  of  the  extremity  of  the  root  may  be  controlled 
by  creasote,  carbolic  acid,  or  other  disinfectants  and  antiseptics, 
applied  through  the  fistulous  or  an  artificial  opening  in  the  alveolus. 
(See  Alveolar  Abscess.) 

Chlorid  of  zinc  may  be  used  instead  of  creasote  when  the  smell  of 
the  latter  is  particularly  repulsive  to  the  patient ;  also,  a  combination 
of  carbolic  acid  or  creasote  and  iodin,  as  Dr.  Leech's  formula,  which 
is  composed  of  iodin  (crystals),  gj ;  carbolic  acid  (crystals),  5J  ;  alco- 
hol, fgij,  applied  on  a  pledget  of  cotton  or  on  floss  silk;  or  a  saturated 
solution  of  iodoform  and  ether  ;  or  eucalyptus  combined  with  iodo- 
form, as  Dr.  Parmele's  formula,  which  is  composed  of  eucalyptus  oil, 
3j;  iodoform,  gr.  x  ;  water,  gj ;  or  Dr.  Black's  mixture,  composed  of 
carbolic  acid  one  part,  oil  of  cassia  two  parts,  and  oil  of  gaultheria  three 
parts,  all  of  which  are  excellent  antiseptics.  Any  trace  of  the  living 
pulp  should  be  treated  with  some  devitalizing  agent,  which  may  be  intro- 
duced upon  floss  silk  before  commencing  the  antiseptic  treatment. 

The  following  are  the  methods  of  treating  pulpless  teeth  pursued  by 
Prof.  Gorgas  and  others:  — 

The  temporary  or  deciduous  teeth  should  be  retained  for  their  full 
natural  term,  and  if  from  any  cause  their  pulps  become  diseased  before 
such  a  period,  the  first  thing  to  be  done  is  to  open  the  pulp  chamber. 
Should  such  a  tooth  be  painful  to  the  touch,  it  should  not  be  further 
operated  on  until  the  soreness  has  disappeared.  Then  the  cavity  of 
decay  should  be  thoroughly  cleansed,  the  dead  pulp  removed,  and 
a  pellet  of  cotton,  saturated  with  such  a  solution  as  the  following  : 
Carbolic  acid  (5  per  cent,  solution)  5J,  cinnamon  or  peppermint 
water  gtt.  Ix,  placed  in  the  pulp-chamber  and  covered  with  a  pellet 
of  dry  cotton  or  soft  rubber  (such  as  a  piece  of  rubber-dam).  Pres- 
sure should  then  be  made  upon  the  cotton  or  rubber  with  a  blunt  in- 
strument until  the  fluid  appears  at  the  fistulous  opening,  if  one  exists. 
The  cotton  or  rubber  should  then  be  removed,  the  crown-cavity  and 
root-canals  dried,  then  by  means  of  a  small  pellet  of  cotton  wound  on 
a  broach,  a  solution  of  gutta-percha  in  chloroform,  of  the  consistence 
of  cream,  should  be  forced  into  the  root-canals,  after  which  the  canals 
should  be  filled  with  gutta-percha  cones,  which  may  be  easily  intro- 
duced owing  to  the  solvent  action  of  the  chloroform  already  in  the 
canals. 

Pulpless  deciduous  teeth  without  fistulous  openings  are  treated  in  the 
same  manner  as  permanent  teeth  with  blind  abscesses. 

In  cases  of  the  permanent  teeth  where  it  is  necessary  to  devitalize 
the  pulp,  the  rubber-dam  should  first  be  adjusted,  the  carious  cavity 


554  DENTAL    SURGERY. 

freely  opened,  and  all  loose  matter  and  softened  dentine  removed,  so 
that  the  pulp  is  freely  exposed.  A  small  pellet  of  cotton  is  then  dipped 
in  pure  wood  creasote,  and  -^^  or  -jig-  of  a  grain  of  the  oxid  of  arsenic 
taken  up  on  it  and  placed  directly  in  contact  with  the  exposed  point 
of  the  pulp,  and  the  crown-cavity  carefully  sealed  in  such  a  manner  by 
a  temporary  filling  as  not  to  cause  any  pressure  on  the  pulp.  This 
preparation  of  arsenic  should  be  permitted  to  remain  for  24  hours, 
when  it  should  be  removed  and  the  cavity  carefully  washed  out.  After 
the  removal  of  the  devitalized  pulp,  acces3  to  which  is  made  by  freely 
opening  the  root-canals,  the  drilb  employed  for  this  purpose  being 
frequently  dipped  into  eugenol,  or  a  5  per  cent,  solution  of  carbolic 
acid,  or  other  disinfectants  and  antiseptics,  such  as  oil  of  cassia  and 
wintergreen,  or  a  solution  of  bichlorid  of  mercur)^ — -^^  or  yoir^ — o"* 
peroxid  of  hvdrogen,  or  peroxid  of  sodium.  The  use  of  sulphuric 
acid  is  also  recommended  for  opening  the  pulp-canals  (page  559). 
The  root-canals  should  be  thoroughly  disinfected  by  any  of  the  agents 
just  mentioned  and  permanently  filled  with  the  gutta-percha  cones  or 
the  zinc  filling  materials. 

For  the  treatment  of  pulpless  teeth  affected  with  blind  abscesses, 
the  rubber-dam  should  first  be  adjusted,  the  main  cavity  of  decay  ex- 
cavated, and  all  softened  dentine  removed.  The  pulp-chamber  should 
be  opened  thoroughly  and  well  syringed  with  tepid  water.  The  root- 
canals  should  then  be  opened  and  carefully  syringed  with  an  antisep- 
tic solution,  then  thoroughly  dried  and  injected  with  peroxid  of 
hydrogen  until  all  bubbling  ceases;  peroxid  of  sodium  (50  per  cent, 
solution)  may  also  be  injected  into  the  root-canals  and  into  the  apical 
space,  or  they  may  be  bathed  with  eugenol,  or  with  oil  of  cassia,  car- 
bolic acid,  and  wintergreen,  or  with  oil  of  cassia  and  guaiacol,  or  car- 
bolic acid  (5  per  cent,  solution),  or  pure  wood  creasote,  when  the 
crown-cavity  is  loosely  filled  with  dry  cotton.  After  three  days  this 
treatment  should  be  repeated,  and  continued  at  the  same  intervals  until 
it  is  quite  evident  that  the  discharge  of  pus  has  ceased.  When  such 
is  the  case  the  root-canals  should  be  tightly  packed  or  well  saturated 
with  one  of  the  disinfecting  combinations  before  referred  to,  and  the 
crown  cavity  filled  with  a  temporary  filling  material,  and  the  tooth  per- 
mitted to  remain  at  rest  for  four  or  five  days.  After  this  time,  if  no 
soreness  is  apparent  on  percussion  or  pressure,  or  any  evidence  of  pus 
is  apparent  on  removing  the  temporary  filling,  the  canals  should  be 
thoroughly  dried  and  permanently  filled  with  gutta-percha  or  other 
root-canal  filling  material.  The  vapor  of  crystals  of  iodin  forced  into 
the  apical  space  with  a  hot-air  syringe  constructed  for  such  a  purpose 
has  also  given  satisfactory  results  in  cases  of  blind  abscess,  as  well  as 
those  with  fistulous  openings. 


FILLING    PULP    CHAMBERS    AND    CANALS    OF    TEETH.  555 

Dr.  C.  N.  Johnson's  method  of  treating  pulpless  teeth  with  no  fistu- 
lous openings  is  as  follows: — 

The  rubber-dam  should  be  applied  before  any  drilling  is  attempted, 
and  an  antiseptic  (such  as  carbolic  acid  one  part,  oil  of  cassia  two  parts, 
and  oil  of  gaultheria  three  parts)  placed  near  at  hand  for  immediate  use 
the  moment  the  pulp-chamber  is  penetrated.  This  antiseptic  should 
be  non-irritating  and  non-effervescing,  in  order  that  no  septic  matter 
in  the  canal  be  forced  into  the  apical  space.  As  soon  as  the  chamber 
is  reached  by  the  drill,  it  should  at  once  be  flooded  with  the  antiseptic, 
care  being  taken  not  to  cause  any  pressure  upon  the  contents  of  the 
canal.  After  a  little  time  a  bit  of  absorbent  cotton  or  bibulous  paper 
may  be  lightly  applied  to  the  opening  to  absorb  enough  of  the  anti- 
septic to  admit  of  drilling  to  enlarge  the  opening,  and  when  this  is 
done  the  chamber  may  repeatedly  be  flooded,  and  the  contents  absorbed 
as  before,  till  the  greater  part  of  the  putrescent  matter  has  been  re- 
moved from  the  chamber  and  greater  portion  of  the  canals  without 
causing  disturbance  at  the  apical  foramen.  When  this  process  has  been 
carried  to  the  limit  of  safety,  the  cavity  is  flooded  with  absolute  alco- 
hol for  its  dehydrating  effect,  and  this  evaporated  to  dryness.  The 
dryer  the  canals  the  less  chance  there  is  for  micro-organic  life  to  exist, 
and  when  an  antiseptic  is  applied  the  greater  will  be  the  amount  taken 
up  by  the  tubuli.  The  crown  of  the  tooth,  however,  must  not  be 
heated  too  hot  in  the  process  of  drying  the  root,  nor  should  it  be  kept 
dry  too  long  for  fear  of  injury  through  the  checking  of  the  tooth- 
structure.  When  dryness  of  the  canals  is  obtained,  they  should  once 
more  be  flooded  with  an  antiseptic,  this  time  to  remain  sealed  in  the 
cavity  until  the  next  sitting.  The  canals  are  left  thus  filled,  but  no 
cotton  is  forced  into  them  at  this  time.  A  small  pledget  of  cotton 
may  be  placed  loosely  in  the  chamber,  and  the  opening  closed  with 
gutta-percha.  The  case  may  then  be  dismissed  for  one  week,  with 
instructions  to  return  sooner  in  case  of  trouble.  If  in  any  doubt,  the 
patient  should  be  seen  in  24  or  48  hours,  and  the  dressing  changed. 
At  the  end  of  the  week,  if  no  symptoms  of  irritation  have  been  felt, 
and  if  the  canals  show  no  signs  of  putrescent  matter  on  the  removal 
of  the  dressing,  the  roots  may  be  filled,  first,  however,  washing  them 
out  with  alcohol,  drying  them,  flooding  with  the  antiseptic,  and 
finally  drying.  In  case,  however,  after  the  first  treatment  the  dressing 
should  show  signs  of  a  blind  abscess  in  the  apical  space,  the  treatment 
should  be  continued  till  all  weeping  of  pus  stops  and  the  abscess  heals. 

Management  of  Pulpless  Teeth  with  Fistulous  Opening. — First,  the 
soft  decalcified  dentine  should  be  cleansed  from  the  cavity  and  the 
pulp-chamber  thoroughly  opened,  the  putrescent  contents  of  the 
canals  removed  as  thoroughly  as  possible,  and  to  accomplish  this  the 


556  DENTAL   SURGERY. 

chamber  and  canals  should  be  flooded  with  an  antiseptic,  and  this 
absorbed  with  cotton  or  bibulous  paper.  When  the  canals  are  cleaned 
the  abscess  should  be  injected  with  the  antiseptic  through  the  canal, 
and  the  process  kept  up,  if  possible,  till  the  medicine  appears  at  the 
fistulous  opening  on  the  gum.  This  may  be  done  by  packing  the  canal 
tightly  with  cotton  saturated  with  the  medicine,  and  then  forcing 
down  upon  it  a  mass  of  soft  rubber  such  as  is  used  for  packing  plates  of 
dentures.  When  the  medicine  appears  at  the  fistulous  opening,  if  the 
case  is  one  of  recent  occurrence,  the  cavity  may  at  once  be  sealed — 
after  replacing  the  cotton  in  the  canal  with  freshly  saturated  cotton — 
and  the  patient  dismissed  for  one  week.  If  the  case  is  one  of  long 
standing,  where  the  dentine  of  the  root  is  much  infected,  it  is  best 
after  the  injection  to  flood  the  canal  with  alcohol  and  evaporate  to 
dryness  before  applying  the  antiseptic  and  sealing  the  cavity.  This 
insures  a  more  thorough  saturation  of  the  tubuli  with  the  antiseptic, 
and  the  tooth  will  return  to  a  better  condition  than  if  the  drying  had 
been  omitted.  When  the  patient  returns,  and  the  fistula  is  found  per- 
fectly closed,  the  root  may  be  filled  at  this  sitting,  the  same  process 
being  followed  prior  to  filling  as  that  advised  in  the  case  of  roots  with- 


99 


Fig.  509. 

out  fistulous  openings.  If  the  patient  returns  with  the  fistula  still  dis- 
charging, carbolic  acid  (95  per  cent,  solution)  is  injected  till  it  appears 
at  the  fistulous  opening.  The  canal  is  then  packed  with  cotton  satu- 
rated with  carbolic  acid,  the  cavity  sealed,  and  the  patient  dismissed. 
If  there  has  been  much  discharge  with  a  free  opening,  pyrozone  (3  per 
cent,  solution)  may  be  injected  prior  to  the  use  of  carbolic  acid. 
Seal  such  a  case  for  a  week,  and  repeat  the  treatment  if  the  fistula  is 
found  open  at  the  end  of  that  time.  In  chronic  cases,  where  a 
third  treatment  has  been  found  necessary,  the  dressing  in  the  canal 
should  not  be  disturbed  for  a  month.  The  operator  may  see  the  patient 
in  the  meantime,  and  if  he  deems  it  necessary  may  treat  the  fistula 
through  the  opening,  but  in  very  many  of  these  cases  no  treatment  at 
all  is  preferable  to  any  treatment. 

The  immediate  filling  of  the  root-canal  in  such  cases  has  also  been 
recommended.     (See  Low's  Method,  page  561.) 

Fig.  509  represents  iridio-platinum  nerve  broaches  for  extracting 
dead  pulps  of  teeth  and  for  introducing  into  the  pulp-canal  medicinal 
agents  in  the  treatment  of  diseased  teeth.     They  do  not  corrode  when 


FILLING    PULP   CHAMBERS    AND   CANALS    OF    TEETH. 


557 


exposed  to  moisture,  acids,  iodin,  etc.,  and  can  be  cleansed  perfectly 
by  heating  to  redness  in  the  flame  of  a  spirit  lamp. 

Fig.  510  represents  a  set  of  Dr.  B.  F.  Arrington's  devitalized  nerve 
extractors  and  canal  pluggers,  of  drawn  and  spring  temper. 

Fig.  512  represents  Dr.  Donaldson's  spring-tempered  nerve-bristles 
and  pulp-canal  cleansers. 

Fig.  513  represents  Dr.  Walker's  nerve-canal  drills. 


Soft. 


Spring  Temper. 


Soft. 


Spring  Temper. 


Fig.  510. 

Filling  Pulp  Cha?nbers  and  Canals  of  Teeth. — For  filling  pulp  canals 
very  nice  instruments  may  be  made  from  piano  wire  filed  to  any  desired 
size  and  fitted  into  suitable  handles.  This  wire  is  very  tough  and 
elastic.  The  gold  used  for  filling  pulp  canals  should  be  non-cohesive 
and  folded  into  a  very  light  ribbon,  and  this  cut  into  square  pieces, 
which  should  be  placed  upon  a  piece  of  folded  chamois  skin  and 


Fig.  511. 


carried  to  the  pulp  canal  by  means  of  the  nerve-canal  plugger  point. 
Piece  after  piece  of  the  gold  is  carefully  introduced  to  the  apex  or 
upper  extremity  of  the  root  until  the  entire  canal  is  filled.  Strips  of 
heavy  gold  foil  conveyed  to  the  apex  of  the  canal  in  a  similar  manner, 
or  by  mallet  force,  are  also  employed  for  filling  root  canals.  Malleting 
the  gold  into  the  canals  is  also  preferred  by  many  to  pressure  with  the 


558 


DENTAL   SURGERY. 


hand,  as  percussion  causes  no  deflection  of  the  instrument  such  as  may 

occur  under  pressure  with  delicate  canal  pluggers.     The  cavity  in  the 

crown  is  then  filled  in  the  usual  manner. 

Fig.  511   represents  a  set   of  nerve   instruments  contrived  by  Dr. 

Corydon  Palmer  for  entering  and  enlarging  the  canals  in  the  roots  of 

the  teeth. 

Fig.  514  represents 
Dr.  Hunter's  set  of 
pulp-canal  pluggers, 
some  of  which  are  of 
drawn  and  others  of 
spring  temper. 

After  the  cavity  of 
decay  in  the  crown  has 
been  properly  prepared 
by  means  of  the  instru- 
ments represented  in 
Fig.  512,  the  pulp 
chamber  can  be  exca- 
vated and  so  shaped  as 
to  assist  in  the  retention 
of  the  gold.  Some  op- 
erators drill  out  these 
canals    and    thus    give 


Fig.  512. 


Fig.  513. 


them  the  same  diameter  from  their  orifice  at  the  pulp  chamber  to  the 
apex  of  the  root,  but  this  is  considered  by  many  to  Ije  an  unnecessary 
as  well  as  dangerous  operation,  as  the  instrument  may  pass  through  the 
side  of  the  root,  particularly  where  the  root  happens  to  be  curved. 
Reaming  out  and  enlarging  the  orifice  of  the  canal  may  be  sufficient 
in  the  majority  of  cases. 


FILLING    PULP    CHAMBERS    AND    CANALS    OF    TEETH. 


559 


Others  are  satisfied  with  cleansing  them  perfectly  of  all  debris  and 
decomposed  dentine,  and  thoroughly  disinfecting  them  and  rendering 


Fig.  514. 

the  contents  of  the  tubuli  aseptic.  Whichever  method  is 
pursued,  care  is  necessary  that  the  instrument  is  not  passed 
beyond  the  foramen,  which  is  more  liable  to  occur  in  the 
case  of  young  patients,  when  the  teeth  are  not  fully  devel- 
oped, than  afterward;  for  in  adult  teeth  there  is  generally 
such  a  decided  contraction  of  the  root  canal  near  the  apex  as 
to  arrest  the  progress  of  the  instrument. 

Figs.  515  and  516  represent  sets  of  nerve-canal  drills  and 
reamers,  devised  for  the  enlargement  of  the  canals  prior  to  the 
filling  of  the  same,  and  also  for  pivoting. 

For  facility  of  treating  and  filling,  free  access,  however, 
should  be  had  into  root-canals  by  means  of  the  instruments 
referred  to.  Recently  the  use  of  a  40  or  50  per  cent,  aqueous 
solution   of  sulphuric  acid   has  been   cmploNtd    u;r    oiiening 


I      t  M 


Fig.  515- 


Fig.  516. 


root-canals.     This  process  is  described  as  follows  by  Dr.  J.  R.  Calla- 
han :    "Adjust  the  rubber-dam,  open  the  pulp-chamber  thoroughly, 


560  DENTAL    SURGERY. 

twist  a  little  cotton  on  the  end  of  a  broach,  bend  the  broach  to  a 
right  angle,  so  that  it  will  reach  well  down  into  the  cavity ;  place  the 
broach  in  a  suitable  handle,  and  by  means  of  broach  and  cotton  place 
upon  the  dead  pulp  a  drop  or  two  of  the  sulphuric  acid  solution, 
which,  by  a  process  of  dehydration,  will  cause  the  pulp  to  shrink  and 
toughen,  when  it  can  be  easily  removed.  By  the  broach  and  cotton, 
a  drop  of  the  solution  is  placed  over  the  entrance  to  each  canal,  then 
with  a  pumping  motion  enter  the  canal  slowly  and  carefully  ;  the  acid 
will  destroy  all  septic  matter  and  enlarge  the  diameter  of  the  canals. 
By  means  of  a  syringe  the  root  canals  are  then  filled  with  a  saturated 
solution  of  bicarbonate  of  soda,  which  will  neutralize  the  acid  and 
liberate  carbonic  acid  gas  in  such  quantities  that  the  effervescence  will 
carry  all  the  broken-up  tooth-  and  pulp-substances  out  of  both  the 
canal  and  tooth,  leaving  a  deposit  of  bicarbonate  of  soda,  which  can 
be  removed  by  a  little  sterilized  water,  alcohol,  or  peroxid  of  hydro- 
gen. The  roots  can  then  be  filled  if  no  inflammatory  symptoms  are 
present." 

Besides  the  method  of  filling  the  roots  described  above,  there  are 
several  others,  one  of  which  consists  in  rolling  strips  or  folds  of  gold 
on  a  fine  broach  in  such  a  manner  as  to  form  cone-shaped  cylinders, 
somewhat  longer  than  the  canal  is  deep,  of  different  sizes  and  density. 
The  soft  rolls  are  first  introduced  on  a  smooth  broach,  or,  if  the  canal 
is  large  and  easily  approached,  by  means  of  the  pliers,  and  carried  up 
as  near  to  the  apex  of  the  root  as  is  possible,  each  one  being  condensed 
as  it  is  introduced.  Successive  cylinders  are  introduced  in  this  man- 
ner and  condensed  until  the  canal  is  filled,  the  last  ones,  which  com- 
plete the  filling,  being  larger,  of  heavier  gold,  and  more  densely  rolled. 
Pure  gold  or  platinum  wire  is  sometimes  employed  for  filling  these 
canals,  so  shaped  as  to  correspond  in  size  and  taper  with  the  cavity. 
These  wires  should  be  coated  with  gutta-percha  or  oxyphosphate  of 
zinc  before  introducing  them. 

It  sometimes  happens  that  the  canals  in  the  buccal  roots  of  the 
superior  molars  are  so  small  as  to  preclude  the  introduction  even  of  a 
small-sized  bristle.  In  cases  of  this  kind  it  is  impossible  to  fill  them, 
and  fortunately,  from  their  small  size,  they  cannot  serve  as  reservoirs 
for  the  accumulation  of  morbid  matter.  Such  canals,  however,  should 
be  thoroughly  disinfected  before  the  larger  ones  are  filled.  The  canal 
in  the  palatine  root  is  always  much  larger  than  in  either  of  the  buccal 
roots,  and  in  a  majority  of  the  cases  is  filled  with  comparative  ease. 
Although  gold  and  tin  have  long  been  used  for  falling  root  canals,  yet 
some  non-metallic  substances  have  answered  well  when  employed  for 
this  purpose,  such  as  cones  of  gutta-percha,  chloro-percha,  gutta-percha 
and  eucalyptol.  Hill's  stopping,  and  the  zinc  filling  materials.     When 


FILLING    PULP    CHAMBERS    AND    CANALS    OF    TEETH. 


561 


cones  of  gutta-percha  are  used  for  filling  pulp-canals  one 
end  of  the  cone  is  dipped  in  chloroform,  which  softens 
it  and  facilitates  its  introduction  and  adaptation  to  the 
canal.  Gold  may  be  employed  for  filling  the  space  of 
one-third  of  the  canal  from  the  apex,  and  the  remaining 
portion  maybe  filled  with  gutta-percha  or  oxyphosphate 
of  zinc.  Amalgam  has  also  been  employed  for  filling 
root-canals.  An  instrument  represented  by  Fig.  517  is 
the  invention  of  Dr.  Geo.  Evans  for  drying  root  canals 
preparatory  to  filling  them.  The  oval  mass  of  copper  is 
heated  in  the  flame  of  the  lamp  to  a  dull  red,  and  the 
heat  passes  rapidly  along  the  silver  probe,  which  is 
inserted  as  far  up  the  canal  as  possible.  The  effect  is 
to  evaporate  the  moisture  and  gases  and  carbonize  any 
organic  material  in  the  canal  and  tubuli.  For  bleaching 
teeth  which  have  become  discolored  from  loss  of  vitality, 
the  reader  is  referred  to  the  chapter  on  that  subject. 

In  the  treatment  of  the  canals  of  devitalized  teeth,  if 
there  is  a  secretion  of  liquid  (protoplasm)  through  the 
foramen  into  the  pulp  canal,  bibulous  paper  or  absorbent 
cotton  may  be  employed  for  drying  the  canal,  when 
chlorid  of  zinc  in  a  deliquesced  form  should  be  intro- 
duced on  cotton  wound  about  a  broach,  which  will 
coagulate  the  fluid  emanating  from  the  elements  of  the 
tissues  about  the  apex  of  the  roots,  and  the  canal  can  at 
once  be  permanently  filled.  A  putrescent  pulp  remain- 
ing in  the  root  canals  gives  rise  to  the  formation  of  sul- 
phureted  and  phosphoreted  hydrogen  gas  from  the  dis- 
integrating tissue,  which,  with  the  particles  of  such 
tissue  and  the  foreign  matter  forced  through  the  foramen, 
causes  irritation  of  the  tissues  surrounding  the  apex  of 
the  root.  The  secretion  of  pus  will  continue  as  long 
as  the  putrescent  matter  remains  in  the  canal  and  the 
mephitic  gas  evolves  from  it  through  the  apical  foramen, 
and  relief  is  experienced  only  when  the  suppurating  sur- 
face is  destroyed  and  a  normal  action  brought  about  by 
removal  of  the  irritating  matter  and  the  action  of  an  es- 
charotic  or  disinfectant,  such  as  carbolic  acid  or  creasote, 
iodoform,  eucalyptus,  peroxid  of  hydrogen,  etc.,  assisted 
by  injections  of  warm  water  as  a  cleansing  process. 

The  method  of  "  immediate  root-filling  "  is  described 
by  Dr.  Frank  W.  Low  as  follows  : — 

"The  instruments  best  adapted  for  general  use, 
36 


1 


Fig.  .'U7. 


,62 


DENTAL    SURGERY. 


especially  in  the  deeper  portions  of  the  pulp  canals,  are  Donaldson's 
spring-tempered  pulp-canal  cleansers.     First,  because,  if  they  penetrate 

a  root  in  which  is  present  a 
sloughing  and  partly  disorgan 
ized  filament  of  the  pulp,  they 
seem  to  cause  less  pain  than 
barbed  broaches,  and  are  more 
likely  to  so  engage  the  fibre  as  to 
bring  it  away  entire.  Second, 
in  the  absence  of  any  sensitive 
filaments  the  debris  is  removed 
rapidly,  engaging  itself  in  the 
screw  threads  of  the  instrument 
its  entire  length,  from  which  it 
can  be  readily  removed  when 
withdrawn  by  brushing  with  an 
ordinary  tooth-brush.  Third, 
because  if  it  is  found,  when 
screwed  into  the  canal,  that  it 
will  not  strip  out — thus  bringing 
its  load — it  can  be  safely  and 
easily  disengaged  by  turning  to 
the  left,  as  you  would  remove 
any  other  screw-threaded  instru- 
ment. Fourth,  because  the  worn- 
out  instruments  are  of  such  fine 
temper  that  they  can  be  ground 
on  the  lathe  corundum  wheel 
into  four  or  five-sided  broaches, 
and  as  such  can  be  utilized  to 
wrap  minute  shreds  of  absorbent 
cotton  upon  for  the  final  drying 
process  before  the  gutta-percha 
cones  are  introduced.  Several 
of  these  can  be  wound,  even  by 
an  inexperienced  assistant,  and 
thus  be  ready  at  once  for  rapid 
successive  introduction  just  pre- 
ceding that  of  the  cones. 

"  The   penetration    of  canals 
will  be  accelerated  by  frequent 
^'^'  5'^-  injection   of  peroxid  of  hydro- 

gen, because  of  the  expulsion  of  their  contents,  incident  to  the  efifer- 


FILLING    PULP    CHAMBERS    AND    CANALS    OF   TEETH.  563 

vescence  of  this  compound,  as  well  as  its  chemical  combination  with 
and  consequent  softening  of  the  products  of  infection  present. 

"When  the  instruments  have  at  length  penetrated  the  apex  of  the 
root — of  which  fact  you  may  safely  trust  the  patient  to  make  you  aware 
— it  will  often  be  found  upon  injecting  the  peroxid  solution  once  more 
that  effervescence  (which  perhaps  just  before  had  nearly  or  quite 
ceased)  will  again  manifest  the  presence  of  septic  matter  ;  this,  how- 
ever, is  caused  by  the  pus  so  often  confined  in  the  '  apical  space,'  and 
any  further  penetration  of  the  broach  is  contraindicated.  It  is  not  suf- 
ficient merely  to  inject  in  order  to  obtain  the  full  benefit  of  the  peroxid 
in  this  new  territory  of  infection,  but  the  plunger  of  the  syringe  should 
be  worked  with  a  rapid  churning  motion  for  several  seconds,  while  the 
nozzle  of  the  instrument  remains  as  deeply  fixed  as  possible  in  the 
pulp  canal  under  treatment,  for  by  this  reciprocating  motion  of  the 
plunger  the  fluid  is  forced  beyond  the  apex  of  the  root  and  into  the 
infected  territory,  and  thoroughly  mixed  with  any  pus  which  may  then 
be  present. 

"An  instrument  well  adapted  for  the  purpose  of  thus  injecting  the 
peroxid  of  hydrogen  is  the  Lewis  abscess  syringe  (Fig.  518).  The  ad- 
vantages to  be  derived  from  its  use  are  that  it  can  be  operated  with  one 
hand  and  the  pumping  or  churning  motion  above  mentioned  be  easily 
accomplished.  The  capacity  of  the  syringe  is  so  small  that  the  inject- 
ing process  is  prevented  from  becoming  a  sloppy  one,  while  at  the  same 
time  the  fit  of  the  plunger  is  so  perfect  that  the  injection  is  accom- 
plished with  considerable  force. 

"  When  effervescence  again  ceases — which  will  be  indicated  if,  upon 
removal  with  cotton  or  spunk  of  all  the  '  lather '  previously  made,  it 
is  found  that  further  injection  produces  only  such  bubbles  as  may  be 
expected  from  the  confinement  of  particles  of  air  in  any  liquid — the 
canal  should  be  wiped  out  and  an  injection  of  the  y^^TT  bichlorid  of 
mercury  solution  substituted.  It  is  just  possible  that  the  use  of  the 
bichlorid  solution  might  be  dispensed  with;  but  it  is  the  most  power- 
ful known  germicide,  and  besides  it  is  just  sufficiently  irritant  to  cause 
the  inner  walls  of  the  abscess — if  one  be  present — when  collapsed,  to 
become  obliterated  by  adhesion. 

"  To  facilitate  this  collapse  of  the  walls  of  the  pus  sac,  the  syringe 
again  comes  into  use  as  an  aspirator.  The  use  of  the  dry  hot  air  cur- 
rent is  next  indicated,  and  last  of  all  the  little  broaches  wound  with 
cotton  shreds.  Several  of  these  latter  should  be  used,  even  though  the 
first  one  withdrawn  appears  to  be  dry,  because  they  are  the  most  per- 
fect exhaust  plungers  after  all.  Following  their  use,  the  canals  should 
be  quickly  sealed  with  gutta-percha  cones  dipped  in  a  thin  chloro- 
percha  solution  to  facilitate  their  deep  penetration  into  the  canal  and 


564  DENTAL   SURGERY. 

at  once  to  varnish  them  tight  to  its  walls.  A  moment's  wait — which 
usually  is  gratefully  accepted  both  by  operator  and  patient — is  now  ad- 
visable in  order  that  the  chloroform  of  the  chlora-percha,  which,  as  the 
cone  descends  into  the  cavity  of  the  canal,  will  "be  found  to  have  re- 
gurgitated, may  have  an  opportunity  to  evaporate.  After  wiping  this 
off  with  spunk  or  cotton,  the  cone  will  be  found  very  soon  to  be  dry. 


Fig.  519. 


and  then  it  can  be  condensed  a  trifle,  after  which,  if  the  material  to  be 
used  be  other  than  gold,  the  crown  filling  can  safely  be  made  at  once. 

"  If  gold  is  to  be  the  material  used,  the  operation  had  better  be 
deferred  for  a  few  days,  lest  the  impact  of  the  plugger  should  cause 
acute  inflammation  of  the  irritable  peridental  membrane." 

Another  convenient  syringe  is  the  Laskey  (Fig.  519),  from  which  an 
obstruction  of  the  discharge-pipe  can  be  readily  removed. 


CHAPTER  V. 
EXTRACTION  OF  TEETH. 


There  are  few  operations  in  surgery  that  excite  stronger  feelings  of 
dread,  and  to  which  most  persons  submit  with  more  reluctance,  than 
the  extraction  of  a  tooth.  Many  endure  the  torture  of  toothache  for 
weeks,  and  even  months,  rather  than  undergo  the  operation  ;  and, 
indeed,  when  we  take  into  consideration  the  frequent  accidents  occur- 
ring in  its  performance  by  awkward  and  unskillful  individuals,  it  is  not 
surprising  that  it  should  be  approached  with  apprehension.  But  when 
performed  by  a  skillful  hand  and  with  a  suitable  instrument,  the  opera- 
tion is  always  safe,  and  in  a  large  majority  of  the  cases  may  be  effected 
with  ease. 

Numerous  cases  of  serious  injuries  show  the  impropriety  and  danger 


EXTRACTION    OF    TEETH.  565 

of  intrusting  this  operation  to  individuals  possessing  neither  knowl- 
edge of  its  principles  nor  skill  in  its  performance.  Injuries  occasioned 
by  the  operations  of  such  persons  have  frequently  come  under  the 
immediate  observation  of  the  author,  with  whom  it  has  always  been  a 
matter  of  surprise  that  an  operation  to  which  such  universal  repug- 
nance is  felt  should  ever  be  confided  to  them. 

The  removal  of  a  wrong  tooth,  or  of  two  or  three  instead  of  one,  are 
such  common  occurrences  that  it  were  well  if  the  precautions  given  by 
the  illustrious  Ambrose  Pare  were  more  generally  observed.  So  fearful 
was  he  of  injuring  the  adjacent  teeth,  that  he  always  isolated  the  tooth 
to  be  extracted  with  a  file  before  he  attempted  its  removal.  He 
regarded  it  as  of  the  greatest  importance  that  a  person  who  extracted 
teeth  should  be  expert  in  the  use  of  his  "  tooth  mullets;  for  unless  he 
knows  readily  and  cunningly  how  to  use  them,  he  can  scarcely  so  carry 
himself  but  that  he  will  not  force  out  three  teeth  at  once."  Although 
great  improvements  have  been  made  since  his  time  in  the  construction 
of  extraction  instruments,  yet  even  now  the  accidents  to  which  he 
alluded  are  of  frequent  occurrence. 

It  is  surprising  that  an  operation  so  frequently  called  for  should  re- 
ceive so  little  attention  from  medical  practitioners,  by  whom,  though 
not  strictly  belonging  to  their  province,  it  must  frequently  be  per- 
formed. This  neglect  can  only  be  accounted  for  by  the  too  general 
prevalence  of  the  idea  that  little  or  no  surgical  skill  is  necessary  to  its 
performance.  But  every  physician  residing  in  the  country,  or  where 
the  services  of  a  skillful  dentist  cannot  always  be  commanded,  should 
provide  himself  with  the  proper  instruments,  and  make  himself 
acquainted  with  the  manner  of  performing  this  operation. 

INDICATIONS    FOR    THE    EXTRACTION    OF    TEETH. 

With  regard  to  the  indications  that  determine  the  propriety  of  ex- 
traction, the  author  does  not  deem  it  necessary  to  say  much  in  this 
place,  as  they  are  fully  pointed  out  in  other  parts  of  the  work.  It  may 
be  well,  however,  to  briefly  mention,  in  this  connection,  a  few  of  the 
circumstances  which  call  for  the  operation. 

Beginning  with  the  teeth  of  first  dentition,  it  will  be  sufficient  to 
state  that  when  a  tooth  of  replacement  is  about  to  emerge  from  the 
gums,  or  has  actually  made  its  appearance,  either  before  or  behind  the 
corresponding  deciduous  tooth,  the  latter  should  at  once  be  removed  ; 
and  when  the  aperture  formed  by  the  loss  of  this  is  so  narrow  as  to  pre- 
vent the  former  from  acquiring  its  proper  position,  it  may  sometimes  be 
necessary  to  extract  an  adjoining  temporary  tooth.  For  more  explicit 
directions  upon  this  subject,  the  reader  is  referred  to  the  chapter  on 
Second  Dentition.     Alveolar  abscess,  necrosis  of  the  walls  of  the  alve- 


566  DENTAL   SURGERY. 

olus,  and  pain  in  a  temporary  tooth  which  cannot  be  cured  b}^  any  of 
the  usual  remedies,  may  be  regarded  as  indications  which  call  for  the 
operation. 

The  principal  conditions  which  should  determine  the  extraction  of  a 
permanent  tooth  may  be  enumerated  in  the  following  order: — 

First,  when  a  molar,  from  the  loss  of  its  antagonizing  tooth,  or  from 
other  causes,  has  become  partially  displaced,  or  is  a  source  of  constant 
irritation  to  the  surrounding  parts. 

Second,  a  constant  discharge  of  fetid  matter  from  the  pulp  cavity 
through  a  carious  opening  in  the  crown.  There  may,  however,  be  cir- 
cumstances which  would  justify  a  practitioner  in  permitting  or  even 
advising  the  retention  of  such  a  tooth,  as,  for  example,  when  the  dis- 
charge of  fetid  matter  is  not  very  considerable ;  also,  where  the  tooth 
is  situated  in  the  anterior  part  of  the  mouth,  and  cannot  be  securely 
replaced  with  an  artificial  substitute.  The  secretion  of  fetid  matter 
may  in  some  cases,  by  judicious  treatment,  be  arrested,  the  tooth  pre- 
served for  many  years  by  filling,  and  so  the  morbid  influence  it  would 
otherwise  exert  upon  the  surrounding  parts  may  be  counteracted.  A 
front. tooth  should  not  be  sacrificed  unless  called  for  by  some  very 
urgent  necessity  ;  neither  should  an  upper  incisor  nor  cuspid  be  per- 
mitted to  remain  in  the  mouth  if  it  exerts  a  manifestly  morbid  action 
upon  the  surrounding  parts,  for  in  this  case  the  consequences  resulting 
from  its  retention  in  the  mouth  may  be  worse  than  the  loss  of  the  tooth. 

Third,  a  tooth  which  is  the  cause  of  an  incurable  alveolar  abscess 
should  not  be  permitted  to  remain  ;  but  if  it  be  an  incisor  or  cuspid, 
and  the  discharge  of  matter  through  the  gum  is  small,  occurring  only 
at  long  intervals,  and  especially  if  the  organ  cannot  be  securely  re- 
placed with  an  artificial  substitute,  it  maybe  permitted  to  remain.  An 
incurable  abscess  in  the  socket  of  a  bicuspid  or  molar  should  always  le 
considered  as  a  sufficient  indication  for  the  removal  of  the  tooth. 

Fourth,  irregularity  in  the  arrangement  of  the  teeth,  arising  from 
disproportion  between  the  size  of  the  teeth  and  the  size  of  the  alveolar 
arch,  usually  requires  for  its  correction  the  extraction  of  some  one  or 
more  teeth.  But  with  regard  to  the  teeth  most  proper  to  be  removed 
the  reader  is  referred  to  the  chapter  on  Irregularity,  where  he  will  find 
full  directions  for  the  management  of  such  cases. 

Fifth,  all  dead  teeth  and  roots  of  teeth  which  act  as  irritants,  and 
teeth  which  have  become  so  much  loosened,  from  the  destruction  of 
their  sockets,  as  to  be  a  constant  source  of  disease  to  the  adjacent 
parts,  or  teeth  otherwise  diseased  that  are  a  cause  of  neuralgia  of  the 
face,  disease  of  the  maxillary  sinus,  dyspepsia,  or  any  other  local  or 
constitutional  disturbance,  such  teeth  should,  as  a  general  rule,  be 
extracted. 


EXTRACTION    OF    TEETH. 


567 


There  are  other  indications  which  call  for  the  extraction  of  teeth, 
but  the  foregoing  are  among  the  mosi  common ;  they  will  be  found 
sufficient  in  most  instances  to  determine  the  propriety  or  impropri- 
ety of  the  operation.  Cases  are,  however,  continually  presenting 
themselves  to  which  no  fixed  rule  would  be  found  applicable,  and 
where  an  experienced  judgment  alone  can  determine  the  practice 
proper  to  be  pursued. 

In  conclusion,  it  is  scarcely  necessary  to  say  that  whenever  a  tooth 
can  be  restored  to  health  it  should  always  be  done ;  but  tampering 
with  such  as  cannot  be  rendered  healthy  and  useful,  and  which,  bv 
remaining  in  the  mouth,  exert  a  deleterious  influence,  not  only  upon 


the  adjacent  parts,  but  also  upon  the  general  health,  cannot  be  too 
strongly  deprecated. 

Fig.  520  represents  the  permanent  teeth  of  the  left  side,  a  study  of 
which  will  enable  the  student  to  form  a  correct  idea  concerning  crowns 
and  roots  of  the  different  classes  of  teeth. 


INSTRUMENTS    EMPLOYED    IN    THE    OPERATION. 

Different  operators  employ  different  instruments.  For  about  fifty 
years  the  key  of  Garengeot  was  almost  the  only  instrument  used  in  the 
performance  of  the  operation  ;  but  this  has  in  a  great  measure  been 
superseded  by  forceps,  which,  when  properly  constructed,  are  far 
preferable ;  yet  as  the  key  is  still  used  by  some,  a  brief  description  of 
it  is  here  given. 


568  DENTAL    SURGERY. 

Key  Instrument. — "  The  common  tooth-key,"  says  Dr.  Arnot,  "  may 
be  regarded  in  the  light  of  a  wheel  and  axle,  the  hand  of  the  operator 
acting  on  two  spokes  of  the  wheel  to  move  it,  while  a  tooth  is  fixed  to 
the  axle  by  the  claw  and  is  drawn  out  as  the  axle  turns.  The  gum  and 
alveolar  process  of  the  jaw  form  the  support  on  which  the  axle  rolls." 

Different  dentists  have  their  keys  differently  constructed,  but  the 
principle  upon  which  they  all  act  is  precisely  the  same.  Some  prefer 
the  bent  shaft  (Fig.  521),  others  the  straight.  Some  give  a  decided 
preference  to  the  round  fulcrum,  others  to  the  flat ;  and  though  the 
success  of  the  operator  depends  greatly  upon  the  perfection  of  the 
instrument,  yet  he  may  remove  a  tooth  more  expertly  by  means  of  a 
key  with  which  he  is  familiar  than  by  one  to  which  he  is  unaccustomed, 
though  its  construction  be  even  better.  Fig.  521  represents  a  key  with 
bent  shaft  and  two  hooks,  one  for  molars  and  the  other  for  bicuspids. 

The  principle  of  action  of  the  key  is,  in  fact,  not  unlike  that  of  a 
nail  drawer  or  tack  puller,  and  may  be  adapted  to  a  certain  class  of 


Fig.  521. 


cases,  namely,  where  one  wall,  either  the  inner  or  outer,  is  decayed 
below  the  alveolus,  while  the  opposite  one  is  still  standing.  The  ful- 
crum, with  a  folded  napkin  or  other  soft  substance  interposed,  is  placed 
against  the  gum  on  the  side  of  the  tooth  most  decayed  and  the  hook 
adjusted  to  the  neck  of  the  tooth  on  the  opposite  side.  With  the 
improved  forms  of  forceps  now  in  use,  teeth  can  be  extracted  with 
greater  facility,  less  pain  to  the  patient,  and  also  with  less  risk  of  frac- 
ture than  is  possible  with  the  key  instrument ;  hence,  the  latter  is  rarely 
employed  at  the  present  time. 

Forceps. — Forceps  were  not  very  generally  or  extensively  employed, 
except  for  the  extraction  of  the  front  teeth,  until  about  the  year  1830 ; 
but  the  improvements  made  in  their  construction  since  that  period  are  so 
great  that  their  use  has  now,  among  dentists,  superseded  that  of  the  key.* 

*  To  Prof.  Chapin  A.  Harris  is  due  the  credit  of  having  devised  the  first  improved 
set  of  forceps  for  the  extraction  of  teeth,  of  which  many  of  the  later  inventions  are 
modifications. 


EXTRACTION    OF    TEETH.  569 

In  order  that  forceps  may  be  used  with  ease,  it  is  necessary  they 
should  be  properly  constructed.  Every  operator  should  possess  a  num- 
ber of  pairs  (nine  at  least),  each  with  a  differently  shaped  beak  adapted 
to  the  necks  of  the  teeth  to  which  they  are  respectively  designed  to  be 
applied. 


Fig.  522. 


For  the  upper  molars  two  (Fig.  522)  are  required,  one  for  each  side, 
curved  just  below  the  joint,  so  that  the  beak  shall  form  an  angle  of 
twenty  or  twenty-five  degrees  with  the  handles,  just  enough  to  clear 
the  lower  teeth.  The  inner  blade  is  grooved  to  fit  the  neck  of  the 
palatine  root;  the  outer  blade  has  two  grooves,  with  a  point  in  the 


Fig.  523, 


center  to  fit  the  depressions  just  below  the  bifurcation  of  the  two  buccal 
roots.  Another  valuable  improvement  consists  in  having  one  of  the 
handles  bent  so  as  to  form  a  hook.  This  passes  round  the  operator's 
little  finger,  to  prevent  the  hand  from  slipping. 

Fig.  523  represents  another  form  of  superior  molar  forceps,  right  and 


•j-jO  ,  DENTAL   SURGERY. 

left,  with  a  greater  curvature  in  the  handles  than  the  C.  A.  Harris  pat- 
tern, which  some  consider  an  improvement. 

The  handles  of  forceps  should  be  wide  and  large  enough  to  prevent 
them  from  springing  under  the  grasp  of  the  hand,  to  which  they  should 
be  accurately  fitted,  and  'the  ends  of  the  straight  handles  should  be 
thick  and  rounded  to  prevent  injury  to  the  palms  of  the  hands.  For 
the  comfort  of  the  fingers,  the  inner  corners  of  the  handles  should  also 
be  rounded.  Every  dentist,  therefore,  in  having  forceps  manufactured, 
should  give  special  directions  with  regard  to  their  shape  and  size.  The 
beak  should  be  bent  no  more  than  is  absolutely  necessary  to  prevent 
the  handles  from  coming  in  contact  with  the  teeth  of  the  lower  jaw ; 
for  in  proportion  to  the  degree  of  curvature  will  the  muscular  power  of 
the  operator  be  disadvantageously  exerted. 

Each  blade  of  the  beak  of  the  lower  molar  forceps  has  two  grooves, 
with  a  point  in  the  center  so  situated  that  in  grasping  the  tooth  it  comes 
between  the  two  roots  just  at  the  bifurcation.  An  improvement  made 
by  Prof.  C  A.  Harris  in  1833  consists  in  having  the  handles  of  the 


Fig.  524. 

instrument  so  bent  that  it  maybe  as  readily  applied  to  one  side  of  the 
mouth  as  the  other,  while  the  operator  occupies  a  position  to  the  right 
and  a  little  ]:)ehind  the  patient.  By  this  improvement  the  necessity  for 
two  pairs  is  superseded  ;  it,  moreover,  enables  him  to  control  the  head 
of  the  patient  with  his  left  arm  and  the  lower  jaw  with  his  left  hand, 
rendering  the  aid  of  an  assistant  wholly  unnecessary. 

The  shape  of  the  instrument  as  improved  by  the  author  is  shown  in 
Fig.  524.  It  is  now  used  by  many  hundreds  of  operators,  who  prefer 
it  to  any  other  instrument  they  have  ever  employed.  When  applied  to 
a  tooth  the  handles  turn  toward  the  operator  at  an  angle  of  about 
twenty-five  or  thirty  degrees.  Without  this  curvature  in  the  handles 
the  arm  of  the  operator  would  often  be  thrown  so  far  from  his  body  as 
to  prevent  the  proper  control  over  the  instrument.  It  is  also  impor- 
tant that  the  handles  should  be  wide  and  accurately  fitted  to  the  hand. 
The  inferior  dentes  sapientise  can  also,  in  the  majority  of  cases,  be  re- 
moved with  this  form  of  forceps. 

Fig.   525  represents  Wolverton's  inferior  molar  forceps  for  either 


EXTRACTION    OF    TEETH. 


571 


side,  with  longer  points  in  the  center  of  each  blade  of  the  beak,  which 
answer  a  good  purpose  where  the  roots  slightly  diverge  and  admit  the 
points  within  the  bifurcation. 


Fir..  525. 


Fig.  526  represents  inferior  molar  forceps  for  the  right  and  left  sides 
of  the  mouth,  which  some  prefer  to  the  single  forceps  on  account  of 
the  position  of  the  hand  grasping  the  instrument. 


Fig.  526. 

Fig.  527  represents  a  lower  molar  forceps  with  plain  beaks,  for  use 
on  either  side,  intended  more  especially,  however,  for  the  inferior  third 
molars. 


Fig.  527. 


For  the  extraction  of  the  upper  incisors  and  cuspids  one  pair  only 
may  be  used,  although  an   instrument  with  the   inner  concave  beak 


572  DENTAL   SURGERY. 

somewhat  narrower  than  the  outer  conforms  more  nearly  to  the  shape 
of  the  necks  of  the  superior  cuspids,  and  is  preferred  by  many  for  the 
removal  of  these  teeth  (Fig.  528).  These  should  be  straight,  with 
grooved  or  crescent-shaped  jaws  accurately  fitted  to  the  necks  of  the 
teeth.     The  beaks  should  also  be  thin,  so  that  they  may  be  easily  in- 


FiG.  528. 


troduced  under  the  gum,  up  to  the  edge  of  the  alveolus.  And,  like 
the  superior  and  inferior  molar  forceps,  the  handles  should  be  large 
enough  to  prevent  them  from  springing  in  the  hand  of  the  operator, 
with  a  hook  formed  at  the  end  of  one  of  them. 


Fig.  529. 

Owing  to  the  difference  in  size  between  the  superior  central  and 
lateral  incisors,  forceps  with  beaks  much  narrower  than  those  of  the 
common  form  of  superior  incisor  forceps  are  frequently  required  for 
the  extraction  of  the  latter  teeth.  Fig.  529  represents  an  upper  lat- 
eral incisor  forceps  with  narrow  beaks. 


Fig.  530. 

Fig.  530  represents  another  form  of  a  superior  cuspid  and  bicuspid 
forceps,  in  which  the  beaks  curve  more  than  those  of  the  incisor  for- 
ceps. 

For  the  extraction  of  the  lower  incisors  a  pair  of  very  narrow 
beaked  forceps  is  necessary,  to  prevent  interfering  with  the  teeth 
adjoining  the  one  to  be  removed.     The  beaks  below  the  joint  of  the 


EXTRACTION    OF    TEETH. 


5  73 


instrument  should  be  bent  downward  at  an  angle  of  about  twenty-five 
degrees  with  the  handles  (Fig.  531).  This  is  also  a  very  valuable  in- 
strument for  the  extraction  of  the  roots  of  teeth. 

An  instrument  similarly  shaped,  but  with  the  beaks  much  longer, 


Fig.  531. 

■ 

makes  one  of  the  most  universally  applicable  instruments  that  can 
be  devised  (Fig.  532).  The  beaks  should  be  made  strong,  but  very 
narrow. 

Fig.  533  represents  an  inferior  incisor  hawk-bill  forceps,  which  is 


Fig.  532. 


a  very  convenient  instrument  for  the  removal  of  these  teeth.     It  is 
also  used  for  the  removal  of  the  lower  cuspids. 

Forceps  for  the  extraction  of  bicuspids  should  have  their  jaws  so 
bent  as  to  be  easily  adapted  to  these  teeth;   they  should  be  narrow 


Fig.  533. 

and  have  a  deeper  groove  on  the  inside  than  those  for  the  upper 
incisors  and  cuspids;  like  them,  they  should  be  thin,  yet  strong 
enough  to  sustain  the  pressure  which  it  may  be  necessary  to  apply. 
One  pair  will  answer  for  the  right  and  left  bicuspids  of  the  upper 
jaw  (Fig.  534). 


574 


DENTAL    SURGERY, 


For  f.he  removal  of  the  cuspids  and  bicuspids  of  the  lower  jaw  the 
hawk's-bill  forceps  (Fig.  533),  with  crescent-shaped  beaks,  is  often 
employed;  but  the  instruments  lepresented  in  Figs.  535  and  536  are, 
we  think,  better  suited  to  the  extraction  of  these  teeth,  and  can  be 


Fig.  534. 


more  conveniently  applied.     No   separate   instrument,    therefore,    is 
required  for  the  removal  of  the  inferior  cuspids. 

The  dentes  sapientiae  can,  in  many  cases,  be  extracted  with  the 
universal  bicuspid  forceps,  as  shown  in  Fig.  535,  which  is  half  curved. 


Fig.  535. 

with  two  concave  beaks.  But  there  is  another  kind  of  forceps 
which  may  be  more  conveniently  employed  for  the  removal  of  the 
upper  wisdom  teeth.  The  beak  of  these  is  bent  above  the  joint, 
forming  nearly  two  right  angles,  as  shown  in  Fig.  537.    These  forceps 


Fig.  536. 


were,  we  believe,  invented  by  Dr.  Edward  P.  Church  about  the 
year  1830,  and  in  those  cases  where  the  superior  dentes  sapientiae 
are  considerably  shorter  than  the  second  molars,  they  can  be  success- 
fully and  advantageously  employed  ;  and,  indeed,  in  many  cases  they 


EXTRACTION    OF    TEETH. 


575 


cannot  be  reached  with  any  of  the  above-described  extracting  instru- 
ments.    The  handles  of  these,  as  of  all  other  forceps,  should  be  p^« 


Fig.  557- 


longer  than  is  absolutely  necessary  for  the  accommodation  of  the  hand 
of  the  operator. 


Fig.  538. 


For  the  removal  of  the  inferior  dentes  sapientise,  the  forceps  repre- 
sented in  Fig.  524,  Harris's  pattern,  or  the  ones  represented  in  Figs. 


Fig.  539. 


526  and  527  may  be  employed.     Fig.  538  represents  Physick's  dentes 
sapientise  for  either  side,  which  is  used  as  an  elevating  forceps. 


Fig.  540. 


For  the  removal  of  the  roots  of  the  teeth  the  inferior  incisor  forceps 
represented  in  Figs.  531  and  532  are  very  useful ;  also  the  forms  repre- 
sented in  Figs.  539  and  540. 


576 


DENTAL   SURGERY. 


Figs.  541,  542,  543,  544,  and  555  represent  Parmley's  patterns  of 
alveolar  forceps  for  cutting  through  the  alveolar  process  to  the  roots  of 
the  teeth. 


Fig.  541. 


Fig.  542. 


Fig.  543. 


Fig.  544. 


The  following  figures  (545,  546,  547,  548,  549,  550,  551,  552,  553, 
554)  represent  a  set  often  forceps,  called  "  Common  Sense  Forceps," 
which  have  recently  been  devised,  and  which  present  many  useful  fea- 
tures worthy  of  consideration  : — 


Fig.  545.— For  Upper  Central  Incisors  and  Cuspids,  Either  Side. 


EXTRACTION    OF    TEETH. 


577 


^^^ 'J^. :-•']'' :y:-?^, 


Fig.  540.— loR  L'ppfcK  Latkral  Incisors,  Bicuspids,  and  Roots,  Eithkr  Siuk. 


Fig.  547. — For  Right  Upper  Molars. 


Fig.  548.— For  Left  Upper  Molars. 


Fig.  =49  — For  Upper  Third  Molars,  Either  Side. 


Fig.  550.— For  Upper  Roots  and  Spicule;,  Eiihkr  Side. 


37 


57^ 


DENTAL   SURGERY. 


Fig.  551.— For  Lower  Incisors  and  Single  Roots,  Either  Side. 


Fig.  552. — For  Lower  Cuspids  and  Bicuspids,  Either  Sidr. 


I  iG.  553. — For  Lower  Molars,  Eiihi.r  t<tu 


Fig.  554. — For  Lower  Third  Molars,  Either  Side. 


Dr.  W.  Storer  How  writes  of  the  "Common  Sense  Forceps"  as 
follows:  "There  is  scarcely  any  instrument  used  in  dentistry  that 
has  called  forth  more  ingenuity  in  devising  various  shapes  than  for- 
ceps. The  object  has  been  to  provide  a  series  of  instruments  of  this 
class  which  will  closely  conform  to  the  several  classes  of  teeth,  so  that 
they  may  be  removed  with  the  least  pain  possible  to  the  patient,  and 


EXTRACTION    OF    TEETH. 


579 


the  expenditure  of  only  the  necessary  force  by  the  operator.     As  a 
general  rule,  ten  forceps  will  answer  for  a  complete  set,  but  for  the 


Fig.  555- 


requirements  of  wide  ranges  of  practice,  supplemental  forms  of  for- 
ceps will  be  desirable.     Skill  in  the  use  of  a  moderate  number  of  these 


Fig.  556.— Superior. 

instruments  is  preferable  to  crowding  one's  case  with  an  unnecessary 
number." 


Fig.  557.— Inferior. 


The  form  of  forceps  represented  by  Fig.  555  is  very  useful  for  the 
extraction  of  inferior  cuspids  and  bicuspids,  both  right  and  left ;  also 
for  the  extraction  of  roots  of  inferior  teeth. 

Figs.  556  and  557  represent  Stellwagen's  superior  and  inferior  fpr- 


58o 


DENTAL    SURGERY. 


ceps  for  separating  the  diverging  roots  of  molar  teeth,  and 
which  may  also  be  used  as  elevating  forceps. 


MANNER   OF   USING    THE    FORCEPS. 

In  describing  the  manner  of  using  these  instruments  we 
shall  commence  with  the  extraction  of  the  incisors  of  the 
upper  jaw.  These  are  generally  more  easily  removed  than 
any  of  the  other  teeth. 

The  use  of  the  gum  lancet  should  generally  precede  the 
application  of  either  the  forceps  or  the  key.  Many  den- 
tists object  to  the  operation  as  unnecessarily  inflicting  dou- 
ble pain.  Some  have  their  forceps  made  with  thin,  sharp 
blades,  so  as  to  sever  the  gum  on  two  sides  in  the  act  of 
pressing  up  the  instrument.  This  practice  may  be  admis- 
sible, perhaps  necessary,  in  certain  exceptional  cases,  as 
with  children  or  nervous  persons,  whom  the  act  of  lancing 
might  deter  from  permitting  the  operation  to  be  com- 
pleted. But  we  are  fully  satisfied  that,  as  a  rule,  it  is  very 
objectionable,  either  in  the  use  of  the  key  or  of  the  for- 
ceps. Owing  to  the  great  improvement  in  the  form  of  the 
edges  of  the  beaks  of  the  forceps  now  manufactured,  the 
use  of  the  gum  lancet  is  scarcely  necessary,  except  in  the 
case  of  teeth  that  stand  alone,  where  lancing  of  the  gum 
may  prevent  the  laceration  or  tearing  of  the  soft  tissues, 
and  also  in  the  case  of  the  wisdom 
teeth  and  roots  of  teeth  imbedded 
in  the  gum. 

Figs.  558  and  559  represent  sev- 
eral forms  of  gum  lancets. 

Fig.  559  represents  a  convenient 
two-blade  gum  lancet  with  stop. 

After  separating  the  gum,  when 
necessary,  from  the  neck  of  the 
tooth,  the  latter  should  be  grasped 
with  a  pair  of  straight  forceps  (Fig. 
528  or  Fig.  530,  or,  in  case  the 
tooth  is  a  lateral  incisor,  with  a 
narrow  crown.  Fig.  529),  and 
pressed  several  times  in  quick  suc- 
cession outward  and  inward,  giving 
it  at  the  same  time  slight  rotary 
'^"  ^^  ■  motion,  which  should  be  continued 

until  it  begins  to  give  way;  then,  by  a  slight  downward  pull,  it  is 


EXTRACTION    OF    TEETH. 


581 


easily  removed.  If  the  tooth  is  much  decayed,  it  should  be  grasped 
as  high  up  under  the  gum  as  possible,  and  no  more  pressure  applied  to 
the  handles  of  the  instrument  than  may  be  necessary  to  prevent  it 
from  slipping.  Teeth  are  often  unnecessarily  broken  by  not  attending 
to  this  precaution. 

The  same  directions  will,  in  most  cases,  be  found  applicable  for  the 
removal  of  a  lower  incisor.  But  the  arrangement  of  these  teeth  is 
sometimes  such  as  to  render  their  extraction  rather  more  difficult. 
The  forceps  best  calculated  for  their  removal  are  represented  in  Figs, 
531  and  533. 

For  the  extraction  of  a  cuspid  more  force  is  usually  required  than 
for  the  removal  of  an  incisor,  because  of  the  greater  size  and  length 
of  its  root.  The  straight  forceps  (see  Fig.  528  or  Fig.  530)  should  be 
employed  for  the  removal  of  the  superior,  and  the  curved-beaked 
forceps  (Figs.  531,  536,  and  545)  for  the  inferior  cuspids.     In  the  ex  ■ 


Fig.  559- 


traction  of  these  teeth  less  rotary  motion  should  be  given  to  the  hand 
than  in  the  removal  of  the  incisors ;  in  every  other  respect  the  oper- 
ation is  performed  in  the  same  manner.  The  inferior  cuspids  usually 
have  longer  roots,  and  are  more  difficult  to  remove  than  the  superior. 
Very  little  rotary  motion  can  be  given  to  a  bicuspid,  especially  an 
upper  one,  in  its  extraction.  After  it  has  been  pressed  outward  and 
inward  several  times,  or  until  it  begins  to  give  way,  it  should  be 
removed  by  pulling  in  the  direct  line  of  its  axis.  For  the  extraction 
of  the  upper,  the  forceps  represented  in  Fig.  528  and  Fig.  530,  and 
for  the  lower,  those  represented  in  Fig.  536  and  Fig.  545  are  the 
proper  instruments  to  be  employed,  unless  the  crown  has  become  so 
much  weakened  by  decay  that  it  will  not  bear  the  requisite  amount  of 
pressure.  In  this  case  the  gum  on  each  side  should  be  separated  from 
the  alveolus  about  an  eighth  or  three-sixteenths  of  an  inch,  and  slitted 
so  as  to  permit  the  application  of  the  narrow-beaked  forceps,  Fig. 


5t'2  DENTAL   SURGERY. 

531.  With  these  the  alveolar  wall  on  each  side  maybe  easily  cut 
through,  and  a  sufficiently  firm  hold  obtained  upon  the  root  of  the 
tooth  for  its  removal.  The  forceps  represented  in  Fig.  565  and  Fig. 
566  will  be  found  better  adapted  for  the  removal  of  the  molars,  when 
in  a  similar  condition,  than  any  other  instrument. 

The  upper  molars,  having  three  roots,  generally  require  a  greater 
amount  of  force  for  their  removal  than  any  of  the  other  teeth.  They 
should  be  grasped  as  high  up  as  possible,  with  one  of  the  forceps 
represented  in  Fig.  522  or  523,  and  then  pressed  outward  and  inward 
until  the  tooth  is  well  loosened,  when  it  may  be  pulled  from  the  socket. 
If  the  forceps  used  for  the  extraction  of  the  upper  molars  are  of  the 
right  description  and  properly  applied,  they  will  be  found  the  safest 
and  most  efficient  instruments  that  can  be  employed  for  their  removal. 

The  superior  dentes  sapientiae  are  usually  less  firmly  articulated  to 
the  jaw  than  are  the  first  and  second  molars ;  they  are  therefore  more 
easily  removed.  When  their  crowns  are  sufficiently  long  to  admit  of 
being  grasped  with  the  bicuspid  forceps  (Fig.  535),  they  may  be 
removed  with  this  instrument;  but  when  this  cannot  be  applied  with- 
out interfering  with  the  anterior  teeth,  the  forceps  represented  in  Fig. 
536  may  be  substituted. 

The  inferior  molars,  although  they  have  but  two  roots,  are  often 
very  firmly  articulated,  and  require  considerable  force  for  their  re- 
moval ;  and  it  sometimes  happens  that,  when  the  approximal  side  of 
one  has  been  destroyed  by  caries,  the  adjoining  tooth  has  impinged 
upon  it  in  such  a  manner  as  to  constitute  a  formidable  obstacle  to  its 
extraction.  Two  teeth  are  often  removed  in  attempting  to  extract 
one  thus  situated,  unless  the  precaution  is  taken  of  cutting  away  the 
side  of  the  encroaching  tooth.  This  should  never  be  omitted  in  the 
extraction  of  a  lower  molar  or  bicuspid  locked  in  the  manner  just 
described.  It  sometimes,  though  less  frequently,  happens  that  the 
upper  teeth  impinge  upon  each  other  in  the  same  manner;  in  this 
case,  also,  the  adjoining  tooth  should  be  cut  away  sufficiently  to  liberate 
the  one  that  is  to  be  extracted  before  attempting  its  removal.  In 
applying  forceps  to  an  inferior  molar,  the  points  on  the  beak  of  the 
instrument  should  be  forced  down  between  the  roots  ;  after  having 
obtained  a  firm  hold,  the  tooth  should  be  forced  inward  and  outward 
several  times  in  quick  succession,  until  its  connection  with  the  jaw  is 
partially  broken  up,  and  then  raised  from  the  socket.  If  the  tooth 
has  decayed  down  to  the  neck,  the  points  of  the  beak  may  include  the 
upper  edge  of  the  alveolus,  through  which  they  will  readily  pass  on 
applying  pressure  to  the  handles,  and  in  this  manner  a  secure  hold 
will  be  obtained  upon  the  tooth.  The  same  should  also  be  done  in 
the  extraction  of  a  superior  molar  in  this  condition. 


■EXTRACTION    OF    TEETH.  583 

The  denies  sapientiae  in  the  lower  jaw,  when  situated  far  back  under 
the  coronoid  process,  are  oftentimes  exceedingly  difficult  to  extract ; 
but  with  forceps  like  those  represented  in  Figs.  524,  527,  or  545,  they 
may  always  be  grasped  by  an  expert  operator,  except  in  those  cases 
where  their  crowns  have  been  destroyed  by  caries,  when  the  cowhorn 
forceps  represented  in  Fig.  567  will  generally  prove  useful.  It  occa- 
sionally happens  that  the  roots  of  these  teeth  are  bent  in  such  a  man- 
ner as  to  constitute  a  considerable  obstacle  to  their  removal.  But  when 
this  is  the  case,  the  roots  are  almost  always  turned  posteriorly  toward 
the  coronoid  processes ;  so  that  after  starting  the  tooth,  if  the  operator 
is  unable  to  lift  it  perpendicularly  from  the  socket,  he  will  have  reason 
to  suspect  its  retention  to  be  owing  to  an  obstacle  of  this  nature.  To 
overcome  this,  as  he  raises  his  hand  he  should  push  the  crown  of  the 
tooth  backward,  making  it  describe  the  segment  of  a  circle;  for  should 
he  persist  in  his  efforts  to  remove  it  directly  upward,  the  root  will  be 
broken  and  left  in  the  jaw.  Fig.  538  represents  an  elevating  forceps 
useful  in  removing  the  dentes  sapienLJcC  when  they  are  but  partially 
erupted  or  badly  decayed.  The  points  of  the  beaks  of  this  forceps  are 
inserted  between  the  .second  molar  and  partially  erupted  wisdom  tooth, 
the  crown  of  the  second  molar  being  the  fulcrum. 

It  sometimes  happens  that  the  roots  of  the  first  and  second  molars 
of  both  jaws  and  those  of  the  superior  dentes  sapientiae  are  bent,  or  else 
diverge  or  converge  so  much  as  to  render  their  extraction  exceedingly 
difficult.  The  convergency  of  these  roots  is  often  so  great  that,  in 
their  removal,  the  intervening  wall  of  the  alveolus  is  brought  away ; 
but  neither  from  this,  nor  from  the  removal  of  a  small  portion  of  the 
exterior  wall,  will  any  unpleasant  results  follow.  Similar  malformations 
are  occasionally  met  with  in  the  roots  of  the  bicuspids,  the  cuspids, 
and  even  the  incisors. 

Other  obstacles  sometimes  present  themselves  in  the  extraction  of 
teeth,  which  the  judgment  and  tact  of  the  operator  alone  will  enable 
him  to  overcome.  The  nature  and  peculiarity  of  each  case  will  sug- 
gest the  method  of  procedure  most  proper  to  be  pursued.  The  dentist 
should  never  hesitate  to  embrace  a  portion  of  the  alveolus  between  the 
jaws  of  the  forceps  when  necessary  to  enable  him  to  obtain  a  firm  hold 
upon  the  tooth.  The  removal  of  the  upper  edge  of  the  socket  is  never 
productive  of  injury,  as  it  is  always  subsequently  removed,  more  or  less 
rapidly,  by  the  process  of  absorption.  When  the  crown  of  a  tooth  has 
become  so  much  weakened  by  disease  that  it  will  not  bear  the  pressure 
of  the  instrument,  it  may  be  removed  in  this  manner  without  inflicting 
upon  the  patient  half  the  pain  that  would  be  caused  by  the  attempt  to 
spare  the  thin,  perishable  alveolar  walls. 


584  DENTAL  SURGERY. 

MANNER  OF  EXTRACTING  ROOTS  OF  TEETH. 

The  extraction  of  roots  of  teeth  is  sometimes  attended  with  con- 
siderable difficulty ;  but  generally  they  are  more  easily  removed  than 
the  whole  teeth,  especially  the  roots  of  the  molars,  for,  after,  the 
destruction  of  their  crowns,  an  effort  is  usually  made  by  the 
economy  to  expel  them  from  the  jaws.  This  is  done  by  the 
gradual  absorption  of  the  alveolus,  together  with  the  filling  up  of  the 
socket  by  a  deposition  of  ossific  matter  at  the  bottom,  whereby  the 
articulation  of  the  root  becomes  weakened  and  its  removal  rendered 
proportionately  easier.  The  alveolar  cavities  are  often  wholly  obliter- 
ated in  the  course  of  two  or  three  years  after  the  destruction  of  the 
crowns  of  the  teeth,  and  the  roots  retained  in  the  mouth  simply  by 
their  connection  with  the  gums,  so  that  for  their  removal  little  more  is 
necessary  than  to  sever  this  bond  of  union  with  a  lancet  or  sharp- 
pointed  knife. 

The  instruments  usually  employed  in  the  extraction  of  roots  of  teeth 
are  the  hook,  punch,  elevator,  and  screw,  all  of  which  are  represented 
in  Fig.  560,  and  also  the  root  forceps  shown  in  subsequent  figures. 
Although  every  dentist  has  the  former  made  to  suit  his  own  peculiar 
notions,  the  manner  of  using  them  and  the  principles  upon  which  they 
act  are  the  same.  It  will,  therefore,  be  sufficient  to  say  that  they 
should  be  of  a  convenient  size,  made  of  good  steel,  and  so  tempered 
as  neither  to  bend  nor  break. 

The  hook,  No.  7,  Fig.  560,  is  chiefly  used  for  the  extraction  of  the 
roots  of  molar  and  bicuspid  teeth  on  the  left  side  of  the  mouth  ;  the 
punches,  Nos.  3,  4,  5,  6,  10,  11,  12,  Fig.  560,  for  the  removal  of  those 
on  the  right  side;  the  elevators,  Nos.  2,  8,  9,  13,  Fig.  560,  for  the  ex- 
traction of  roots  on  either  side,  as  occasion  may  require ;  and  the 
screw.  No.  i.  Fig.  560,  for  the  removal  of  those  of  the  upper  front 
teeth. 

Considerable  tact  is  necessary  for  the  skillful  use  of  these  instru- 
ments, and  this  can  only  be  obtained  by  practice.  Great  care  is  re- 
quisite, in  using  the  punch  and  elevator,  to  prevent  them  from  slipping 
and  injuring  the  mouth  of  the  patient.  Whenever,  therefore,  either  of 
these  are  used,  the  forefinger  of  the  left  hand  of  the  operator  should 
be  wrapped  with  a  napkin  and  placed  on  the  side  of  the  root  opposite 
to  that  against  which  the  instrument  is  applied,  so  as  to  catch  the 
point  in  case  it  should  slip. 

But  for  the  removal  of  the  roots  of  bicuspids  and  molars,  and  often 
for  those  of  the  cuspids  and  incisors,  the  narrow-beaked  forceps  recom- 
mended for  the  extraction  of  the  lower  incisors  (see  Fig.  531)  may  be 
used  more  effectively  than  any  other  instrument.     When  the  root  is 


EXTRACTION    OF   TEETH. 


585 


decayed  down  to  the  alveolus  the  gum  should  be  separated  from  it, 
and  so  much  of  it  as  may  be  necessary  to  obtain  a  secure  hold  upon 
the  root  included  between  the  beaks  of  the  forceps,  for  these,  being 
very  narrow,  readily  pass  through  the  alveolus,  and  a  firm  hold  is  at 


once  obtained  upon  the  root;  then,  after  moving  it  a  few  times  out- 
ward and  inward,  it  may  easily  be  removed  from  its  socket. 

There  are  some  cases,  however,   in  which  the  punch,  hook,  and 
elevator  may  be  advantageously  used.     We  have  also  occasionally  met 


586 


DENTAL    SURGERY. 


with  cases  where  we  have  succeeded  in  removing  roots  of  teeth  with 
great  ease  by  means  of  an  elevator  shaped  like  the  blade  of  a  knife, 
first  forcing  it  into  the  socket  by  the  side  of  the  root  and  then  turning 
it  so  as  to  make  the  back  press  against  the  former  and  the  edge  against 
the  latter.  When  this  instrument,  represented  in  Fig.  561,  is  used, 
the  blade  should  not  be  more  than  an  inch  in  length,  and  it  should  be 
straight,  short  at  the  point,  and  have  a  very  thick  back,  that  it  may 
not  break  in  the  operation.  In  using  the  common  elevator  it  is  neces- 
sary that  there  should  be  an  adjoining  tooth  or  root  to  act  as  a  fulcrum. 
When  this  can  be  employed,  a  root,  or  even  a  whole  tooth,  may  some- 


FiG.  561. 

times  be  removed  with  it  ;  but,  as  a  general  rule,  forceps  should  be 
preferred  to  any  of  these  instruments. 

For  the  extraction  of  the  roots  of  the  upper  front  teeth,  after  they 
have  become  so  much  funneled  out  by  decay  as  to  render  their  walls 
incapable  of  sustaining  the  pressure  of  forceps,  the  conical  screw  may 
be  employed.  With  this  a  sufficiently  firm  hold  for  the  removal  of  the 
root  may  be  obtained  by  screwing  it  into  the  cavity.  But  before  it  is 
introduced  the  soft  decomposed  dentine  should  be  removed  from  the 
interior  of  the  root  with  a  triangular-pointed  instrument  like  the  one 
represented  in  Fig.  562. 

Dr.  S.  P.  Hullihen  has  invented  a  most  valuable  and  useful  instru- 


FiG.  562. 

ment  for  the  removal  of  the  roots  of  the  superior  incisors  and  cuspids 
when  in  the  condition  just  described.  It  combines  the  advantages 
both  of  the  screw  and  forceps,  as  may  be  seen  by  the  accompanying 
cut.  It  is  thus  described  by  the  author:  "Lengthwise,  within  and 
between  the  blades  of  the  beak,  is  a  steel  tube,  one  end  of  which  is 
open,  the  other  solid  and  flat,  and  jointed  in  a  mortise  in  the  male 
part  of  the  joint  of  the  forceps.  When  the  forceps  are  opened,  this 
joint  permits  the  tube  to  fall  backward  and  forward  from  one  blade  of 
the  beak  to  the  other,  without  any  lateral  motion.  Within  this  tube 
is  a  spiral  spring,  which  forces  a  shaft  up  two-thirds  of  the  tube ;  the 
other  part  is  a  well-tapered  or  conical  screw.  .  .  .  The  shaft  and 
tube  are  so  fitted  together  and  to  the  beak  of  the  forceps  that  one- 


EXTRACTION    OF    TEETH. 


587 


half  of  the  rounded  part  of  the  shaft  projects  beyond  the  end  of  the 
tube,  so  that  the  shaft  may  play  up  and  down  upon  the  spring  about 
half  an  inch,  and  the  screw  or  shaft  be  embraced  between  the  blades 
of  the  beak  of  the  instrument." 

Dr.  Hullihen's  instrument  is  represented  in  Fig.  563. 

"The  forceps,"  says  Dr.  Hullihen,  "  are  used  by  first  embracing  the 
shaft  between  the  blades.*     Then,  screwing  it  as  gently  and  deeply 


Fig.  563. 

^into  the  root  as  possible,  the  blades  are  opened  and  pushed  up  on  the 
root,  which  is  then  seized  and  extracted.  The  screw  thus  combined 
with  the  forceps  prevents  the  root  from  being  crushed.  It  acts  as  a 
powerful  lever  when  a  lateral  motion  is  given  ;  it  is  likewise  of  advan- 
tage when  a  rotary  motion  is  made ;  it  prevents  the  forceps  from  slip- 
ping or  from  losing  their  action  should  one  side  of  the  root  give  way 
in  the  act  of  extracting  it,  and  is  used  with  equal  advantage  where  one 
side  of  the  root  is  entirely  gone." 

Fig.   564  represents  Dubs's  screw  forceps:    i.  Conical  screw,  with 


Fig.  564. 


square  ratchet  shaft.  2.  Beaks  of  forceps,  grooved  inside.  3.  Socket 
with  square  hole  to  receive  shaft.  4.  Spring  trigger,  by  which  the 
screw  can  be  detached  at  pleasure  at  any  given  point. 

For  the  extraction  of  the  roots  of  the  upper  molars  before  they  have 


*  The  author  has  a  pair  constructed  so  that  the  blades  of  the  beak  of  the  forceps 
grasp  the  upper  extremity  of  the  screw  instead  of  the  shaft. 


588 


DENTAL   SURGERY. 


become  separated  from  each  other  by  decay,  the  forceps  (Fig.  565) 
invented  by  Dr.  Maynard  will  be  found  highly  valuable.  The  outer 
beak  of  each  instrument  is  brought  to  a  sharp  point  for  perforating 
the  alveolus  between  the  buccal  roots  and  for  securing  between  them  a 
firm  hold,  while  the  inner  beak  is  intended  to  rest  upon  the  edge  of 


Fig.  565- 

the  alveolus  and  embrace  the  palatine  root.     By  this  means  a  sufficiently 
firm  hold  is  secured  to  enable  the  operator  to  remove  the  roots  of  an 
upper   molar   without  difficulty.     Two    pairs,   as   represented  in  the 
engraving,  one  for  the  right  and  one  for  the  left  side,  are  required. 
Fig.  566  represents  a  form  of  forceps  recently  introduced,  which 


Fig.  566. 


is  also  used  for  the  extraction  of  the  roots  of  the  superior  molars 
before  they  have  become  separated  by  decay ;  a  right  and  left  are 
required. 

Fig.  567  represents  a  lower  molar  cowhorn  forceps  for  either  side; 
right  and  left  forceps  of  this  pattern  are  also  used. 


EXTRACTION    OF   TEETH. 


589 


Fig.  568  represents  a  lower  molar  cowhorn  forceps  for  either  side, 
one  beak  being  longer  than  the  other. 

The  advantage  to  be  derived  from  forceps  of  this  description  must 
be  apparent  to  every  dentist. 


Fig.  568. 


Fig.  570. 


Fig.  569  represents  Tomes's  universal  root  forceps,  which  is  a  very 
useful  form  for  the  extraction  of  fragments  and  small  roots  of  teeth. 
Fig.  570  represents  Arrington's  bayonet-shape,   slender  beak  for- 


59° 


DENTAL    SURGERY. 


ceps  for  the  extraction  of  difficult  roots  in  the  upper  jaw  and  roots 
of  front  teeth  in  the  lower  jaw. 

Figs.  571  and  572  represent  front  and  back  alveolar  nipping  for- 


FlG.  571. 


Fig.  573. 


ceps,  for  cutting  away  processes  after  extraction,  and  which  may  also 
be  used  for  removing  roots  of  teeth. 

Fig.  573  represents  Tees' s  sub-alveolar  thin-pointed  forceps,  which 


EXTRACTION    OF    TEETH. 


591 


are  designed  to  slip  within  the  alveolar  process  and  into  the  tooth- 
socket  to  remove  teeth  the  crowns  of  which  are  entirely  decayed  or 
broken  off. 

EXTRACTION  OF  THE  TEMPORARY  TEETH. 

The  temporary  teeth  should  be  extracted  in  the  same  manner  as 
the  permanent,  and  with  the  same  instruments.  If  the  power  be 
properly  directed  very  little  force  is  required  for  their  removal,  because 
the  roots  of  these  teeth  have  generally  suffered  more  loss  of  substance 
before  the  operation  is  called  for ;  and  when  they  remain,  the  alveolar 
processes  at  this  early  age  are  so  soft  and  yielding  as  to  offer  little  resist- 
ance to  the  tooth. 

The  operator  should  be  careful  not  to  injure  the  pulps  of  the  perma- 
nent teeth  or  the  bone  of  the  jaw.  Serious  accidents  sometimes  occur 
from  an  improper  or  awkward  removal  of  these  teeth.  But,  as  has  been 
before  remarked,  their  extraction  is  seldom  required.  It  should  only 
be  resorted  to  for  the  relief  of  toothache,  the  cure  of  alveolar  abscess, 
to  prevent  irregularity  in  the  permanent  teeth,  or  in  case  of  necrosis 
of  the  socket.  And  even 
in  such  cases  it  is  necessary 
to  exercise  much  judgment 
in  deciding  how  far  pain 
and  inconvenience  should 
be  endured  rather  than  ex- 
tract the  offending  tooth ; 
or  how  far  the  chance  of 
injury  to  the  permanent 
teeth  demands  the  removal 

of  the  diseased  temporary  teeth.  Their  premature  extraction  is  so  often 
followed  by  a  crowded  state  of  the  permanent  teeth,  that  their  indis- 
criminate removal  for  trifling  causes  cannot  be  too  strongly  condemned. 

Fig.  574  represents  forceps,  curved  and  straight,  for  the  extraction 
of  children's  teeth. 


Fig.  574. 


Fig.  575. 


^ig-  575  represents  forceps  for  the  extraction  of  children's  teeth, 
and  which  will  also  answer  as  universal  root  forceps. 

The  possibility  of  septic  affections  in  connection  with  the  extraction 


592 


DENTAL    SURGERY. 


of  teeth,  such  as  necrosis  of  jaws,  diffuse  abscess,  erysipelas,  etc.,  is 
now  universally  admitted,  hence  the  necessity  existing  for  antiseptic 
precautions,  such  as  the  effective  sterilization  of  all  instruments 
employed.     The  immersion  of  instruments  in  a  boiling  one  or  two 


Fig.  576. 

per  cent,  solution  of  soda  will  answer  such  a  purpose.     Fig.  576  repre- 
sents Dr.  E.  D.  Downs's  apparatus  for  sterilizing  instruments. 


HEMORRHAGE    AFTER    EXTRACTION. 

It  rarely  happens  that  excessive  hemorrhage  follows  the  extraction 
of  a  tooth.  Indeed,  it  is  oftener  more  desirable  to  promote  bleeding 
by  rinsing  the  mouth  with  warm  water  than  to  attempt  its  suppression, 
especially  after  the  extraction  of  teeth  affected  with  periodontitis,  as 
such  hemorrhage  relieves  the  congestion  of  the  parts  and  hastens  re- 
covery. Nevertheless,  cases  do  sometimes  occur  in  which  it  becomes 
excessive  and  alarming.  It  has  been  known  in  some  instances  to  ter- 
minate fatally  ;  this,  however,  does  not  appear  to  be  dependent  upon 
the  manner  in  which  the  operation  is  performed,  but  rather  upon  a 
hemorrhagic  diathesis  of  body,  attributable  to  a  deficiency  in  the 
coagulating  property  of  the  blood,  a  defibrinating  condition,  or  hered- 
itary predisposition.  Hence,  whenever  a  tendency  to  it  exhibits  itself 
in  one  member  of  a  family,  it  is  usually  found  to  exist  in  all. 


HEMORRHAGE   AFTER   EXTRACTION.  593 

There  are  two  forms  of  hemorrhage — the  "primary,"  which  imme- 
diately follows  the  extraction  of  a  tooth,  and  the  "secondary,"  which 
occurs  after  the  arrest  of  the  primary.  A  patient  may  have  a  tooth 
extracted  during  the  day,  and  no  unusual  hemorrhage  result,  which  is 
the  common  experience ;  but  during  the  night,  or  the  next  day,  or  even 
later,  a  serious  flow  of  blood  may  ensue,  which  is  secondary  hemorrhage, 
and  more  difificult  to  arrest  than  the  primary  form.  Of  the  many  cases 
which  have  fallen  under  our  own  observation,  we  shall  mention  only 
the  following :  — 

In  the  fall  of  1834  Miss  I.,  fifteen  years  of  age,  had  the  second 
molar  on  the  left  side  of  the  upper  jaw  removed.  The  hemorrhage 
immediately  after  the  operation  was  not  greater  than  usually  occurs, 
and  in  the  course  of  half  or  three-quarters  of  an  hour  it  ceased  alto- 
gether. But  at  about  twelve  o'clock  on  the  following  night  it  com- 
menced again,  the  blood  flowing  so  profusely  as  to  excite  considerable 
alarm.  A  messenger  was  immediately  sent  to  ask  our  advice,  and  we 
directed  that  the  alveolar  cavities  should  be  filled  with  pledgets  of  lint, 
saturated  with  tincture  of  nutgalls.  Two  days  after,  at  about  six 
o'clock  in  the  morning,  we  were  hastily  sent  for  by  the  young  lady's 
mother,  and  when  we  arrived  at  her  residence  we  were  informed  that 
the  bleeding  had  been  going  on  for  about  four  hours.  During  this 
time  more  than  two  quarts  of  blood  had  been  discharged.  The  blood 
was  still  oozing  very  fast.  After  we  had  removed  the  coagulum  we 
filled  the  socket  with  pieces  of  sponge,  saturated,  as  the  lint  had  been, 
with  tincture  of  nutgalls.  When  firmly  pressed  in  and  secured  by  a 
compress,  the  hemorrhage  ceased.  These  were  permitted  to  remain 
until  they  were  expelled  by  the  suppurative  and  granulating  processes. 
We  afterward  had  occasion  to  extract  one  tooth  for  a  sister  and  two 
for  the  mother  of  the  young  lady,  and  a  hemorrhage  similar  to  that 
just  described  occurred  in  each  case.  Where  the  tendency  to  hemor- 
rhage exists,  due  care  should  be  exercised,  immediately  after  the 
extraction  of  teeth,  to  guard  against  its  occurrence  by  the  application 
of  a  reliable  styptic.  Some  of  the  more  simple  local  remedies  for  its 
arrest  are  spider-web  as  a  mechanical  obstructor ;  also  compressed 
sponge  saturated  with  sandarac  varnish  or  coated  with  soft  wax  ;  the 
return  of  single-root  teeth,  coated  with  wax,  to  the  cavity ;  the  lint  of 
black  silk,  owing  to  the  efficacy  of  the  coloring  matter;  the  scrapings 
of  leather,  on  account  of  the  tannin  used  in  preparing  it ;  lint  of  old 
linen,  saturated  with  phenol  sodique,  all  of  which  may  be  packed  into 
a  bleeding  cavity  after  freeing  it  from  blood,  and  kept  in  place,  if 
necessary,  by  a  compress ;  also  the  adaptation  of  a  rubber  plate  accu- 
rately to  the  part,  or  of  modeling  composition  as  compresses  for  the 
retention  of  the  styptic ;  also  alum ;  also  matico  leaf,  prepared  by 
38 


594  DENTAL    SURGERY. 

immersing  a  piece  in  water  for  a  few  minutes  and  rolling  it  into  pel- 
lets, or  into  a  cone,  with  the  under  surface  of  the  leaf  outward,  and 
packing  these  into  the  cavity,  after  which  a  compress  is  applied,  and 
also  a  bandage  round  the  head  and  under  the  chin  to  keep  the  mouth 
at  rest.  The  more  powerful  styptics  for  local  application  consist  of 
tannic  acid,  gallic  acid,  nitrate  of  silver,  tincture  perchlorid  of  iron, 
solution  of  persulphate  of  iron,  powdered  subsulphate  of  iron.  A  styp- 
tic and  antiseptic  cotton  is  prepared  by  saturating  purified  cotton  with 
tannic  acid  five  parts,  carbolic  acid  four  parts,  and  alcohol  fifty  parts  ; 
the  cotton  is  dried  and  preserved  air-tight.  Tannin  is  an  excellent  styp- 
tic, and  answers  well  in  connection  with  the  compress  of  lint  or  cotton 
in  most  cases,  also  gallic  acid,  and  their  clots  are  not  soluble  in  the 
blood.  The  tincture  perchlorid  of  iron  and  the  solution  persulphate 
of  iron,  although  powerful  styptics,  are  not  reliable,  on  account  of  the 
danger  of  sloughing  and  the  occurrence  of  secondary  hemorrhage. 
The  same  is  the  case  with  the  nitrate  of  silver,  the  use  of  which, 
although  it  may  prove  successful  in  some  cases,  is  attended  with 
destruction  of  tissue,  and  its  clot  is  soluble  in  the  blood.  The  pow- 
dered subsulphate  of  iron  (Monsel's)  applied  to  the  bleeding  cavity 
on  pledgets  of  cotton  saturated  with  sandarac  varnish,  with  a  compress 
so  adjusted  as  to  act  directly  upon  the  mouth  of  the  bleeding  vessel, 
will  generally  prove  effectual  in  arresting  alveolar  hemorrhage.  The 
compression  should  be  moderate,  and  the  packing  be  allowed  to  re- 
main until  all  danger  of  a  return  of  the  bleeding  is  past.  In  many 
cases  of  severe  alveolar  hemorrhage  it  is  better  to  allow  the  packing  to 
come  away  of  itself.  Constitutional  treatment  is  frequently  necessary 
in  connection  with  the  local  treatment,  and  such  internal  remedies  as 
acetate  of  lead,  two  grains;  opium,  one  grain;  tincture  of  perchlorid 
of  iron,  n\,  xv-xxx;  gallic  acid,  gr.  v-x;  tincture  of  erigeron  cana- 
densis, gtt.  j,  every  minute ;  dilute  hydrochloric  acid,  gtt.  xv  in  a 
wineglass  of  water  every  four  hours,  will  prove  serviceable  in  obstinate 
and  severe  cases.  Veratrum  viride,  in  doses  of  gtt.  v  to  water  ^  ss, 
will  depress  the  action  of  the  heart,  and,  as  a  consequence,  prove 
beneficial.  Dr.  W.  L.  Roberts,  uses  three  grains  of  tannic  acid  in  one- 
third  glass  of  water,  giving  as  a  dose  two  teaspoonfuls  of  this  solution 
every  five  minutes  until  three  doses  are  taken  ;  then  two  teaspoonfuls 
every  fifteen  minutes  if  required.  Rest,  and  the  horizontal  position, 
with  the  head  and  shoulders  raised,  are  valuable  adjuncts  to  the  treat- 
ment. In  some  cases  it  may  be  found  necessary  to  have  recourse  to 
the  actual  cautery.  (See  Gorgas's  Dental  Medicine  for  ftirther  details 
on  alveolar  hemorrhage.) 

The  late  Professor  Gross  was  the  first  to  call  attention  to  a  form  of 
neuralgia  occurring  after  the  extraction  of  teeth,  and  depending  upon 


ANESTHETIC    AGENTS    IN    THE    EXTRACTION    OF    TEETH.  595 

thickening  and  induration  of  the  alveolar  margin,  by  which  the  remains 
of  the  dental  nerves  after  the  removal  of  teeth  become  compressed  and 
irritated.  The  treatment  in  such  cases  consists  in  the  removal  of  the 
margin  of  the  alveolus  compressing  the  nerve  with  cutting  forceps,  and 
thus  freeing  the  irritated  tissue. 


CHAPTER  VI. 


THE  USE  OF  ANESTHETIC  AGENTS  IN  THE  EXTRACTION  OF 

TEETH. 

Of  the  various  agents  that  have  been  employed  for  the  prevention 
of  pain  during  surgical  operations,  sulphuric  ether  and  chloroform  have 
been  more  generally  used  than  any  others.  The  practicability  of  pro- 
ducing anesthesia  with  ether  was  first  demonstrated  by  Dr.  Horace 
Wells,  of  Hartford,  Conn.,  in  1846,  and  soon  afterward  brought 
prominently  before  the  medical  and  dental  professions  by  Dr.  W.  G.  S. 
Morton,  of  Boston,  Mass.,  both  practical  dentists;  and  with  chloro- 
form, in  1847,  by  Prof.  J.  Y.  Simpson,  of  Edinburgh,  Scotland.  The 
anesthetic  effect  is  obtained  by  inhalation  of  the  vapor,  and  is  supposed 
to  be  nothing  more  than  a  transient  state  of  intoxication,  which  usually 
disappears  almost  immediately  after  the  discontinuance  of  the  adminis- 
tration, though  in  many  cases  it  has  proved  fatal.  For  this  reason  we 
do  not  think  that  agents  capable  of  producing  such  powerful  and  dan- 
gerous effects  as  ether  and  chloroform  should  be  used  in  so  simple  an 
operation  as  the  extraction  of  a  tooth.  The  first,  however,  is  less 
dangerous  than  the  second  ;  but  its  anesthetic  effect  is  less  certain  and 
prompt,  from  seven  to  ten  minutes  being  usually  required,  whereas,  with 
the  other,  it  is  obtained  in  from  thirty  seconds  to  two  minutes.  When 
ether  is  used,  from  six  to  ten  or  fifteen  ounces  are  employed  ;  but  with 
chloroform  it  is  rarely  necessary  to  administer  more  than  thirty  to  one 
hundred  and  fifty  drops.  What  we  have  said  about  sulphuric  ether 
applies  equally  to  chloric  ether,  a  substance  very  extensively  used,  if  not 
first  proposed,  by  the  late  Prof.  Warren,  of  Boston. 

A  number  of  instruments  have  been  devised  for  the  inhalation  of  the 
vapor  of  these  agents ;  but  the  simplest  method  of  administration  is 
from  a  hollow  sponge,  a  napkin,  or  a  pocket  handkerchief. 

It  may  not  always  be  possible  for  any  one,  in  the  administration  of 
either  of  the  foregoing  agents,  even  to  a  person  supposed  to  be  free 
from  any  special  proclivity  to  disease  from  organic  derangement,  to 
pronounce,  a  priori,  that  no  bad  effect  will  result  from  it;  but  all  agree 


596 


DENTAL   SURGERY. 


that  it  is  unsafe  to  give  it  to  a  patient  laboring  under  disease  of  the 
heart,  brain,  or  lungs.  The  practitioner,  therefore,  whether  medical  or 
dental,  should  be  well  assured,  before  giving  ether  or  chloroform,  and 
especially  the  latter,  that  these  organs  are  not  only  free  from  disease, 
but  also  from  any  morbid  tendency,  as  ignorance  with  regard  to  this 
matter  might  lead  to  fatal  consequences.  It  should  be  given  cautiously 
under  any  circumstances,  and  the  pulse  should  never  be  permitted 
to  fall,  during  the  inhalation,  below  sixty,  or,  at  least,  fifty-five  beats 
a  minute  ;  but  if,  from  carelessness  or  any  other  cause,  the  patient 
should  sink  and  the  pulsation  cease,  the  agent  should  be  immediately 
removed  from  the  mouth,  and  if  occupying  a  sitting  posture  he  should 
be  placed  in  a  reclining  position,  air  freely  admitted,  cold  water  dashed 
in  the  face,  the  feet  and  hands  rubbed  with  hot  salt  or  mustard,  and, 
if  necessary,  artificial  respiration  made  and  galvanism  applied.  In 
addition  to  these  means  the  tongue  should  be  depressed  and  drawn  for- 
ward by  a  finger  thrust  deeply  into  the  mouth,  as  recommended  by 
Ricord ;  or  Marshall  Hall's  or  Sylvester's  or  Howard's  methods  may  be 
faithfully  and  patiently  practiced.  Ellis  gives  the  following  simplified 
formula  of  his  method  for  cases  of  asphyxia  from  drowning:  "In- 
stantly place  the  patient  on  the  face  and  side,  supporting  the  head. 
Unfasten  the  clothes  about  the  neck  and  chest,  braces,  etc.  Wipe  and 
clean  the  mouth  and  nostrils.  Raise  and  support  the  chest  on  a  folded 
coat  or  bundle.  Roll  the  patient  constantly  and  gently  from  the  face 
to  the  side,  and  back  again,  occasionally  changing  the  side,  supporting 
the  head.  On  the  completion  of  each  turn  to  the  face  make  a  brisk 
pressure  on  the  back,  between  and  below  each  shoulder  blade.  Dry 
and  rub  the  patient  briskly,  rubbing  upward." 

The  inversion  of  the  body,  a  method  devised  by  the  celebrated 
French  surgeon  Nelaton,  has  been  resorted  to  successfully.  Nitrite  of 
amyl,  a  powerful  stimulant,  has  been  successfully  inhaled  in  cases  of 
chloroform  necrosis  with  dangerous  symptoms,  but  care  is  necessary 
in  its  use;  and  not  more  than  ni^ij  should  be  administered  by  inhala- 
tion to  persons  unaccustomed  to  its  effects. 

It  is  thought  by  those  who  have  had  most  experience  in  the  use  of 
ether  and  chloroform  as  anesthetic  agents  that  their  administration  is 
attended  with  less  danger  when  the  patient  is  in  a  reclining  than  when 
in  a  sitting  posture.  It  would  be  well,  therefore,  when  ether  is  used 
preparatory  to  the  extraction  of  teeth,  to  place  the  patient  as  nearly  as 
possible  in  such  a  position  ;  when  the  dentist  is  provided  with  an  oper- 
ating chair  having  a  movable  back,  this  can  be  very  readily  done. 

Nitrous  Oxid  Gas  is  more  generally  employed  as  an  anesthetic  in 
the  practice  of  dentistry  than  any  other,  and  the  immunity  from  acci- 
dent with  which  it  is  administered  is  an  evidence  of  its  safety  when 


ANESTHETIC    AGENTS    IN    THE    EXTRACTION    OF    TEETH. 


597 


compared  witn  chloroform  and  some  other  general  anesthetics ;  due 
care,  however,  should  be  exercised  in  the  use  of  all  general  anesthetics. 
The  anesthetic  effect  of  nitrous  oxid,  or  laughing  gas,  was  first  sug- 
gested by  Sir  Humphry  Davy,  in  1776,  and  practically  demonstrated 


Fig.  577. 


by  Dr.  Horace  Wells.  This  gas  is  manufactured  from  the  salt  nitrate  of 
ammonia,  either  in  a  fused  or  granulated  form,  by  slowly  melting  and 
boiling  it  in  a  glass  retort,  over  a  sand  bath,  until  nearly  all  of  the 
nitrate  is  decomposed.     The  gas,  on  leaving  the  retort,  passes  through 


598  DENTAL    SURGERY. 

several  wash  bottles,  one  of  which  contains  either  a  solution  of  the  sul- 
phate of  iron  or  caustic  potash,  and  the  other  two  pure  water,  for  the 
purpose  of  purifying  it  before  it  enters  a  holder  and  receiver,  from 
which  it  is  administered  to  the  patient  by  means  of  an  inhaling  tube. 
One  pound  of  the  granulated  nitrate  of  ammonia  will  produce  about 
thirty  gallons  of  the  gas,  which  should  be  administered  to  the  patient 
in  a  pure  state — unmixed  with  atmospheric  air. 

Fig.  577  represents  an  apparatus  for  generating  nitrous  oxid  gas. 

Liqicefied  Nitrous  Oxid  is,  however,  a  more  convenient  form  for 
use.  To  obtain  this  form  the  nitrous  oxid  gas,  after  being  subjected 
to  intense  cold  and  pressure,  is  condensed  in  the  form  of  a  liquid,  in 
a  strong  iron  cylinder,  one  hundred  gallons  of  the  gas  weighing  but 
ten  pounds,  and  capable  of  being  condensed  into  a  cylinder. 

Fig.  580  represents  the  Justi  gas  cylinder  holder  for  use  in  the  oper- 
ating room.     To  this  cylinder  holder  the  bag  and  inhaler,  with  metal 


Fig.  578.  Fig.  579. 

mouth-shield,  are  attached.  When  it  is  desired  to  administer  ether, 
the  ehd  tube,  to  which  the  rubber  tubing  is  connected,  can  be  un- 
screwed, and  the  globe,  which  contains  a  sponge  to  hold  the  ether, 
attached  in  its  stead. 

In  administering  this  gas  for  dental  operations,  the  patient  is  seated 
in  an  operating  chair  with  a  movable  back,  a  cork  or  piece  of  wood 
to  which  a  string  is  attached  placed  between  the  jaws,  or,  what  is 
better,  a  soft  rubber  bite-block,  of  which  four  sizes  are  made,  Fig. 
578,  which  do  not  need  a  string,  as  they  are  readily  removed  with  the 
crooked  fingers,  and  are  too  large  to  be  swallowed.  Fig.  579  repre- 
sents Daintree's  adjustable  mouth-prop. 

The  operator,  who  occupies  a  position  on  the  right  side  of  the 
patient,  supports  the  inhaler  with  his  right  hand,  some  of  the  fingers 
of  which  press  the  lower  lip  tightly  about  the  mouth-piece.  The 
thumb  and  index  finger  of  the  left  hand  close  the  nostrils,  while  the 


ANESTHETIC    AGENTS    IN    THE    EXTRACTION    OF    TEETH. 


599 


remaining  fingers  press  the  upper  lip  about  the  mouth-piece  of  the 
inhaler.  The  patient  is  then  instructed  to  make  long  but  otherwise 
natural  inspirations,  one  of  the  valves  of  the  inhaler  permitting  the 
exhalations  to  pass  off. 

After  thus  inhaling  the  gas  for  a  few  minutes,  its  anesthetic  effects 
are  shown  by  strong  involuntary  respirations  attended  by  a  snoring 
sound,  owing  to  the  relaxation  of  the  muscles  of  the  pharynx.  Then 
follows  a  livid  appearance  of  the  lips,  from  the  discolored  blood  in 
the  capillaries.     A  spasmodic  twitching  of  the  muscles  is  observed  at 


Fig.  580. 


this  stage  in  many  patients,  when  complete  narcosis  follows.  The 
narcotic  effects  of  the  gas  continue  from  thirty  seconds  to  one  and  a 
half  minutes,  and  the  number  of  teeth  which  can  be  extracted  varies 
from  four  to  twelve.  It  is  no  unusual  occurrence,  however,  for  the 
extraction  of  one  tooth  to  consume  the  entire  time  the  patient  is  under 
the  narcotic  influence  of  the  gas,  while  in  other  cases  more  than  the 
highest  number  just  mentioned  may  be  removed  before  the  patient 
becomes  conscious  of  pain. 

Fig.  581  represents  rubber  inhaler  hoods,  which  fit  closely  to  the 


6oo 


DENTAL   SURGERY. 


face  without  unpleasant  pressure,  such  as  may  be  caused  by  the  metal 
mouth-shield. 

Nitrous  oxid  gas  is  considered  to  be  the  safest  general  anesthetic 
now  in  use,  and  does  not  produce  the  nauseating  and  debilitating 
effects  which  are  often  caused  by  ether  and  chloroform.  Extreme  cau- 
tion, however,  is  necessary  in  administering  this  gas  under  circum- 
stances which   prohibit    the  use  of  other  general  anesthetic  agents. 

The  greatest  objection  to 
the  use  of  this  gas,  aside 
from  the  question  of  safety, 
is  the  rapidity  in  operating 
which  its  transient  effect 
necessitates;  and  it  is  much 
better  to  carefully  extract  a 
few  teeth  than  to  attempt 
the  removal  of  many  by  an 
operation  which  may  be  at- 
tended with  severe  lacera- 
tion of  the  gums  and  frac- 
ture of  the  alveolus. 


Fig.  581. 


Bromid  of  Ethyl. — Hydrobromic  ether  is  obtained  from  bromid  of 
potassium  and  sulphuric  ether,  by  distillation,  and  by  redistillation  with 
chlorid  of  lime.  Although  a  pleasant  anesthetic  and  very  prompt  in 
its  effect,  yet  its  administration  is  not  without  danger,  and  hence 
caution  is  necessary  in  its  employment.  It  is  administered  in  the 
same  manner  as  ether  or  chloroform,  and  recovery  from  its  influence 
is  more  rapid  than  with  either  of  these  agents.  From  thirty  seconds 
to  five  minutes  are  required  to  manifest  its  anesthetic  effects.  The 
quantity  required  differs,  according  to  the  susceptibility  of  the  patient. 


ANESTHETIC   AGENTS    IN    THE    EXTRACTION    OF    TEETH.  6oi 

the  usual  rule  being  to  commence  with  one  dram,  then  administer 
a  second,  and  if  necessary  a  third  dram  may  be  inhaled  in  two 
minutes  after  the  administration  of  the  second  dram.  Two  dram& 
will,  however,  in  most  cases,  be  sufficient  to  cause  profound  anesthesia. 

Dr.  B.  W.  Richardson,  of  London,  introduced  an  anesthetic  agent, 
known  as  the  dichlorid  of  ??iethylene,  which  is  formed  by  the  action  of 
sulphuric  acid  on  zinc  in  chloroform.  It  differs,  however,  from  chloro- 
form, in  the  circumstance  that  one  atom  of  chlorin  is  replaced  by  one 
atom  of  hydrogen.  Bichlorid  of  methylene  produces  as  great  a 
degree  of  insensibility  as  chloroform,  and  its  action  is  more  rapid  and 
the  narcotism  very  prolonged.  It  also  interferes  less  with  muscular 
irritability  than  either  ether  or  chloroform,  and  the  recovery  from  i-ts 
effects  is  sudden  ;  but  more  of  it  is  required.  When  it  destroys  life,  as 
it  has  in  several  cases,  the  respiring  and  circulating  functions  are 
equally  paralyzed. 

Hydrate  of  chloral  is  another  general  anesthetic  agent  which  has 
been  extensively  employed.  Chloral  is  by  no  means  a  new  anesthetic, 
Liebig  having  discovered  it  in  1830;  but,  as  Dr.  B.  W.  Richardson 
states,  the  introduction  of  it  into  medicine  is  a  fact  of  the  year  1871, 
its  introducer  being  Liebreich,  of  Berlin. 

The  hydrate  is  made  from  the  chloral  by  the  simple  addition  of  a 
little  water,  and  on  the  application  of  heat  solidifies  into  a  white 
crystalline  substance. 

The  manner  in  which  hydrate  of  chloral  is  administered  is  in  solu- 
tion with  water,  either  by  the  mouth  directly  into  the  stomach,  or  by 
subcutaneous  injection.  The  best  solution  is  made  by  mixing  one 
grain  of  the  hydrate  with  two  of  water.  Dissolved  in  an  excess  of 
water,  the  taste  is  agreeable,  with  the  odor  of  a  ripe  melon.  It  is 
administered  to  human  subjects  in  doses  varying  from  25  to  30  grains, 
causing  unconsciousness  to  pain  and  a  profound  sleep  lasting  over 
several  hours.  The  sleep  is  gentle  and  quiet,  induced  without  distress, 
and  leaving  no  other  symptom  behind  except  nausea,  which  is  occa- 
sionally experienced  after  recovery.  In  administering  this  agent,  it 
appears  to  act  more  promptly  when  subcutaneously  injected  than  when 
administered  directly  by  the  mouth ;  and  as  chloral  dissolved  in  water 
is  slightly  caustic,  it  cannot  be  administered  by  the  mouth  when  there 
are  lesions  of  mucous  membrane  or  ulcerated  tracts  of  intestinal  canal. 
In  administering  hydrate  of  chloral  to  the  human  subject.  Dr.  Rich- 
ardson states  that  allowance  will  have  to  be  made  not  only  in  relation 
to  size  and  weight,  but  to  obesity  or  leanness,  to  natural  habit  and 
actual  state  of  body  in  respect  to  sensibility. 

Fig.  582  represents  the  full  size  of  a  hypodermic  syringe  with  grad- 
uated rod  and  steel  points. 


6o2 


DENTAL   SURGERY. 


Local  A, esthetics. — Suspension  of  nervous  sensibility  induced  by 
inhaling  the  vapor  of  ether,  chloroform,  nitrous  oxid,  bromid  of 
ethyl,  etc.,  is  general,  every  part  of  the  body  being  affected  alike; 
but  partial  or  local  anesthesia  may  be  procured  by  other  and  less  dan- 
gerous means.  Congelation  or  freezing,  first  proposed  and  employed 
in  the  Charity  Hospital,  Paris,  by  an  interne  of  M.  Velpeau,  and  sub- 
sequently recommended  by  Dr.  James  Arnott,  of  London,  was  for- 
merly resorted  to  both  by  surgeons  and  dentists,  and  practiced  to  a 
limited  extent  with  success.  This  may  be  effected  by  applying  a  mix- 
ture of  pounded  ice  and  common  salt,  in  the  proportion  of  two  or 
three  parts  of  the  former  to  one  of  the  latter,  to  the  part  on  which  the 
operation  is  to  be  performed.  But  in  the  use  of  this  care  is  necessary 
to  prevent  reducing  the  temperature  too  much,  as  in  this  case  loss  of 
vitality  would  be  occasioned  by  it.  We  have  heard  of  a  few  cases  in 
which  this  has  occurred,  but  we  believe  it  was  owing  in  every  instance 


Fig.  582. 


to  carelessness  or  want  of  judgment  on  the  part  of  the  operator  as  to 
the  length  of  time  the  application  of  the  mixture  should  be  continued. 

Several  instruments  have  been  invented  for  the  application  of  this 
freezing  mixture  to  teeth  preparatory  to  extraction.  One  of  the  first 
adapted  for  the  purpose  was  designed  by  Dr.  Branch,  of  Chicago,  111. 
It  consisted  of  a  hollow  tube  about  an  inch  or  a  little  more  in  diam- 
eter, with  about  five-eighths  of  an  inch  cut  out  at  one  end,  on  either 
side,  that  it  might  readily  be  passed  over  a  tooth.  To  this  was  attached 
a  sac  of  finely  prepared  membrane,  large  enough  to  hold  a  tablespoon- 
ful  of  the  mixture.  The  hollow  of  the  tube  was  occupied  by  a  steel 
wire  spiral  spring.  Just  before  using  it  a  sufficient  quantity  of  the 
freezing  mixture  was  put  in  the  tube ;  the  end  of  the  latter  was  placed 
over  the  tooth,  when  the  ice  and  salt  were  forced  up  gently  around  it 
by  pressing  on  the  spring  at  the  other  extremity  of  the  instrument. 
Two  tubes  were  employed,  one  straight,  for  teeth  in  the  anterior  part 
of  the  mouth,  the  other  bent  near  one  end  for  the  more  convenient 
application  of  the  mixture  to  a  molar  tooth. 

The  sudden  application  of  such  intense  cold  to  a  sensitive  tooth,  or 


ANESTHETIC    AGENTS    IN    THE    EXTRACTION    OF    TEETH.  603 

to  one  which  has  not  lost  its  vitality,  is  often  productive  at  first  of 
severe  pain  ;  on  this  account  many  objected  to  its  use,  preferring  the 
momentary  suffering  consequent  upon  the  operation  of  extraction 
rather  than  that  occasioned  by  the  freezing  mixture.  But  this  effect 
is  rarely  experienced  in  its  use  on  dead  teeth,  or  the  roots  of  teeth 
which  have  lost  their  vitality ;  hence,  the  application  of  it  to  such 
teeth  proved  more  satisfactory  than  to  living  teeth. 

In  the  year  1858  Mr.  J.  B.  Francis,  dentist,  of  Philadelphia,  an- 
nounced the  discovery  of  an  original  method  of  producing  local 
anesthesia,  said  to  be  peculiarly  applicable  to  the  extraction  of  teeth, 
which  consists  in  passing  an  electro-galvanic  current  through  the  tooth 
at  the  moment  of  its  removal.  The  discovery  was  submitted  to  the 
Franklin  Institute,  Philadelphia,  and  the  committee  to  whom  it  was 
referred  for  examination,  composed  in  part  of  dentists,  reported  favor- 
ably in  regard  to  the  claims  of  the  inventor.  One  of  the  members  of 
the  committee,  W.  S.  Wilkinson,  stated  that  he  had  extracted  between 
four  and  five  hundred  teeth,  applying  the  electric  current,  and  that  in 
ninety-five  per  cent,  of  the  cases  it  was  done  without  pain  to  his 
patients. 

The  method  of  applying  it  is  very  simple.  One  pole  (the  negative 
is  preferable)  of  the  electro-galvanic  machine  is  attached  to  one  of  the 
handles  of  the  forceps  by  means  of  a  flexible  conductor,  while  the 
metallic  handle  of  the  other  is  grasped  by  the  patient,  the  power  of  the 
current  being,  previously  to  the  operation,  graduated  by  the  piston  of 
the  coil,  while  the  patient  holds  the  forceps  in  the  other  hand.  The 
current  should  only  be  sufficiently  powerful  to  be  distinctly  felt.  The 
circuit  through  the  tooth  is  not  made  until  at  the  instant  the  operation 
begins.  The  closing  and  breaking  of  the  galvanic  circuit  is  managed 
either  by  the  foot  of  the  operator  or  by  an  assistant. 

A  small  electro-galvanic  battery,  arranged  for  this  purpose,  having 
been  placed  in  the  office  of  the  author  soon  after  the  announcement  of 
the  discovery,  he  has  had  frequent  opportunities  of  applying  this  new 
agent  in  the  extraction  of  teeth.  Thus  far.  about  nine  out  of  ten  of 
those  who  were  placed  under  its  influence  while  undergoing  the  opera- 
tion assured  him  that  they  either  experienced  no  pain  at  all  or  only 
very  little — not  a  tenth  part  of  what  they  had  experienced  under  the 
operation  on  former  occasions.  In  almost  every  case  in  which  the 
tooth  was  grasped,  allowing  the  instrument  to  come  in  contact  with 
only  the  edge  of  the  gum,  the  operation  appeared  to  be  painless,  or 
nearly  so.  But  when  pushed  up  a  considerable  distance  between  it  and 
the  tooth  the  suffering  was  not  appreciably  diminished,  the  electric 
current  in  such  cases  seeming  to  be  too  much  diffused.  It  is  stated  by 
those  who  have  made  the  experiment  that  this  diffusion  of  the  electric 


6o4  DENTAL   SURGERY. 

current  may  be  prevented  by  insulating  the  outer  portion  of  the  instru- 
ment with  a  coating  of  gutta-percha,  or  by  japanning.  The  author 
has  not  tried  this  expedient. 

How  it  is  that  the  passage  of  an  electric  current  through  a  tooth 
should  prevent  pain  may  be  explained  by  supposing  the  subtle  fluid  to 
exhaust  the  sensibility  of  the  nerves  of  the  parts  comprised  in  the  opera- 
tion ;  and  that  it  does,  in  a  majority  of  cases,  is  attested  by  many  who 
have  been  placed  under  its  influence.  It  may  be  nothing  more  than  a 
mere  substitution  of  one  sensation  for  another;  but  whether  its  appli- 
cation will  become  general,  or  its  efficacy  as  an  anesthetic  agent  be  fully 
established,  remains  for  future  experience  to  settle. 

The  experience  of  the  profession  may  be  briefly  summed  up  thus  : 
In  one-fourth  the  cases  it  relieves  or  neutralizes  the  peculiar  pain  of 
extraction,  in  one-half  it  has  but  little  effect,  and  in  the  remaining 
fourth  it  very  decidedly  aggravates  the  pain.  It  has,  however,  the  ad- 
vantage over  chloroform  and  the  freezing  process  of  being  without  any 
serious  sequelae. 

"Voltaic  narcotism"  is  a  term  applied  by  Dr.  B.  W.  Richardson 
to  a  method  of  local  anesthesia,  in  which  the  galvanic  current  is  passed 
through  a  narcotic  solution  placed  in  contact  with  the  part  to  be  oper- 
ated upon.  Dr.  Richardson  claims  that  by  such  a  method  complete  local 
anesthesia  can  be  produced  by  solutions  of  narcotic  agents  which  are 
inert  when  applied  without  the  galvanic  current.  While  this  method 
may  be  used  with  satisfactory  results  in  cases  where  the  cavity  of  the 
tooth  is  exposed,  it  has  never  come  into  general  use. 

Dr.  B.  W.  Richardson  also  introduced  a  much  more  speedy  and 
effectual  method  of  congelation  than  those  before  described,  by  taking 
advantage  of  the  intense  cold  occasioned  by  the  rapid  evaporation  of 
ether  spray  when  forced  through  one  of  the  instruments  invented  for 
the  atomization  of  fluids. 

"  The  principle,"  Dr.  Richardson  remarks,  "consists  in  directing 
on  a  part  of  the  body  a  volatile  liquid,  having  a  boiling  point  at  or 
below  blood  heat,  in  a  state  of  fine  subdivision  or  spray,  such  sub- 
division being  produced  by  the  action  of  air  or  other  gaseous  sub- 
stance on  the  volatile  liquid  to  be  dispersed.  When  the  volatile  fluid, 
dispersed  in  the  form  of  spray,  falls  on  the  human  body,  it  comes 
with  force  into  the  most  minute  contact  with  the  surface  upon  which  it 
strikes.  As  a  result  there  is  rapid  evaporation  of  the  volatile  fluid,  and 
so  great  an  evolution  of  heat  force  from  the  surface  of  the  body  struck, 
that  the  blood  cannot  supply  the  equivalent  loss.  The  part,  conse- 
quently, dies  for  the  momeiit,  and  is  insensible,  as  in  death  ;  but  as  the 
vis  a  tergo  of  the  body  is  unaffected,  the  blood,  as  soon  as  the  external 
reducing  agency  is  withdrawn,  quickly  makes  its  way  again  through 


ANESTHETIC    AGENTS    IN    THE    EXTRACTION    OF    TEETH. 


605 


the  dead  parts,  and  restoration  is  immediate.  The  extreme  rapidity 
of  the  action  of  this  deadening  process  is  the  cause  of  its  safety." 

Fig.  583  represents  the  apparatus,  which  consists  of  a  spray-tube, 
bottle,  and  hand-bellows,  for  producing  local  anesthesia  by  narcotic 
spray. 

Either  absolute  ether  or  rhigolene  may  be  employed,  both  of  which 
are  highly  inflammable.  Some  prefer  rhigolene  on  account  of  its  ac- 
tion being  more  prompt  than  that  of  the  ether,  while  others  consider 
the  latter  more  agreeable  and  easily  controlled.  To  produce  the  local 
anesthetic  effect  with  these  agents  in  the  form  of  spray  requires  from 
thirty  to  sixty  seconds.  Before  the  application  of  the  spray  the  crown 
of  the  tooth  to  be  extracted  and  mucous  membrane  over  the  root 
should  be  carefully  dried,  otherwise  a  film  of  ice  may  be  formed  which 


Fig.  583. 


will  prevent  the  full  influence  of  the  agent,  such  as  is  shown  by  the 
blanching  of  the  gum. 

Local  blood-letting,  such  as  follows  lancing  of  the  gums,  prior  to  the 
application  of  the  spray  is  said  to  prevent  desquamation. 

Obtunding  mixtures,  consisting  of  a  combination  of  pyrethrum, 
aconite,  chloral,  veratria,  and  alcohol ;  or  chloroform,  aconite,  bella- 
donna, and  opium,  have  been  employed  to  produce  local  anesthesia, 
and  in  many  cases  with  satisfactory  results.  For  although  entire  insen- 
sibility to  pain  cannot  in  all  cases  be  brought  about,  yet  some  diminu- 
tion of  it  may  be  eff"ected  by  the  use  of  such  agents.  They  have  the 
merit,  at  least,  of  being  less  dangerous  than  the  general  anesthetics. 
Such  pain-obtunding  mixtures  are  best  applied  to  the  parts  about  the 
neck  and  over  the  root  of  a  tooth  by  means  of  a  simple  apparatus  de- 
vised by  Von  Bonhorst.  It  consists  of  two  small  metallic  cups 
attached  to  the  free  ends  of  a  spring  some  seven  inches  long,  and 
which  contain  sponges  to  hold  the  liquid  (Fig.  584). 


6o6 


DENTAL   SURGERY. 


When  used,  the  sponges  in  the  cup  are  saturated  with  the  obtunding 
mixture  and  applied  by  pressing  them  on  the  gum  on  each  side  of  the 
tooth  to  be  removed,  where  they  are  retained  from  one-half  to  two 
minutes.  Previous  to  the  application  the  patient  should  be  cautioned 
against  swallowing  any  portion  of  the  mixture. 

A  local  anesthetic  known  as  cocain  was  discovered  and  first  applied 
in  Germany,  with  astonishing  and  satisfactory  results,  in  operations 
upon  the  eye.  This  local  anesthetic  has  been  employed  with  more  or  less 
satisfactory  results  in  cases  of  sensitive  dentine  and  the  extirpation  of  the 
pulps  of  teeth  by  the  surgical  method,  with  satisfactory  results  in  teeth 
of  a  loose  structure.  The  four  or  five  per  cent,  solution  of  hydrochlo- 
rate  of  cocain,  may  be  used,  a  drop  being  applied  to  the  sensitive  sur- 
face three  times,  at  intervals,  during  a  period  often  or  fifteen  minutes  ; 
at  the  end  of  twenty-five  minutes  a  condition  of  anesthesia  is  caused. 

The  unsatisfactory  results  from  the  use  of  cocain  as  a  local  anes- 
thetic for  the  extraction  of  teeth,  owing  to  the  dense  and  impermeable 
character  of  the  gum-tissues,  when  the  agent  is  applied  directly  to  the 


Fig.  584. 


mucous  membrane,  led  to  its  application  by  injection  with  the  hypo- 
dermic syringe,  represented  by  Fig.  582,  either  deeply  into  the  gum- 
tissues,  or  to  a  point  as  near  as  possible  to  the  main  branches  of  nerves 
supplying  the  teeth  with  sensation.  For  injecting  the  cocain  deeply 
into  the  gum-tissues,  the  syringe,  which  should  be  an  easy-working 
instrument,  is  charged  with  from  12  to  15  minims  of  a  four  or  five 
per  cent,  solution,  and  the  needle-point  introduced  through  the  mucous 
membrane,  so  as  to  inject  the  solution  deeply  into  the  gum-tissues 
around  the  tooth  to  be  extracted.  To  reach  the  branches  of  nerves 
supplying  the  superior  teeth  it  has  been  suggested  to  pass  the  needle- 
point of  the  syringe  through  the  mucous  membrane  to  a  point  as  close 
to  the  infraorbital  foramen  as  is  possible,  and  inject  about  eight  minims 
of  the  cocain  solution ;  for  reaching  the  inferior  dental  nerve,  the 
needle-point  is  carried  as  near  the  inferior  dental  foramen  as  is  possible, 
or,  in  the  case  of  the  front  teeth,  near  to  the  mental  foramen.  Dr. 
Raymond  recommends  mixing  the  soluble  alkaloid  at  the  time  of  using 
it,  taking  care  to  exhaust  the  air  from  the  syringe  when  charged  ready 
for  use,  which  may  be  done  by  drawing  in  more  of  the  solution  than 


ANESTHETIC    AGENTS    IN    THE    EXTRACTION    OF    TEETH.  6O7 

is  needed,  and  pressing  it  out  to  the  required  number  of  minims  (about 
eight),  and  then  to  hold  the  needle-point  up  so  as  to  allow  the  air  to 
get  above  the  solution,  when  the  piston  should  be  pressed. 

"  The  Herbst  Obtundent"  consists  of  a  saturated  solution  of  hydro- 
chlorate  of  cocain  in  chemically  pure  sulphuric  acid,  to  which  a  solu- 
tion of  sulphuric  ether  is  added  to  the  point  of  saturation,  the  excess 
of  ether  evaporating  from  the  surface  on  which  it  floats.  About 
70  grains  of  the  cocain  hydrochlorate  are  required  to  saturate  two 
drams  of  the  sulphuric  acid.  Several  applications  are  required  to 
produce  the  anesthetic  effect. 

Cocain  is  the  alkaloid  of  the  leaves  of  the  Erythroxylon  coca,  a 
shrub  of  South  America,  and  has  long  been  used  by  the  natives  of 
Peru  and  Bolivia  as  a  nerve-stimulant.  Small  animals  have  been  killed 
by  its  causing  paralysis  of  the  respiratory  centers. 

Other  local  anesthetics  have  recently  been  suggested,  such  as  tropa- 
cocain,  coryl,  chlorid  of  ethyl,  etc.     (See  Gorgas's  Dental  Medicine.') 

Rapid  Breathing  as  a  Rain  Obtunder. — The  possibility  of  producing 
an  anesthetic  effect  by  rapid  breathing  was  suggested  by  Dr.  W.  G.  A. 
Bonwill,  in  1875.  ^7  t^is  method  it  is  claimed  that  teeth  may  be 
extracted  without  pain.  In  applying  it  the  patient  should  rest  upon 
the  side  and  in  as  reclining  a  position  as  is  possible  to  operate.  A 
handkerchief  is  then  placed  over  the  face  to  insure  quiet,  and  direc- 
tions are  given  to  breathe  rapidly  at  the  rate  of  about  100  respirations 
per  minute — blowing-out  movement.  At  the  end  of  from  two  to  five 
minutes  of  such  rapid  breathing  it  is  claimed  that  an  entire,  or  at  least 
partial,  state  of  anesthesia  results,  which  may  continue  for  a  half  or  for 
one  or  two  minutes.  This  method  is  apparently  a  harmless  one,  but 
some  have  connected  with  it  such  a  danger  as  venous  congestion  of  the 
brain.  Females  appear  to  be  more  susceptible  to  this  method  than 
males,  and  children  under  ten  years  of  age  can  rarely  be  induced  to 
breathe  properly. 

In  the  case  of  females  with  a  highly  nervous  organization  it  may 
now  and  then  be  advisable  to  give  a  temporary  courage  to  endure  pain 
by  the  administration  of  a  teaspoonful  of  brandy.  But  there  is  often 
less  trouble  with  delicate  females  than  with  stalwart  men.  The  extrac- 
tion of  a  tooth  is,  in  the  majority  of  cases,  so  simple  an  operation, 
seldom  requiring  more  than  from  two  to  five  seconds  for  its  perform- 
ance, that  most  persons  should  rather  submit  to  it  at  once  than  have  it 
protracted  by  the  application  of  an  agent  for  the  prevention  of  the 
momentary  pain  which  it  occasions. 


6o8  DENTAL   SURGERY. 


CHAPTER   VII. 

REPLANTATION,    TRANSPLANTATION,    AND    IMPLANTATION    OF 

TEETH. 

Closely  connected  with  the  subject  of  extraction  of  teeth  are 
Replantation  and  Transplantation,  which  appear  to  have  been  prac- 
ticed several  centuries  ago,  both  in  France  and  Germany. 

Later,  both  of  these  operations  attracted  the  attention  of  John 
Hunter,  in  England,  and  some  interesting  experiments  were  made  by 
him  in  transplanting  teeth,  although  he  did  not  advocate  the  latter 
practice. 

The  operation  of  "replantation  "  consists  in  the  return  of  a  tooth 
to  the  same  cavity  from  which  it  has  been  extracted,  and  also  the 
necessary  antiphlogistic  treatment  which  will  result  in  the  re-establish- 
ment of  the  connection  which  originally  existed  between  the  tooth  so 
returned  and  its  cavity.  Replantation  is  performed  where  a  tooth  has 
been  accidentally  removed,  and  also  for  the  cure  of  alveolar  abscess, 
more  especially  such  cases  where  the  extreme  end  of  the  root  is  affected 
with  abscess,  and  a  considerable  portion  of  the  investing  membrane  or 
periosteum  is  in  a  healthy  condition.  Under  such  circumstances  the 
operation  of  replantation  may  be  performed  as  follows:  The  tooth  is 
to  be  very  carefully  extracted,  and  at  once  placed  in  warm  water,  to 
which  a  little  tincture  of  iodin  has  been  added.  The  cavity  from 
which  the  tooth  has  been  removed  should  be  carefully  and  gently  wiped 
out  with  a  cone  of  soft  Japanese  paper,  wrapped  about  the  end  of  an 
excavator  or  other  suitable  instrument,  to  remove  any  shreds  of  the 
abscess  sac  that  may  remain  attached  to  its  walls,  and  a  delicate, 
spear-shaped  nerve  instrument  passed  through  the  alveolus  to  detach 
the  cyst.  The  cavity  is  then  syringed  with  warm  water  and  packed 
lightly  with  cotton  saturated  with  tincture  of  iodin. 

When  this  is  accomplished,  attention  is  again  given  to  the  tooth, 
from  which  all  traces  of  the  abscess  sac  should  be  removed,  as  well  as 
salivary  calculus,  if  present,  care  being  taken,  however,  not  to  injure 
or  remove  any  healthy  periosteum  that  may  remain  attached  to  the 
root.  The  pulp  chamber  is  then  to  be  exposed,  and,  with  the  root 
canals,  thoroughly  cleansed  and  disinfected,  and  filled  to  the  apex 
with  gold  or  other  suitable  material.  The  packing  is  then  carefully 
removed  from  the  cavity,  which  is  again  syringed  with  warm  water, 
and  the  tooth  firmly  pressed  into  its  former  position  and  held  there 
for  a  few  moments  with  the  fingers.  The  mouth  may  then  be  rinsed 
with  an  astringent  mouth  wash  and  the  tooth  secured  by  ligatures,  or, 


REPLANTATION,    TRANSPLANTATION,    AND    IMPLANTATION.       609 

with  what  answers  better,  a  cap  of  modeling  composition  or  gutta- 
percha. The  mouth  should  be  rinsed  with  an  astringent  wash  three 
or  four  times  daily,  and  be  kept  thoroughly  clean. 

The  following  mouth  washes,  from  Gorgas's  Dental  Medicine,  will 
prove  useful : — 

R.     Acidi  carbolici  (cryst.), 

Glycerini  and  aquae  rosse, aa  .    .    .    .    ,^ij.  M. 

SiG. — Five  to  eight  or  ten  drops  in  a  wineglass  of  water. 

R.      Tincturse  arnicas, 5^ 

Glycerini,     .    .    .    , 3^ 

Aqu;E  rosae, ^  ij 

Aquas  destillatae, ^  x.  M. 

SiG. — To  be  used  as  a  gargle. 

Where  the  apex  of  the  root  of  the  tooth  is  necrosed,  this  portion 
should  be  excised  and  made  smooth  before  the  tooth  is  returned  to  its 
cavity,  the  same  treatment  as  above  described  being  pursued.  When 
a  replanted  tooth  has  been  returned  to  its  cavity,  the  lymph  present 
either  coagulates  and  becomes  organized,  so  that  no  pus  is  formed, 
which  is  the  process  of  healing  by  "first  intention,"  or  the  lymph 
may  degenerate  into  pus,  in  which  latter  case  the  operation  may 
prove  a  failure.  To  obviate  such  a  condition,  it  has  been  suggested 
to  make  an  opening  through  the  alveolus  to  the  apex  of  the  root  of 
the  tooth,  and,  by  means  of  floss  silk  or  a  pledget  of  cotton,  to 
establish  a  drainage,  or  to  insert  a  drain  tube  from  the  surface  of  the 
crown  through  the  canal  to  the  apex  of  the  root. 

The  operation  of  "  transplantation"  consists  in  the  extraction  of  a 
tooth  from  the  mouth  of  one  person  and  transferring  it  to  a  cavity  in 
the  mouth  of  another ;  in  some  cases  the  teeth  of  animals  have  been 
substituted  for  human  teeth. 

The  defective  tooth  is  first  extracted,  and  having  previously  selected 
a  tooth  in  the  mouth  of  another,  which  will  correspond  in  size,  color, 
location,  and  other  characteristics,  it  is  carefully  extracted  and  im- 
mediately transferred  to  the  cavity  from  which  the  defective  tooth 
has  been  removed,  as  soon  as  the  hemorrhage  has  ceased.  When  the 
tooth  to  be  transplanted  is  of  a  different  form  from  the  one  it  is  to 
replace,  it  must  be  made  to  correspond  to  the  new  cavity  by  properly 
changing  its  dimensions,  a  procedure  that  would  not  be  possible, 
to  the  same  degree  at  least,  in  the  case  of  replantation,  for  many 
examples  are  presented  of  dried  teeth  having  been  successfully  trans- 
planted. The  operation  of  transplantation  is  completed  by  securing 
the  new  tooth  in  position  and  employing  the  necessary  antiphlogistic 
treatment,  as  in  replantation.  Such  teeth,  however,  never  perfectly 
39 


6lO  DENTAL   SURGERY. 

harmonize  with  their  new  relation,  and  when  a  dried  tooth  is  used  its 
pulp  canal  should  be  previously  filled  with  gold.  It  is  also  suggested 
to  excise  a  portion  of  the  end  of  the  tooth,  from  one-sixteenth  to 
one  eighth  of  an  inch,  and  to  separate,  by  a  non-conducting  substance, 
the  root  filling  from  that  in  the  crown,  and,  as  in  the  case  of  replan- 
tation, to  prescribe  an  unstimulating  diet.  In  the  operation  of  re- 
plantation we  depend  for  success  upon  a  reattachment  of  the  peridental 
membrane ;  but  in  the  case  of  transplantation,  and  especially  where 
dried  teeth  are  made  use  of,  stability  is  due  to  absorption  of  the 
dead  tissue,  on  the  one  hand,  and  a  corresponding  hypertrophy  of 
living  tissue,  on  the  other,  the  root  of  the  tooth  undergoing  loss  of 
structure  in  the  form  of  small  cavities,  and  the  wall  of  the  alveolar 
cavity  thickened  by  ossific  deposit  at  points  corresponding  to  the 
cavities  formed  in  the  dead  tissue  of  the  root.  And  while  it  may 
require  one  week  for  a  replanted  tooth  to  become  firm,  two  or  more 
may  be  necessary  in  the  case  of  a  transplanted  tooth.  For  retaining 
replanted  and  transplanted  teeth  in  position,  either  the  modeling 
composition  and  gutta-percha  splints  before  alluded  to  may  be  em- 
ployed, or  the  ingenious  device  of  Dr.  Herbst,  which  is  represented 
by  Fig.  246  (p.  384).  An  interdental  splint  of  either  modeling 
composition  or  red  gutta-percha,  pressed  while  soft  over  the  newly- 
placed  tooth,  and  the  teeth  of  both  jaws  brought  in  contact  and 
pressed  slightly  into  the  plastic  mass,  will  also  prove  effectual  as 
a  retaining  appliance. 

While  the  operation  of  "replantation"  is  a  justifiable  one,  that  of 
"transplantation"  is  objectionable  for  several  reasons,  namely:  the 
necrosed  condition  of  such  a  tooth,  and,  as  a  consequence,  its  uncer- 
tain duration  ;  the  liability  to  failure ;  the  liability  of  inoculation  by 
the  transmission  of  disease  ;  and  the  inhumanity  of  inflicting  loss  and 
pain  on  one  person  in  order  to  give  another  a  very  uncertain  advantage. 

An  operation  known  as  "  implantation  "  has  recently  been  advocated 
by  Dr.  W.  J.  Younger.  It  consists  in  drilling  artificial  sockets  in  the 
maxillary  bones,  and  inserting  therein  natural  teeth  of  the  proper 
size,  shape,  and  shade,  or  at  least  so  nearly  resembling  the  shade  of 
the  adjoining  teeth  as  devitalized  teeth  can  present.  Dr.  Younger's 
method  is  to  carefully  dissect  from  the  bone  the  overlying  soft  tissues, 
such  as  the  gum  and  periosteum,  in  such  a  manner  as  to  retain  their 
connection  in  the  form  of  a  continuous  flap,  so  that  it  may  be  replaced 
about  the  neck  of  the  implanted  tooth  and  assist  in  securing  it. 
Graded  trephines  and  burs,  operated  by  the  dental  engine,  are  then 
applied  to  the  maxillary  bone,  a  socket  drilled  of  the  size  and  shape 
of  the  tooth  to  be  implanted,  which  is  selected  prior  to  commencing 
the  operation  of  dissecting  the  soft  tissues. 


REPLANTATION,    TRANSPLANTATION,    AND    IMPLANTATION.         6ll 

If  the  tooth  is  a  recently  extracted  one  (although  it  is  claimed  that 
teeth  which  have  been  extracted  months  previously  can  be  implanted), 
the  pulp  is  removed  and  the  canal  filled  with  gold  at  its  apex  and  with 
gutta-percha  in  the  remaining  portion.  The  tooth  is  then  subjected 
to  a  solution  of  bichlorid  of  mercury,  two  parts  to  looo  of  water,  at 
the  temperature  of  iio°  F.  for  some  fifteen  minutes.  The  instruments 
employed  in  the  operation  are  immersed  in  the  bichlorid  solution. 
and  also  the  root  of  the  tooth.  The  artificial  socket,  which  has  been 
prepared  in  the  manner  above  described,  is  then  carefully  cleansed 
with  the  same  solution,  cold  water  being  employed  to  arrest  the  heo- 
orrhage,  and  the  tooth  placed  in  position  and  secured  by  means  of 
ligatures.  The  theory  upon  which  Dr.  Younger's  method  is  based  is 
that  the  natural  alveolar  cavity  has  no  periosteum,  and  that  the  forma- 
tion of  these  cavities  depends  upon  the  thin  and  delicate  membrane 
lining  the  cells  and  interspaces  of  the  osseous  structure.  He  regards 
the  peridental  membrane  as  possessing  no  "  callus  generative  energy 
except  from  its  dental  aspect;  "  the  other  side,  he  asserts,  has  the 
power  only  of  forming  attachment.  He  also  claims  that  the  vitality 
of  the  peridental  membrane  is  kept  up  for  many  months  after  the 
extraction  of  the  tooth,  and  cites  examples  of  teeth  having  been  suc- 
cessfully implanted  after  they  had  been  extracted  for  more  than  a  year. 
The  failures  attending  the  operations  of  replantation  and  transplanta- 
tion he  ascribes  to  the  existence  of  disease  at  the  time  of  treatment,  a 
condition  that  does  not  exist  when  a  healthy  root  is  implanted  into 
an  artificially  formed  cavity  in  the  bone. 

The  records  of  the  cases  of  implantation,  however,  do  not  show  that 
this  operation  has  been  to  any  degree  more  successful  than  those  of 
replantation  and  transplantation  ;  and  the  failures  only  prove  that 
physiological  law  cannot  be  violated  with  impunity,  as  there  are 
certain  factors  which  must  not  be  ignored.  The  operation  of  implan- 
tation is  a  most  interesting  one,  as  it  is  novel  and  unique,  and  aside 
from  the  pain  experienced  by  the  patient,  one  of  its  greatest  dangers 
is  the  inoculation  of  disease  ;  and  this  objection  can  also  be  urged 
against  transplantation  with  equal  force. 

Figs.  585,  586,  587,  and  588,  represent  implantation  instruments 
for  Dr.  Younger's  operation. 

The  hole  in  the  jaw  bored  to  that  depth  by  the  trephine  is  then 
enlarged  by  the  reamers  to  fit  the  root  which  is  to  be  implanted. 

Tubular  Knife  No.  3  is  a  medium  size,  with  which  the  soft  tissues 
are  cut  to  the  bone.  For  the  incisors  and  cuspids,  the  hole  this 
makes  corresponds  fairly  with  the  shape  of  the  tooth  at  the  neck. 
For  the  bicuspids,  which  have  a  more  or  less  oblong  shape  on  cross- 
section,   this  round  hole  would,   apparently,   not  be  of   the  correct 


6l2 


DENTAL   SURGERY. 


shape.  It  is  only  necessary,  however,  to  have  a  tubular  knife  which 
measures  a  little -less  in  circumference  than  the  tooth  at  its  neck  to  in- 
sure a  perfect  fit,  for  the  soft  tissues  are  elastic 
enough  to  conform  to  the  tooth  if  the  hole  is 
large  enough. 

Spiral  Knife  No.  i  has  two  blades.     In  use  it 


TUBULAR 
SPIRAL  KNIVES.    KNIVES. 


TREPHINES. 


©  o  OOO 


2       3       4       5 
Fig.  585. 


OTTOLENGUI 
IMPLANTATION  REAMERS. 


Fig.  587. 

is  pressed  against  the  bone  and  pushed  in 
to  the  shoulder,  which  should  be  adjusted 
to  the  proper  position.  This  instrument 
cuts  the  bone  with  great  rapidity  and  with- 
out any  special  pain. 

No.  2  is  a  similar  knife,  only  more  coni- 
cal. This  is  pressed  into  the  hole  previously 
made,  and  then  swayed  to  enlarge  the  cavity 
to  fit  the  root.  It  will  be  necessary  to  use 
this  but  twice,  as  the  eye  carries  the  shape 
of  the  root  with  enough  accuracy  to  enable 
one  to  get  the  hole  of  almost  the  right  shape 
the  first  time. 


CHAPTER  Vril. 

DISLOCATION  AND  FRACTURE  OF  THE  JAW. 

From  the  peculiar  manner  in  which  the  inferior  maxilla  is  articu- 
lated to  the  temporal  bones,  it  is  not  very  liable  to  dislocation.  When 
it  occurs  in  one  or  both  of  the  condyles,  the  luxation  is  always  forward, 
the  conformation  of  the  parts  preventing  it  from  taking  place  in  any 


DISLOCATION    AND    FRACTURE    OF    THE    JAW.  613 

Other  direction.  The  oblong,  rounded  head  of  each  condyle  is  re- 
ceived into  the  forepart  of  a  deep  fossa  in  the  temporal  bone,  situated 
just  before  the  meatus  auditorius  externus,  and  under  the  beginning  of 
the  zygomatic  arch.  The  articular  surface  of  each  is  covered  with  a 
smooth  cartilage,  and  between  them  there  is  a  movable  cartilage.  This 
latter  is  connected  with  the  articulating  surfaces  of  the  condyle  and 
glenoid  cavity,  externally  by  the  external  lateral  ligament,  internally 
by  the  capsular  ligament,  and  in  front  by  the  tendon  of  the  external 
pterygoid.  This  cartilage  is  sometimes  called  the  meniscus,  from  its 
shape,  being  thickest  around  its  circumference,  especially  at  the  back 
part.  The  temporo-maxillary  articulation  is  strengthened  by  an  in- 
ternal, an  external,  and  a  capsular  ligament,  also  by  the  tendinous  and 
muscular  insertions  of  the  masseter,  temporal,  and  pterygoid  muscles. 
The  intervening  movable  cartilage,  being  more  closely  connected  with 
the  head  of  the  condyle  than  with  the  glenoid  cavity,  escapes  with  the 
former  whenever  dislocation  of  the  jaw  takes  place. 

Dislocation  of  the  lower  jaw  is  rarely  caused  by  a  blow,  unless  given 
when  the  mouth  is  open  ;  it  is  more  frequently  occasioned  by  yawning 
or  laughing.  It  has  been  known  to  occur  in  the  extraction  of  teeth, 
and  in  attempting  to  bite  a  very  large  substance.  Sir  Astley  Cooper 
mentions  the  case  of  a  boy  who  had  his  jaw  dislocated  by  suddenly 
putting  an  apple  into  his  mouth  to  keep  it  from  a  playfellow. 

After  the  jaw  has  been  dislocated  once,  it  is  always  more  liable  to 
this  accident ;  consequently,  Mr.  Fox  very  properly  recommends  to 
those  with  whom  it  has  once  happened  the  precaution  of  supporting 
the  jaw  whenever  the  mouth  is  opened  very  widely  in  gaping  or  for  the 
purpose  of  having  a  tooth  extracted.  None  of  these  causes  would  be 
sufficient  to  produce  the  accident,  unless  the  ligaments  of  the  temporo- 
maxillary  articulation  are  very  loose  and  the  muscles  of  the  jaw  much 
relaxed. 

The  author  witnessed  a  case  of  dislocation  of  the  lower  jaw  in  which 
the  displacement  occurred  during  an  attempt  to  extract  the  first  right 
inferior  molar.  The  patient  was  a  young  lady  from  Virginia,  about 
seventeen  years  of  age.  Both  condyles  were  luxated,  but  so  completely 
were  the  muscles  of  the  jaw  relaxed  that  he  immediately  reduced  it 
without  the  least  difficulty,  and  afterward,  by  supporting  the  jaw  with 
his  left  hand,  succeeded  in  removing  the  tooth. 

When  the  lower  jaw  is  dislocated  the  mouth  remains  wide  open,  as 
seen  in  Fig.  589,  and  a  great  deal  of  pain  is  experienced  ;  this,  accord- 
ing to  Boyer,  is  caused  by  the  pressure  of  the  condyles  on  the  deep- 
seated  temporal  nerves  and  those  which  go  to  the  masseter  muscles, 
situated  at  the  root  of  the  zygomatic  process.  The  condyles,  having 
left   their   place  of  articulation,   are   advanced   before   the   articular 


6i4 


DENTAL   SURGERY. 


Fig.  589. 


eminences  and  lodged  under  the  zygomatic  arches.  The  jaw  cannot 
be  closed ;  the  coronoid  processes  may  be  felt  under  the  malar  bones; 
the  temporal,  masseter,  and  buccinator  muscles  are  extended ;  the 
articular  cavities  being  empty,  a  hollow  may  be  felt  there ;  the  saliva 

flows  uninterruptedly  from  the  mouth, 
and  deglutition  and  speech  are  either 
wholly  prevented  or  very  greatly  im- 
paired. Boyer  says  that  during  the 
first  five  days  after  the  accident  the 
patient  can  neither  speak  nor  swallow. 
The  jaw,  when  only  one  condyle  is 
displaced,  is  forced  more  or  less  to 
one  side. 

If  the  dislocation  continues  for  sev- 
eral days  or  weeks,  the  chin  gradually 
approaches  the  upper  jaw,  and  the 
patient  slowly  recovers  the  functions 
of  speech  and  deglutition.  We  are  told 
by  Mr.  Samuel  Cooper  that  it  may 
prove  fatal  if  it  remains  unreduced;* 
but  Sir  Astley  Cooper  says  he  has  never  known  any  dangerous  effects 
to  result  from  this  accident;  on  the  contrary,  after  it  has  continued 
for  a  considerable  length  of  time  the  jaw  partially  recovers  its  motion. f 
In  the  reduction  of  dislocation  of  the  lower  jaw  the  older  surgeons 
employed  two  pieces  of  wood,  which  were  introduced  on  each  side  of 
the  mouth,  between  the  molar  teeth  ;  while  these  were  made  to  act  as 
levers  for  depressing  the  back  part  of  the  bone,  the  chin  was  raised  by 
means  of  a  bandage. 

The  method  usually  adopted  by  modern  surgeons  for  reducing  a 
dislocation  of  this  bone  consists  in  introducing  the  thumbs,  wrapped 
in  a  napkin  or  cloth  (to  prevent  them  from  being  hurt  by  the  teeth), 
as  far  back  upon  the  molars  as  possible  ;  then  depressing  the  back 
part  of  the  jaw  and  at  the  same  time  raising  the  chin  with  the  fingers. 
In  this  way  the  condyles  are  disengaged  from  under  the  zygomatic 
arches  and  made  to  glide  back  into  their  articular  cavities.  But  the 
moment  the  condyles  are  disengaged  the  thumbs  of  the  operator 
should  be  slipped  outward  between  the  teeth  and  the  cheeks,  as  the 
action  of  the  muscles  at  this  instant,  in  drawing  the  jaw  back,  causes 
it  to  close  very  suddenly  and  with  considerable  force.  This  precau- 
tion is  necessary  to  avoid  being  hurt,  unless  a  piece  of  cork  or  soft 
wood  has  been  previously  placed  between  the  teeth. 


*  "  Surgical  Dictionary,"  p.  306.  f  A.  Cooper  on  "  Dislocations,"  p.  389. 


DISLOCATION    AND    FRACTURE    OF    THE   JAW.  615 

By  the  foregoing  simple  method  the  dislocation  may,  in  almost 
every  case,  be  readily  reduced  ;  but  Mr.  Fox  mentions  a  case  in 
which  it  failed.  The  subject  was  a  lady  whose  lower  jaw  had  been 
luxated  several  times  before ;  this  time  the  accident  was  occasioned 
by  an  attempt  which  he  made  to  extract  one  of  the  inferior  dentes 
sapientiae.  After  having  failed  to  reduce  the  luxated  bone  by  the 
usual  method,  he  "  happened  to  recollect  a  statement  made  to  him  by 
M.  de  Chemant,  who,  having  been  frequently  applied  to  by  a  person 
in  Paris  who  was  subject  to  this  accident,  had  always  succeeded  in 
immediately  reducing  the  luxation  by  means  of  a  lever  of  wood,  as 
recommended  by  Dr.  Monroe."  Profiting  by  this  statement,  Mr. 
Fox  procured  a  piece  of  Avood  about  an  inch  square  and  ten  or  twelve 
inches  long.  He  placed  one  end  of  this  upon  the  lower  molars,  and 
then  raised  the  other,  so  that  the  upper  teeth  acted  as  a  fulcrum.  As 
soon  as  the  jaw  was  depressed  the  condyle  of  the  side  upon  which  the 
wood  was  applied  immediately  slipped  back  into  its  articular  cavity. 
The  wood  was  then  applied  to  the  opposite  side  of  the  jaw,  and  the 
other  condyle  reduced  in  the  same  manner.* 

The  method  practiced  by  Sir  Astley  Cooper  consists,  when  both 
condyles  are  displaced,  in  introducing  two  corks  behind  the  molars 
and  then  elevating  the  chin.  He,  however,  first  places  his  patient  in 
a  recumbent  posture ;  f  but  this  is  seldom  necessary.  The  reduction 
of  the  dislocation  can  be  as  conveniently  effected  with  the  patient  in 
a  sitting  as  in  «  recumbent  posture. 

After  the  reduction  of  the  dislocation  the  patient  is  recommended 
to  abstain  for  several  days  from  the  use  of  solid  aliments  and  to  wear 
a  four-tailed  bandage  ;  |  or,  what  is  still  better,  the  bandage  contrived 
by  Mr.  Fox  (Fig,  271,  p.  395),  to  prevent  its  recurrence  iw  the  ex- 
traction of  teeth.  When  this  bandage  is  used  for  the  latter  purpose 
the  mouth  is  first  opened  to  the  proper  extent,  with  the  condyles  in 
their  articular  cavities ;  it  is  then  applied  and  the  straps  tightly 
buckled.  This  done,  it  is  impossible  to  advance  the  jaw  sufficiently 
to  produce  a  dislocation. 

FRACTURES    OF   THE   JAWS. 

Fractures  of  the  jaws  rarely  occur  except  from  direct  violence. 
In  the  upper  jaw  this  violence  is  usually  of  a  character  that  com- 
plicates the  fracture  with  severe  injury  to  adjacent  parts.  Gunshot 
wounds   are  by   far   the   most   frequent   source  of   fractures   in    this 


*  American  edition  of  Fox  on  "The  Human  Teeth,"  p.  330. 
•f-  A.  Cooper  on  "  Dislocations,"  p.  391. 
J  Cooper's  "  Surgical  Dictionary,"  p.  306.  " 


6l6  DENTAL    SURGERY. 

locality ;  and  it  is  wonderful  what  an  amount  of  injury  to  the  bones 
of  the  face  may  be  recovered  from  without  ill  result.  The  bones  of 
the  face  are  of  softer  character  than  those  found  elsewhere,  and  con- 
sequently the  whole  injury  is  at  the  place  of  impact  and  along  the 
course  of  the  ball ;  no  long  fractures  or  extensive  contusions  are 
found,  or  very  rarely  so,  and  the  parts  are  abundantly  supplied  with 
blood,  hence  the  restorative  process  proceeds  very  rapidly ;  but  this 
abundant  sanguineous  supply,  so  useful  in  the  restoration  of  parts,  is 
also  the  chief  source  of  danger.  Hemorrhage  is  generally  excessive 
and  difficult  to  control,  and  to  secondary  hemorrhage  is  due  the 
greatest  fatality  in  injuries  of  this  kind,  ligature  of  the  carotid  artery, 
which  has  been  frequently  practiced,  usually  serving  but  to  postpone 
the  fatal  termination.  Owing  to  the  liberal  supply  of  blood,  necrosis 
seldom  occurs,  and  it  is  seldom  necessary  to  remove  fragments  of 
bone,  even  after  the  most  extensive  comminution  ;  they  should  be 
left,  except  for  some  peculiar  reason,  until  death  is  manifest  in  them, 
when  they  may  be  abstracted  without  additional  trouble.  Loosened 
teeth  should  always  be  left  to  contract  adhesions,  which  they  will 
generally  readily  do.  Indeed,  but  little  surgical  interference  is 
required  in  cases  of  this  kind,  and  should  usually  be  limited  to  efforts 
to  secure  the  proper  apposition  of  the  teeth.  Numerous  cases  of  the 
most  extraordinary  injuries  to  the  face  are  to  be  found  in  the  surgical 
reports  of  the  late  war  in  the  States,  and  in  those  of  the  French  and 
English  surgeons  during  the  wars  of  the  first  Napoleon  and  the 
Crimea.  Fractures  of  the  superior  maxilla  may,  however,  occur  from 
other  violence  than  gunshot  wounds.  Mr.  Salter  reports  a  case 
resulting  from  the  collision  of  the  face  and  head  of  two  "cricketers." 
The  kick. of  a  horse,  as  in  the  well-known  Wiseman  case,  has  occa- 
sioned frightful  injury  of  this  character.     In   this  case  the  "  face  was 

driven  in,   the  lower  jaw  projecting  forward The  bones 

of  the  palate  were  driven  so  far  back  it  was  impossible  to  pass  my 
finger  behind  them."  The  patient  made  a  good  recovery.  Mr.  Heath 
records  a  case  reported  by  Dr.  Tyffe,  in  which,  "  on  watching  the 
patient's  profile  while  in  the  act  of  swallowing  food,  the  whole  of  the 
bones  of  the  face  were  observed  to  move  up  and  down  upon  the  fixed 
part  of  the  skull  as  the  different  parts  were  brought  into  motion.  It 
appeared  as  if  the  integuments  only  retained  them  in  their  position. 
It  was  a  curious  feature  in  the  case  that,  notwithstanding  the  very 
extensive  injury  done  and  the  violent  character  of  the  force  which 
caused  it  (the  upsetting  of  a  cab),  not  a  single  tooth  was  fractured  or 
misplaced.  Fractures  in  the  dentist's  chair,  from  ill-directed  efforts 
to  remove  teeth,  not  uncommon  when  "keys"  were  in  general  use, 
are  now  so  infreq.uent  as  to  be  undeserving  of  special  mention. 


DISLOCATION    AND    FRACTURE    OF    THE   JAW.  617 

Among  the  complications  of  fracture  of  the  upper  jaw  may  be  men- 
tioned breaking  and  displacement  of  teeth,  closure  of  the  nasal  duct 
with  consequent  epiphora,  secondary  hemorrhage,  and  paralysis  of  the 
infra-orbital  nerve  as  the  most  common. 

Diagnosis  of  fractures  of  the  upper  jaw  is  usually  attended  with  but 
little  difficulty.  It  is  determined  by  pain,  crepitation,  irregularity  in 
the  line  of  the  teeth,  and  excessive  secretion  of  saliva.  The  treatment 
consists  in  the  nice  adaptation  of  the  teeth  and  their  permanent  secu- 
rity in  proper  position.  This  is  generally  effected  with  but  little  diffi- 
culty, by  a  single  finger  passed  into  the  mouth  to  press  the  fragments 
into  position,  where  they  may  be  secured  by  wires,  or,  in  cases  of  great 
displacement,  by  the  interdental  splint.  The  hemorrhage  should  be 
controlled  by  styptics,  of  which  the  persulphate  of  iron  is  the  best,  by 
the  actual  cautery,  and,  when  not  otherwise  manageable,  by  ligation 
of  the  carotid  artery. 

Fractures  of  the  lower  jaw  are  much  more  common  than  those  of 
the  upper.  They  give  comparatively  little  trouble,  are  readily  diag- 
nosed, and  are  occasioned  by  direct  violence,  as  in  the  upper  jaw. 
The  most  common  seat  of  fracture  is  the  middle  of  the  horizontal 
ramus.  Before  the  use  of  interdental  splints,  fractures  of  the  lower 
jaw  were  difficult  of  adjustment  and  were  frequently  attended  with 
bad  results,  and  in  rare  cases  they  still  are  so.  A  good  many  forms  of 
apparatus  have  been  devised,  of  which  the  simplest  is  the  four-tailed 
bandage,  which  consists  of  a  slip  of  muslin,  of  suitable  dimensions, 
torn  from  each  extremity  toward  the  center,  leaving  enough  space  to 
receive  the  chin.  It  is  secured  by  passing  the  tails  over  the  top  of  the 
head  and  around  the  back  of  the  neck,  and  tying  them  in  this  position. 
This  apparatus  may  be  supplemented  by  a  pasteboard  splint  molded  to 
the  form  of  the  jaw.  Sometimes  the  bones  are  secured  in  position  by 
passing  wires  around  the  firm  teeth  and  binding  them  together.  They 
may  also  be  secured  by  sutures,  the  bones  having  been  drilled  to  per- 
mit their  passage.  Mr.  Wheelhouse,  of  Leeds,  recommends  that,  after 
drilling  through  the  bones  on  either  side  of  the  fracture,  silver  pins, 
"with  flat,  circular,  and  perforated  heads,"  be  passed  through  the 
opening  from  within  outward,  and  their  points  bent  in  opposite  direc- 
tions so  as  to  form  hooks,  and  the  fragments  secured  by  passing  silver 
<3r  gold  wire  in  a  figure-of-eight  over  the  pins.  The  perforations  in 
Vii^  liead  of  the  wires  are  for  silk  sutures,  by  which  they  may  be  readily 
removed  when  necessary.  It  is  also  recommended  that  not  only  should 
the  fragments  be  secured  together  in  this  way,  but  that  they  also  be 
bound  to  the  upper  jaw.  Wedges  of  cork  cut  into  suitable  shapes; 
of  gutta-percha,  introduced  and  molded  to  the  teeth ;  Mutter's  sil- 
■«er  clamps,  or  their  modification  by  Mr.   Tomes;  Hayward's  silver 


6i8 


•  DENTAL    SUKGERV. 


caps,  and  other  more  complicated  apparatuses  may,  in  our  judgment, 
be  all  superseded  by  the  vulcanite  interdental  splint  contrived  about 
the  same  time  and  independently  of  each  other  by  the  late  Dr.  Bean, 
of  Baltimore,  Md.,  and  Dr.  Gunning,  of  New  York,  except  in  cases 
of  obstinate  vertical  displacement.  An  impression  in  wax  is  first 
taken  of  both  jaws,  from  which  a  plaster  cast  is  taken,  and  upon  this 
the  vulcanite  plate  is  accurately  molded  with  indentations  correspond- 
ing exactly  to  the  adjusted  teeth,  and  with  an  interspace  at  the  most 
convenient  point  for  administering  food.  The  splints  are  now  intro- 
duced into  the  mouth,  the  teeth  arranged  in  their  appropriate  indenta- 
tions, and  the  whole  fixed  in  position  by  a  mental  compress  and  occip- 
ito-frontal  bandage,  thus  securing  the  jaws  from  motion  and  the  splint 

from  displacement.  The  compress 
consists  of  a  light  piece  of  wood,  on 
which  is  fixed  a  metallic  cup  of  form 
and  size  adapted  to  the  patient's  chin, 
to  each  extremity  of  which  is  affixed 
a  metallic  side-piece  four  or  five  inches 
in  length  and  from  three-quarters  to 
one  inch  in  width.  Encasing  these 
side-pieces  are  the  temporal  straps, 
made  of  stout  cloth  and  secured  by  a 
strong  cord  at  the  base  of  each  piece. 
The  occipi to-frontal  bandage  is  com- 
posed of  a  band  passing  around  the 
head  from  the  forehead  to  the  occipital 
protuberance  behind,  and  secured  by 
a  buckle  one  inch  to  the  right  of  the 
median  line  behind  ;  of  another  strap 
secured  to  the  band  in  front  and  behind  ;  and  a  third  strap  extending 
from  the  temporal  buckles  on  either  side  and  secured  to  the  middle 
strap  at  the  point  of  crossing.     (See  Fig.  590.) 

An  '•'  impromptu  interdental  splint,"  the  suggestion  of  Professor 
Gorgas,  and  which  he  has  employed  with  great  satisfaction  in  hos- 
pital practice,  both  in  the  case  of  single  and  double  fractures  of  the 
maxillae,  is  described  as  follows  :  — 

Taking  the  case  of  fracture  of  the  inferior  maxillary,  for  example, 
after  all  the  parts  are  brought  in  apposition  and  secured  by  wire  or  silk 
ligatures,  a  partial  lower  mouth  cup  or  tray,  of  the  proper  size  to  suit 
the  arch,  is  selected.  This  mouth  cup  is  of  the  form  having  an  open- 
ing or  cavity  to  allow  the  front  teeth  under  other  circumstances  to  pass 
through,  or,  what  is  better,  is  cut  out  in  the  form  represented  by  Fig. 
591  for  the  lower  jaw  and  Fig.  592  for  the  upper  jaw. 


Fig.  590. 


DISLOCATION    AND    FRACTURE    OF    THE    JAW. 


619 


Fig.  591. 


The  partial  lower  cups  with  flat  bottoms  and  square  sides  are  more 
suitable  than  the  round-bottom  cups,  but  the  latter  may  be  used  with 
advantage  where  the  jaw  is  edentulous. 

When  the  fractured  portions  are  secured  in  position  by  ligatures,  the 
cup  is  filled  with  softened 
modeling  composition  and 
introduced  into  the  mouth 
in  the  same  manner  as 
when  taking  an  impression 
for  a  partial  lower  set  of 
teeth  and  pressed  carefully 
into  place.  The  opening 
or  cavity  in  the  front  part 
of  the  cup  will  allow  the 
modeling  composition  to 
press   through    the    upper 

surface,  and  into  this  excess  the  patient  is  directed  to  bite  with  the 
superior  front  teeth,  and  the  modeling  composition  is  adapted  by 
pressing  on  it  with  the  finger  to  the  labial  surfaces  of  these  teeth. 
This  completes  the  formation  of  the  interdental  splint,  which  the 
patient  is  to  wear  until  union  of  the  fractured  parts  takes  place.  The 
handle  of  the  cup,  which  is  necessary  for  its  introduction  into  the 
mouth,  is  then  cut  off  close  to  the  cup  with  a  fine  saw,  in  order  that 

it  may  not  inconvenience 
the  patient  by  projecting 
beyond  the  lips.  The 
openings  on  each  side  over 
the  bicuspid  and  molar 
teeth  will  permit  the  in- 
troduction of  nourishment 
without  disturbing  the  ap- 
pliance. A  bandage  is 
thfen  passed  over  the  top 
of  the  head  and  under  the 
chin,  and  thus  an  easy  and 
rapidly  formed  "interden- 
tal splint  "  is  improvised,  which  has  given  satisfaction  in  every  case 
where  it  has  been  applied,  and  permitted  of  removal  in  from  three  to 
four  weeks  from  the  time  it  was  applied.  Special  splints  with  an  adjust- 
able handle,  which  maybe  removed  by  unscrewing  it,  have  been  devised 
by  Professor  Gorgas,  for  the  treatment  of  fracture  of  both  jaws,  which 
are  better  adapted  to  the  parts  than  the  ordinary  mouth  cups  employed 
for  obtaining  impressions  in  the  construction  of  sets  of  artificial  teeth. 


Fig.  592. 


620  DENTAL    SURGERY. 

Dr.  Edward  H.  Angle's  system  of  treating  fractures  of  the  maxillary 
bones  is  as  follows  : — 

"  The  most  important  consideration,  after  securing  perfect  apposi- 
tion of  the  parts,  is  that  they  shall  have  uninterrupted  rest,  and  this 

phase  of  the  subject  will  be  set  forth 

^■■i^.  strictly  with  reference   to  certain 

^^^^^IJSP"  ^       plans  for  securing  fixation  of  the 

^^^^^^B:  -  £      ^  ^/       fractured  maxillce  while  undergo- 

iw^^if|  ^^^^*^^=vi-_ //  ing   the   healing   process;     plans 

i^^P^mHjjIIh^  which  are  original  with  the  author, 

^^^^^^^^^p=^^?^^^^i  and    have   been    successfully   em- 

y^^^^_    '^K^~^F^^^^~  '::'.:^[,_        ployed  in  an  extensive  experience 
^^^^p^::r"    ^         "  "         ■  ::5  in  the  treatment  of  these  lesions. 

^^^^     ~_ --— ^-.     "— -  \  --        "  The  first  plan  is  that  of  firmly 

Fig.  593.  and  immovably  holding  the  injured 

jaw  in  contact  with  the  firm  and 

uninjured  jaw  by  means  of  wire  ligatures  wrapped  in  the  form  of  the 

figure   eight   around    buttons   attached    to   bands  encircling  suitable 

opposite  or  nearly  opposite  teeth,  as  shown  in  Fig.  593. 

"All  the  teeth  are  thus  kept  in  perfect  occlusion,  and,  as  a  result, 
the  fractured  ends  of  the  bones  must  necessarily  be  in  apposition,  so 
that  the  conditions  are  most  favorable  to  the  process  of  repair  ;  for  it 
will  be  apparent  upon  reflection  that  no  matter  at  what  point  the  frac- 
ture has  occurred,  if  the  jaw  contains  sufficient  teeth  and  they  are 
placed  in  perfect  occlusion,  not  only  will  the  fracture  be  properly  set, 
but  the  powerful  muscles  will  be  greatly  relaxed  and  the  parts  be  con- 
sequently freed  from  that  tension  and  tendency  to  displacement  so 
difficult  to  combat  in  the  treatment  of  fractures,  in  the  long  bones 
especially,  or  in  the  maxillae  when  the  jaws  are  kept  apart,  as  is  neces- 
sary when  the  heavy  interdental  splints  are  employed. 

"  Indeed,  we  believe  this  plan  to  be  a  most  natural  and  easy  one,  for 
the  cusps  of  the  teeth  lock  and  interlace  so  perfectly  that  displacement 
in  any  direction  is  impossible,  provided  the  jaws  are  kept  closed.  And 
in  this  we  are  further  assisted  by  the  natural  contraction  of  the  powerful 
muscles  of  mastication,  it  being  necessary  in  most  cases  only  to  antago- 
nize the  anterior,  feeble  depressor  muscles,  by  attachments  on  each  side 
to  the  cuspids,  or  other  teeth  in  this  region,  if  more  suitable. 

"The  bands,  which  we  term  fracture-bands.  Fig.  594,  are  made  very 
thin  and  strong,  are  adjustable,  and,  by  means  of  the  screw  and  nut, 
they  may  be  firmly  clamped  about  the  teeth.  Little  buttons,  strong 
and  of  sufficient  size  to  admit  the  requisite  number  of  wraps  of  the 
ligatures,  are  firmly  soldered  to  the  band.  Care  should  always  be 
exercised  to  work  the  band  well  over  the  crown  of  the  tooth  and  down 


FRACTURES    OF    THE    MAXILLi«. 


521 


Fig.  594. 


upon  the  neck,  then  tighten  the  nut  until  the  band  is  firmly  clamped, 
being  careful  not  to  weaken  the  band  by  crimping  or  tearing.  The 
fingers  alone  are  usually  sufficient,  al- 
though a  dull  instrument  and  mallet  may 
be  used  to  assist  in  placing  the  band. 
If  the  teeth  are  crowded,  a  thin  spatula 
pressed  between  them  and  allowed  to 
remain  for  a  iew  moments  will  provide 
ample  space.  For  the  ligatures,  almost  any  of  the  usual  materials 
may  be  employed,  such  as  waxed  floss  silk,  strong  linen  thread,  or 
the  gut  ligature  so  extensively  employed  in  surgery,  but  fine  copper 
wire  is  preferable  on  account  of  its  strength,  pliability,  and  clean- 
liness. 

"  That  the  reader  may  become  more  familiar  with  this  method  of  treat- 
ment, as  well  as  with  a  few  of  the  many  modifications  of  which  it  is 
susceptible,  reports  of  a  few  cases  from  practice  are  subjoined,  with 
illustrations  from  models  made  accurately  in  each  instance  after  treat- 
ment. 

"  Case  I. — The  first  is  represented  by  Fig.  595. 


Fig.  595- 


'^  On  July  14,  1889,  Wm.  Fraley,  aged  forty-five,  was  admitted  to  the 
Minneapolis  City  Hospital.  A  blow  from  a  policeman's  club  had  pro- 
duced one  simple  and  one  compound  fracture  of  the  inferior  maxilla. 
.The  first  was  an  oblique  fracture  on  the  right  side,  beginning  with  the 
socket  of  the  second  bicuspid,  extending  downward  and  backward,  and 
involving  the  socket  of  the  first  molar.  The  second  bicuspid  had  fallen 
out,  and  the  first  molar  was  much  loosened.  The  second  molar  had  been 
lost  years  before,  while  the  third  molar  and  the  remaining  teeth  were 
much  abraded,  and  much  loosened  by  salivary  calculus.     The  second 


622  DENTAL   SURGERY. 

fracture  was  on  the  opposite  side,  high  up  in  the  ramus  of  the  jaw.  I 
could  not  detect  the  exact  course  the  line  of  fracture  had  taken,  but 
the  crepitation  of  the  ends  of  the  bones,  and  the  pain  occasioned 
thereby,  were  unmistakable  evidence  of  a  fracture.  The  patient,  as  is 
usual  in  such  cases,  was  unable  to  close  his  jaws.  The  parts  on  the 
right  side  were  widely  separated,  and  the  anterior  piece  much  depressed 
by  reason  of  the  action  of  the  digastric  muscle,  the  posterior  piece  of 
bone  being  drawn  firmly  up,  and  the  molars  occluding  by  reason  of  the 
contraction  of  the  masseter  muscle.     He  was  treated  as  follows: — 

"  Bands  were  made  to  encircle  all  four  of  the  cuspids  (they  being  most 
firmly  attached  in  their  sockets).  The  fractured  ends  of  the  bones 
were  placed  in  careful  apposition,  and  the  lower  jaw  closed,  the  lower 
teeth  being  correctly  occluded  with  the  upper. 

"The  points  on  the  bands,  where  the  little  tubes (C,  Set  No.  i )  shown 
in  the  engraving  should  be  attached,  were  carefully  noted  and  marked. 
The  bands  were  slipped  off  and  the  tubes  soldered  to  them,  after  which 
the  bands  were  cemented  in  proper  position  upon  the  teeth,  and  two 
small  traction-screws  (B,  Fig.  273),  shown  in  the  engraving,  inserted 
in  the  tubes.     The  jaws  were  closed  and  the  nuts  tightened. 

"  During  an  attack  of  coughing  the  following  night,  one  of  the  bands 
was  loosened,  but  it  was  easily  replaced  the  next  day.  No  further 
accident  or  trouble  occurred,  the  patient  readily  taking  nourishment 
through  the  spaces  between  the  teeth.  Thus  the  fractured  jaw  was 
firmly  supported  without  motion  for  twenty-two  days,  when  the  appli- 
ance was  removed,  showing  most  excellent  results. 

"  That  the  patient  was  a  great  lover  of  the  clay  pipe  is  shown  in  the 
engraving  by  the  much  worn  ends  of  the  lateral  incisors,  which  re- 
sulted from  holding  the  stem  of  the  pipe.  While  wearing  the  appli- 
ance he  was  not  debarred  from  his  favorite  enjoyment,  although  com- 
pelled to  grasp  the  stem  between  his  lips  instead  of  the  teeth. 

^'Case  II. — December  28,  1889,  Thomas  Bremen  was  admitted  to 
the  Dental  Infirmary  of  the  University  of  Minnesota,  suffering  from 
the  effects  of  a  blow  received  on  the  left  side  of  the  jaw  from  a  cant- 
hook  while  working  in  a  lumber  camp.  The  result  was  two  fractures 
of  the  jaw. 

"The  first  fracture  was  on  the  right  side,  beginning  between  the  first 
and  second  bicuspids  and  extending  downward  and  backward  so  far  as 
to  involve  the  lower  part  of  the  anterior  root  of  the  first  molar.  The 
second  was  on  the  left  side  directly  through  the  angle  of  the  jaw  (see 
Fig.  596).  The  accident  had  occurred  thirty-two  days  previous  to  his 
admission  to  the  infirmary,  during  which  time  nothing  had  been  done 
to  reduce  the  fracture.     He  reported  that  he  had  called  upon  a  physi- 


FRACTURES    OF    THE    MAXILLA. 


023 


cian,  who  supposed  the  trouble  was  merely  an  abscessed  toc/ih  and  had 
lanced  the  gum  with  a  view  of  reducing  the  swelling.  Later,  the 
patient  had  called  upon  a  dentist  in  one  of  the  smaller  towns,  who  also 
failed  to  diagnose  the  fracture,  and  extracted  both  bicuspids  in  the 
hope  of  giving  relief. 

"  Upon  examination  I  found  considerable  swelling  in  the  region  of 
the  fracture,  with  the  usual  result :  the  patient  being  unable  to  close 
his  mouth  by  reason  of  the  anterior  piece  of  the  fractured  bone  being 
drawn  down  by  the  depressor  muscles.  A  false  joint  had  also  become 
established,  and  could  be  easily  moved  without  causing  pain.  At  the 
fracture  of  the  right  side  there  was  but  little  displacement ;  the  swell- 
ing also  was  slight. 

"  The  patient  was  anesthetized,  and,  with  a  view  to  breaking  up  the 
false  attachments  and  stimulating  activity  in  repair,  the  ends  of  the 


Fig.  596. 

bones  rubbed  forcibly  together,  placed  in  perfect  apposition,  and  the 
jaw  closed,  great  care  being  taken  to  articulate  the  teeth  correctly  with 
the  upper  ones.  The  jaw  was  now  firmly  bound  in  this  position  in 
the  same  manner  as  described  and  shown  in  Fig.  593,  which  is  quite 
as  efficient  and  much  easier  to  adjust.  Four  bands  were  used,  encir- 
cling the  four  cuspids,  as  shown  in  Fig.  596.  The  bands  shown  upon 
the  molars  in  the  engraving  were  not  used,  as  I  found  them  unneces- 
sary, since  the  jaws  were  firmly  supported  by  the  anterior  band  alone. 
"Case  No.  3  is  represented  by  Fig.  597,  and  is  that  of  a  healthy 
young  Swede,  twenty-two  years  of  age,  who,  while  washing  windows, 
had  fallen  from  the  second  story  to  the  hard  pavement.  Besides  re- 
ceiving several  minor  injuries  he  sustained  a  double  fracture  of  the 
lower  jaw,  one  extending  from  between  the  central  incisors,  and  one 
posterior  to  the  second  molar,  the  third  molar  having  been  extracted. 


624 


DENTAL   SURGERY. 


The  right  superior  lateral  and  cuspid  were  knocked  out,  the  first  bicus- 
pid broken  off  near  the  neck,  and  the  alveolar  process  badly  shattered. 
The  centrals  and  left  lateral  were  bent  inward  and  forced  deeper  into 
their  sockets.  He  had  been  treated  by  the  attending  physician  at  the 
City  Hospital,  the  method  employed  being  that  of  the  Barton  style  of 
bandaging,  with  the  usual  result,  when  the  bandage  is  employed  in 
such  cases,  of  aggravating  the  condition  by  forcing  the  pieces  inward 
and  the  jaw  backward. 

"Upon  examination  three  weeks  after  the  accident,  I  found  much 
displacement.  The  jaw  was  drawn  backward  and  the  right  middle 
section  of  the  bone  tipped  inward.  No  attention  had  been  paid  to 
the  bent  and  broken  condition  of  the  superior  alveoli.  The  teeth 
had  become  quite  firm  in  their  new  but  abnormal  positions,  and  I 
allowed  them  to  remain  so.      A  fibrous  attachment  had  been  estab- 


FlG.  597. 


lished  in  the  lower  fracture,  which  admitted  of  considerable  move- 
ment, and  occasioned  but  little  pain.  There  was  much  swellin-g,  and 
pus  was  discharging  into  the  mouth  from  the  anterior  fracture.  I 
found  it  impossible  to  restore  normal  occlusion  at  that  time.  Bands 
were  made  to  encircle  the  four  bicuspids,  and  between  the  two  lower 
bands,  on  the  inside  of  the  mouth,  was  placed  one  of  the  jack-screws 
(E  and  J,  Set  No.  i),  held  in  place  by  the  staple  and  spur  (E,  Fig. 
286,  and  B,  Fig.  285).  The  nut  was  tightened  until  the  piece  of  bone 
had  been  tipped  outward  about  one-half  the  distance  to  its  normal 
position,  but  the  operation  caused  so  much  pain  that  further  move- 
ment was  deferred.  The  jaws  were  then  closed  and  the  buttons  con- 
nected by  ligatures,  but  occlusion  was  far  from  being  normal.  On 
the  next  day,  by  again  tightening  the  nut  on  the  jack-screw  and  with 


FRACTURES    OF    THE    MAXILL/E.  625 

renewed  ligatures  bound  very  tightly,  I  was  enabled  to  secure  nearly 
the  normal  occlusion.  On  the  third  day  following,  by  the  same 
means,  correct  occlusion  was  established.  The  jack-screw  was  allowed 
to  remain  in  position  to  steady  the  tipping  section. 

"  The  abscess  was  frequently  syringed  with  fresh  peroxid  of  hydro- 
gen. A  few  fragments  of  bone  were  washed  out.  The  fractures 
readily  united,  and  on  the  twenty-seventh  day  the  jaw  was  released 
and  found  to  be  quite  firm. 

"  Case  No.  4  shows  another  modification,  and  is  represented  by  Fig. 
598.  A  young  machinist  received  a  severe  blow  from  the  fist  of  an 
antagonist,  by  which  two  compound  fractures  were  sustained, — one 
posterior  to  the  first  molar,  the  other  in  the  region  of  the  cuspid, 
which  was  involved  and  greatly  loosened. .  Occlusion  was  established 
and   maintained    in    the     previously    described    way.       Suppuration 


Fig.  598. 


occurred  in  both  fractures  on  about  the  tenth  day,  and  received 
proper  treatment.  The  union  of  the  anterior  fragment  was  slow,  as 
the  patient  was  troubled  by  a  persistent,  hacking  cough,  which  occa- 
sioned a  slight  movement  between  the  ends  of  the  bone,  just  sufficient 
to  interfere  with  the  healing  process.  On  the  twentieth  day  the 
ligatures  were  cut,  a  jack-screw  placed  in  position  between  the  bands 
on  the  inside  in  the  same  manner  as  in  Fig.  597,  with  an  additional 
ligature  firmly  connecting  the  two  buttons  on  the  lower  bands,  and 
resting  in  contact  with  the  labial  surfaces  of  the  intervening  teeth. 
This  additional  support  proved  successful ;  the  union  proceeded 
slowly,  and  was  found  complete  when  the  bands  were  removed  on  the 
sixty-second  day  after  the  accident. 

"Another  modification  is  shown  in  a  somewhat  peculiar  case,  repre- 
40 


626 


DENTAL    SURGERY. 


sented  in  Fig.  599.  The  patient,  a  man  of  about  forty  years  of  age, 
had  sustained  a  complete  fracture  of  the  left  angle  of  the  jaw,  as  the 
result  of  a  kick  from  a  horse.  The  jaw  was  enormously  large  and  pro- 
truding, and  the  occlusion  so  unusually  faulty,  that  I  was  at  a  loss  to 
determine  what  the  patient's  normal  occlusion  was;  but  upon  ques- 
tioning him,  he  informed  me  that  when  a  boy  of  ten  years  he  had  been 
hit  with  a  stone,  causing  a  fracture  on  the  right  side  of  the  jaw,  which 
had  been  allowed  to  heal  without  any  treatment.  This  statement, 
with  the  worn  facets  upon  the  cusps  of  some  of  the  teeth,  and  the  read- 
iness with  which  they  occluded  only  at  these  points,  showed  conclu- 
sively the  position  in  which  the  jaw  must  be  secured.  I  at  first,  of 
course,  supposed  that  the  usual  number  of  four  bands  and  two  liga- 
tures would  be  necessary,  but  I  found  the  single  ligature,  as  shown, 
was  quite  sufficient  to  firmly  retain  the  jaw  in  this  abnormally  normal 


Fig.  599. 


position.  The  jaw  was  set  a  few  hours  after  the  accident.  Very  little 
swelling  ensued,  the  fractured  parts  uniting  rapidly.  I  saw  the  patient 
but  four  times,  and  removed  the  bands  on  the  twentieth  day,  as  fur- 
ther support  seemed  unnecessary.  I  admonished  the  patient,  however, 
to  avoid  using  his  jaw  as  much  as  possible  for  at  least  ten  days  there- 
after. 

"Fig.  600  represents  a  case  where  the  patient  suffered  in  a  railroad 
wreck  two  compound  fractures  of  the  inferior  maxilla,  one  on  each 
side,  posterior  to  the  second  molar.  The  left  side  was  quite  badly 
comminuted.  The  full  complement  of  teeth  was  present,  with  the 
exception  of  the  third  molars.  The  occlusion  of  all  the  teeth  was 
excellent.  The  incisors,  however,  were  crossed  (not  well  shown  in 
this  engraving) ;  that  is,  the  left  superior  central  and  lateral  closed 


FRACTURES    OF    THE    MAXILLA. 


627 


just  inside  of  the  points  of  the  lower  incisor  and  cuspid,  while  the 
right  central  and  lateral  closed  just  outside  of  the  points  of  the  oppos- 
ing lower  cuspid,  central,  and  lateral. 

"  The  teeth  being  so  perfect  and  the  occlusion  so  accurate,  liquid 
foods  only  were  possible.  The  conditions  were  made  more  unfavor- 
able on  account  of  the  patient  suffering  from  severe  spinal  injury 
received  at  the  time  of  the  accident,  but  with  the  exception  of  con- 
siderable suppuration  in  the  left  fracture,  which  yielded  readily  to 
treatment,  nothing  unusual  occurred.  The  ligatures  were  removed  on 
the  fortieth  day,  and  excellent  results  were  apparent. 

"It  might  be  urged  against  a  method  of  treatment  which  involves 
the  closure  of  the  teeth  and  the  binding  of  the  jaws  firmly  together, 
that  the  patient  would  be  unable  to  take  sufficient  nourishment.  Ex- 
perience, however,  shows  that  this  argument  has  practically  no  founda- 


FiG.  600. 


tion,  for  it  rarely  happens  that  a  patient  is  found  without  some  missing 
teeth,  thereby  providing  abundant  opportunity  for  the  inception  of  all 
ordinary  chopped  foods,  and  more  especially  for  the  large  number  of 
foods  now  available  in  liquid  form.  Even  when  all  the  teeth  are  sound 
and  in  perfect  position,  there  is  plenty  of  space  between  the  teeth,  or 
behind  the  molars  and  between  the  upper  and  lower  incisors,  for  taking 
all  the  nourishment  necessary.  Of  course,  in  these  rare  cases  more 
time  would  be  required  for  eating.  This  inconvenience  is  very  slight 
when  we  consider  the  advantages  of  freedom  from  an  uncleanly,  bulky, 
and  inconvenient  apparatus  within  the  mouth,  often  accompanied  by 
the  disfigurement  of  bandages  and  splints  without,  as  well  as  the  great 
importance  of  the  accuracy  in  results  which  it  assures,  so  uncertain  of 
attainment  in  many  other  methods  commonly  employed. 

*'  There  is  also  another  class  of  lesions  in  the  treatment  of  which  this 


628 


DENTAL   SURGERY. 


Fig.  6oi. 


plan  of  fixation  may  be  employed  to  great  advantage.  I  refer  to  excis- 
ion of  the  lower  maxilla,  or  those  cases  where  a  large  portion  of  the 
jaw  has  been  removed,  as  in  Fig.  6oi. 

"  In  all  these  cases  there  is  a  strong  tendency  for  the  remaining  por- 
tion of  the  jaw  to  be  drawn  greatly  to  one  side  (about  three-quarters 

of  an  inch,  by  actual 
measurement,  in  the 
case  represented),  due 
to  the  contraction  of 
the  cicatricial  tissues 
following  the  healing  of 
the  wound.  The  plan 
I  propose  will  prevent 
this  contraction,  by  se- 
curing the  remaining 
portion  of  the  jaw  in 
proper  occlusion,  by 
means  of  the  fracture- 
bands  and  ligatures  in 
the  manner  already  de- 
scribed. The  jaw  thus  firmly  held  will  exert  sufficient  tension  upon 
the  healing  muscles  to  prevent  their  contraction.  I  would  also  sug- 
gest the  advisability  of  increasing  the  tension  by  the  attachment  of  a 
plumper,  by  means  of  a  clamp-band,  to  one  of  the  molars  in  the  upper 
jaw  on  the  side  from  which  the  section  has  been  removed,  allowing  the 
shield  or  plumper  to  extend  downward  and  outward,  to  occupy  some- 
what the  position  of  the 
missing  bone.  This  shield 
may  also  serve  a  useful  pur- 
pose in  holding  in  better 
position  the  dressing  of  the 
wound. 

' '  The  next  plan  may  be 
said  to  be  a  modification 
of,  or  an  improvement 
upon,  the  plan  advocated  _. 
by  Hippocrates  in  the  fifth 
century  B.  C,  and  which 
has   been    employed   from 

that  time  to  this.  It  consists  in  holding  the  fractured  ends  of  the 
bone  in  apposition  by  wrapping  ligatures  about  the  teeth,  or,  as  physi- 
cians now  term  it,  wiring  the  teeth.  The  principal  disadvantage  has 
always  been  the  slipping  of  the  ligatures,  which  produced  displacement 


Fig.  602. 


FRACTURES    OF    THE    MAXILLA.  629 

of  the  bones,  and  caused  inflammation  by  the  pressure  of  the  sliding 
ligature  upon  the  gums. 

"My  plan  is  shown  in  Fig.  602,  and  consists  in  encircling  suitable 
teeth  with  fracture-bands  and  attaching  ligatures  to  the  buttons  upon 
the  bands,  so  that  loosening  of  the  bones  or  pressure  upon  the  gums 
is  impossible. 

"  A  modification  of  the  plan  is  shown  in  Fig.  603,  in  which  addi- 
tional support  is  secured  by  connecting  the  labial  and  lingual  wire 
ligatures  by  loops  of  wire  passed  between  the  teeth,  with  their  ends 
united  by  twisting. 

"  In  favorable  cases,  as  in  simple  transverse  fractures  with  little  or 
no  displacement  and  where  the  teeth  are  very  firm,  if  the  apparatus  is 
adjusted  with  skill,  the  plan  will  be  found  valuable,  as  it  is  very  neat, 


Fig.  603. 

clean,  and  compact,  and  does  not  interfere  with  the  freedom  of  th6 
jaw. 

"  A  few  suggestions  may  assist  the  inexperienced  in  the  adjustment 
of  the  apparatus,  so  that  it  will  surely  afford  equal  pressure  and 
support  upon  the  intervening  teeth.  The  only  difficulty  is  in 
regard  to  the  proper  length  of  the  lingual  ligature  when  completed. 
This  is  easily  overcome  by  using  two  small  copper  wires,  passing 
respectively  above  and  below  the  buttons  and  extending  beyond  them 
a  half-inch  or  more  at  each  end.  Tension  is  not  exerted  on  *he  but- 
tons by  uniting  the  ends  by  twisting  until  offer  the  external  and  trans- 
verse ligatures  have  been  completed.  The  engraving  is  incorrect  in 
this  respect,  that  only  one  end  of  the  lingual  ligature  shows  union  of 
the  ends,  instead  of  both. 

Fig.  604  represents  a  modification  of  this  plan  used  for  holding  in 
position  a  large  section  of  the  alveolus,  including  the  incisors  and 
left  lower  cuspids,  which  had  been  broken  outward  as  the  result  of 


630 


DENTAL   SURGERY. 


falling  from  a  sled  while  the  individual  was  coasting  with  the  knotted 
end  of  a  rope  held  in  the  mouth.  The  second  bicuspids  were  banded, 
and  a  wire  ligature  made  to  encircle  the  buttons  and  bear  against  the 
loosened  teeth.  '  The  ligatures  showed  a  slight  tendency  to  slide  down 
and  impinge  upon  the  gum,  but  this  was  easily  remedied  by  encir- 


npwv 


Fig.  604. 

cling  the  main  ligature  and  the  incisors  with  two  or  three  fine  wire 
ligatures,  thus  giving  additional  support  in  a  downward  direction. 

"  Fig.  605  shows  another  plan  for  securing  fixation  which  possesses 
several  valuable  features.  It  is  a  thin  metal  cap,  swaged  to  fit  the 
crowns  accurately  and  covering  a  sufficient  number  of  the  teeth  in  the 


Fig.  605. 


arch  to  afford  the  necessary  support,  the  whole  being  firmly  cemented 
to  the  teeth  with  oxyphosphate  of  zinc.  Copper,  gold,  silver,  alumi- 
num, or  vulcanite  may  be  used  ;  my  preference  is  aluminum.  The  plan 
is  excellent,  in   that  it  allows  fredom  of  the  jaw,  is  very  clean,  com- 


FRACTURES    OF    THE    MAXILLA. 


631 


pact,  and  retains  the  fractured  ends  of  the  bone  firmly  in  apposition. 
Considering  the  simplicity  of  this  appliance,  and  the  familiarity  of 
dentists  with  oxyphosphate  of  zinc,  it  is  surprising  that  the  value 
of  this  idea  in  treating  fractures  has  not  been  before  recognized ;  but 
I  find  no  record  of  its  use,  although  dentists  frequently  use  similar 
splints  in  the  retention  of  teeth  after  they  have  been  regulated,  and 
Hullihen  employed  a  similar  device  in  1848  to  hold  the  section  of  a 
jaw  after  a  surgical  operation,  using  ligatures  to  keep  the  appliance  in 
place. 

"For  several  years  I  supposed  I  had  been  the  first  to  employ  this 
method  of  retaining  fractures,  but  I  now  believe  it  was  first  used  by 
Dr.  John  H.  Martindale,  of  Minneapolis,  who  preceded  me  a  year  or 
so,  by  cementing  in  position  a  splint  made  after  Kingsley's  pattern, 
in   order  to  dispense   with  the  submental  cap  and  bandages,  which 


would  interfere  with  the  treatment  of  serious  external  wounds  on  the 
side  of  the  face. 

"My  first  case  treated  after  this  method  is  shown  in  Fig.  606. 
Michael  P.,  a  baker  by  trade,  had  .fallen  down  stairs,  knocking  out 
the  superior  incisors,  cuspids,  and  one  bicuspid,  also  loosening  the 
lower  central  incisors  and  fracturing  the  jaw  at  the  symphysis.  As  I 
remember,  he  also  received  a  fracture  of  one  of  the  femurs.  He  was 
admitted  to  the  Minneapolis  City  Hospital  some  time  in  June,  1888. 
I  saw  him  first  some  two  months  after  the  accident  occurred,  during 
which  time  the  attending  surgeon  had  employed  the  Barton  style  of 
bandaging  in  treatment.  Union  of  the  bone  had  not  taken  place  ; 
on  the  contrary,  a  complete  fibrous  joint  had  been  established,  with 
the  ends  of  the  bones  more  or  less  absorbed  and  rounded,  admitting 
of  a  free  hinge  movement,  with  pus  discharging,  for  which  a  large 


632 


DENTAL    SURGERY. 


rubber  drainage-tube  had  been  inserted.  The  tube  was  removed,  the 
wound  thoroughly  washed,  and  an  impression  taken  without  any 
attempt  at  changing  the  collapsed  condition  of  the  sides  of  the  arch. 
A  model  was  made  and  sawed  through  at  the  point  of  fracture.  It 
was  then  placed  in  the  articulator  and  adj.usted  to  restore  the  original 
occlusion  as  nearly  as  possible.  Over  this  readjusted  model  a  very 
thin  vulcanite  splint  was  formed,  the  outlines  of  which  corresponded 
to  the  dotted  lines  in  the  engraving. 

"  The  first  attempt  at  cementing  it  in  position  upon  the  teeth  was 
unsuccessful,  the  cement  hardening  too  rapidly,  but  the  next  proved 
successful.  The  splint  remained  in  position  without  any  trouble  for 
nearly  four  months,  when  it  worked  loose,  and  we  found,  upon  exami- 
nation, that  firm  union  had  taken  place. 

"Of  course,  the  range  of  usefulness  of  this  splint  is  quite  limited, 
as  a  sufficient  number  of  firm  teeth  must  be  present  on  each  side  of 
the  fracture.  Its  principal  value  will,  I  think,  be  found  in  treating 
fractures  in  the  anterior  part  of  the  jaw,  more  especially  in  that  class 
of  cases  resulting  from  gunshot  wounds  in  which  large  sections  of  the 
alveolus  have  been  carried  away. 

"Another  plan  which  I  have  made  use  of  in  a  few  favorable  cases 
with  much  satisfaction  is  shown  in  Fig.  607,  which  represents  my  first 
case  treated  by  the  method  in  question.  On  May  29,  1889,  a  young 
man  of  twenty-one  years  was  admitted  to  the  St.  Anthony  Hospital 
of  Minneapolis.  During  an  attack  of  epilepsy  he  had  fallen  from  a 
lumber  pile  to  the  ground,  a  distance  of  fifteen  or  twenty  feet. 
r>esides  receiving  severe  bruises,  he  sustained  a  compound  fracture  at 

the  symphysis,  terminating  in 
<-!?"'*\  front  between  the  central  and 
lateral,  as  shown  by  the  line  in 
the  engraving.  The  fractured 
bone,  when  first  seen,  was  quite 
widely  separated  at  the  top,  and 
the  left  central  incisor  was  much 
loosened.  He  was  treated  as 
follows :  The  ends  of  the  frac- 
tured bones  were  carefully  placed 
in  position  and  temporarily  fast- 
ened by  lacing  the  teeth  together  with  silk  ligatures.  The  cuspids, 
being  very  firm,  were  carefully  fitted  with  plain  bands.  Tubes  were 
soldered  to  these  bands  horizontally.  The  large  traction-screw  shown 
at  A,  Fig.  273,  was  now  slipped  through  the  tubes,  and  the  bands 
were  firmly  cemented  in  position  upon  the  teeth.  The  nut  was  then 
turned  upon   the  screw  until  the  fractured  ends  of  the  bones  were 


Fig.  607. 


FRACTURES    OF    THE    MAXILLAE.  633 

drawn  snugly  together.  This  appliance  was  worn  without  displace- 
ment or  further  trouble  for  twenty-one  days,  when  it  was  removed, 
the  bones  having  become  firmly  united. 

"  I  may  add  that  during  the  time  the  appliance  was  worn,  so  firmly 
w^as  the  jaw  supported  that  the  patient  suffered  but  little  inconvenience, 
and  after  the  third  day  partook  regularly  of  his  meals,  using  his  jaw^s 
freely,  but  of  course  avoiding  the  very  hard  foods. 

"Suggestions. — In  adjusting  bands  for  the  treatment  of  a  fracture, 
carefully  consider  the  direction  in  which  to  exert  the  proper  pressure 
for  securing  the  jaw.  It  usually  happens  in  cases  of  fracture  that  the 
muscles  in  contracting  tend  not  only  to  depress  the  jaw,  but  to  draw 
it  backward,  especially  if  the  fracture  be  in  the  region  of  the  last 
molar.  Consequently  such  teeth  for  anchorage  should  be  selected  as 
shall  use  pressure  not  only  upward  but  forward,  as  in  Fig.  599. 

"  This  is  only  a  general  rule,  however,  but  I  would  specially  advise 
that  the  direction  of  force  necessary  in  each  case  should  be  carefully 
considered,  and  then  the  bands  and  buttons  be  adjusted  accordingly. 

"  Sometimes  it  is  an  advantage  to  band  more  than  one  tooth  in  order 
to  distribute  the  power  exactly  in  the  direction  necessary.  Should  any 
of  the  teeth  which  have  been  selected  for  anchorage  show  a  tendency 
to  elongation,  the  bands  should  be  shifted  to  other  teeth,  or  the  direc- 
tion of  the  force  be  changed.  In  but  two  instances  have  I  noted  this 
complication,  and  I  am  inclined  to  believe  that  one  of  the  cases  was 
due  to  the  band  slipping  and  impinging  upon  the  gum,  and  thus  prob- 
ably producing  the  same  result  as  when  a  ligature  is  carelessly  left 
about  the  tooth. 

"Should  it  be  found  advisable  to  employ  the  plan  illustrated  by 
Fig.  606  or  Fig.  607  in  the  treatment  of  a  case,  it  will  sometimes  be 
found  an  advantage  to  support  the  jaw  by  the  first  plan  (Fig.  593), 
for  a  few  days,  or  until  the  wounds  are  in  more  favorable  condition 
for  taking  an  impression  or  adjusting  the  apparatus. 

"After  the  jaw  has  been  properly  set,  the  muscles  relax  in  a  {t\w 
hours,  so  that  the  strain  upon  the  ligature  and  anchor-tooth  is  slight. 

"Very  often  patients  receive  severe  bruises  and  internal  injuries  at 
the  time  the  fracture  is  sustained,  and  these  may  occasion  vomiting, 
more  or  less  violent.  Therefore  especial  caution  should  be  observed 
that  the  securing  of  the  jaw  be  delayed  until  all  tendency  to  nausea 
has  subsided.  Be  in  no  haste,  for  I  knoAv  of  no  ill  effects  from  a  few 
hours'  or  even  days'  delay  in  setting  a  fracture.  Should  it  be  advisable 
to  immediately  set  the  fracture,  it  might  be  well  to  provide  the  attend- 
ant with  a  pair  of  strong  scissors  to  cut  the  ligatures  if  symptoms  of 
nausea  develop. 

"  It  should  require  but  little  argument  to  impress  the  importance  of 


134  DENTAL   SURGERY. 

extreme  cleanliness  about  the  mouth  during  the  treatment  of  fractures. 
Frequent  rinsing  of  the  mouth  with  proper  antiseptic  solutions  should 
be  insisted  upon.  If  the  fracture  is  more  or  less  comminuted,  as  is 
frequently  the  case,  suppuration  may  be  expected.  The  plan,  then, 
which  has  been  the  most  successful  with  me,  is  extra  cleanliness  of  the 
wound  by  frequent  injections  of  pure,  fresh  peroxid  of  hydrogen  with 
a  suitable  syringe.  The  patient  or  the  attendant,  with  a  little  experi- 
ence, can  accomplish  this  quite  as  well  as  the  surgeon.  Patience  and 
persistence  in  this  line  will  soon  cause  the  necrotic  fragments  to  be 
washed  out.  Only  in  one  instance,  in  my  experience,  has  it  seemed 
necessary  to  interfere  with  the  wound  by  scraping  the  bone  with  in- 
struments. 

"While  the  patient  is  undergoing  treatijient,  his  general  health 
should  also  not  be  allowed  to  become  impaired.  Plenty  of  exercise  in 
the  open  air,  if  other  injuries  do  not  prevent,  should  be  insisted  upon, 
as  well  as  a  requisite  amount  of  nourishing  food,  and  the  surgeon 
should  occasionally  inspect  the  bands  and  ligatures  to  see  that  they 
are  in  order,  so  that  the  jaw  shall  not  be  allowed  to  get  loose,  admit- 
ting movement  between  the  fractured  ends  of  the  bones.  •  Should  one 
of  the  bands  become  broken,  it  should  be  replaced  as  quickly  as  pos- 
sible. No  special  harm  will  come  from  cutting  the  ligatures  and  sepa- 
rating the  jaws  for  the  purpose  of  replacing  it. 

"  In  cases  where  a  section  of  the  bone  shows  a  tendency  to  lean,  so 
that  the  teeth  do  not  properly  occlude,  a  finger  of  metal,  made  to  bear 
against  a  tooth  in  the  leaning  section  and  soldered  to  a  band  encircling 
some  favorably  located  anchor-tooth,  will  effectually  restore  the  proper 
occlusion. 

"  In  like  manner  the  range  of  application  of  this  method  of  retain- 
ing fractures  may  be  extended  to  cases  where  fractures  occur  in  the 
body  of  the  bone  and  the  molars  are  absent.  The  edentulous  portion 
of  the  jaw  may  be  securely  held  in  proper  position  by  a  prop  made  to 
bear  against  the  section  of  bone,  and  kept  in  place  by  attachment  to  a 
band  secured  about  one  of  the  molars  or  bicuspids  in  the  upper  jaw. 

"  The  methods  so  far  offered  will,  I  believe,  nearly  cover  the  entire 
range  of  cases  requiring  treatment.  There  still  remains,  however,  one 
distinct  class  for  consideration,  namely:  the  edentulous  patient. 
Fortunately,  patients  of  this  class  requiring  treatment  are  exceedingly 
rare,  and  probably  the  best  plan  is  the  Gunning  splint,  or  what  is  the 
same  in  principle,  attaching  together  by  wire  or  vulcanite  the  artificial 
dentures,  should  the  patient  possess  them. 

"  The  cases  of  fractures  so  far  described  have  been  confined  to  the 
inferior  maxilla.  The  methods,  however,  of  securing  fixation  are  all 
more  or  less  applicable  to  the  treatment  of  fractures  in  the  upper  jaw 


DISEASES    OF    THE    ANTRUM.  635 

as  well,  though  I  believe  the  one  first  described  is  most  applicable ;  for 
the  reason  that,  if  one  of  the  superior  maxillary  bones  is  fractured,  it 
will  be  more  or  less  displaced  and  usually  forced  downward.  After 
carefully  replacing  the  pieces,  the  jaws  are  closed  and  the  teeth  articu- 
lated, and  the  pieces  thus  supported  and  held  upward  in  position  by  the 
lower 'jaw  secured  in  the  usual  way  by  bands,  buttons,  and  ligatures, 
attached  on  the  uninjured  side. 

"Finally,  as  all  the  apparatus  possessing  any  special  merit  in  the 
treatment  of  fractures  of  the  maxillae  have  been  invented  by  dentists, 
and  their  familiarity  with  the  parts,  special  knowledge  of  mechanics, 
and  facilities  at  their  command  fit  them  above  all  other  surgeons  for 
this  work,  I  w'ould  recommend  that  the  different  dental  societies 
throughout  the  country  shall  secure  appointrhents  of  competent  den- 
tists in  all  hospitals  for  the  treatment  of  these  lesions,  for  to  them  this 
special  line  of  surgery  justly  belongs. ' ' 


CHAPTER  IX. 
DISEASES  OF  THE  ANTRUM. 

The  cavity  known  as  the  antrum  of  Highmore,  or  maxillary  sinus, 
is  situated  in  the  body  of  the  superior  maxillary  bones,  on  either  side 
of  the  nose  and  beneath  the  orbit  of  the  eye.  It  is  an  irregular  cavity, 
varying  in  size  in  nearly  every  superior  maxillary  bone,  and  often 
divided  into  several  parts  by  vertical  partitions  (septi)  of  bone,  an  ob- 
servation of  many  bones  being  necessary  to  show  its  extent  and  general 
form.  The  alveolar  process  immediately  over  the  ends  of  the  roots  of 
the  first  and  second  superior  molars  and  bicuspids  forms  the  floor  of  the 
antrum  ;  hence  it  is  readily  seen  how  abscesses  of  the  roots  of  these 
teeth  may  involve  this  cavity. 

One  of  the  nasal  openings  of  the  antrum,  of  w'hich  there  are  two  in 
the  middle  meatus  of  the  nose,  when  in  a  normal  condition,  is  very 
nearly  closed  by  a  duplicature  of  the  membrane  lining  the  turbinated 
and  other  adjoining  bones,  and  secretions  may  readily  accumulate  when 
this  outlet  into  the  nose  is  closed  by  congestion  of  the  membrane, 
giving  rise  to  serious  symptoms,  such  as  disfigurement,  pain,  etc.  The 
other  opening  is  very  small,  and  can  only  be  entered  with  the  point  of 
a  probe.  The  mucous  membrane  which  lines  the  nares  passes  through 
these  openings  into  the  antrum,  and  lines  this  cavity  also. 

The  antrum  is  subject  to  some  of  the  most  formidable  and  danger- 


636  DENTAL   SURGERY. 

ous  diseases  the  medical  or  surgical  practitioner  is  ever  called  upon  to 
treat ;  and  yet  there  are  few  diseases  incident  to  the  human  body  that 
have  received  less  attention  from  writers  on  pathology  and  therapeutics 
than  these.  There  are  diseases  here  met  with  over  which  neither  the 
surgeon  nor  physician  can  exercise  any  control,  the  progress  of  which 
ceases  only  with  the  life  of  the  unfortunate  sufferer. 

All  of  the  diseases  to  which  the  maxillary  antrum  is  subject,  however, 
are  not  of  so  dangerous  a  character,  for  some  are  very  simple  and  easily 
cured  ;  but  even  those  which  are  regarded  as  the  least  dangerous,  and 
which  yield  most  readily  to  treatment  when  instituted  during  their 
incipient  or  earlier  stages,  may  assume,  if  neglected  or  improperly 
treated,  a  form  so  aggravated  as  to  bid  defiance  to  the  skill  both  of  the 
physician  and  surgeon.  'While  thus,  on  the  one  hand,  the  most  simple 
affections  of  this  cavity  may,  by  neglect  or  improper  treatment,  become 
ultimately  incurable,  many  of  those,  on  the  other  hand,  which  are  con- 
sidered the  most  malignant  and  dangerous,  might,  we  have  no  doubt, 
by  timely  and  judicious  treatment,  be  effectually  and  radically  re- 
moved. 

The  form  which  the  disease  puts  on  is  determined  by  the  state  of  the 
constitutional  health  or  some  specific  tendency  of  the  general  system  ; 
and  vfe  can  readily  imagine  that  a  cause  which,  in  one  person,  would 
give  rise  to  simple  inflammation  of  the  lining  membrane,  or  mucous 
engorgement  of  the  sinus,  would  in  another  produce  an  ill  conditioned 
ulcer,  fungus  hematodes,  or  osteo-sarcoma.  Simple  inflammation  and 
mucous  engorgement  not  unfrequently  causes  caries  and  exfoliation  of 
the  surrounding  osseous  tissues,  and,  in  some  instances,  even  the 
destruction  of  the  life  of  the  patient. 

The  importance  of  early  attention  to  the  diseases  of  this  cavity  is, 
therefore,  very  apparent ;  and  this  is  the  more  necessary  as  it  is  often 
difficult  and  sometimes  impossible  to  determine  the  character  of  the 
malady  until  it  has  progressed  so  far  as  to  involve,  to  a  greater  or  less 
extent,  the  neighboring  parts,  when,  if  it  has  not  become  incurable, 
its  removal  is,  to  say  the  least,  rendered  less  easy  of  accomplishment. 
It  may  be  safely  assumed,  therefore,  that  in  a  very  large  majority  of 
the  cases  of  diseases  of  the  maxillary  sinus,  the  danger  to  be  appre- 
hended arises  more  from  neglect  than  from  any  necessarily  fatal 
character  of  the  malady,  so  that  in  forming  a  prognosis,  the  circum- 
stances to  be  considered  are  the  state  of  the  constitutional  health,  the 
progress  made  by  the  affection,  and  the  nature  of  the  injury  inflicted 
by  it  upon  the  surrounding  tissues.  If  the  general  health  is  not  so 
much  impaired  as  to  prevent  its  restoration  by  the  employment  of  pro- 
per remedies,  and  the  neighboring  structures  have  not  become  impli- 
cated, the  prognosis  will  be  favorable  ;  but  if  the  functional  operations 


DISEASES    OF    THE    ANTRUM.  637 

of  the  body  have  become  very  much  deranged,  and  the  bones  of  the 
face  and  nose  seriously  affected,  the  combined  resources  both  of 
medicine  and  surgery  will  prove  unavailing. 

In  young  and  middle-aged  subjects  of  good  constitution,  a  morbid 
action  may  exist  in  the  antrum  for  years  without  giving  rise  to  any 
alarming  symptoms,  while  the  same  affection  in  another  less  healthy 
might  rapidly  extend  and  degenerate  into  a  form  of  disease  so  malig- 
nant as  to  threaten  the  speedy  destruction  of  the  life  of  the  patient. 
Medical  history  abounds  with  examples  of  this  kind,  and  conclusively 
establishes  the  fact  that  the  state  of  the  general  health  and  habit  of 
body,  whatever  may  have  been  the  primitive  characteristics  of  the 
malady,  ultimately  determines  its  malignancy ;  in  the  treatment  of 
affections  of  this  cavity,  therefore,  as  well  as  of  other  local  diseases 
of  the  body,  the  condition  of  the  system  should  not  be  overlooked. 

Independently  of  the  danger  arising  from  the  local  affection,  dis- 
eases of  the  antrum  are,  for  the  most  part,  very  loathsome,  and  subject 
the  patient  to  great  annoyance.  They  change  the  quality  of  its  secre- 
tions, and  cause  them  to  exhale  a  fetid,  nauseating  odor.  This,  in 
many  instances,  is  almost  insufferable  to  the  patient,  and  when  they 
are  prevented  from  escaping  through  the  natural  opening  into  the 
nose,  they  pass  through  one  artiiicially  formed  by  the  surgeon,  or 
made  by  the  disease  through  the  cheek,  alveolar  border,  or  palatine 
arch,  always  causing  the  patient  great  inconvenience. 

The  progress  of  disease  in  this  cavity  is  often  very  insidious.  It 
not  unfrequently  happens  that  it  exists  for  weeks  and  even  months  be- 
fore its  presence  is  suspected.  The  slight  uneasiness  felt  is  attributed 
to  some  morbid  condition  of  the  teeth  or  gums,  and  the  symptoms 
attendant  upon  one  description  of  affection  are  often  so  similar  to 
those  that  accompany  another,  that  it  is  impossible  to  determine  its 
true  character  until  it  has  made  considerable  progress. 

The  morbid  affections  of  the  maxillary  sinus  are,  for  the  most  part, 
similar  to  those  of  the  nasal  fossae. 

The  most  simple  form  of  disease  that  occurs  here  is  inflammation  of 
the  lining  membrane,  and  this,  in  most  instances,  may  be  said  to  pre- 
cede all  others.  It  often  subsides  spontaneously  ;  but  when  it  con- 
tinues for  a  long  time  it  is  apt  to  become  chronic,  and  may  then  give 
rise  to  other  and  more  formidable  kinds  of  disease.  When  un- 
attended by  any  other  morbid  affection,  either  local  or  constitutional, 
it  is  easily  cured. 

A  purulent  condition  of  the  fluids  of  the  antrum  is  a  common  affec- 
tion, but  is  seldom  met  with  in  persons  of  good  constitution.  It 
seems  to  be  dependent  upon  a  bad  habit  of  the  body ;  also  upon 
inflammation   of  the   mucous  membrane   of    the  sinus,  which   arises 


638  DENTAL   SURGERY. 

more  frequently  from  dental  irritation  than  any  other  cause.  This 
condition  of  the  secretions  sometimes  gives  rise  to  caries  and  exfolia- 
tion of  portions  of  the  surrounding  bone  and  to  fistulous  ulcers  ;  but 
when  dependent  upon  no, other  local  cause  than  simple  inflammation 
of  mucous  membrane,  it  is  seldom  that  such  effects  result  from  it. 
When  complicated  with  other  morbid  conditions  of  the  cavity  they 
are  not  infrequent. 

Ulceration  of  the  lining  membrane  is  an  affection  less  frequently 
met  with.  It  is  rarely,  if  ever,  idiopathic,  but  seems  rather  to  be  de- 
pendent upon  some  other  local  malady  or  some  specific  constitutional 
vice.  Scorbutic  and  scrofulous  diatheses,  and  those  affected  with  a 
venereal  taint,  are  more  liable  to  ulceration  of  this  membrane  than 
persons  of  sound  constitution.  Consequently,  it  is  seldom  cured  by 
local  remedies  alone.  It  is  almost  always  complicated  with  fungus  of 
the  membrane  and  caries  of  the  walls  of  the  sinus,  and  may,  if 
neglected,  take  on  a  cancerous  form  and  become  incurable. 

The  next  form  of  disease  is  caries  of  the  antral  parietes.  This, 
though  always  complicated  with  other  forms  of  diseased  action,  seems, 
nevertheless,  to  be  worthy  of  separate  consideration.  Like  ulcera- 
tion of  the  lining  membrane,  it  is  the  result  of  some  other  affection. 
It  may  result  from  accumulation  of  the  secretions  of  the  sinus,  from 
ulceration,  or  from  tumors. 

The  occurrence  of  fungus  or  polypus  and  of  various  kinds  of  tumor 
is  less  frequent  than  any  of  the  preceding  affections;  yet  this  cavity  is 
not  exempt  from  them,  and  they  constitute  the  most  dangerous  form 
of  disease  to  which  the  superior  maxilla  is  subject.  Although  it  is 
probable  that  in  their  incipient  stage  they  might  in  nearly  every  in- 
stance be  radically  removed,  it  is  seldom  they  are  cured  after  they  have 
attained  a  very  large  size,  and  have  implicated  to  a  considerable  extent 
the  surrounding  tissues.  They  have,  however,  been  successfully  extir- 
pated even  after  they  had  acquired  great  volume,  and  implicated  to 
such  an  extent  the  surrounding  parts  as  to  render  necessary  the  removal 
of  the  whole  of  the  superior  maxillary  bone.  They  usually  grow  with 
great  rapidity,  and  if  not  completely  removed  are  soon  reproduced. 

Besides  these,  other  varieties  of  disease  are  occasionally  met  with 
here.  The  antrum  is  liable  to  injuries  from  blows  and  other  kinds  of 
mechanical  violence,  and  from  the  introduction  of  insects  and  foreign 
bodies.  The  diseases  of  the  maxillary  sinus  are  supposed  to  be  depend- 
ent upon  certain  specific  constitutional  vices ;  upon  the  obliteration 
of  the  opening  of  this  cavity  into  the  nose,  and  upon  dental  irritation. 
That  all  of  these  may  at  times  be  concerned  in  their  production  is 
more  than  probable.  But  actual  disease  rarely  develops  itself  sponta- 
neously as  a  consequence  merely  of  a  bad  habit  of  body  or  constitu- 


DISEASES    OF    THE   ANTRUM.  639 

tional  vice.  This  does  not  of  itself  originate  disease,  but  only  occa- 
sions an  increase  of  susceptibility  of  the  tissues  to  morbid  impressions; 
so  that  when  an  unhealthy  action  is  once  induced  here,  a  more  aggra- 
vated or  a  different  form  of  disease  occurs  than  that  which  would 
otherwise  have  been  produced. 

Thus  it  may  be  seen  that  disease  of  the  maxillary  sinus  is  dependent 
upon  some  exciting  cause,  favored  by  some  constitutional  vice ;  for 
without  this  no  serious  morbid  effects  would  be  produced,  or  if  pro- 
duced, they  would  be  of  a  different  or  less  aggravated  character.  Any 
disposition  or  vice  of  body  which  weakens  the  vital  energies  of  the 
system  increases  the  susceptibility,  or  rather  excitability,  of  all  its  parts 
— those  of  this  cavity  equally  with  the  rest.  There  are  various  kinds 
which  have  this  effect ;  as,  for  example,  the  scorbutic,  scrofulous,  vene- 
real, mercurial,  etc.,  each  of  which  may  influence  the  character  of  the 
morbid  action  in  a  manner  peculiar  to  itself;  or  it  may  be  similar  to 
that  which  might  be  exercised  by  another,  only  causing  it  to  assume  a 
greater  or  less  degree  of  malignancy,  accordingly  as  the  functional 
operations  of  the  body  generally  are  more  or  less  enervated  by  it. 

This  seems  to  be  the  way  in  which  a  bad  habit  of  body  is  capable 
of  affecting  the  maxillary  sinus.  It  is  a  predisposing,  but- not  an 
exciting  cause  of  disease;  and  it  is  important  that  this  distinction 
should  be  borne  in  mind.  The  one  should  never  be  confounded  with 
the  other,  because  an  error  of  this  sort  might,  in  many  instances,  lead 
to  the  adoption  of  incorrect  views  concerning  the  therapeutical  indi- 
cations of  the  disease.  This  part  of  the  subject  we  shall  have  occasion 
to  advert  to  hereafter. 

Inflammation  and  ulceration  of  the  nasal  pituitary  membrane  some- 
times extend  themselves  to  the  maxillary  sinus ;  but  disease  is  not  so 
frequently  propagated  from  the  nasal  fossae  to  this  cavity  as  the  inti- 
mate relationship  between  the  two  might  lead  one  to  suppose.  It  is 
seldom  that  both  are  affected  at  the  same  time.  Hence,  we  infer  that 
although  lined  by  one  common  membrane,  the  propagation  of  disease 
from  one  to  the  other  is  a  rare  occurrence. 

The  obliteration  of  the  nasal  opening  of  this  cavity  is  sometimes 
caused  by  disease  in  the  nose,  and  is  followed  by  mucous  engorgement 
of  the  sinus,  inflammation  of  the  lining  membrane,  distention  of  the 
osseous  walls,  and  not  unfrequently  by  other  and  more  complicated 
forms  of  disease.  But  the  closing  of  this  opening  is  oftener  an  effect 
than  a  cause  of  disease  in  this  cavity,  and  it  generally  re-establishes 
itself  without  any  assistance  of  art  after  the  cure  of  the  affection  which 
caused  it. 

If  all  the  circumstances  connected  with  the  history  of  the  diseases 
under  consideration  could  be  ascertained,  we  think  it  would  be  found 


640  DENTAL   SURGERY. 

that  these  affections  are  more  frequently  induced  by  a  morbid  condi- 
tion of  the  teeth,  gums,  and  alveolar  processes  than  any  other  cause. 
There  are,  in  fact,  no  sources  of  irritation  to  which  this  cavity  is  so 
much  and  so  often  exposed  as  those  arising  from  dental  organism.  It 
is  separated  from  the  apices  of  the  roots  of  the  superior  molars  and 
bicuspids  by  only  a  very  thin  plate  of  bone,  and  is  sometimes  even 
penetrated  by  them ;  so  that  it  could  scarcely  be  otherwise  than  that 
aggravated  and  protracted  disease  in  the  teeth  and  alveoli  should  exert 
an  unhealthy  influence  upon  it.  The  pain  occasioned  by  diseased  teeth 
is  often  very  severe,  sometimes  almost  excruciating,  and  inflammation 
in  the  alveolo-dental  periosteum  and  gums  frequently  extends  itself  to 
the  whole  of  one  side  of  the  face.  It  would  hardly  be  possible,  there- 
fore, for  this  cavity  to  escape.  Alveolar  abscess  and  sometimes  necrosis 
and  exfoliation  of  the  socket  of  the  affected  tooth  arise  from  the  in- 
flammation thus  lighted  up.  It  often  happens  that  the  gums  and  alve- 
olar periosteum  are  affected  for  years  with  chronic  inflammation  and 
other  morbid  conditions. 

If,  in  addition  to  these  facts,  other  proofs  be  necessary  to  establish 
the  agency  of  dental  and  alveolar  irritation  in  the  production  of  dis- 
ease in  the  maxillary  sinus,  they  may  be  found.  Many  of  the  affections 
here  met  with  are  often  cured  by  the  removal  of  diseased  teeth  after 
other  remedies  have  been  employed  in  vain,  and  that  without  even 
perforating  the  antrum.  This  would  not  be  the  case  if  the  irritation 
did  not  arise  as  a  consequence  of  the  dental  malady. 

Inflammation  of  the  Lining  Membrane  of  the  Maxillary  Sinus. — In- 
flammation, when  not  complicated  with  any  other  morbid  affection,  is 
the  most  simple  form  of  disease  to  which  the  pituitary  membrane  of 
the  antrum  is  subject.  As  it  precedes  and  accompanies  all  others,  it 
will  be  proper  to  offer  a  {ew  remarks  upon  it  before  entering  upon  the 
consideration  of  those  of  a  more  aggravated  nature. 

Inaccessible  as  it  is  here  to  most  of  the  acrid  and  irritating  agents  to 
which  it  is  exposed  in  the  nasal  fossae  and  some  other  cavities  of  the 
body,  it  would  rarely  become  the  seat  of  inflammation  were  it  not  for 
its  proximity  to  the  teeth  and  alveolar  border  ;  and  simple  inflamma- 
tion rarely  gives  rise  to  any  other  form  of  diseased  action,  unless 
favored  by  some  general  morbid  tendency,  but  usually  subsides  spon- 
taneously on  the  removal  of  the  exciting  cause.  In  good  constitutions 
it  is  less  subject  to  inflammation,  and  consequently  to  any  other  descrip- 
tion of  morbid  action,  than  those  in  whom  there  exists  some  vice  of 
body  or  constitutional  predisposition.  Febrile  and  gastric  affections, 
eruptive  diseases,  such  as  measles,  smallpox,  etc.,  syphilis,  and  exces- 
sive and  protracted  use  of  mercurial  medicines,  a  scorbutic  or  scroiti- 
lous  diathesis  of  the  general  system — in  short,  everything  that   lias 


DISEASES   OF   THE    ANTRUM.  641 

a  tendency  to  enervate  the  vital  powers  of  the  body,  increases  its  irri- 
tability. 

When  in  a  healthy  condition  it  secretes  a  slightly  viscid,  transparent, 
and  inodorous  fluid,  by  which  it  is  constantly  lubricated  ;  but  inflam- 
mation changes  the  character  of  the  secretion.  It  causes  it  to  become 
vitiated  ;  at  first  less  abundant,  it  is  afterward  secreted  in  larger 
quantities  than  usual,  becomes  more  serous,  and  so  acrid  as  sometimes 
to  irritate  the  membrane  of  the  nose,  over  which  it  passes  after  having 
escaped  from  the  antrum.  It  also  exhales  an  odor  more  or  less  offen- 
sive, accordingly  as  the  inflammation  is  mild  or  severe.  It  moreover 
gives  rise  to  a  thickening  of  a  membrane,  and  sometimes  to  oblitera- 
tion of  the  nasal  opening.  This  last  rarely  occurs,  but  when  it  does 
happen  an  accumulation  of  the  secretion  and  other  morbid  phenomena, 
of  which  we  shall  hereafter  treat,  result  as  a  necessary  consequence. 

If  at  any  time  during  the  continuance  of  the  inflammation  the 
patient  is  attacked  with  severe  constitutional  disease,  the  local  affec- 
tion will  be  aggravated  and  sometimes  assume  a  different  character. 

The  inflammation,  when  long  continued,  degenerates  into  a  chronic 
form,  and  is  sometimes  kept  up  for  several  years  without  giving  rise  to 
any  other  unpleasant  symptoms  than  occasional  paroxysms  of  dull  and 
seemingly  deep-seated  pain  in  the  face  and  a  vitiated  condition  of  the 
fluids  of  this  cavity.  The  slightly  fetid  odor  which  they  exhale  ceases 
to  be  annoying  or  even  perceptible  to  the  patient  when  he  becomes 
accustomed  to  it. 

Symptoms. — The  symptoms  of  inflammation  here,  though  not  always 
precisely  the  same  as  elsewhere,  are,  for  the  most  part,  very  similar. 
They  are  severe,  fixed,  and  deep-seated  pain  under  the  cheek,  extend- 
ing from  the  alveolar  border  to  the  lower  part  of  the  orbit ;  local  heat, 
pulsation,  and  sometimes  fever.  Boyer  says  these  symptoms  are  not 
always  present,  and  that  inflammation  may  exist  when  it  is  not  expected. 
Other  affections  of  the  face  and  superior  maxilla  may  be  mistaken  for 
this,  and  this  for  others  ;  but  that  inflammation  should  exist  without 
being  attended  with  pain  or  any  other  signs  indicative  of  its  presence, 
is  scarcely  probable. 

Deschamps  distinguishes  the  symptoms  of  this  from  those  of  other 
affections  of  this  cavity  by  a  dull,  heavy  pain  in  the  region  of  the  sinus, 
which,  he  says,  becomes  sharp  and  lancinating  and  extends  from  the 
alveolar  arch  to  the  frontal  sinus.  The  disease  goes  on  without  inter- 
ruption, increasing  until  the  superior  maxilla  of  the  affected  side  is 
more  or  less  involved.  This  malady,  he  says,  cannot  be  confounded 
with  any  other,  even  where  there  is  no  external  visible  cause  ;  differing 
from  a  simple  retention  of  mucus  by  being  painful  at  the  commence- 
ment, and  by  not  being  accompanied  with  swelling  of  the  bones  ;  from 
41 


642  DENTAL   SURGERY. 

polypus,  by  the  continuance  of  pain  ;  and  from  cancer,  by  the  charac- 
ter of  the  pain.  "  Suppuration  and  ulcers  have  peculiar  signs  which 
cannot  be  confounded  with  those  of  inflammation."  Pain  in  the  molar 
and  bicuspid  teeth,  accompanied  by  a  sense  of  fluctation  in  the  parts, 
he  seems  to  regard  as  a  very  certain  indication  of  inflammation,  and 
especially  when  joined  to  the  other  symptoms.  "If  an  external  cause 
is  discovered,  it  will  furnish  a  certain  diagnosis;"  he  also  mentions 
fever  and  headache  as  almost  invariable  accompaniments. 

The  inflammation,  if  not  subdued  by  appropriate  remedies,  after 
having  continued  for  a  length  of  time,  gradually  assumes  a  chronic 
form ;  the  pain  then  begins  to  diminish  and  is  less  constant ;  it  be- 
comes duller  and  is  principally  confined  to  the  region  of  the  antrum. 
The  teeth  of  the  afiected  side  cease  to  ache,  or  ache  only  at  times, 
but  still  remain  sensitive  to  the  touch.  The  mucous  membrane  of  the 
nostril  next  the  diseased  sinus  is  often  tender  and  slightly  inflamed; 
and  if  in  the  morning,  or  after  two  or  three  hours*  sleep,  the  other 
nostril  be  closed  by  pressing  upon  it  with  the  thumb  or  one  of  the 
fingers,  and  a  violent  expiration  be  made,  a  thin,  watery  fluid  of  a 
slightly  fetid  odor  will  be  discharged,  and  pain  will  be  experienced  in 
the  region  of  this  cavity. 

Causes. — All  morbid  conditions  of  the  teeth  and  gums,  causing 
irritation  in  the  alveolar  periosteal  tissue,  may  be  regarded  as  among 
the  most  frequent  of  its  exciting  causes,  especially  caries,  necrosis, 
and  exostosis  ;  also  loose  teeth,  and  the  roots  of  such  as  have  been 
either  fractured  in  an  attempt  at  extraction,  or  by  a  blow  or  fall,  and 
left  in  their  sockets,  or  that  have  remained  after  the  destruction  of 
their  crowns  by  decay.  It  sometimes  happens,  too,  that  inflammation 
is  excited  in  this  membrane  by  fractured  alveoli  ;  but  when  an  acci- 
dent of  this  sort  occurs  the  detached  portions  of  bone  are  generally 
soon  thrown  off  by  the  economy,  and,  the  cause  being  removed,  the 
inflammation  immediately  subsides.  Not  so  with  the  roots  of  the 
teeth.  They  often  remain  concealed  in  their  sockets  for  years,  unless 
removed  by  art.  Nature,  it  is  true,  makes  an  effort  to  expel  them 
from  the  jaw,  but  this  is  accomplished  only  by  a  slow  and  very  tedious 
process,  and  not,  in  many  instances,  until  they  have  given  rise  to 
some  serious  affection.  But  of  the  deleterious  effects  that  result  from 
necrosed  roots  of  teeth  in  the  alveoli  it  is  not  necessary  now  to  speak ; 
as  extraneous  bodies,  they  are  always  productive  of  more  or  less  irrita- 
tion. We  might  also  mention  exposure  to  sudden  transitions  of 
temperature  and  certain  constitutional  diseases  as  among  the  causes 
which  occasionally  give  rise  to  inflammation  of  this  membrane. 

Treatment. — The  curative  indications  of  inflammation  of  the  lining 
membrane  of  the  antrum  are  simple,  and,  for  the  most  part,  similar 


DISEASES   OF   THE   ANTRUM.  643 

to  those  of  inflammation  in  other  parts  of  the  body.  In  many  cases 
great  benefit  will  be  derived  from  the  application  of  leeches  to  the 
cheek,  as  recommended  by  Mr.  Thomas  Bell.  When  the  disease  is 
dependent,  as  in  most  cases  it  is,  upon  an  unhealthy  condition  of  the 
alveolar  processes,  the  first  thing  to  be  done  is  to  remove  all  such  teeth 
or  roots  of  teeth  as  are  productive  of  the  least  irritation  ;  for,  while 
any  local  sources  of  irritation  are  permitted  to  remain,  neither  topi- 
cal nor  general  bleeding,  or,  indeed,  any  other  treatment,  will  be  of 
permanent  advantage. 

Simple  inflammation  of  the  lining  membrane  of  the  antrum  would 
be  of  little  consequence  were  it  not  that  it  is  liable  to  give  rise  to 
other  and  more  dangerous  forms  of  disease,  such,  for  instance,  as  en- 
gorgement or  a  purulent  condition  of  its  secretions.  It  should  never, 
therefore,  be  permitted  to  continue,  but  be  as  speedily  arrested  as 
possible ;  and  for  the  accomplishment  of  this  the  means  here  pointed 
out  will,  if  timely  and  properly  applied,  be  found  fully  adequate. 

Purulent  Condition  of  the  Secretions  and  Engorgement  of  the  Antrum. 
— A  purulent  condition  ot  the  secretions  of  the  antrum  and  mucous 
engorgement  are  indiscriminately,  though  very  improperly,  denomi- 
nated by  many  writers  on  the  affections  of  this  cavity,  abscess.  To 
this  neither  bears  the  slightest  resemblance. 

There  is  no  doubt  that  a  purulent  condition  of  the  fluids  of  this  cav- 
ity is  often  complicated  with  ulceration  of  the  lining  membrane ;  but 
that  the  affection  is  different  from  abscess,  its  very  nature  and  situation 
are  sufficient  to  show. 

When  complicated  with  ulceration  of  the  mucous  membrane — and 
it  is  probable  that  a  purulent  condition  of  its  secretions,  in  most  in- 
stances, is  thus  complicated — the  affection  is  analogous  to  ozena,  and 
many  of  the  older  writers  designate  it  by  that  name.  Mr.  Bell  de- 
scribes it,  and  very  properly,  too,  as  being  similar  to  gonorrhea;  both 
diseases  alike  consist  in  an  alteration  of  secretion  ;  in  the  one  case  of 
the  pituitary  membrane,  and  in  the  other  of  the  mucous  lining  of  the 
urethra;  but  in  neither  instance  does  it  possess  any  of  the  characteris- 
tics of  abscess,  though  the  matter  in  both  is  purulent. 

It  has  been  before  stated  that  the  obliteration  of  the  nasal  opening 
was  more  frequently  an  effect  than  a  cause  of  disease  in  the  maxillary 
sinus;  it  does,  however,  sometimes  become  closed  from  other  causes 
than  an  unhealthy  condition  of  this  cavity;  when  this  happens, 
engorgement  of  the  sinus  is  the  inevitable  consequence.  The  fluids 
thus  accumulated  are  not  always  at  first  purulent,  although  they  may 
subsequently  become  so  ;  when  the  closing  of  the  opening  is  the  result 
of  previous  disease  in  the  antrum,  the  secretions  are  more  or  less 
altered  from  the  very  first. 


644  DENTAL   SURGERY. 

Accumulation  of  any  secretion  within  the  antrum,  whether  of  mucus 
or  pus,  is  a  source  of  irritation  to  the  lining  membrane,  and  the  pres- 
sure which  it  ultimately  exerts  upon  the  surrounding  walls  causes  a  new 
form  of  diseased  action,  which  not  unfrequently  involves  in  disease  all 
the  bones  of  the  face  as  well  as  those  of  the  base  of  the  cranium. 
When  prevented  from  escaping  through  the  nasal  opening,  the  secretion 
eventually  makes  for  itself  a  way  of  escape — sometimes  through  the 
cheek ;  at  other  times  beneath  it,  just  above  the  alveolar  ridge ;  or 
through  the  palatine  arch  or  alveoli  by  the  sides  of  the  roots  of  one  or 
more  of  the  teeth ;  and  from  a  fistula  thus  established,  fetid  matter  will 
be  almost  constantly  discharged.  From  openings  of  this  sort  the  mat- 
ter is  sometimes  discharged  for  years,  while  the  disease  in  the  antrum, 
very  frequently,  does  not  seem  to  undergo  any  apparent  change.  At 
other  times  the  membrane  ulcerates  and  the  bony  walls  become  carious. 

A  purulent  secretion  from  the  mucous  membrane  of  this  cavity,  in- 
dependently of  caries  of  the  bone,  or  even  of  simple  fistulous  openings, 
is  an  exceedingly  troublesome  and  unpleasant  affection.  The  odor 
from  the  matter  is  often  very  annoying,  even  to  the  patient,  and  when 
the  secretions  are  retained  for  some  days  in  the  sinus  before  they  escape, 
the  fetor  is  almost  insufferable. 

In  good  constitutions  the  secretions  of  the  antrum  are  not  so  liable 
to  become  purulent,  though  they  be  confined  for  a  long  time  in  the 
cavity,  and  thus  become  more  or  less  offensive.  Inflammation  of  the 
lining  membrane  (the  immediate  or  proximate  cause)  may  exist  for 
years  without  giving  rise  to  it.  It  is  only  in  scrofulous,  scorbutic,  or 
debilitated  habits  that  they  are  liable  to  become  thus  altered.  The 
difference  in  the  effects  produced  upon  them  and  the  surrounding  parts 
by  inflammation,  is  owing  to  the  difference  in  the  state  of  the  consti- 
tutional health  of  those  affected  with  it. 

Where  a  puriform  state  of  the  secretions  is  complicated  with  ulcer- 
ation of  the  membrane,  the  matter  will  have  mixed  with  it  a  greater 
or  less  quantity  of  flocculi,  sometimes  of  so  firm  a  consistence  as  to 
block  up  the  nasal  opening  and  prevent  its  exit.  Mr.  Thomas  Bell 
says  he  has  seen  more  than  one  case  in  which  a  considerable  accumu- 
lation had  taken  place  in  the  antrum,  accompanied  by  the  usual  indi- 
cation of  this  affection  (muco-purulent  engorgement  of  the  sinus), 
when  a  sudden  discharge  of  the  contents  into  the  nose  took  place, 
"  in  consequence  of  the  pressure  having  overcome  the  resistance  which 
had  thus  been  offered  to  its  escape."  Cases  of  a  very  similar  nature 
have  fallen  under  our  observation,  the  history  of  one  of  which  will  be 
given  in  the  course  of  this  chapter.  The  formation  of  these  flocculi 
rarely  ceases,  except  with  the  cure  of  the  ulcers  on  the  membrane. 
They  give  rise  to  considerable  irritation,  and  their  presence  always 


DISEASES    OF    THE    ANTRUM.  645 

constitutes  an  obstacle  to  the  cure.  They  are  usually  removed  by 
injections. 

The  pituitary  membrane  of  the  antrum,  when  in  a  healthy  state, 
secretes,  as  we  have  before  stated,  a  transparent,  slightly  viscid,  and 
inodorous  fluid,  poured  out  only  in  sufficient  quantity  to  lubricate  the 
cavity.  But  when  inflammation  is  excited  in  the  membrane,  its  secre- 
tions soon  become  more  abundant,  and  are  at  first  thinner,  afterward 
thicker  and  more  glutinous.  Their  color  and  consistence  are  not 
always  the  same  :  instead  of  being  transparent,  they  sometimes  have  a 
dirty,  opaque  appearance  ;  at  other  times  they  assume  a  greenish, 
whitish,  or  yellowish  color,  and  in  some  instances  they  bear  a  consider- 
able resemblance  to  pus,  which,  it  has  been  conjectured,  might  be 
owing  to  suppuration  of  some  of  the  mucous  follicles  and  a  mixture  of 
pus  with  its  secretions.  Mr.  Thomas  Bell,  however,  inclines  to  the 
opinion  that  it  is  attributable  to  an  "  alteration  simply  "  of  the  secre- 
tions of  the  cavity.  Their  color  and  consistence  are  determined  by 
the  degree  of  inflammation  ;  the  length  of  time  it  has  existed ;  the 
state  of  the  health  of  the  lining  membrane,  and  that  of  the  surrounding 
osseous  walls  ;  the  egress  which  the  matter  has  from  the  sinus  ;  and 
the  general  habit  of  the  body. 

Affections  of  this  sort  are  more  common  to  young  subjects  than  to 
middle-aged  or  persons  in  advanced  life.  An  eminent  French  writer 
says  that  of  three  individuals  affected  with  dropsy  (mucous  engorge- 
ment), the  oldest  was  not  twenty  years  of  age. 

Symptoms. — The  diagnoses  of  the  several  affections  of  the  antrum 
are  so  much  alike,  that  it  is  often  difficult  to  distinguish  those  that 
belong  to  one  from  those  attendant  upon  another.  The  symptoms  of 
mucous  engorgement  and  purulent  accumulation,  however,  are  gene- 
rally such  as  will  enable  the  practitioner  to  distinguish,  with  consider- 
able certainty,  these  from  other  affections.  They  are  always  preceded 
by  inflammation  of  the  lining  membrane  ;  a  description  of  the  symp- 
toms of  which,  having  already  been  given,  need  not  be  repeated. 
Omitting  these,  we  at  once  proceed  to  mention  those  by  which  they  are 
accompanied. 

In  speaking  of  the  symptoms  more  particularly  belonging  to  a 
purulent  condition  of  the  secretions  of  the  antrum,  Deschamps  says 
the  affection  may  be  distinguished  by  dull,  heavy  pain,  extending 
along  the  alveolar  border.  Upon  this  symptom  alone  little  reliance 
can  be  placed,  as  it  is  always  present  in  chronic  inflammation.  In 
■addition  to  this  he  mentions  the  presence  of  decayed  teeth ;  soreness 
in  those  that  are  sound ;  and,  on  the  patient's  inclining  his  head  to 
the  side  opposite  to  the  one  affected,  the  discharge  of  fetid  matter 
from   the   nose.     These  are  very  conclusive  indications  of  purulent 


646  DENTAL   SURGERY. 

effusions  in  this  cavity.  Bordenave,  after  enumerating  the  symptoms 
indicative  of  inflammation,  mentions  the  following  as  belonging  t^^  the 
affection  of  which  we  are  now  speaking  :  dull  and  constant  pain  in  the 
sinus,  extending  from  the  maxillary  fossae  to  the  orbit  ;  a  discharge  of 
fetid  matter  from  the  nose,  when  the  patient  inclines  his  head  to  the 
opposite  side,  or  when  the  nose  is  blown  from  the  nostril  of  the  affected 
side.  These  symptoms  are  mentioned  by  almost  every  writer  upon  the 
subject,  as  indicative  of  a  purulent  condition  of  the  secretions  of  the 
maxillary  sinus. 

The  symptoms  of  engorgement  differ  materially  from,  those  which 
denote  simply  a  purulent  condition  of  the  mucous  secretions.  The 
pain,  instead  of  being  dull  and  heavy,  as  just  described,  becomes  acute, 
and  a  distressing  sense  of  fullness  and  weight  is  felt  in  the  cheek,  ac- 
companied by  redness  and  tumefaction  of  the  integument  covering  the 
antrum.  The  nasal  opening  having  become  closed,  the  fluids  of  the 
cavity  gradually  accumulate  until  they  fill  it;  when,  finding  no  egress, 
they  press  upon  and  distend  the  surrounding  osseous  walls,  causing  those 
parts  which  are  the  thinnest  ultimately  to  give  way.  The  effects  are 
generally  first  observable  anteriorly  beneath  the  malar  prominence, 
where  a  smooth,  hard  tumor  presents  itself,  covered  with  the  mucous 
membrane  of  the  mouth.  But  this  is  not  always  the  point  which  first 
gives  way  ;  the  sinus  sometimes  bursts  into  the  orbit,  at  other  times  out- 
wardly through  the  cheek,  or  through  the  palatine  arch.  The  long- 
continued  pressure  thus  exerted  upon  the  bony  walls  often  causes  the 
breaking  down  or  softening  of  their  tissues. 

The  tumor,  which  is  at  first  hard,  becomes  in  a  short  time  so  soft  as 
readily  to  yield  to  pressure.  A  distention,  Deschamps  says,  may  be 
distinguished  from  other  diseases  that  affect  the  skin  or  subcutaneous 
tissues  by  the  uniformity  or  regularity  of  the  tumor,  its  firmness  at  the 
commencement,  the  slowness  with  which  it  progresses,  and,  above  all, 
by  the  natural  appearance  of  the  skin,  and  the  absence  of  pain  when 
pressure  is  made  upon  the  tumor.  Obliteration  of  the  nasal  opening, 
he  says,  may  be  suspected  by  the  dryness  of  the  nostril  of  the  affected 
side,  the  mucous  membrane  of  which  becomes  thickened  and  the  cavity 
contracted,  inflammation  and  sponginess  of  the  gums,  loosening  and, 
sometimes,  in  consequence  of  the  destruction  of  their  sockets,  displace- 
ment of  the  teeth,  may  also  be  mentioned  as  occasional  accompani- 
ments of  engorgement. 

Causes. — Inflammation  of  the  mucous  membrane  is  the  cause  of  a 
purulent  condition  of  the  secretions  of  the  maxillary  sinus,  and  this 
arises  more  frequently  from  peridental  irritation  than  from  any  par- 
ticular habit  of  body  or  constitutional  disturbance.  Engorgement 
results  from  the  obliteration  of  the  nasal  opening,  which,  in  the  case  of 


DISEASES   OF   THE    ANTRUM.  647 

altered  secretion,  is  usually  caused  by  inflammation  and  thickening  of 
the  lining  membrane. 

Treatment. — The  curative  indications  of  muco-purulent  secretion 
and  engorgement  of  the  maxillary  sinus  are,  firstly,  if  the  nasal  open- 
ing be  closed,  the  evacuation  of  the  retained  matter ;  secondly, 
the  removal  of  all  local  and  exciting  causes  of  irritation  ;  thirdly, 
and  lastly,  the  restoration  of  the  lining  membrane  to  its  normal 
function. 

For  the  fulfillment  of  the  first  an  opening  must  be  made  into  the 
antrum,  and  this  should  be  effected  in  that  part  which  will  afford  the 
most  easy  exit  to  the  retained  matter.  Several  ways  have  been  pro- 
posed for  the  accomplishment  of  this  object ;  and  before  we  proceed 
further,  it  may  not  be  amiss  to  notice  some  of  the  various  methods 
that  have  been  adopted  by  different  practitioners. 

With  regard  to  the  tooth  most  proper  to  be  extracted,  authors  differ. 
Cheselden  preferred  the  first  or  second  molar.  Junker  recommended 
the  extraction  of  the  first  or  second  bicuspid,  and  if  a  fistula  had 
formed,  to  enlarge  it  instead  of  perforating  the  floor  of  the  antrum. 
But  the  second  molar,  being  directly  beneath  the  most  dependent  part 
of  the  cavity,  is  the  most  suitable  tooth  to  be  removed.  If  this  be 
sound,  the  first  or  third  molar,  or  either  of  the  bicuspids,  if  carious, 
may  be  extracted  in  its  stead,  and,  in  fact,  no  tooth  beneath  the  an- 
trum in  an  unhealthy  condition  should  be  permitted  to  remain. 
Heath  recommends  the  extraction  of  the  first  molar  on  account  of 
the  depth  of  its  socket,  and  because  it  is  more  liable  to  decay  than 
any  of  the  other  teeth. 

An  opening  having  been  effected  through  the  palatine  cavity  of  a 
molar  tooth  into  the  antrum,  it  should  be  kept  open  until  the  health 
of  the  cavity  is  restored.  For  this  purpose,  a  sound,  bougie,  or  cannula 
adapted  to  the  purpose  may  be  introduced. 

When  the  natural  opening  is  closed,  the  first  indication,  as  has  been 
stated,  is  the  evacuation  of  the  matter ;  and  for  this  purpose  a  perfor- 
ation should  be  made  into  the  sinus,  and  the  most  proper  place  for 
effecting  this,  it  has  been  shown,  is  through  the  alveolar  cavity  of  the 
second  molar.  It  may,  however,  be  penetrated  from  that  of  either  of 
the  other  molars  or  bicuspids. 

The  perforation,  after  the  extraction  of  the  tooth,  is  made  with  a 
straight  trocar,  which  will  be  found  more  convenient  than  those 
usually  employed  for  the  purpose.  The  point  of  the  instrument,  hav- 
ing been  introduced  into  the  alveolus  through  which  it  is  intended  to 
make  the  opening,  should  be  pressed  against  the  bottom  of  the  cavity  in 
the  direction  toward  the  center  of  the  antrum.  A  few  rotary  motions 
of  the  instrument  will  suffice  to  pierce  the  intervening  plate  of  bone. 


648  DENTAL    SURGERY. 

Fig.  608  represents  trephines  for  opening  the  antrum,  either  through 
the  palatine  cavity  of  a  second  or  first  molar,  or  through  the  alveolus 
between  these  two  teeth. 

If  the  first  opening  be  not  sufficiently  large,  its  dimensions  may  be 
increased  to  the  necessary  size  by  means  of  a  spear-pointed  instru- 
ment. The  entrance  is  usually  attended  with  a  momentary  severe 
pain,  and  the  withdrawal  of  the  instrument  followed  by  a  sudden  gush 
of  fetid  mucus.  In  introducing  the  trocar,  care  should  be  taken  to 
prevent  a  too  sudden  entrance  of  the  instrument  into  the  cavity. 
Without  this  precaution  it  might  be  suddenly  forced  against  the  oppo- 
site wall.  It  is  not  always  necessary  to  perforate  the  floor  of  the 
antrum  after  the  extraction  of  the  tooth ;  it  occasionally  happens,  as 
has  already  been  remarked,  that  some  of  the  alveolar  cavities  com- 
municate with  it. 

An  opening  having  thus  been  eff'ected,  it  should  be  prevented  from 
closing  until  a  healthy  action  is  established  in  the  lining  membrane, 
and  for  this  purpose  a  bougie,  or  leaden  or  silver  cannula,  or, 
still  better,  a  small  metal  plate,  fitted  by  impression  and 
dies  to  the  portion  of  the  ridge  about  the  opening,  with  a 
small  tube  attached  to  fill  the  aperture,  to  facilitate  the 
flow  of  matter,  and  for  syringing,  and  as  preventive  of  the 
premature  closure  of  the  opening,  may  be  inserted  and 
secured  to  one  of  the  adjacent  teeth.  It  should,  how- 
ever, be  removed  for  the  evacuation  of  the  secretions  at 
least  twice  a  day.  The  formation  of  an  opening  at  the 
base  or  most  dependent  part  of  the  sinus  will,  in  those  cases  where 
a  fistula  has  been  previously  formed,  be  followed  in  most  instances 
by  speedy  restoration.  Having  proceeded  thus  far,  the  cure  will  be 
aided  by  the  employment  of  such  general  remedies  as  may  be  indi- 
cated by  the  state  of  the  general  health  ;  and  for  the  dispersion  of 
the  local  inflammation,  leeches  to  the  gums  and  cheeks  will  be  found 
serviceable.  The  antrum  may,  in  the  meantime,  be  injected  with,  at 
first,  some  mild  or  bland  fluid,  and  afterward  with  gently  stimulating 
liquids.  Diluted  port  wine,  weak  solutions  of  the  sulphate  of  zinc 
and  rose-water,  sulphate  of  copper  and  rose-water,  or  permanganate  of 
potash,  answer  admirably,  especially  the  latter,  in  the  proportion 
of  two  grains  to  the  ounce  of  water.  Diluted  tincture  of  myrrh  may 
sometimes  be  advantageously  employed,  and  when  the  membrane  is 
ulcerated,  a  solution  of  nitrate  of  silver  will  be  highly  serviceable. 
The  author  has  used  a  solution  of  iodid  of  potassium  with  advantage, 
also  a  weak  alcoholic  solution  of  tannic  acid  and  diluted  tincture  of 
iodin.  After  the  use  of  the  permanganate  of  potash,  a  carbolic  solu- 
tion, 3J  to  water,  ,^viij,  or  the  antiseptic  preparation,  listerine,  may 


DISEASES    OF   THE    ANTRUM.  649 

be  used  as  an  injection  with  decided  benefit.  The  injection  of  a 
warm  solution  of  salt  and  water  is  highly  recommended  as  a  prepara- 
tory step  before  making  use  of  the  permanganate  of  potash  and  the 
carbolic  solution.  For  correcting  the  fetor  of  the  secretions,  a  weak 
solution  of  chlorinated  soda  or  lime,  or  a  solution  of  permanganate 
of  potash  may  be  occasionally  injected  into  the  antrum. 

In  cases  of  simple  muco-purulent  secretion,  a  weak  decoction  of 
galls  may  be  injected  into  the  sinus  with  advantage.  Injections  of  a 
too  stimulating  nature  are  sometimes  employed.  This  should  be  care- 
fully guarded  against  by  making  them  at  first  weak,  and  afterward  in- 
creasing their  strength  as  occasion  may  require ;  and  if  symptoms 
of  a  violent  character  are  by  this  means  produced,  they  should  be 
combated  by  applying  leeches  to  the  gums  and  fomentations  to  the 
cheek. 

Dependent  as  these  affections  in  most  instances  are  upon  local  irri- 
tants, greater  reliance  is  to  be  placed  upon  their  removal  and  giving 
vent  to  the  acrid  puriform  fluids,  than  on  any  therapeutical  effects 
exerted  upon  the  cavity  by  injections.  As  adjuvants  they  are  service- 
able, but  cure  cannot  be  effected  while  the  exciting  cause  remains  un- 
removed. 

Dr.  Frank  Abbott  recommends  a  thorough  washing  out  of  the 
antrum,  immediately  after  an  opening  is  made  into  it,  with  a  warm 
solution  consisting  of  a  teaspoonful  of  salt  to  half  a  pint  of  water, 
injected  with  slight  force,  and  if  there  is  still  an  offensive  odor,  to 
syringe  with  the  permanganate  of  potash  solution  ;  then  with  the  car- 
bolic solution  or  with  listerine  ;  and  as  a  dressing,  to  be  renewed  daily, 
carbolized  oil  (i  part  of  carbolic  acid  to  15  parts  of  oil  of  sweet 
almonds)  on  cotton,  so  applied  that  it  maybe  retained  in  the  antrum, 
and  secured  by  attaching  it  to  a  tooth  or  to  a  plate  worn  in  the  mouth. 
If  no  improvement  is  apparent  after  two  or  three  days,  the  antrum  is 
to  be  syringed  with  a  solution  consisting  of  one  dram  of  carbolic 
acid,  I  ounce  of  tincture  of  iodin,  and  8  ounces  of  water ;  and  in 
some  cases  with  a  more  powerful  stimulant,  such  as  10  grains  of  chlo- 
rid  of  zinc  to  i  ounce  of  water.  For  systemic  treatment  he  recom- 
mends sulphid  of  calcium,  one-tenth  of  a  grain  pill  three  times  a  day 
after  meals,  doubling  the  dose  if  necessary. 

Epithelioma  of  the  antrum  is  a  malignant  form  of  tumor  which  fills 
this  cavity,  destroying  the  walls  and  also  the  hard  palate.  A  cancer- 
ous, mushroora-like  formation  sometimes  attaches  itself  to  the  roof  of 
the  mouth.  It  may  involve  much  surface  before  its  true  character  is 
discovered,  and  it  is  very  difficult  to  remove.  In  some  cases  the  jaw 
must  be  removed,  while  in  others,  especially  if  the  character  of  the 
disease  is  easily  determined,  a  free  opening  must  be  made  and  the  can- 


650  DENTAL   SURGERY. 

cerous   tissue   scraped   away,   followed    by    repeated   applications   of 
chlorid  of  zinc  or  other  strong  escharotics. 

For  other  tumors,   etc.,   of  the  antrum,   the  reader  is  referred  to 
"Tumors  of  the  Mouth." 


CHAPTER  X. 

CARIES  OF  THE  MAXILLARY  BONES. 

Caries  of  the  maxillae,  like  necrosis,- is  not  a  very  common  disease, 
and  differs  from  the  latter  in  being  analogous  to  ulceration  in  the  soft 
parts,  and  in  being  free  from  the  odor,  when  cleanliness  is  observed, 
which  characterizes  necrosis. 

The  symptoms  of  caries  of  bone  resemble  those  of  alveolar  abscess, 
and  when  the  acute  form  of  the  disease  is  present  it  is  associated  with 
inflammation  of  the  gums  and  peridental  membrane  ;  periodontitis 
being  early  manifested  when  the  carious  condition  of  the  bone  results 
from  diseased  teeth.  When  caries  of  the  maxillae  is  well  established, 
one  or  more  fistulous  openings  exist  in  the  gum  or  in  some  adjacent 
part;  these  openings  being  surrounded,  in  the  majority  of  cases,  by 
fungous  granulations.  The  bone  beneath  is  full  of  minute  cells,  and 
is  of  a  soft  consistence — a  condition  readily  detected  by  the  probe  or 
an  excavator,  and  differing  very  materially  from  the  solid,  resisting 
structure  presented  by  bone  when  in  a  normal  condition.  Commencing 
like  ordinary  periostitis,  there  is  present,  in  the  early  stage,  increased 
vascularity  and  congestion,  which  terminates  in  ulceration;  the  bone 
cells  becoming  enlarged  by  the  breaking  down  of  their  walls,  and  filled 
with  semi-organized  lymph,  the  accumulation  of  which  is  attended 
with  a  rapid  advance  of  the  destructive  process.  The  numerous  irreg- 
ular cavities  existing  in  the  bone  are  lined  by  a  glazed  secreting  sur- 
face. According  to  Virchow,  "the  bone  breaks  up  in  its  territories, 
the  individual  corpuscles  underg®  new  developmental  changes  (granu- 
lation and  suppuration),  and  remnants  composed  of  the  oldest  basis 
substance  remain  in  the  form  of  small,  thin  shreds  in  the  midst  of  the 
soft  substance.  In  ossification  (in  cartilage)  there  is  a  portion  of  the 
original  intercellular  substance  of  the  cartilage  cells  (secondary  cells), 
which,  though  it  belongs  to  the  group  as  a  whole,  yet,  when  these,  in 
the  course  of  ossification,  are  transformed  into  a  number  of  isolated 
bone  cells,  becomes,  comparatively  speaking,  almost  entirely  indepen- 
dent of  those  cells  individually,  and  therefore  escapes  the  changes 
which  befall  them." 


CARIES    OF    THE    MAXILLARY    BONES.  65 1 

It  is  this  portion  which  remains  behind  the  caries,  while  the  sec- 
ondary intercellular  substance  perishes.  "At  the  moment  a  periosteal 
tissue  quits  the  surface  of  a  bone,  and  the  vessels  are  drawn  out  from 
the  cortex  in  inflammatory  condition,  we  see,  not  as  in  normal  bone, 
mere  threads,  but  little  plugs,  thicker  masses  of  substance;  and  if  they 
have  been  entirely  drawn  out,  there  remains  a  disproportionately  large 
hole,  much  more  extensive  than  it  would  be  under  normal  circum- 
stances. On  examining  one  of  these  plugs  you  will  find  that  around 
the  vessel  a  certain  quantity  of  soft  tissue  lies — the  cellular  elements 
of  which  are  in  a  state  of  fatty  degeneration.  At  the  spot  where  the 
vessel  has  been  drawn  out  the  surface  does  not  appear  even,  as  in  nor- 
mal bone,  but  rough  and  porous ;  and  when  placed  under  the  micro- 
scope you  remark  those  excavations,  those  peculiar  holes,  which  cor- 
respond to  the  liquefying  bone  territories.  If  it  be  asked,  therefore, 
in  what  way  bone  becomes  porous  in  the  early  stage  of  caries,  it  may 
be  said  that  the  porosity  is  certainly  not  due  to  the  formation  of 
exudations,  seeing  that  for  these  there  is  no  room,  inasmuch  as  the  ves- 
sels within  the  medullary  canals  are  in  immediate  contact  with  the 
osseous  tissue.  On  the  contrary,  the  substance  of  the  bone  in  the  cel- 
lular territories  liquefies;  vacuities  form,  which  are  first  filled  with  a 
soft  substance  composed  of  a  slightly  streaky  connective  tissue,  with 
fatty  degenerated  cells.  The  whole  process  is  a  degenerative  ostitis, 
in  which  the  osseous  tissue  changes  its  structure,  loses  its  chemical  and 
morphological  character,  and  so  becomes  a  soft  tissue,  which  no  longer 
contains  lime." 

Causes. — In  the  early  stages  of  caries  of  the  maxillae,  there  is  nothing 
to  distinguish  it  from  periodontitis;  and  although  the  causes  of  this 
disease  are  various,  yet  one  of  the  most  common  is  the  presence  of  dead 
teeth  and  roots  of  teeth,  and  the  superior  maxilla  is  much  more  prone  to 
its  attacks  than  the  inferior,  and  especially  where  the  bone  is  of  a  loose, 
spongy  character,  as  in  the  strumous  and  mercurial  diathesis.  In  cases 
of  ulceration  and  extensive  destruction  of  the  tissues  of  the  face,  re- 
sulting from  syphilis  or  lupus,  the  maxillary  bones  may  become  carious, 
and  terrible  deformity  follow,  as  in  cases  where  it  commences  in  the 
palate,  and,  destroying  it,  makes  a  common  cavity  of  the  mouth  and 
nose  and  involves  the  face. 

Treati7ient. — In  the  early  stage  of  the  acute  form  of  caries  of  the 
bones  of  the  jaws,  such  antiphlogistic  remedies  as  cathartics,  diapho- 
retics, hot  foot  baths,  leeches,  and  counter-irritants  may  be  resorted  to. 
If  a  diseased  tooth  or  teeth  give  rise  to  the  inflammation,  such  should 
be  removed  if  they  cannot  be  successfully  treated.  Blood  taken  from 
the  arm,  and  also  dry  cups,  are  often  serviceable.  If  a  depraved  con- 
dition of  the  system  is  present,  as  is  frequently  the  case,  the  disease 


652  DENTAL   SURGERY. 

being  of  an  asthenic  type,  such  constitutional  remedies  as  iron,  quinin, 
cod-liver  oil,  and  like  tonics  are  indicated ;  and  when  the  caries  is 
established,  injections  of  aromatic  sulphuric  acid  in  full  strength,  or 
the  official  sulphuric  acid,  one  part  to  six  or  eight  parts  of  water,  or, 
when  required,  in  equal  parts,  will  dissolve  the  carious  bone,  relieve  the 
irritation  caused  by  its  presence,  and  hasten  the  cure,  having  a  stimu- 
lant effect  upon  diseased  tissues,  and  exerting  an  antiseptic  influence. 
Listerine  may  also  be  employed  for  its  antiseptic  properties  in  conjunc- 
tion with  the  aromatic  sulphuric  acid,  no  other  remedy  proving  so 
satisfactory  in  the  treatment  of  this  disease  as  the  latter  agent.  Other 
agents  in  the  form  of  injections  have  also  been  recommended,  such  as 
carbolic  acid  solution,  tincture  of  iodin,  compound  tincture  of  capsi- 
cum, and  chlorid  of  zinc. 

The  removal  of  the  carious  bone  is  often  necessary  by  such  appli- 
ances as  rose-head  drills,  made  for  the  purpose  and  operated  by  the 
dental  engine,  chisels,  etc. 

An  incision  is  first  made  to  expose  the  bone,  and  the  carious  portion 
is  then  cut  away  with  the  rose-head  drill  or  chisel,  causing  but  little 
pain,  until  normal  structure  is  reached,  which  is  easily  distinguished 
by  the  difference  in  touch  of  the  instrument.  Comparatively  slight 
hemorrhage  occurs,  as  a  general  rule,  and  it  is  readily  controlled  by 
such  styptics  as  a  saturated  solution  of  chlorid  of  zinc,  Monsel's  powder, 
or  compression  by  means  of  hot  sponges.  In  employing  injections  in 
the  treatment  of  well-established  caries  of  bone,  great  benefit  results 
from  the  preparatory  cleansing  of  the  parts  with  warm  water,  and  its 
use  should  never  be  omitted. 


PART   FOURTH. 


MECHANICS.— DENTAL   PROSTHESIS. 


MECHANICS. 


This  branch  of  dental  science  teaches  the  art  of  replacing  lost 
organs  of  the  Mouth,  or  any  lost  parts  thereof.  It  is  now  generally 
called  Dental  Prosthesis  (replacement).  Mechanical  detail  is  its  pre- 
vailing feature;  substitution  or  replacement  is  its  distinctive  pecu- 
liarity. 

Mechanical  detail  also  distinguishes  the  Surgery  of  dentistry  as 
compared  with  general  surgery ;  but  as  a  branch  of  dentistry,  thera- 
peusis,  or  the  arrest  of  disease,  is  its  distinctive  peculiarity. 

The  one  treats  disease  or  irregularity  of  the  natural  organs  ;  the 
other  substitutes  their  loss  by  artificial  ones.  Both  demand  a  skillful 
training  of  the  hands,  and  equally  require,  for  their  fullest  develop- 
ment, all  the  knowledge  comprehended  under  the  term  Dental  Science. 

Dental  Prosthesis  includes  the  laws  and  principles  which  determine 
and  regulate  the  processes  employed  in  the  construction  of  all  forms 
of  dental  mechanism  ;  also  the  properties  and  relations  of  all  mate- 
rials used  in  these  processes.     It  gives  rules  for  the  replacement  of — 

1.  Lost  teeth. 

2.  Lost  alveoli,  or  parts  thereof. 

3.  Lost  palate,  hard  and  soft,  or  parts  thereof. 

The  first  division  is  the  most  important,  because  the  most  univer- 
sally demanded. 

The  following  is  the  order  of  operations  in  the  Replacement  op 
Lost  Teeth  and  classification  of  the  various  styles  of  work: — 

1.  Preparation  of  the  mouth  ;  including 
{a)  Treatment  of  the  mucous  membrane. 

(<^)  Extraction  or  treatment  of  teeth  and  roots. 

2.  Impression  of  the  mouth  ;  including 

{a)  Form  and  material  of  impression  cups. 
(^)  Description  of  impression  materials. 
(<r)  Selection  and  manipulation  of  the  same. 
(d)  Preparation  for  the  model. 

3.  The  plaster  model ;  including 

(a)  General  directions  for  making  model. 
(F)  Special  forms  adapted  to  subsequent  uses. 
(/)  Removal  from  impression. 

(^)  Preparation  for  the  operation  of  making  the  plate. 

655 


656  MECHANICS — DENTAL   PROSTHESIS. 

4.  The  base-plate ;  which  is  either 

Qa)  Permanent,  in  swaged  work,  or 

(3)  Temporary,  in  plastic  work. 
The  subsequent  operations  differ  in  their  order   and  character  so 
widely  as  to  require  a  separate  classification  in 

(A)  Swaged  work  : — 

(i)  Metallic  die  and  counter-die,  made  by 
(a)  Sand  molding ; 
(/5)  Dipping,  or  pouring  ; 
(r)  Fusible  metal  process,  or  by 
(</)  Pouring  directly  into  the  impression. 

(2)  Refining  and  rolling  plate. 

(3)  Swaging  plate  (gold,  silver,  platinum,  or  aluminum). 

(4)  Articulating  impressions. 

(5)  Adjustment  on  articulator. 

(6)  Selection  and  fitting  of  teeth,  and 

(7)  Attaching  them  to  base-plate,  by 
(a)  Soldering  ; 

((5)  Vulcanite;  Celluloid; 
(<:)  Porcelain  continuous  gum. 

(8)  Finishing  process. 

(B)  Plastic  work  :  — 

(i)  Temporary  plate  of 
(a)  Wax,  or  gutta-percha ; 
(^)  Thick  tin,  or  lead,  foil. 

(2)  Articulating  impressions. 

(3)  Adjustment  on  articulator. 

(4)  Selection  and  fitting  of  teeth. 

(5)  Preparation  of  the  matrix. 

(6)  Molding  and  hardening  of  the  base-plate,  made  of 
(a)  Vulcanite  compounds,  which  harden  by  heat ; 
((^)  Celluloid  compounds,  which  harden  by  heat ; 

(<:)  Molten  tin  and  other  alloys,  which  harden  on  cooling; 
(dT)  Molten  and  swaged  aluminum  ; 

(7)  Which  process  at  the  same  time  attaches  the  teeth. 

(8)  Finishing  process. 

The  details  of  Swaged  work  vary  according  to  the  mode  of  making 
dies,  the  metal  chosen  for  the  plate,  and  the  manner  of  attaching  the 
teeth  ;  but  the  order  of  operations  is  the  same.  The  details  of  Plastic 
work  vary  also,  according  to  the  material  composing  the  plate ;  but 
the  order  of  operations  is  the  same — differing  from  the  former  mainly 
because  articulation  follows  the  formation  of  the  base-plate  in  one 
case,  while  in  the  other  it  precedes  it. 


DENTAL    PROSTHESIS.  657 

These  differences  in  the  material  of  the  base-plate  give  rise  to  a 
classification  of  Swaged  work  into 

1.  Gold  plate ; 

2.  Aluminum  plate  ; 

3.  Platinum  plate. 

The  first  (and  third)  allows  attachment  of  the  teeth  by  soldering  ; 
the  second  demands  a  vulcanite  attachment ;  the  third  alone  permits, 
by  virtue  of  its  resistance  to  furnace  heat,  the  addition  of  a  continuous 
porcelain  gum. 

Plastic  work  is  divided  into 

1.  Vulcano-plastic ; 

2.  Cellulo-plastic ; 

3.  Metallo-plastic ; 

4.  Ceramo-plastic ; 

The  first  is  known  as  rubber  work ;  the  second  is  known  as  celluloid 
work;  the  third  includes  cheoplastic work,  the  old-fashioned  block-tin 
base,  all  tin  alloys  and  cast  aluminum,  etc.  ;  the  fourth  is  known  as 
the  porcelain  base. 

In  Prosthetic  dentistry,  swaged  work  is  the  patrician  element ; 
plastic  work  the  plebeian.  When  the  latter  runs  riot,  without  the 
conservative  influence  of  the  former,  the  power  of  the  people  be- 
comes a  power  for  evil.  This  is  precisely  the  danger  which  now 
threatens  dentistry,  in  the  abuse  of  certain  most  valuable  processes  and 
materials. 

Facility  of  construction  and  cheapness  of  material  have  encouraged 
a  style  of  practice  in  the  highest  degree  detrimental  to  the  profession. 
If  such  practice  is  inseparable  from  plastic  work,  it  should  be  un- 
hesitatingly abandoned  by  every  one  who  holds  the  honor  of  dentistry 
dear  to  him.  It  becomes,  also,  a  grave  question  how  far  the  present 
mania  for  patents  (another  abuse  of  a  valuable  privilege)  is  beneficial 
to  the  reputation  of  a  liberal  profession. 


CHAPTER  I. 
DENTAL  PROSTHESIS. 


Contributing,  as  the  teeth  do,  to  the  beauty  and  expression  of  the 
countenance,  to  correct  enunciation,  and,  through  improved  facility 
of  mastication,  to  the  health  of  the  whole  organism,  it  is  not  surpris- 
ing that  their  loss  should  be  considered  a  serious  affliction,  and  that 
art  should  be  called  upon  to  replace  such  loss  with  artificial  substitutes. 
42 


658  MECHANICS — DENTAL    PROSTHESIS. 

So  great,  indeed,  is  the  liability  of  the  human  teeth  to  decay,  and  so 
much  neglected  are  the  means  of  their  preservation,  that  few  persons 
at  the  present  day  reach  even  adult  age  without  losing  one  or  more  of 
these  invaluable  organs.  Happily  for  suffering  humanity,  they  can 
now  be  replaced  with  artificial  substitutes  so  closely  resembling  the 
natural  organs  as  to  be  readily  mistaken  for  them,  even  by  critical  and 
practiced  observers.  Although  there  is  a  perfection  in  the  work  of 
nature  that  can  never  be  equaled  by  art,  artificial  teeth  are  now  so 
constructed  as  to  subserve,  at  least  to  a  great  extent,  the  purposes  of 
the  natural  organs.  When  properly  adjusted,  they  are  worn  without 
the  slightest  discomfort ;  so  much  so,  in  many  cases,  that  the  patient, 
after  they  have  been  in  the  mouth  a  few  weeks,  is  scarcely  conscious  of 
their  presence. 

The  construction  of  artificial  teeth  is  an  operation  which,  though 
acknowledged  to  be  of  great  importance,  and  performed  by  every 
one  having  any  pretension  to  a  knowledge  of  dentistry,  is,  unfortu- 
nately, but  little  understood  by  the  majority  of  practitioners.  The 
mouth  is  often  irreparably  injured  by  their  improper  application.  A 
single  artificial  tooth,  badly  inserted,  may  cause  the  destruction  of 
the  two  adjacent  natural  teeth  or  those  to  which  the  artificial  appli- 
ance is  secured  ;  and  if  the  deficiency  thus  occasioned  be  unskillfully 
supplied  it  may  cause  the  loss  of  others  ;  in  this  way  all  the  teeth  of 
the  upper  jaw  are  sometimes  destroyed. 

The  utility  of  artificial  teeth  depends  upon  their  proper  construc- 
tion and  correct  application.  There  is  no  branch  of  dental  practice 
that  requires  more  skill  and  judgment  or  more  extensive  and  varied 
scientific  information.  A  knowledge  of  the  anatomy  and  physiology 
of  the  mouth,  of  its  various  pathological  conditions  and  their  thera- 
peutical indications,  is  as  essential  to  the  mechanical  as  to  the  surgical 
dentist.  To  correct  information  upon  these  subjects  must  be  added  the 
ability  to  execute,  with  the  nicest  skill  and  most  perfect  accuracy,  all 
the  mechanism  required  in  dental  prosthesis. 

There  are  difficulties  connected  with  the  insertion  of  artificial  teeth 
of  which  none  but  an  experienced  dentist  has  any  idea.  They  must 
be  constructed  and  applied  in  such  a  manner  that  they  may  be  easily 
removed  and  replaced  by  the  patient,  if  upon  a  base  ;  at  the  same 
time  they  must  be  securely  fixed  in  the  mouth  and  be  productive  of 
no  injury  to  the  parts  with  which  they  are  in  relation. 

But  perfect  mechanism  is  not  the  sole  element  of  success ;  often 
it  is  not  the  most  essential  one.  To  know  when  to  extract  and  when 
to  retain  a  root  or  a  tooth  ;  when  to  secure  a  piece  by  clasps  and  when 
by  simple  adaptation ;  when  to  use  gold  and  when  some  other  mate- 
rial ;  to  determine  the  best  form  of  a  plate  and  the  proper  time  for  its 


DENTAL    PROSTHESIS.  659 

insertion  ;  finally,  to  determine  when  and  what  prosthetic  skill  can 
do,  when  and  why  it  will  fail — are  a  few  of  the  problems  in  dental 
mechanics  which  demand  for  their  correct  solution  a  fullness  and  ex- 
tent of  information  which  are  not  always  brought  to  bear,  perhaps 
because,  unfortunately,  the  necessity  is  not  recognized  as  it  should  be. 

Notwithstanding  the  triumphs  of  prosthetic  dentistry  and  the  high 
state  of  excellence  to  which  it  has  arrived,  at  no  previous  time  was 
there  ever  so  much  injury  inflicted  and  suffering  occasioned  by  arti- 
ficial teeth  as  at  present,  resulting  solely  from  their  bad  construction 
and  incorrect  application.  That  such  should  be  the  case  when  there  are 
so  many  scientific  and  skillful  dentists  in  every  city  and  in  many  of  the 
villages  of  the  country  may  seem  strange,  but  the  fact  is  nevertheless 
undeniable.  We  may  explain  it  in  part  by  the  very  rapidly  increasing 
demand  for  dental  services,  which  has  not  allowed  time  for  the  develop- 
ment of  intelligent  and  skilled  labor,  either  of  head  or  hand  ;  in  part, 
also,  by  the  universal  "experience  that  all  new  professions  are  full  of 
immature  and  crude  rnaterial.  But  these  explanations  cannot  long  be 
received  in  excuse  for  a  state  of  things  which  ought  to  be  rapidly  dis- 
appearing— which  is,  in  fact,  giving  way  under  the  combined  influence 
of  our  colleges,  our  periodicals,  and  text-books,  the  teachings  and 
example  of  our  eminent  practitioners,  and  the  more  appreciative  judg- 
ment of  the  public. 

These  remarks  apply  alike  to  the  surgery  and  mechanism  of  dentis- 
try. The  latter  has  an  additional  barrier  to  progress  in  the  common 
practice  of  delegating  the  greater  part  of  its  details  to  inexperienced, 
uninformed,  and  irresponsible  assistants.  Perfect  dentistry  demands 
equal  skill  and  education  in  both  departments.  Each  requires  that  itf 
complete  series  of  operations  shall  be  the  work  of  one  person.  I^ 
therefore,  the  work  of  the  two  are  so  far  incompatible  that  they  canno' 
be  combined,  the  separation  should  be  complete.  The  semi-mechanisr* 
of  the  surgeon  is  like  the  semi-surgery  of  the  mechanism.  Each  in- 
jures an  otherwise  perfect  reputation  ;  both  do  harm  to  the  profession 
they  seek  to  honor. 

In  an  excellent  article  on  "  Temperament  in  Relation  to  the  Teeth," 
in  the  Dental  Cosmos,  Dr.  James  W.  White  writes  as  follows  :  — 

"  The  value  of  a  practical  application  of  the  study  of  temperament 
in  the  practice  of  dentistry  is  apparent.  That  the  relation  of  the  teeth 
to  temperament  is,  as  a  rule,  ignored  by  those  engaged  in  prosthetic 
dentistry  is  evident  in  the  mouths  of  a  majority  of  those  who  are  so 
unfortunate  as  to  be  under  the  necessity  of  wearing  substitutes  for  lost 
natural  dentures. 

"  A  certain  law  of  harmony  in  nature  between  the  teeth  and  other 
physical  characteristics  necessitates  respect  to  size,  shape,  color,  and 
other  qualities  in  an  artificial  denture,  in  order  that  it  shall  correspond 


66o 


MECHANICS  —  DENTAL    PROSTHESIS, 


with  Other  indications  of  temperament;  and  if  teeth  correlated  in 
their  characteristics  to  those  which  nature  assigns  to  one  temperament 
be  inserted  in  the  mouth  of  one  Avhose  physical  organization  demands 
a  different  type,  the  effect  is  abhorrent.  The  artificiality  of  artificial 
teeth  is  the  subject  of  remark  by  those  who  have  little  or  no  conception 
of  the  reason  therefor — simply  an  instinctive  appreciation  of  the  in- 
congruity and  unreality.  It  is,  indeed,  rare  to  see  a  case  in  which 
there  is  occasion  for  a  moment's  hesitation  as  to  the  fact  of  replacement. 
There  is  no  dental  service  that,  from  the  esthetic  standpoint,  is,  as  a 
rule,  so  ill  performed  as  the  prosthetic.  Thousands  of  dentures  are 
constructed  which  serve  the  needs  of  the  wearer  for  speech  and  masti- 
cation, but  which  are  nevertheless  deserving  of  utter  condemnation  as 
art  productions.  More  attention  has  been  paid  to  the  best  methods 
of  restoring  impaired  function — securing  comfort  and  usefulness  in 
artificial  dentures — than  to  a  correlation  of  the  substitutes  to  the 
physical  characteristics  of  the  patient. 

"  What  is  needed  is  such  an  appreciation  of  the  law  of  correspond- 
ence that  the  dentist  can  cipher  out,  as  by  the  rule  of  three,  the 
character  of  teeth  required  in  the  case  of  an  edentulous  mouth,  with 
the  same  precision  as  the  comparative  anatomist  can  from  a  single  bone 
indicate  the  anatomical  structure  of  the  animal  to  which  it  belonged." 

The  following  illustrations  and  descriptions  of  the  teeth  as  indi- 
cated by  temperament  are  interesting  and  instructive  : — 


General 
Divisions. 

Bilious. 

General 
Divisions. 

Sanguineous. 

General    color 
and     quality     of 
color. 

Bronze  -  y  e  1 1  o  w,    with 
strength  or  power  of  col- 
oring. 

General   color 
and    quality    of 
color. 

Cream-yellow, and  inclined 
to  translucency. 

General  form. 

Large  and    inclined  to 
angular;    rather    long   in 
proportion  to  breadth. 

General  form. 

Well    proportioned; 
abounding    in    curved    or 
rounded   outlines;    cusps 
rounding. 

Surfaces  of  the 
teeth. 

Inclined    to    transverse 
ridges  and   abounding  in 
strong  lines;  neither  bril- 
liancy nor  transparency  of 
surface,  but  slight  trans- 
lucency. 

Surfaces  of  the 
teeth. 

Smooth,  or  nearly  so;  ele- 
vations and  depressions 
rounded  ;  cutting-edges  and 
cusps  translucent.  Fair  de- 
gree of  brilliancy. 

Articulation. 

Firm    and   close;    well 
locked. 

Articulation. 

Moderately  firm ;  jaw  in- 
clined to  rotate  in  mastica- 
tion. 

Gum  margin  or 
festoon. 

Heavy  and  firm,  but  in- 
clined to  angularity. 

Gum  margin 
or  festoon. 

Round  and  full,  as  regards 
both  breadth  and  depth. 

Rugae. 

Heavy  and    rugged    in 
shape ;  squarely  set. 

Rugae. 

Numerous  and  graceful  in 
outline:  not  heavy,  but  well 
rounded. 

DENTAL    PROSTHESIS. 


66£ 


Fig.  609, — Bilious. 


Fig.  610.— Sanguineous. 


Fig.  611. — Nervous. 


Fig.  612. — Lymphatic. 


General 
Divisions. 

Nervous. 

General 
Divisions. 

Lymphatic. 

General    color 
and     quality    of 
color. 

Pearl-blue  or  gray  ;   in- 
clined to  transparency. 

General   color 
and    quality    of 
color. 

Pallid  and  opaque,  or 
muddy  in  coloring. 

General  form. 

Length     predominating 
over  breadth ;    fine,   long 
cutting-edges  and  cusps. 

General  form. 

Large,  but  not  shapely ; 
breadth  predominating  over 
length;  cusps  poorly  defined. 

Surfaces  of  the 
teeth. 

Brilliant   and    transpar- 
ent depressions  and  eleva- 
tions ;  abounding  in  long 
curves. 

Surfaces  of  the 
teeth. 

Surfaces  of  incisors  devoid 
of  depressions  or  elevations  ; 
opaque  and  dead  in  finisli, 
even  to  cutting-edges. 

Articulation. 

Very  long  and  penetrat- 
ing. 

Articulation. 

Loose  and  flat. 

Gum  margin  or 
festoon. 

Delicate,  shapely,  and 
fine  ;  oval  in  curve. 

Gum   margin 
or  festoon. 

Thick  and  undefined  in 
shape. 

Rugae. 

Close,   not    numerous; 
small  and  long. 

Rugae. 

Sparse  and  flat. 

66'  MECHANICS DENTAL    PROSTHESIS. 

We  shall  enumerate  some  of  the  different  kinds  of  dental  substitutes 
that  have  been  employed  since  the  commencement  of  the  present  cen- 
tury. We  shall  also  notice  briefly  the  principal  methods  that  have  been 
adopted  in  their  application,  before  entering  upon  a  minute  descrip- 
tion of  those  practiced  at  the  present  time.  Great  improvements  have 
been  made  in  dental  prosthesis  since  the  publication  of  the  former  edi- 
tions of  this  work.  In  fact,  no  science  or  art,  except  chemistry,  has 
been  so  eminently  progressive  during  the  last  thirty  years  as  mechanical 
dentistry. 


CHAPTER  II. 
SUBSTANCES  EMPLOYED  AS  DENTAL  SUBSTITUTES 

There  are  two  qualities  which  it  is  highly  important  that  dental 
substitutes  should  possess.  They  should  be  durable  in  their  nature, 
and  in  their  ajipearance  should  resemble  the  natural  organs  which  they 
replace  or  with  which  they  are  associated. 

The  kinds  of  teeth  that  have  been  employed  since  1820  are — 

1.  Human  teeth. 

2.  Teeth  of  neat  cattle,  sheep,  etc. 

3.  Teeth  carved  from  the  ivory  of  the  elephant's  tusk  and  from  the 
tooth  of  the  hippopotamus. 

4.  Porcelain  teeth. 

HUMAN    TEETH. 

As  regards  appearance  only,  which  in  a  dental  substitute  is  an  im- 
portant consideration,  human  teeth  are  preferable  to  any  other,  except, 
perhaps,  the  almost  perfect  recent  productions  of  the  dento-ceramic 
art.  When  formerly  used  for  this  purpose  they  were  of  the  same  class 
as  those  the  loss  of  which  they  were  to  replace.  The  crowns  only  were 
employed,  and  if  well  selected  and  skillfully  adjusted  the  artificial  con- 
nection with  the  alveolar  ridge  could  not  easily  be  detected. 

The  durability  of  these  teeth  when  thus  employed  depends  upon  the 
density  of  their  texture,  the  soundness  of  their  enamel,  and  the  condi- 
tion of  the  mouth  in  which  they  are  placed.  If  they  are  of  a  dense 
texture,  with  sound  and  perfect  enamel,  and  are  placed  in  a  healthy 
mouth,  they  may  last  from  eight  to  twelve  years,  or  even  longer.  The 
difficulty,  however,  of  procuring  these  teeth  was  generally  so  great  that 
it  was  seldom  that  such  as  we  have  described  could  be  obtained  ;  and 
even  when  it  was  possible  the  mouth,  in  half  the  cases  in  which  such 
teeth  were  placed,  was  not  in  a  healthy  condition  ;  its  secretions  often 


DENTAL    SUBSTITUTES — HUMAN    TEETH,  663 

SO  vitiated  and  of  so  corrosive  a  nature  as  to  destroy  them  in  lebs  than 
four  years.  We  have  even  known  them  to  be  destroyed  in  two,  and  in 
one  case  in  fifteen  months. 

A  human  tooth  artificially  applied  is  more  liable  to  decay  than  one 
of  equal  density  having  a  vital  connection  with  the  general  system, 
for  the  reason  that  its  dentinal  structure  is  more  exposed  to  the  action 
of  deleterious  chemical  agents.  Yet  of  all  ihe.  aniftial  substances  tm.- 
ployed  for  this  purpose  human  teeth  are  unquestionably  the  best. 
They  are  harder  than  bone,  and  being  more  perfectly  protected  by 
enamel,  are  consequently  more  capable  of  resisting  the  action  of  cor- 
rosive agents. 

Many  object  to  having  human  teeth  placed  in  the  mouth,  under  the 
belief  that  infectious  diseases  may  be  communicated  by  them.  But 
the  purifying  process  to  which  they  are  previously  submitted  greatly 
diminishes  this  danger.  When  the  practice  of  transplanting  teeth  was 
in  vogue  occurrences  of  this  sort  were  not  unfrequent,  but  since  that 
has  been  discontinued  these  have  seldom,  if  ever,  happened.  Still, 
the  prejudice  against  human  teeth  is  so  strong  that  it  is  impossible,  in 
most  cases,  to  overcome  it.  This  feeling,  the  difficulty  of  procuring 
them,  the  high  price  they  command,  and  their  want  of  durability, 
have  gradually  led  to  their  entire  disuse,  which  is  scarcely  to  be  re- 
gretted, now  that  art  can  produce  in  porcelain  such  accurate  imitations 
of  nature.  The  only  case  in  which  we  might  feel  called  upon  to  insert 
natural  teeth  is  where  any  of  the  twelve  front  teeth  become  loosened 
by  periosteal  disease  and  drop  from  their  sockets  while  yet  perfectly 
free  from  caries.  These  teeth  may  often  be  adjusted  to  a  plate  so  as 
to  present  an  exceedingly  natural  appearance. 

TEETH    OF    CATTLE. 

Of  the  various  kinds  of  natural  teeth  employed  for  dental  substi- 
tutes, those  of  neat  cattle  are,  perhaps,  after  human  teeth,  the  best. 
By  slightly  altering  their  shape  they  may  be  made  to  resemble  the 
incisors  of  some  persons ;  but  a  configuration  similar  to  the  cuspids 
cannot  be  given  to  them,  and  in  most  cases  they  are  too  white  and 
glossy.  The  contrast,  therefore,  which  they  form  with  the  natural 
organs  should  constitute,  were  they  in  all  other  respects  suitable,  a 
very  serious  objection  to  their  use.  Imitation  of  nature  has  been  too 
much  disregarded,  both  by  dentists  and  patients.  Indeed,  many  of 
those  who  need  artificial  teeth  wish  to  have  them  as  white  and  brilliant 
as  possible,  and  some  practitioners  lack  either  the  decision  or  the 
judgment  to  refuse  compliance  with  a  practice  which  destroys  all  that 
beauty  and  fitness  which  it  is  the  aim  of  dental  esthetics  to  cultivate. 

There  are  other  objections  to  the  use  of  these  teeth.     In  the  first 


664  MECHANICS — DENTAL    PROSTHESIS. 

place,  they  are  only  covered  anteriorly  with  enamel;  in  the  second, 
their  dentinal  structure  is  less  dense  than  that  of  human  teeth,  and, 
consequently,  they  are  more  easily  acted  on  by  chemical  agents. 
They  are,  therefore,  less  durable,  seldom  lasting  more  than  from  two 
to  four  years.  Another  objection  to  their  use  is,  they  can  be  employed 
in  only  the  very  few  cases  where  short  teeth  are  required,  owing  to  the 
large  size  of  their  nerve  cavities.  It  is  seldom,  therefore,  that  they 
can  be  advantageously  used  as  substitutes  for  human  teeth. 

IVORY    OF    THE    ELEPHANT    AND    HIPPOPOTAMUS. 

Artificial  teeth  made  from  the  ivory  of  the  tusk,  both  of  the  ele- 
phant and  the  hippopotamus,  have  been  sanctioned  by  usage  from  the 
earliest  periods  of  the  existence  of  this  branch  of  the  art.  We  must 
not  hence  conclude  that  it  has  been  approved  by  experience ;  on  the 
contrary,  of  all  the  substances  that  have  been  used  for  this  purpose 
this  is  certainly  the  most  objectionable. 

The  ivory  of  the  elephant's  tusk  is  decidedly  more  permeable  than 
that  obtained  from  the  hippopotamus.  So  readily  does  it  absorb  the 
buccal  fluids  that,  in  three  or  four  hours  after  being  placed  in  the 
mouth,  it  becomes  completely  saturated  with  them.  Consequently,  it 
is  not  only  liable  to  chemical  changes,  but  the  absorbed  secretions 
undergo  decomposition  ;  and  when  several  such  teeth  are  worn,  they 
affect  the  breath  to  such  a  degree  as  to  render  it  exceedingly  offensive. 
Again,  on  account  of  its  softness,  teeth  are  easily  shaped  from  it ;  but, 
not  being  covered  with  enamel,  they  soon  become  dark,  and  give  to 
the  mouth  a  repulsive  appearance.  Fortunately,  however,  in  the 
United  States  elephant's  ivory  is  rarely  used,  either  as  a  base-plate  or 
for  the  teeth  themselves. 

The  ivory  of  the  tusk  of  the  hippopotamus  is  much  firmer  in  its 
texture  than  that  obtained  from  the  elephant ;  being  covered  with  a 
hard,  thick  enamel,  teeth  may  be  cut  from  it  which,  at  first,  very 
closely  resemble  the  natural  organs.  There  is,  however,  a  peculiar 
animation  about  human  teeth,  which  those  made  from  this  substance 
do  not  possess ;  moreover,  they  soon  change  their  color,  assuming  first 
a  yellow,  and  then  a  dingy  bluish  hue.  They  are,  also,  like  elephant 
ivory,  very  liable  to  decay.  We  have  in  our  possession  a  number  of 
blocks  of  this  sort,  some  of  which  are  nearly  half  destroyed.  The 
same  objection  lies  against  teeth  made  from  the  hippopotamus  ivory, 
sufficient  to  condemn  its  use.  Like  those  formed  from  elephant  ivory, 
they  give  to  the  breath  an  offensive  odor,  which  no  amount  of  care  or 
cleanliness  can  wholly  correct  or  prevent. 


DENTAL  SUBSTITUTES PORCELAIN  TEETH.  665 

PORCELAIN  OR  INCORRUPTIBLE  TEETH. 

The  manufacture  of  porcelain  teeth  did  not  for  a  long  time  promise 
to  be  of  much  advantage  to  dentistry.  But  through  the  ingenuity 
and  indefatigable  exertions  of  a  kw,  they  have,  within  the  last  thirty 
years,  been  brought  to  such  perfection  as  to  supersede  all  other  kinds 
of  artificial  teeth. 

The  French,  with  whom  the  invention  of  these  teeth  originated, 
encouraged  their  manufacture  by  favorable  notices  ;  and  the  rewards 
offered  by  some  of  the  learned  and  scientific  societies  of  Paris  contri- 
buted much  to  bring  it  to  perfection.  They  were  still,,  however,  de- 
ficient in  so  many  particulars  that  they  received  the  approbation  of 
very  few  of  the  profession,  and  then  only  in  some  special  cases.  It  is 
principally  to  American  dentists  that  we  are  indebted  for  that  which 
the  French  so  long  labored  in  vain  to  accomplish. 

A  want  of  resemblance  to  the  natural  organs  in  color,  translucency, 
and  animation  was  the  great  objection  urged  against  porcelain  teeth ; 
and,  had  not  this  been  obviated,  it  would  have  constituted  an  insuper- 
able objection  to  their  use.  Until  1833  all  that  were  manufactured 
had  a  dead,  opaque  appearance,  which  rendered  them  easy  of  detection 
when  placed  beside  the  natural  teeth,  and  gave  to  the  mouth  an  un- 
natural aspect.  But  so  great  have  been  the  improvements  in  their 
manufacture  that  few  can  now  distinguish  betwen  the  natural  teeth  and 
their  artificial  companions,  if  well  selected  and  skillfully  applied. 

The  advantages  which  mineral  teeth  possess  over  every  sort  of  ani- 
mal substance  are  numerous.  They  can  be  more  readily  secured  to  the 
plate  and  are  worn  with  greater  convenience.  They  do  not  absorb  the 
secretion,  and,  consequently,  when  proper  attention  is  paid  to  their 
cleanliness  they  do  not  contaminate  the  breath  or  become  in  any 
way  offensive.  Their  color  never  changes.  They  are  not  acted  on  by 
the  chemical  agents  found  in  the  mouth,  and  hence  the  name  incorrupt- 
ible, which  has  been  given  them. 

Porcelain  teeth  are  divided  into  single,  sectional,  carved-block,  con- 
tinuous gum,  pivot-crown  teeth,  and  porcelain  facings,  all  of  which 
consist  of  a  body  and  enamel. 

The  body  or  base  is  composed  of  silex,  feldspar,  and  kaolin,  while 
the  enamel  is  principally  composed  of  feldspar,  and  is  colored  by 
means  of  metals  in  a  state  of  minute  division,  or  in  the  form  of  oxids. 
The  principal  metals  employed  for  this  purpose,  and  which  give  the 
positive  tints,  are  gold,  platinum,  and  titanium.  Gold,  in  a  state  of 
fine  division,  imparts  a  rose-red  tint;  the  same  metal,  in  the  form  of 
an  oxid,  gives  a  bright  rose-red  tint.  Platinum,  in  the  form  of  sponge 
and  filings,  imparts  a  grayish-blue  tint.     Titanium,  in  the  form  of  an 


666  MECHANICS DENTAL    PROSTHESIS. 

oxid,  imparts  a  bright  yellow  tint.  Other  metals,  in  the  form  of  oxids, 
are  also  employed  to  color  porcelain  teeth,  such  as  uranium,  which 
gives  a  greenish-yellow  tint ;  manganese,  a  purple  tint ;  cobalt,  a  bright 
blue  tint ;  silver,  a  lemon-yellow  tint  ;  zinc,  also  a  lemon-yellow  tint ; 
and  purple  of  Cassius,  a  rose-purplish  tint.  By  combining  the  tints, 
using  some  to  soften  others,  the  different  shades  of  color  required  to 
impart  character  and  a  life-like  appearance  to  artificial  teeth  are  ob- 
tained. 

The  vast  extension  of  mechanical  practice  is  due,  more  than  to  any 
other  one  cause,  to  these  improvements  in  the  manufacture  of  porcelain 
teeth — improvements  essentially  American,  and  so  important  as  fairly 
to  justify  a  little  of  that  boasting  spirit  which,  transplanted  from  the 
mother  country,  has  attained  such  luxuriant  growth  on  American  soil. 

The  beautiful  exact  imitation  of  the  varying  shades  of  the  natural 
gum,  which  as  yet  has  been  found  possible  only  in  porcelain,  would  of 
itself  give  to  this  material  a  claim  over  every  other.  All  attempts  to 
color  ivory  have  failed  to  produce  any  permanent  results.  More 
recent  experiments  in  the  several  vulcanizable  materials  have  thus  far 
given  opaque  and  lifeless  colors,  which  no  stretch  of  imagination  can 
compare  with  the  natural  gum,  the  nearest  approach  to  a  proper  color 
being  the  celluloid  base.  When  a  material  shall  have  been  discovered 
possessing  the  valuable  properties  of  the  vulcanite  combined  with  the 
beauty  of  a  porcelain  artificial  gum,  dental  prosthesis  will  have  nearly 
reached  perfection. 

The  late  Dr.  James  W.  White,  in  a  popular  treatise  on  "The 
Teeth,"  remarked:  "The  observant  dentist  will  take  into  account 
complexion,  age,  sex,  height,  the  color  of  hair  and  eyes,  and  other 
characteristics  of  the  individual,  when  selecting  teeth  to  replace  lost 
ones ;  and  the  manufacturer  should  be  skilled  in  the  observance  of  the 
varied  classes  of  denture  required.  To  inattention  in  this  direction 
on  the  part  of  the  dentist,  or  to  dictation  on  the  part  of  the  patient, 
is  to  be  charged  the  unseemly  incongruities  constantly  staring  the  ob- 
server in  the  face  from  mouths  whose  lost  organs  have  been  replaced  in 
disregard  of  this  universal  law.  No  matter  how  anatomically  correct 
or  how  skillfully  adapted  for  speech  and  mastication  an  artificial  den- 
ture may  be,  yet  if  it  bear  not  the  relation  demanded  by  age,  temper- 
ament, facial  contour,  etc.,  it  cannot  be  otherwise  than  that  its  artifi- 
ciality will  be  apparent  to  every  beholder.  Artificial  teeth  should  be 
natural  as  to  shape,  color,  and  vital  appearance ;  there  should  be  a  nice 
blending  of  the  colors  of  the  body  and  enamel,  not  an  abrupt  union 
of  the  two ;  there  should  be  the  precise  amount  of  translucency  and 
the  peculiar  texture  of  the  surface ;  and  these  characteristics  should  be 
maintained  by  artificial  light  as  well  as  ])y  daylight ;  for  many  teeth 


RETENTION    OF   ARTIFICIAL    TEETH.  667 

which  in  daylight  look  reasonably  well  have  an  artificial  appearance 
when  exposed  in  the  mouth  to  an  artificial  light.  They  should  also 
possess  strength  sufficient  for  the  uses  for  which  they  are  designed. 
Besides  all  this  there  must  be  taken  into  account  the  varying  forms  of 
the  jaws  or  maxillary  ridge,  so  that  the  dentist  may  be  enabled  to 
select  teeth  which  are  adapted  to  each  particular  case,  and  which  can 
be  made  to  articulate  nicely  with  other  or  with  the  natural  teeth,  if 
there  are  any  remaining  in  the  mouth  ;  otherwise  his  best  efforts  will 
not  secure  a  good  appearance,  comfort  to  the  wearer,  or  usefulness  in 
mastication." 


CHAPTER  III. 

RETENTION  OF  ARTIFICIAL  TEETH. 

The  methods  of  retaining  artificial  teeth  in  place  are — first,  by 
pivoting  to  the  natural  roots  ;  second,  by  attaching  to  metallic  or  other 
kind  of  base-plate,  secured  either  by,  i,  clasps  or  caps;  2,  spiral 
springs;  or,  3,  atmospheric  pressure.  The  peculiar  advantages  of 
each  of  these  methods  we  shall  now  proceed  to  point  out,  and  the 
cases  to  which  they  are  particularly  applicable. 

ARTIFICIAL    teeth    PLACED    ON    NATURAL    ROOTS. 

This  method  of  securing  artificial  teeth  was  formerly,  on  account  of 
its  simplicity,  more  extensively  practiced  than  any  other ;  and,  under 
favorable  circumstances,  it  answers  as  well  as  any  that  can  be  adopted. 
If  the  roots  on  which  they  are  placed  be  sound  and  healthy,  and  the 
back  part  of  the  jaws  supplied  with  natural  teeth,  so  as  to  prevent 
those  with  which  the  artificial  antagonize  from  striking  them  too 
directly,  they  will  subserve  the  purposes  of  the  natural  organs  as 
perfectly  as  any  other  description  of  dental  substitute,  and  can  be 
made  to  present  an  appearance  so  natural  as  to  escape  detection  upon 
the  closest  scrutiny.  If  properly  fitted  and  secured,  not  only  is  their 
connection  with  the  natural  roots  not  easily  detected,  but  they  may 
render  valuable  service  for  many  years. 

The  pivoting  of  the  lower  incisors,  from  their  small  size  and  the 
dangerous  sequelae  of  abscess,  is  frequently  an  unsatisfactory  operation. 
Many  upper  laterals  are  also  too  small  to  admit  a  pivot.  In  practice 
the  pivoting  of  cuspids  is  seldom  called  for.  These  teeth  being  very 
persistent,  their  loss  usually  implies  that  of  many,  perhaps  all  others, 
and  the  entire  deficiency  is  replaced  by  teeth  attached  to  a  base-plate. 


668  MECHANICS DENTAL    PROSTHESIS. 

The  insertion  of  an  artificial  tooth  on  a  diseased  root,  or  on  a  root 
having  a  diseased  socket,  is  almost  always  followed  by  injurious  conse- 
quences. Filling  the  root,  together  with  proper  accompanying  treat- 
ment, will  sometimes  so  completely  arrest  disease  as  to  make  pivoting 
safe ;  but  there  is  always  risk  in  these  cases.  The  morbid  action 
already  existing  in  the  root  or  its  socket  is  aggravated  by  the  operation, 
and  often  caused  to  extend  to  the  contiguous  parts,  and  occasionally 
even  to  the  whole  mouth.  Even  in  a  healthy  root  it  is  not  always 
proper  to  apply  a  tooth  immediately  after  having  prepared  the  root. 
If  any  irritation  is  produced  by  this  preparatory  process,  the  tooth 
should  not  be  inserted  until  it  has  wholly  subsided.  The  neglect  of 
this  precaution  not  unfrequently  gives  rise  to  inflammation  of  the 
peridental  membrane  and  to  alveolar  abscess. 

Apart  from  the  condition  of  the  root,  the  question  of  pivoting — or 
of  a  plate  tooth  without  gum  resembling  a  pivot  tooth — may  depend 
upon  the  adjoining  tooth  or  roots.  If  in  any  space  to  be  supplied 
one  root  is  absent  all  should  be  extracted,  for  the  peculiar  beauty  of 
a  pivot  tooth  is  lost  if  its  neighbor  has  an  artificial  gum. 

Although  this  method  of  securing  artificial  teeth  has  received  the 
sanction  of  the  most  eminent  dental  practitioners,  and  is  one  of  the 
best  that  can  be  adopted  for  replacing  loss  in  the  six  upper  front  teeth, 
yet,  on  account  of  the  facility  with  which  the  operation  is  performed, 
it  is  often  resorted  to  under  most  unfavorable  circumstances,  in  conse- 
quence of  which  the  method  has  been  undeservedly  brought  into 
discredit.  Apart  from  the  proneness  of  operators  to  resort  to  this 
method  when  its  adoption  is  unjustifiable,  we  may  name  two  objections 
to  the  use  of  pivot  teeth  as  formerly  prepared  and  inserted.  First,  the 
difficulty  of  preventing  the  presence  of  secretions  between  the  crown 
and  root,  which  make  the  breath  offensive  and  cause  the  root  gradually 
to  decay.  Secondly,  the  more  or  less  rapid  enlargement  of  the  canal, 
requiring  frequent  replacement  and  the  ultimate  loss  of  the  root.  The 
more  recent  methods,  however,  many  of  which  consist  in  improve- 
ments upon  the  older  methods,  have  obviated  these  objections  in  a 
great  measure. 

The  efforts  of  the  economy  for  the  expulsion  of  the  roots  of  the 
bicuspid  and  molar  teeth  after  the  destruction  of  their  lining  mem- 
brane, are  rarely  exhibited  in  the  case  of  roots  of  teeth  occupying  the 
anterior  part  of  the  mouth.  This  circumstance  has  led  us  to  believe 
that  the  roots  of  these  teeth  receive  a  greater  amount  of  vitality  from 
their  investing  membrane  than  do  the  roots  of  those  situated  further 
back  in  the  mouth;  and  that  the  amount  of  living  principle  thus  sup- 
plied is  sufficient  to  prevent  them  from  becoming  manifestly  obnoxious 
to  their  sockets. 


RETENTION    OF    ARTIFICIAL    TEETH.  669 

Another  explanation  assumes  the  equal  vitality  of  all  the  roots,  and 
attributes  the  persistence  of  front  roots,  upon  which  a  crown  has  been 
placed,  to  the  continuance  of  that  pressure  to  which  it  was  subject  so 
long  as  it  had  its  natural  crown.  It  is  asserted  in  maintenance  of  this 
view,  that  front  roots  left  to  themselves  will  disappear  in  the  same 
manner  as  bicuspid  and  molar  roots,  and  that  the  latter  may  be 
retained  if  the  artificial  crown  (attached  to  a  plate)  is  set  upon  them  ; 
also,  that  the  process  of  expulsion  is  analogous  to  that  by  which 
a  tooth  is  elongated  which  has  lost  its  antagonist. 

It  is  well  known  that  a  dead  root  is  always  productive  of  injury  to 
the  surrounding  parts,  and  that  nature  calls  into  action  certain  agencies 
for  its  expulsion.  Therefore,  attaching  a  tooth  to  a  completely  dead 
root  is  manifestly  improper ;  but  the  roots  of  the  front  teeth  are  rarely 
entirely  deprived  of  vitality,  and  hence,  after  the  destruction  of  their 
pulps,  they  remain  useful  for  many  years  without  very  obviously  affect- 
ing the  adjacent  parts. 

Teeth,  attached  to  a  plate,  and  resting  upon  natural  roots  which  are 
in  as  healthy  condition  as  it  is  possible  for  such  roots  to  be,  have  all 
the  beauty  which  so  strongly  recommends  pivot  teeth.  They  are  not 
so  securely  held  in  position  ;  but  the  ability  to  remove  them  is  in  itself 
an  advantage.  This  method  is  applicable  in  many  cases  where  the 
drilling  for  a  pivot  is  impossible.  The  reader  is  referred  to  the  chapter 
describing  the  different  methods  of  pivoting  teeth. 

THE   ARTIFICIAL   TEETH    SECURED    BY   CLASPS. 

This  method  of  securing  artificial  teeth,  first  introduced  by  the  late 
Dr.  James  Gardette,  of  Philadelphia,  is,  perhaps,  in  particular  and 
otherwise  favorable  cases,  one  of  the  firmest  and  most  secure  that  can 
be  adopted.  By  this  means,  the  loss  of  a  single  tooth,  or  of  several 
teeth,  may  be  supplied.  A  plate  may  be  so  fitted  to  a  space  in  the 
dental  circle  and  secured  with  clasps  to  other  teeth  as  to  afford  a  firm 
support  to  six,  eight,  or  ten  artificial  teeth. 

Teeth  applied  in  this  way,  when  properly  constructed,  will  last  for 
several  years,  and  sometimes  during  the  life  of  the  individual.  But 
it  is  essential  to  their  durability  that  they  should  be  correctly  arranged, 
accurately  fitted,  and  firmly  secured  to  the  plate  ;  that  the  plate  itself 
be  properly  adapted  to  the  gums,  and  the  clasps  attached  with  the 
utmost  accuracy  to  teeth  firmly  fixed  in  their  sockets. 

Gold  is  perhaps  the  best  material  that  can  be  employed  for  both 
plate  and  clasps.  Since  the  application  of  vulcanized  rubber  to 
dental  purposes^  plates  of  this  latter  material  with  gold  clasps  at- 
tached have  been  much  used.  When  gold  is  employed  for  the  plate 
it  should  be  from  20  to  21  carats  fine,  and  from  18  to  19  for  the  clasps. 


670  MECHANICS — DENTAL    PROSTHESIS. 

If  gold  of  an  inferior  quality  is  used,  it  will  be  liable  to  be  acted  on 
by  the  secretions  of  the  mouth.  Platina  perfectly  resists  the  action  of 
these  secretions,  and  would,  perhaps,  answer  the  purpose  as  well  as 
gold  were  it  not  for  its  softness  and  pliancy  ;  in  full  cases,  and  in  some 
partial  cases,  the  shape  of  the  plate  may  more  or  less  overcome  this 
difficulty,  especially  when,  as  in  the  continuous  gum  work,  stiffened 
by  other  materials. 

The  plate  should  be  thick  enough  to  afford  the  necessary  support  to 
the  teeth  ;  but  not  so  thick  as  to  be  clumsy  or  inconvenient  from  its 
weight.  The  clasps  generally  require  to  be  about  one-third  or  one- 
half  thicker  than  the  plate,  and  sometimes  double  the  thickness.  The 
gold  used  for  this  purpose  is  sometimes  prepared  in  the  form  of  half- 
round  wire  ;  but  in  the  majority  of  cases  it  is  preferable  to  have  it 
flat,  as  such  clasps  afford  a  firmer  and  more  secure  support  to  artificial 
teeth  than  those  that  are  half  round  ;  they  also  occasion  less  incon- 
venience to  the  patient,  and  are  productive  of  less  injury  to  the  teeth 
to  which  they  are  attached. 

Artificial  teeth,  applied  in  this  way,  may  be  worn  with  great  com- 
fort and  can  be  taken  out  and  replaced  at  the  pleasure  of  the  person 
wearing  them.  It  is  important  that  they  should  be  very  frequently 
cleansed  to  remove  the  secretions  of  the  mouth  that  get  between  the 
plate  and  gums  and  between  the  clasps  and  teeth,  which,  becoming 
vitiated,  may  irritate  the  soft  parts  and  corrode  the  teeth  and  taint  the 
breath.  This  precaution  should  on  no  account  be  neglected.  Great 
care,  therefore,  should  be  taken  to  fit  the  clasps  in  such  a  manner  as 
will  admit  of  the  easy  removal  and  replacement  of  the  piece,  and  also 
that  they  may  not  exert  any  undue  pressure  upon  the  teeth  to  which 
they  are  applied. 

If  the  clasp,  in  consequence  of  inaccurate  adjustment,  strains  the 
position  of  the  tooth  in  its  socket,  it  may  excite  inflammation  in 
the  peridental  membrane,  and  the  gradual  destruction  of  the  socket 
will  follow  as  a  natural  consequence.  Also,  if  the  clasp  press  too 
closely  upon  the  neck  of  the  tooth  it  may  develop  a  morbid  sensibility 
in  the  cementum,  causing  great  annoyance  and  possibly  exciting  inflam- 
mation and  alveolar  absorption  or  loosening  of  the  tooth. 

Some  years  since  Dr.  Goodall  obtained  a  patent  for  a  method  of  re- 
taining partial  sets  of  artificial  teeth  by  elastic  or  spring  plates  of  vul- 
canized rubber,  the  utility  of  which,  indiscriminately  applied,  as  well 
as  the  validity  of  the  patent,  some  were  disposed  to  doubt,  contending 
that  these  plates  differ  but  little  from  metallic  ones  formerly  in  use,  con- 
structed in  the  same  manner,  and  described  as  partial  or  stay-clasps. 

This  form  of  clasp,  instead  of  embracing  the  natural  tooth,  simply 
presses  against  the  inner  surface  of  the  contracted  portion  of  the  crown 


RETENTION    OF    ARTIFICIAL    TEETH.  67 1 

near  the  gum,  with  a  force  which  is  sufficient  to  keep  the  substitute  in 
place. 

Professor  Austen's  method  of  taking  plaster  impressions  in  partial 
cases  was  designed  by  him  in  1858,  with  special  reference  to  obtaining 
an  accurate  copy  of  the  inner  surface  of  bicuspids  and  first  molars. 
Accurate  fitting  of  the  vulcanite  plate  against  one  or  two  such  teeth 
on  each  side  prevents  lateral  motion  and  gives  great  stability  to  the 
piece.  It  takes  the  place  of  the  vacuum  cavity  with  much  better 
results;  in  fact,  he  regarded  this  form  of  stay-plate  essential  to  every 
partial  piece  not  clasped,  whilst  he  regarded  the  cavity  worse  than  useless. 

The  reader  is  referred  to  the  chapter  describing  the  method  of  reten- 
tion by  clasps. 

ARTIFICIAL    TEETH    WITH    SPIRAL    SPRINGS. 

The  difference  between  the  method  of  applying  artificial  teeth  last 
noticed  and  the  one  now  to  be  considered  consists  in  the  manner  of 
confining  them  in  the  mouth.  The  former  is  applicable  in  cases  where 
there  are  other  teeth  in  fhe  mouth  to  which  clasps  may  be  applied  ;  the 
latter  is  designed  for  confining  a  double  set ;  more  rarely  a  single  set 
or  part  of  a  set.  When  plates  with  spiral  springs  are  used,  the  teeth 
are  attached  to  them  in  the  same  manner  as  when  the  clasps  are 
employed,  but  instead  of  being  fastened  in  the  mouth  to  other  teeth, 
they  are  kept  in  place  by  means  of  the  spiral  springs,  lying  one  on 
each  side  of  the  artificial  dentures  between  them  and  the  cheeks,  pass- 
ing from  the  upper  piece  to  the  lower. 

Spiral  springs  were  formerly  much  used,  and  various  other  kinds  of 
springs  have  since  been  suggested.  When  spiral  springs  are  of  the 
right  size  and  attached  in  a  proper  manner  they  afford  a  very  sure  and 
convenient  support.  They  exert  a  constant  pressure  upon  the  artificial 
pieces,  whether  the  mouth  is  opened  or  closed.  They  do  not  interfere 
with  the  motions  of  the  jaw,  and,  although  they  may  at  first  seem 
awkward,  a  person  will  soon  become  so  accustomed  to  them  as  to  be 
almost  unconscious  of  their  presence.  They  are,  however,  liable  to 
derangement  from  accident  ;  they  make  the  piece  awkward  to  handle 
in  the  necessary  daily  cleansing  ;  they  retain  the  secretions  offensively, 
and  not  unfrequently  are  a  source  of  much  irritation  to  the  cheek. 

It  is,  therefore,  a  subject  of  congratulation  that  successive  improve- 
ments in  the  process  of  adapting  the  plate  to  the  mouth  have 
gradually  lessened  the  number  of  cases  in  which  spiral  springs  are 
thought  necessary.  It  is  now  rare  to  meet  with  a  case  in  which  they 
are  absolutely  essential  for  the  permanent  retention  of  the  piece. 
Occasional  use  is  made  of  them  for  the  temporary  retention  of  a  piece 
made  soon  after  extraction,  in  which  the  plate  is   designedly  made 


672  MECHANICS — DENTAL    PROSTHESIS. 

more  even  than  the  irregular  alveolar  border,  which  plate  cannot,  of 
course,  fit  the  mouth  until  the  inequalities  of  the  gum  have  yielded  to 
the  pressure  of  the  plate. 

TEETH    RETAINED    BY    ATMOSPHERIC    PRESSURE. 

The  method  of  confining  artificial  teeth  in  the  mouth  last  described 
is  often  inapplicable,  inefficient,  and  troublesome,  especially  for  the 
upper  jaw  ;  in  such  cases  the  atmospheric  pressure,  or  suction  method, 
is  very  valuable.  It  was,  for  a  long  time,  thought  to  be  applicable 
only  to  an  entire  upper  set,  because  it  was  supposed  that  a  plate  suffi- 
ciently large  to  afford  the  necessary  amount  of  surface  for  the  atmos- 
phere to  act  upon  could  not  be  furnished  by  a  piece  containing  a 
smaller  number  of  teeth.  Experience,  however,  has  proved  this 
opinion  to  be  incorrect.  A  single  tooth  maybe  mounted  upon  a  plate 
presenting  a  surface  large  enough  for  the  atmosphere  to  act  upon  for 
its  retention  in  the  mouth  ;  but  when  only  a  partial  upper  set  is  re- 
quired it  is  often  more  advisable  to  secure  the  i)iece  by  means  of  cap- 
crowns  to  which  a  bridge  is  attached.  For  a  liJce  reason  it  was  thought 
that  the  narrowness  of  the  inferior  alveolar  ridge  would  preclude  the 
application  of  a  plate  to  it  upon  this  principle,  and  in  this  opinion  the 
author  once  coincided  ;  but  he  has  succeeded  so  perfectly  in  confining 
lower  pieces  by  this  means  that  he  now  never  finds  it  necessary  to 
employ  spiral  springs  for  their  retention. 

The  principle  upon  which  this  plan  is  founded  may  be  simply  illus- 
trated by  taking  two  small  blocks  of  marble  or  glass,  the  flat  surfaces 
of  which  accurately  fit  each  other.  If,  now,  the  air  between  them  is 
replaced  by  water,  the  atmospheric  pressure  upon  their  external  sur- 
faces will  enable  a  person  to  raise  the  under  block  by  lifting  the  upper. 
Upon  the  same  principle  a  gold  plate,  or  any  other  substance  imper- 
vious to  the  atmosphere  and  perfectly  adapted  to  the  gums,  may  be 
made  to  adhere  to  them. 

The  firmness  of  the  adhesion  of  the  plate  or  base  to  the  gums 
depends  on  the  accuracy  of  its  adaptation.  If  this  is  perfect  it  will 
adhere  with  great  tenacity,  but  if  the  plate  is  badly  fitted  or  becomes 
warped  in  soldering  on  the  teeth,  its  retention  will  often  be  attended 
with  difficulty.  It  is  also  important  that  the  teeth  should  be  so 
arranged  and  antagonized  that  they  shall  strike  those  in  the  other 
jaw  on  both  sides  at  the  same  instant.  This  is  a  matter  that  should 
never  be  overlooked,  for  if  they  meet  on  one  side  before  they  come 
together  on  the  other,  the  part  of  the  plate  or  base  not  pressed  upon 
may  be  detached,  and,  by  admitting  the  air  between  it  and  the  gums, 
cause  it  to  drop. 

Since  in  the  act  of  mastication  pressure  is  made  on  one  side  with  no 


RETENTION   OF   ARTIFICIAL   TEETH.  673 

counter-pressure  on  the  other,  this  inequality  will  not  necessarily 
detach  a  well-made  piece.  But  when  the  upper  molars  are  set  so  far 
from  the  median  line  of  the  mouth  that  the  line  of  pressure  falls  out- 
side the  alveolar  ridge,  it  is  difificult  to  retain  the  best-fitting  piece  in 
place  during  mastication. 

It  is  also  of  the  utmost  importance  that,  by  proper  selection  of 
the  impression  material  and  judicious  management  of  subsequent  pro- 
cesses, the  plate  should  bear  upon  the  ridge  more  than  upon  the  palate. 
In  doing  this,  however,  no  more  space  should  be  left  than  a  few  days' 
wear  will  obliterate,  giving  absolute  contact  over  the  entire  surface. 
For  there  is  no  kind  of  space,  cavity,  or  chamber  which  gives  so  com- 
plete a  vacuum  as  contact,  or  which  secures  such  permanently  useful 
adhesion  of  the  plate. 

The  application  of  artificial  teeth  on  this  principle  has  been  prac- 
ticed for  a  long  time.  Its  practicability  was  first  discovered  by  the 
late  Mr.  James  Gardette,  of  Philadelphia.  But  the  plates  formerly 
used  were  ivory  instead  of  gold,  and  could  seldom  be  fitted  with 
sufficient  accuracy  to  the  mouth  to  exclude  the  air ;  so  that,  in  fact, 
it  could  hardly  be  said  that  they  were  retained  by  its  pressure  ;  except 
in  that  class  of  cases  in  which  the  mouth,  by  virtue  of  a  soft  mem- 
brane, has  power  to  adapt  itself  to  the  plate.  Unless  fitted  in  the 
most  perfect  manner,  the  piece  is  constantly  liable  to  drop ;  and  the 
amount  of  substance  necessary  to  leave  in  an  ivory  substitute  renders 
it  so  awkward  and  clumsy  that  a  set  of  teeth  mounted  upon  a  base  of 
this  material  can  seldom  be  worn  with  much  comfort  or  satisfaction. 

The  firmness  with  which  teeth  applied  upon  this  principle  can  be 
made  to  adhere  to  the  gums  and  the  facility  with  which  they  can  be 
removed  and  replaced  renders  them,  in  many  respects,  more  desirable 
than  those  fixed  in  the  mouth  with  clasps.  But  unless  judgment  and 
proper  skill  are  exercised  in  the  construction  of  the  work,  a  total 
failure  may  be  expected,  or,  at  least,  the  piece  will  never  be  worn  with 
satisfaction  and  advantage. 

There  were  few  writers,  at  the  time  of  the  publication  of  the  first 
edition  of  this  work,  who  had  even  adverted  to  this  mode  of  apply- 
ing artificial  teeth.  Drs.  L.  S.  Parmly  and  Koecker  had  each  bestowed 
on  it  a  passing  notice.  The  former,  in  alluding  to  the  subject,  thus 
remarks  :  "  Where  the  teeth  are  mostly  gone  in  both  or  in  either  of 
the  jaws,  the  method  is  to  form  an  artificial  set  by  first  taking  a  mold 
of  the  risings  and  depressions  of  every  point  along  the  surface  of  the 
jaws,  and  then  making  a  corresponding  artificial  socket  for  the  whole. 
If  this  be  accurately  fitted  it  will,  in  most  cases,  retain  itself  suffi- 
ciently firm  by  its  adhesion  to  the  gums  for  every  purpose  of  speech 
and  mastication." 
4:i 


674  MECHANICS DENTAL    PROSTHESIS. 

Modifications  of  the  atmospheric  pressure  principle  have  been  made 
since  1845,  t>y  constructing  the  plate  with  an  air-chamber  or  cavity, 
so  that  when  the  air  is  exhausted  from  between  it  and  the  parts 
against  which  it  is  placed,  a  more  or  less  complete  vacuum  is  formed, 
causing  it  to  adhere  when  first  introduced  with  greater  tenacity  to  the 
gums  than  a  base  fitted  without  such  cavity.  This  modification 
might  be  termed  an  improvement  were  it  not  that  its  introduction 
has  become  so  unnecessarily  general,  has  so  often  induced  a  diseased 
condition  of  the  mucous  membrane,  and  has  led  to  a  slovenly,  care- 
less method  of  swaging  and  fitting  plates.  For  these  and  some 
other  reasons,  Professor  Austen  regarded  its  introduction  as  a  posi- 
tive detriment,  at  the  same  time  that  he  acknowledged  its  occa- 
sional utility.  He  argued  that  theory  and  practice  alike  condemn 
the  use  of  a  cavity  for  the  permanent  retention  of  any  piece,  and 
suggests  for  its  temporary  retention,  whilst  the  work  is  going 
through  its  stage  of  adaptation,  some  other  plan  than  this  permanent 
disfigurement.  The  so-called  vacuum  cavity  can,  at  best,  be  only 
partially  a  vacuum,  hence  cannot  give  the  amount  of  atmospheric 
pressure  that  perfect  contact  will.  So  long  as  it  acts  in  the  retention 
of  a  piece  it  necessarily  draws  the  yielding  membrane  into  the  space, 
and  must  ultimately  fill  it.  When  this  is  done,  the  piece  is  evidently 
retained  by  the  "  vacuum  of  contact."  If,  in  any  case,  the  mouth 
does  not  show  the  size  and  depth  of  the  cavity  imprinted  on  the  pal- 
ate, it  proves  that  the  vacuum  force  is  not  exerted,  and  that  the  piece 
is  retained  by  contact  of  the  parts  around  the  cavity.  In  these  cases, 
of  constant  occurrence,  the  cavity  diminishes  the  adhesion  of  the 
plate,  and  can  only  be  of  service  where  it  helps  to  remove  pressure 
from  a  hard  palate.  But  as  this  can  be  done  in  a  better  way,  it  is  no 
argument  in  favor  of  the  cavity. 

The  only  cases  in  which  this  chamber  is  permanently  useful  are 
very  flat  mouths  with  scarcely  any  perceptible  ridge.  A  sharply 
defined  cavity,  varying  in  depth  from  one-half  to  one  line,  according 
to  the  softness  of  the  membrane,  when  filled  by  this  membrane,  tends  to 
prevent  any  lateral  motion  of  the  piece,  so  troublesome  in  such  cases. 

Partial  pieces  not  retained  by  clasps,  or  the  lateral  pressure  of 
stays,  or  their  closeness  of  adaptation,  are  never  permanently  im- 
proved by  the  cavity.  Even  in  pieces  made  soon  after  extraction  the 
temporary  action  of  the  cavity  is  of  questionable  utility  (see  Chapter 
XIII).  Devices  known  as  "  surface-cohesion  forms"  have  also  been 
suggested,  which  consist  of  thin  metallic  plates,  the  surfaces  of  which 
are  covered  with  minute  papilliform  prominences,  which,  by  displace- 
ment of  mucus  at  the  points  of  gum  contact,  effect  surface  cohesion 
and  cause  no  irritation.  They  can  be  adapted  to  both  upper  and 
lower  dentures. 


PREPARATORY    TREATMENT    OF    THE    MOUTH.  675 

CHAPTER  IV. 
PREPARATORY   TREATMENT   OF   THE   MOUTH. 

The  condition  of  the  mouth  is  not  sufficiently  regarded  in  the 
application  of  artificial  teeth,  and  to  the  neglect  of  this  the  evil 
effects  that  so  often  result  from  their  use  are  frequently  attributable. 
An  artificial  appliance,  no  matter  how  correct  it  may  be  in  its  con- 
struction and  in  the  mode  of  its  application,  cannot  be  worn  with 
impunity  in  a  diseased  mouth.  Of  this  fact  every  day's  experience 
furnishes  the  most  abundant  proof.  Yet  there  are  men  in  the  pro- 
fession so  utterly  regardless  of  their  own  reputation  and  of  the  conse- 
quences to  their  patients  as  wholly  to  disregard  the  condition  of  the 
mouth,  and  are  in  the  constant  habit  of  applying  artificial  teeth  upon 
diseased  roots  and  gums,  or  before  the  curative  process  after  the  ex- 
traction of  the  natural  teeth  is  half  completed. 

The  dentist,  it  is  true,  may  not  always  be  to  blame  for  omitting  to 
employ  the  means  necessary  for  the  restoration  of  the  mouth  to  health. 
The  fault  is  often  with  the  patient.  There  are  many  who,  after  being 
fully  informed  of  the  evil  effects  which  must  of  necessity  result  from 
such  injudicious  practice,  still  insist  on  its  adoption.  But  the  dentist, 
in  such  cases,  does  wrong  to  yield  his  better  informed  judgment  to 
the  caprice  or  timidity  of  his  patient,  knowing,  as  he  should,  the 
lasting  pernicious  consequences  that  must  result  from  doing  so.  If  he 
is  not  permitted  to  carry  out  such  plan  of  treatment  as  may  be  neces- 
sary to  put  the  mouth  of  his  patient  in  a  healthy  condition  previously 
to  the  application  of  artificial  teeth,  he  should  refuse  to  render  his 
services.  No  professional  man  can  be  permitted  to  plead  in  excuse  for 
any  professional  error  that  his  patient  over-persuaded  him.  No  com- 
munity will  accept  such  excuse,  or  hold  the  patient  in  any  degree 
responsible  for  the  consequences. 

Dr.  Koecker,  in  treating  upon  this  subject,  says  :  "  There  is,  per- 
haps, not  one  case  in  a  hundred  requiring  artificial  teeth  in  which 
the  other  teeth  are  not  more  or  less  diseased,  and  the  gums  and 
alveoli,  also,  either  primarily  or  secondarily  affected.  The  mechani- 
cal and  chemical  bearing  of  the  artificial  teeth,  even  if  well  contrived 
and  inserted  upon  such  diseased  structures,  naturally  becomes  an 
additional  aggravating  cause  of  disease  in  parts  already  in  a  sufficient 
state  of  excitement ;  if,  however,  they  are  not  well  constructed,  and 
are  inserted  with  undue  means  or  force,  or  held  by  too  great  or  undue 
pressure,  or  by  ligatures  or  other  pernicious  means  for  their  attachment, 
the   morbid  effects  are  still  more  aggravated,  and  a  general  state  of 


676  MECHANICS DENTAL    PROSTHESIS. 

inflammation  in  the  gums  and  sockets,  and  particularly  in  the  peri- 
osteum, very  rapidly  follows.  The  patient,  moreover,  finds  it  impos- 
sible to  preserve  the  cleanliness  of  his  mouth  ;  and  his  natural  teeth, 
as  well  as  the  artificial  apparatus,  in  combination  with  the  diseases  of 
the  structures,  become  a  source  of  pain  and  trouble ;  and  the  whole 
mouth  is  rendered  highly  offensive  and  disgusting  to  the  patient  him- 
self as  well  as  to  others."* 

The  first  thing,  then,  claiming  the  attention  of  the  dentist,  when 
applied  to  for  artificial  teeth,  is  to  ascertain  the  condition  of  the  gums 
and  of  such  teeth  as  may  be  remaining  in  the  mouth.  If  either  or 
both  are  diseased,  he  should  at  once  institute  such  treatment  as  the 
circumstances  of  the  case  may  indicate  ;  but  as  this  has  been  described 
in  a  preceding  chapter,  the  reader  is  referred  for  directions  upon  the 
subject  to  what  is  there  said.  Without,  however,  repeating  previous 
medical  and  surgical  directions,  a  {ew  brief  hints  are  necessary  as  to 
what  teeth  or  roots  should  be  extracted  and  what  allowed  to  remain 
in  preparation  for  a  dental  plate. 

All  incurably  diseased  roots  or  teeth  should  be  removed,  also  all 
roots  of  molars  in  either  jaw,  and  all  roots,  without  exception,  in  the 
lower  jaw.  Firm  and  healthy  roots  of  bicuspids  may  sometimes  be 
retained,  the  plate  coming  to  the  inner  edge  of  such  root  and  the  arti- 
ficial crown  resting  upon  it.  It  is  desirable  to  retain  upper  incisors 
or  canine  roots,  unless  an  adjacent  tooth  has  lost  its  root  or  is  incur- 
ably diseased.  These  cases  of  retention  of  roots  presuppose  the  pres- 
ence of  other  teeth  ;  for  when  only  roots  remain  in  the  jaw  they 
must  be  extracted.  Also,  they  must  be  removed,  however  sound,  if 
they  are  sources  of  irritation  in,  or  are  partially  covered  with,  mucous 
membrane. 

Very  loose  teeth,  although  not  carious,  should  be  extracted ;  but 
teeth  in  which  caries  or  abscess  can  be  permanently  cured  rank  as 
sound  teeth.  All  sound  teeth  must  be  retained,  if  there  are  more  than 
four  in  either  jaw,  unless  some  peculiar  circumstances  justify  their 
removal.  Cases  of  this  kind  are  so  varying  that  no  fixed  rule  can  be 
laid  down ;  but  a  kw  cases  may  be  given  in  illustration  of  the  princi- 
ples that  should  guide  the  practitioner. 

Two,  three,  or  four  molars  alone  remaining  should  be  retained, 
especially  if  they  have  antagonists.  They  do  not  complicate  the  con- 
struction of  the  piece  or  interfere  with  its  utility;  but  they  should  not 
be  clasped,  since  the  whole  weight  being  in  front  of  the  clasp  brings 
too  much  strain  on  the  teeth.  Two,  three,  or  four  incisors  alone 
remaining  cannot  be  extracted  except  by  request  of  the  patient;  for 


*  Koecker's  "  Essay  on  Artificial  Teeth,"  pp.  27,  28. 


PREPARATORY  TREATMENT  OF  THE  MOUTH.  677 

althcMgh  they  complicate  the  construction,  and  may  interfere  some- 
what with  the  strength  and  beauty  of  the  work,  they  may  be  too  valu- 
able to  justify  their  loss.  The  cuspids  must  be  retained,  if  sound,  not 
,  displaced,  and  free  from  alveolar  absorption,  although  their  retention 
may  /greatly  complicate  the  work. 

In  cases  of  protrusion  of  the  lower  jaw,  it  may  be  advisable  to  extract 
the  fi*'e  front  teeth  in  either  jaw,  where  these  are  the  sole  remaining 
ones,  with  a  view  to  correct,  in  part,  the  protrusion  of  the  mouth. 
But  this  cannot  be  done  without  fullest  consent  of  the  patient ;  even 
then  is  scarcely  advisable  unless  these  teeth  are  frail  in  texture,  or  their 
position  amounts  to  deformity. 

In  all  cases  it  should  be  the  rule  never  to  sacrifice  a  sound  tooth 
for  the  purpose  of  replacing  an  artificial  one,  unless  the  benefit  of  the 
exchange  is  so  undoubted  as  to  be  recognized  by  both  patient  and 
operator. 

When  artificial  teeth  are  to  be  secured  in  the  mouth  in  any  other 
way  than  by  pivoting  upon  the  roots,  if  the  patient  desires  but  one 
piece,  sufficient  time  should  elapse  before  its  insertion  for  the  comple- 
tion of  those  changes  in  the  alveolar  ridge  that  follow  extraction. 

It  is  often  necessary  to  wait  from  eight  to  fifteen  months,  after  the 
removal  of  the  natural  teeth,  for  the  completion  of  these  changes. 
Comparatively  few  persons,  however,  are  willing  to  remain  for  so  long 
a  time  without  teeth ;  nor,  on  many  accounts,  is  it  desirable  that  they 
should.  In  this  long  interval  the  lips  lose  somewhat  their  natural 
expression,  and  the  under  jaw  forgets  its  natural  motion  and  inclines 
to  project.  The  artificial  piece  or  pieces  feel  more  awkward  and  un- 
manageable than  if  inserted  at  once ;  they  also  interfere  more  with  the 
articulation  and  motions  of  the  tongue,  which  have  become  accustomed 
to  the  absence  of  the  teeth. 

Hence  the  insertion  of  artificial  pieces  may  become  advisable  very 
soon  after  extraction  —  the  interval  varying  from  hours  or  days  to 
weeks  or  months.  In  some  of  these  cases  the  piece  will  have  to  be 
remodeled  at  short  intervals;  in  other  cases  the  piece,  as  first  made, 
continues  to  be  worn  for  many  years  with  much  comfort.  It  is  not 
easy  to  explain  these  differences.  Much  depends  upon  the  nature 
of  the  mucous  and  submucous  tissues,  whether  hard  or  soft ;  and 
much  also  upon  the  manner  in  which  the  alveolar  ridge  changes. 
It  may  take  place  rapidly,  and  with  slight  regard  to  the  shape  of  the 
plate ;  in  which  case  the  patient  has  to  use  much  tact  in  retaining 
the  piece  in  place.  Or  it  may  take  place  slowly,  following,  as  it  is 
apt  more  or  less  to  do,  the  shape  of  the  plate  ;  in  which  case  it  may  be 
worn  with  some  comfort,  or  even  with  great  satisfaction,  for  a  long 
time. 


678  MECHANICS DENTAL    PROSTHESIS. 

A  plate  made  immediately  after  extraction  should  not  fit  the  ridge 
exactly  ;  but  allowance  should  be  made  for  the  rapid  absorption  of  the 
prominent  edges  of  the  alveoli.  Some  practitioners  advise  the  antici- 
pation of  this  process  by  "paring  down  "  the  alveolar  ridge.  This 
"  bold  surgery  "  has  its  advantages  and  its  advocates.  The  operators 
say  it  does  not  hurt  much  ;  but  the  testimony  of  the  patient  on  this 
point  is  more  trustworthy. 

The  almost  universal  use  of  the  term  "  temporary,"  applied  to  a 
piece  made  within  six  months  after  extraction  of  the  teeth,  is  much  to 
be  regretted.  It  tempts  the  dentist  to  a  slovenly  style  of  half-made 
work,  good  enough,  in  his  estimation,  for  what  is  so  soon  to  be  replaced. 
It  also  renders  the  patient  reluctant  to  make  proper  compensation  for 
the  time  and  skill  employed.  Both  feelings  react,  until  it  has  become 
a  notorious  fact  that  much  low-priced  work  passes  from  the  hands  of 
skillful  mechanicians  which  they  would  indignantly  disown  as  speci- 
mens of  their  workmanship. 

Yet  they  are  specimens  which  a  community  is  right  in  judging  by. 
It  is  unfortunate  for  dentistry  that  so  many,  using  their  best  efforts, 
accomplish  poor  results.  But  it  is  infinitely  more  damaging  to  its 
character  that  a  skilled  operator  should,  under  any  pretext,  permit 
himself  to  be  false  to  the  trust  reposed  in  his  professional  capacity, 
A  chain  is  judged  by  its  weakest  link,  and  a  workman's  reputation 
turns  on  his  poorest  work.  This  seemingly  harsh  verdict  is  a  just  one, 
because  necessary  to  keep  the  majority  of  men  to  the  full  measure  of 
their  ability. 

Let  the  work  be  done  as  if  it  never  was  to  be  done  again.  Many 
circumstances  may  prevent  the  return  of  the  patient ;  it  also  fre- 
quently happens  that  no  necessity  is  felt,  especially  if  properly  done, 
for  the  renewal  of  the  piece.  If  the  patient  understands  that  the 
necessity  of  renewal  is  not  in  the  work  itself,  but  arises  from  un- 
avoidable changes  in  the  mouth,  there  will  be  no  difficulty  about 
proper  compensation.  But  if  the  absurd  practice  of  half-price  at  one 
time  for  what  receives  full  price  at  another  must  be  maintained,  then 
by  all  means  let  the  second  piece  be  the  half-paid  one. 

The  point,  however,  involves  far  higher  questions  than  the  one  of 
fees.  No  dentist  who  properly  respects  himself  or  his  profession  will, 
either  on  the  score  of  insufficient  pay  or  temporary  use,  permit  himself 
to  issue  two  grades  of  work.  Like  Pharaoh's  lean  kine,  the  low  grade 
will,  slowly,  perhaps,  but  inevitably,  destroy  the  high  grade.  The  only 
safe  rule  is  ' '  excelsior  ' '  in  every  case. 


CROWN    AND    BRIDGE-WORK. 


679 


CHAPTER  V. 
CROWN  AND  BRIDGE-WORK. 

Previous  to  the  preparation  of  a  natural  root  for  the  reception 
of  an  artificial  crown,  the  remaining  teeth  and  gums,  if  diseased, 
should  be  restored  to  health.  This  done,  such  portion  of  the  crown 
as  may  not  have  been  previously  destroyed  by  caries  should  be 
removed. 

A  simple  method  of  performing  this  part  of  the  operation,  when 
much  of  the  crown  remains,  consists  in  cutting  the  tooth  about 
three-fourths  off  with  a  file,  a  very  fine  saw  (Fig.  613),  or  corundum  or 


carborundum  disc,  and  then  removing  it  with  a  pair  of  excising  for- 
ceps. But  the  forceps  should  not  be  applied  until  the  tooth  has  been 
cut  on  every  side,  nearly  to  the  pulp  cavity,  and  even  then  great  care 
is  necessary  to  prevent  jarring,  or  otherwise  injuring  the  root.  When 
too  large  a  portion  of  the  crown  is  clipped  off  suddenly  with  excising 
forceps,  the  concussion  is  often  so  great  as  to  excite  peridental  in- 
flammation and  sometimes  to  fracture  the  root. 

When  excising  forceps  are  used  in  this  way,  they  should  be  strong, 
so  as  not  to  spring  under  the   pressure   of   the  hand,    with  cutting 


Fig.  614. 

edges  about  an  eighth  of  an  inch  wide  (Fig  614").  But  we  should 
prefer,  where  a  large  part  of  the  crown  is  left,  to  remove  it  entirely 
with  the  fine  saw,  or  separating  file,  or  corundum  disc.  Where 
there  is  only  a  jagged  remnant  of  the  crown  left,  it  should  be  grad- 
ually cut  away  by  a  pair  of  cutting  forceps  made  as  light  as  possible, 
with  a  spring  between  the  blades  of  the  handles  to  keep  them  apart. 
The  cutting  edges  may  be  shaped  as  in  the  ordinary  excising  forceps 
(Fig.  614),  or  somewhat  like  the  beaks  of  Parmly's  duck-bill  root 
forceps,  represented  in  Fig.  615. 

After   the   removal  of  the    remaining   portion  of  the  crown,    the 


68o 


MECHANICS — DENTAL   PROSTHESIS. 


pulp,  if  Still  alive,  should  be  immediately  destroyed  by  introducing 
a  silver  or  untempered  steel  wire,  or  barbed  broach,  up  to  the 
extremity  of  the  root  by  giving  it  at  the  same  time  a  quick  rotary 
motion.  It  is  important  that  the  instrument  used  for  this  purpose 
should  be  soft  and  yielding,  otherwise  any  sudden  motion  of  the 
patient  might  break  it  off  in  the  tooth.     Its  extremity  should  also  be 


barbed  or  bent  so  as  to  entangle  and  drag  out  the  pulp  when  with- 
drawn.    (See  Fig.  509,  page  556.) 

The  pulp  having  been  destroyed,  the  remainder  of  the  operation 
will  be  painless.  The  root  may  now  be  filed  or  ground  off  a  little 
above  the  free  edge  of  the  gum  with  an  oval  or  half-round  file,  or  a 
corundum  wheel  with  a  round  edge.  The  file  should  be  new  and  sharp, 
so  as  to  cut  rapidly,  but  not  too  coarse,  lest  it  jar  the  root  too  much. 


U 


V. 


Fig.  616. 


Fig.  617. 


Fig.  61 


It  must  be  kept  cold  and  clean  by  frequently  dipping  in  water ;  also 
the  corundum  wheel.  Fig.  619  represents  pivot  files  and  wheels.  The 
exposed  extremity  of  the  root  after  having  been  thus  filed  should 
present  a  slightly  arched  appearance,  corresponding  with  the  festooned 
shape  of  the  anterior  margin  of  the  gum.  Fig.  620  represents  the 
Herbst  rotary  file  for  rapidly  cutting  natural  roots  to  receive  artificial 


CROWN    AND    BRIDGE  WORK. 


68l 


crowns.  Fig.  621  represents  safe-side  corundum  crown-wheels  to  grind 
off  the  root  without  injuring  the  adjacent  tooth.  Instruments  called 
root-trimmers  or  reducers  are  then  employed  for  trimming  the  edges, 


or  in  the  case  of  collar-crowns,  for  re- 
ducing the  diameters  of  roots  over 
which  collars  are  to  be  placed. 

Figs.  616,  617,  and  618  represent 
Evans',  Starr's,  and  How's  root-trim- 
mers or  reducers. 

After  having  completed  this  part  of 
the  operation,  the  natural  canal  in  the 
root  should  be  slightly  enlarged  with  a 
bur-drill,  or  a  broach  prepared  for  the 
purpose.  A  slightly  projecting  point  on 
the  end  of  the  drill  will  serve,  by  enter- 
ing the  canal,  to  guide  the  instrument, 
which  must  be  held  steadily  in  one 
direction.  The  canal  thus  formed  in  the 
root  for  the  pivot  should  never  exceed 
the  sixteenth  part  of  an  inch  or  a  line 
in  diameter,  or  a  quarter  or  three-eighths 
of  an  inch  in  length. 

If,  from  any  peculiar  constitutional 
susceptibility,  there  is  reason  to  apprehend  inflammation  of  the 
peridental  membrane,  the  insertion  of  the  tooth  may  be  delayed 
a  few  days  for  the  subsidence  of  any  irritation  which  may  have  been 


Fig.  619. 


682  MECHANICS DENTAL    PROSTHESIS. 

occasioned  by  the  preparation  of  the  root.  It  will  be  prudent  to  do 
this  in  all  cases,  although  it  rarely  happens  that  the  operation  is  fol- 
lowed by  any  unpleasant  effects  unless  the  pulp  has  previously  lost  its 
vitality  by  spontaneous  disorganization  or  been  destroyed  by  an  arse- 
nical application. 

In  such  cases  the  contents  of  the  canals  must  be  removed,  and  the 
canals  must  be  disinfected  with  peroxid  of  hydrogen,  and  a  permanent 
aseptic  condition,  by  mummification  of  the  contents  of  the  tubuli, 
be  established,  together  with  closure  of  the  apical  foramen,  after  the 
root-canal  is  prepared. 

The  root-canal  is  then  opened  by  means  of  the  drills  and  reamers 
represented  by  Figs.  515  and  516,  page  559,  and  when  this  is  accom- 
plished it  is  syringed  out  with  tepid  water,  and,  after  drying  with  cot- 
ton, is  dehydrated  with  absolute  alcohol,  or  by  a  current  of  hot  air 
introduced  by  a  hot-air  syringe.  The  application  of  an  antiseptic 
solution,  such  as  bichlorid  of  mercury  or  peroxid  of  sodium,  may  fol- 
low the  dehydrating  process  in  all  cases  where  such  agents  are  deemed 
necessary  for  the  purpose  of  establishing  a  purely  aseptic  condition. 

After  having  prepared  the  root,  an  artificial  crown  of  the  right 
shape,  color,  and  size  is  accurately  fitted  to  it.  It  should  touch  every 
part  of  the  filed  extremity  of  the  root,  and  be  made  to  rest  firmly 
upon  it,  to  give  security  of  support,  and  to  exclude  food  and  other 
substances  which,  by  their  decay,  will  give  rise  to  unpleasant  odors. 
Care  must  also  be  used  to  have  the  tooth  placed  in  exact  line  with  the 
other  teeth,  not  inclining  unnaturally  to  either  side,  and  not  so  long 
as  to  touch  the  lower  teeth  when  the  mouth  is  closed.  To  fit  the 
crown  accurately  is  often  a  tedious  process  and  wearies  the  patient. 
To  avoid  this  an  impression  of  the  exposed  end  of  the  root  and  of  the 
space  between  the  adjoining  teeth  may  be  taken  and  the  crown  adapted 
to  the  model,  which  should  be  hardened  by  varnish  or  soluble  glass; 
an  antagonizing  model  is  also  useful. 

The  canal  in  the  root  and  that  in  the  artificial  crown  should  be 
directly  opposite  to  each  other. 

In  selecting  a  suitable  artificial  crown,  it  is  often  difificult  to  find  the 
several  conditions  of  length,  width,  color,  and  position  of  pivot  hole 
just  as  required.  The  last  two  cannot  be  changed,  but  the  first  two 
may  often  be  modified  by  the  corundum  wheel.  If  the  color  cannot 
be  exactly  matched,  it  is  perhaps  better  to  select  one  a  shade  darker, 
rather  than  lighter. 

For  grinding  the  edges,  sides,  or  base  of  the  tooth,  any  of  the  hand 
or  office  foot-lathes  in  use  will  answer,  or  the  corundum  or  carborun- 
dum points  may  be  employed. 

The  artificial  crown  is  secured  to  the  root  by  means  of  a  pivot  or 


CROWN    AND    BRIDGE-WORK.  683 

post  made  of  metal ;  gold,  platinum,  or  platinum  and  iridium  is  to  be 
preferred,  inasmuch  as  silver  or  any  baser  metal  is  liable  to  be  oxidized 
by  the  fluids  of  the  mouth. 

Wood,  either  seasoned  hickory  or  locust,  was  formerly  employed  for 
the  post,  but  metal  is  now  generally  employed,  as  it  presents  many 
advantages  over  the  wood  on  account  of  strength,  cleanliness,  and 
durability. 

It  is  important  that  the  pivot  should  exactly  equal  the  depth  of  the 
canal.  If  too  long,  the  crown  will  not  go  up  to  its  place  ;  if  too  short, 
there  will  be  either  an  unnecessary  weakening  of  the  root  or  the  crown 
will  be  insecure.     A  small  piece  of  smooth  wire  or  knitting  needle, 


Fig.  622. 

with  a  sliding  collar  of  wood  or  gutta-percha,  forms  a  simple  instru- 
ment for  measuring  the  depth  of  the  canal  in  the  root.  Fig.  622  rep- 
resents a  convenient  gauge  for  this  purpose. 

The  end  of  the  metallic  post  going  into  the  artificial  crown  may  be 
fastened  in  either  of  the  following  ways  :  First,  by  cutting  a  screw  on 
it  with  a  screw-plate,  and  then  filling  the  post-hole  with  zinc  cement 
and  inserting  the  end  of  the  post  into  it,  which  should  be  large  enough 
to  nearly  fill  the  cavity.  The  projecting  part  of  the  pivot  should  be 
about  half  an  inch  in  length.  It  is  generally  made  square  and  pointed, 
as  in  the  figure.  The  appearance  of  a  porcelain  tooth  prepared  with 
a  metallic  pivot  for  insertion  in  this  manner  is 
shown  in  Fig.  623. 

In  some  cases  a  plate  tooth  may  be  consid- 
ered preferable  to  one  made  expressly  for  pivot- 
ing. The  manner  of  attaching  a  post  to  the 
former  is  as  tbllows :  The  root  is  first  prepared,       "^'  ^^'  ^^'  ^^' 

after  which  an  impression  is  taken  ;  from  this  a  plaster  model  is  made, 
and  from  the  latter  metallic  dies.  This  done,  a  piece  of  gold  plate, 
large  enough  to  cover  the  root,  should  be  swaged  up  between  the  dies  ; 
a  plate  tooth  of  the  proper  size,  shape,  and  color  is  then  fitted  to  the 
root,  backed  with  gold,  and  soldered  to  the  plate.  To  the  upper  con- 
vex surface  of  this  last,  and  immediately  beneath  the  canal  in  the 
root,  a  metal  pivot  is  attached.  The  position  and  direction  of  this 
pivot  is  thus  secured.  Press  the  plate,  covered  with  a  very  thin  film 
of  wax,  against  the  root ;  at  the  point  opposite  the  canal,  thus  marked 
on  the  plate,  drill  a  hole  ;  through  this  pass  a  gold  pivot  into  the  canal ; 
press  softened  sealing  wax  around  the  part  of  the  pivot  (made  pur- 


684  MECHANICS — DENTAL    PROSTHESIS. 

posely  too  long)  below  the  plate,  and  remove  the  fixture  from  the 
mouth.  Invest  the  upper  part  of  the  pin  and  plate  in  plaster  (keeping 
it,  by  means  of  a  minute  collar  of  wax,  out  of  the  hole  through  which 
the  pin  passes),  remove  the  sealing  wax,  cut  off  the  pin  even  with  the 
plate,  and  solder.  A  front  and  side  view  of  a  tooth  thus  prepared  is 
shown  in  Fig.  624. 

Porcelain  crowns  are  now  made  with  metallic  posts  baked  in  posi- 
tion.    Fig.  625  represents  such  crowns  with  platino-iridium  posts. 

The  double  pin  in  the  molar  crowns  prevents  the  loosening  of  these 
teeth  by  the  rotary  movements  of  mastication,  which  by  means  of  the 
cusps  exert  such  leverage  as  to  turn  and  break  down  the  ordinary 
crown  where  only  one  pin  is  used. 

The  roots  are  ground  concave  to  fit  the  crowns  with  corundum  or 
carborundum  points  or  a  countersink  bur,  and  the  close  joints  are 
made  well  under  the  gum,  setting  the  pins  with  oxyphosphate  cement. 

It  sometimes  happens  that  the  natural  root,  instead  of  occupying 
its  proper  position  in  the  jaw,  runs  very  obliquely ;  so  that  if  the 
pivot  connecting  the  artificial  tooth  to  it  be  straight,  the  latter  will 


Fig.  625. 

either  overlap  the  adjoining  teeth  or  else  project  outward  or  inward. 
To  obviate  this  an  angle  should  be  given  to  the  pivot  immediately  at 
the  point  of  junction  between  the  tooth  and  root.  If  this  obliquity 
be  slight,  the  pivot  can  easily  be  bent  to  suit;  but  in  cases  of  greater 
obliquity  a  pivot  or  post  made  for  the  case  will  be  required. 

Some  cases  are  met  with  presenting  a  more  formidable  difficulty ; 
as,  for  example,  when  the  root  is  situated  behind  the  circle  of  the 
other  teeth.  In  a  case  of  this  sort  a  different  kind  of  tooth  and  an 
entirely  different  course  of  procedure  are  necessary.  After  having 
prepared  the  root,  an  impression  of  the  parts  is  taken  in  wax,  from 
which  a  plaster  model  is  obtained,  and  from  this  two  metallic  dies. 
With  these  a  gold  plate  is  to  be  swaged,  extending  backward  so  as  to 
cover  the  root,  and  forward  to  form  a  line  with  the  outer  circle  of  the 
teeth.  To  the  posterior  part  of  the  plate  covering  the  root,  and 
directly  beneath  the  cavity  in  it,  a  gold  pivot  about  three-eighths  of 
an  inch  long,  is  soldered,  and  to  the  anterior  part  of  it  a  plate  tooth 
of  the   right  size,    shape,   and   shade   is   attached.     A    hollow   gold 


CROWN   AND    BRIDGE-WORK.  685 

screw  is  now  introduced  into  the  root,  and  into  this  the  gold  pivot  is 
inserted ;  or  the  post  may  be  attached  to  the  root  with  zinc  cement. 
A  right  superior  central  incisor  mounted  on  a  plate  with  a  pivot,  for 
insertion  in   the  manner   here   described,   is  repre- 
sented in  Figs.  626  and  627. 

A  method  of  inserting  an  artificial  tooth  on  a 
metallic  pivot  is  described  by  the  late  Dr.  James  B. 
Bean  in  Vol.  Ill,  1869-70,  of  the  American  Journal  pj^'g^e  fig^27 
of  Dental  Science :  "  Having  filed  or  sawed  off  the 
remaining  portions  of  the  crown,  the  exposed  surface  of  the  root  is 
smoothly  filed  to  within  one-half  or  one-fourth  of  a  line  below  the 
margin  of  the  gum,  giving  it  a  slight  concave  appearance,  so  as  to 
accommodate  the  neck  of  iht  plate  tooth  which  is  to  rest  against  it. 
It  is  well  at  this  stage  of  the  operation  to  stop  the  canal  loosely  with 
a  pellet  of  cotton  or  floss  silk  saturated  with  spirits  of  camphor, 
and  to  dismiss  the  patient  for  two  or  three  days.  If  no  inflam- 
mation be  present,  the  canal  may  then  be  cleaned  out  and  carefully 
filled  with  gold  foil  from  the  apex  to  within  four  or  five  lines  of  the 
orifice. 

"The  remaining  portion  of  the  canal  not  filled  should  now  be 
enlarged  to  about  one  line  in  diameter,  if  the  size  of  the  root  will 
admit  of  it,  down  to  the  gold  filling,  making  the  bottom  smooth  and 
solid  and  the  sides  parallel.  The  orifice,  to  the  depth  of  nearly  a  line, 
is  again  enlarged  with  a  bur-drill  to  about  two  lines  in  diameter, 
and  a  small  groove  or  undercut  is  formed  around  the  margin  for  the 
retention  of  the  gold  filling  subsequently  to  be  introduced  around  the 
tube. 

"  Hollow  gold,  jeweler's  wire,  or  simple  gold  tubes  made  of  gold 
plate  may  be  employed.  If  the  latter  is  chosen,  it  is  formed  by  bend- 
ing a  piece  of  ordinary  gold  plate  around  a  wire,  so  as  to  form  a 
cylinder  sufficiently  large  to  fit  the  smaller  portion  of  the  canal  pre- 
pared for  it ;  then  solder  with  the  finest  gold  solder.  A  piece  of  the 
tube  half  an  inch  in  length  should  be  cemented  with  shellac  into  a 
hole  bored  through  a  piece  of  wood  half  an  inch  in  thickness,  to 
serve  for  a  handle  ;  the  interior  is  then  carefully  dressed  out  with  a 
jeweler's  broach  which  has  a  slight  taper,  making  it  smooth  and  regu- 
lar within.  A  solid  gold  wire  pivot  is  now  carefully  filed  and  fitted  by 
grinding  it  with  fine  emery  and  water,  making  a  'ground  joint,' 
whereby  the  pivot  is  firmly  held  when  in  place.  Any  portion  of  the 
wire  that  may  project  beyond  the  smaller  end  of  the  tube  should  be 
cut  evenly  off,  while  at  the  larger  end  it  should  project  at  least  one- 
fourth  of  an  inch. 

"  The  tube  must  be  taken  out  of  the  cement  and  a  piece  of  plate 


686  MECHANICS DENTAL    PROSTHESIS. 

soldered  to  the  smaller  end,  forming  a  bottom.  An  easier  flowing 
solder  should  be  used  for  this,  so  as  not  to  disturb  the  first.  This  tube 
thus  formed,  after  being  cleansed  in  acid  and  smoothly  filed,  is  ready 
to  be  inserted  into  the  root. 

"Some  have  proposed  to  cut  a  screw  on  the  tube,  whereby  it  is 
firmly  secured  in  its  place,  and  to  fill  then  around  with  gold.  But 
the  most  convenient  way  is  to  cut  a  number  of  barbs  with  a  sharp 
knife,  on  the  outside,  looking  toward  the  open  end  ;  this  retains  the 
gold  in  place  nearly  or  quite  as  well  as  the  screw.  Being  made  so 
as  to  enter  the  root  rather  loosely,  several  folds  of  gold  foil  are 
wrapped  around  it,  and  after  carefully  drying  the  parts  with  bibulous 
paper — the  pivot  being  in  its  place  in  the  tube — the  whole  is  forced  to 
the  bottom  of  the  cavity  and  the  loose  portions  of  foil  removed  ;  zinc 
cement  may  also  be  used  to  secure  the  tube. 

"Another  method  is  to  fill  the  space  around  the  tube  with  gold. 
The  gold  pivot  is  now  removed  and  the  tube  carefully  sawed  or  filed 
off  nearly  level  with  the  end  of  the  root,  and  the  surface  of  the  gold 
and  the  root  well  polished. 

"Thus  far  we  have  the  root  preserved  with  a  good  filling,  and  a  gold 
tube  firmly  secured  in  it  containing  an  accurately  fitting  gold  pivot. 

"The  next  operation  is  to  attach  a  suitable  tooth  to  the  pivot,  and 
for  this  purpose  a  plain  plate  tooth  is  selected  that  will  be  suitable  in 
size,  shape,  and  color.  This  tooth  should  be  so  ground  and  fitted  to 
the  anterior  edge  of  the  root  that  the  free  margin  of  the  gums  will 
cover  the  point  of  union.  Then,  after  soldering  a  strong  backing  to 
the  tooth,  it  is  fitted  to  its  position,  with  the  gold  pivot  in  place,  on 
which  has  been  soldered  a  small  shoulder  or  ring  of  plate,  and  the 
projecting  portion  of  the  wire  cut  off.  This  shoulder  is  to  be  made  in 
the  form  of  a  disc,  cut  out  of  gold  plate,  larger  than  the  diameter  of 
the  pivot,  then  perforated  with  a  hole  just  large  enough  to  admit  the 
pivot  up  to  the  point,  a  little  less  than  the  depth  of  the  tube.  Being 
retained  at  this  point,  it  is  made  to  fit  closely  down  on  the  root  ;  the 
whole  is  then  carefully  withdrawn  and  bedded  up  to  the  ring  in  plas- 
ter and  asbestos,  thoroughly  dried,  the  wax  removed,  and  the  piece 
soldered  with  fine  solder.  If  the  ring  is  loose,  it  must  be  kept  in 
place  by  wax  or  plaster  in  the  act  of  withdrawing  it  from  the  tube. 
The  pivot  is  again  tried  in  the  mouth  and,  if  satisfactory,  the  project- 
ing portion  is  cut  off,  smoothly  filed,  and  the  tooth  attached  to  it  with 
shellac ;  then  try  in  the  mouth,  and  alter  its  position  if  necessary. 
If  the  pivot  does  not  fit  too  tightly,  the  whole  can  be  withdrawn 
together,  carefully  invested  in  plaster  and  asbestos,  and  strongly  sol- 
dered. The  piece  is  now  finished  up,  reducing  the  shoulder  around 
the  pivot  to  less  than  half  a  line  in  breadth;  a  large  plate  covering 


CROWN    AND    BRIDGE-WORK.  687 

the  end  of  the  root  has  no  advantage,  and  would  only  form  a  lodg- 
ment for  food  and  the  secretions  of  the  mouth,  inducing  decomposi- 
tion and  the  destruction  of  the  root. 

"  If  the  pivot  is  not  retained  sufficiently  firm  in  the  tube,  it  may  be 
wrapped  with  a  few  fibres  of  floss  silk  or  cotton,  and  when  forced  into 
its  place  with  a  slight  rotary  motion  it  will  remain  quite  firm,  and 
can  be  used  with  great  satisfaction.  If  the  adjustments  have  been 
properly  made,  the  shoulder  or  flange  will  fit  closely 
on  the  edge  of  the  tube,  the  neck  of  the  tooth  rest- 
ing on  the  beveled  edge  made  for  it,  thereby  pre- 
venting the  tooth  from  turning  on  its  axis.  Proper 
care  and  cleanliness,  removing  the  tooth  at  least 
three  times  a  week,  will  enable  such  a  piece  to  be 
used  with  satisfaction  for  many  years." 

Fig.  628  represents  an  antero-posterior  section  of 
a  superior  central  incisor  root  pivoted  in  the  manner 
above  described,  a,  dentine  of  root ;  l>,  porcelain 
tooth ;  c,  pivot  surrounded  by  the  tube ;  d,  backing, 
which  is  soldered  to  the  tooth  and  to  the  pivot ;  e, 
filling  between  the  end  of  tube  and  apex  of  the  root ;  /,  filling  around 
the  tube  by  which  it  is  retained  in  place;  ^,  flange  resting  on  the  edge 
of  the  tube ;  k,  junction  of  the  tooth  and  root,  concealed  by  the  mar- 
gin of  gum. 

Another  method  for  inserting  an  artificial  crown  on  a  metallic  pivot 
is  that  of  Dr.  T.  J.  Thomas,  by  which  the  end  of  the  root  is  protected 
from  the  action  of  deleterious  agents  and  a  firm  support  given  to  the 
tooth.     It  is  thus  described  by  Professor  Gorgas  : — 

"  Prepare  the  tooth  as  for  an  ordinary  pivot ;  then  select  a  p/a^e 
tooth  of  the  proper  size,  shape,  and  shade,  and  fit  it  by  grinding  accu- 
rately to  the  prepared  root. 

"After  this  is  done,  enlarge  the  pulp  canal  by  reaming  it  out  as 
large  as  the  root  will  permit ;  that  is,  make  a  conical-shaped  cavity  in 
the  exposed  surface  of  the  root,  allowing  the  margin  of  this  cavity  to 
be  quite  near  to  the  periphery  of  the  root,  with  slight  undercuts  or 
retaining  points  on  the  anterior  and  posterior  walls. 

"  After  this  cavity  is  prepared,  and  that  portion  of  the  pulp  canal 
beyond  it  filled  to  the  apex  of  the  root  with  gold,  make  a  square 
metallic  pivot  of  twenty-carat  gold  alloyed  with  platinum,  in  the  pro- 
portion of  five  parts  of  gold  to  one  of  platinum.  This  pivot  is  made 
in  two  parts,  which  are  soldered  together  at  the  base  of  the  artificial 
crown  and  slightly  wedge-shaped.  After  the  pivot  is  prepared,  a  thin 
piece  of  platinum  plate  is  bent  around  it,  thus  forming  a  square  cylin- 
der into  which  the  pivot  perfectly  fits.     The  pivot   is  then  carefully 


688  MECHANICS — DENTAL    PROSTHESIS. 

drawn  out  of  the  square  cylinder,  and  the  edges  of  this  cylinder 
soldered  with  pure  gold.  The  pivot  is  again  inserted,  and  the  excess 
of  solder  and  any  rough  edges  which  may  be  found  in  the  cylinder 
filed  off. 

"  After  this  is  done,  the  cavity  in  the  root  is  carefully  dried  and  pro- 
tected from  moisture,  and  the  square  cylinder,  with  the  pivot  inside 
of  it,  is  placed  in  the  center  of  this  cavity,  which  is  filled  around  it 
with  gold  in  as  careful  and  perfect  a  manner  as  any  crown  cavity, 
or  secured  by  zinc  cement.  The  gold,  or  the  cement,  is  allowed  to 
overlap  the  margin  of  the  cavity,  so  as  to  perfectly  protect  all  of  the 
exposed — or  what,  in  the  ordinary  method,  would  be  the  exposed — 
surface  of  the  root. 

"The  gold  filling,  or  cement,  besides  protecting  the  root,  retains 
the  square  cylinder  in  the  center  of  it.  In  placing  the  cylinder  in  the 
root  with  the  pivot  in  it,  preparatory  to  inserting  the  gold  filling 
around  it,  if  gold  is  used  to  secure  the  cylinder,  the  split  in  the  pivot 
should  range  directly  back  from  the  labial  to  the  palatine  surfaces, 
and  not  transversely.  The  pivot,  after  the  filling  is  inserted,  is  drawn 
out  of  the  cylinder,  which  remains  firmly  fixed  in  the  root,  and  that 
part  of  the  cylinder  which  projects  beyond  the  gold  is  filed  down  to  a 
level  with  the  surface  of  the  filling.  An  impression  of  this  surface  is 
then  taken  with  wax  or  gutta-percha,  and  die  and  counter  die  made  of 
fusible  metal,  by  means  of  which  a  disc  of  platinum  plate  is  swaged 
to  fit  accurately  the  concave  surface  of  the  gold  filling  in  the  root. 

"When  this  is  done,  the  convex  surface  of  the  disc  is  thinly  cov- 
ered with  wax,  and  the  disc  placed  in  its  proper  position  over  the 
gold  filling  in  the  root,  and  slightly  pressed  on  it,  in  order  to  obtain 
an  impression  of  the  square  orifice  of  the  cylinder,  by  which  a  hole 
corresponding  in  shape  and  position  may  be  cut  in  the  disc.  The 
outer  end  of  the  pivot  is  then  inserted  in  the  square  hole  made  in  the 
disc,  secured  by  means  of  wax,  and  the  whole  returned  to  the  root  (with 
pivot  in  the  cylinder),  in  order  to  make  certain  that  the  pivot  is  in  its 
proper  position  ;  then  it  is  carefully  removed  and  secured  by  an  invest- 
ment of  plaster  and  asbestos,  that  the  pivot  may  be  soldered  to  the  disc. 

"  The  projecting  portion  of  the  pivot  above  is  filed  down  to  a  level 
with  the  concave  surface  of  the  disc,  and  the  disc  and  pivot  returned 
to  the  cylinder  in  the  root,  when  the  plate  tooth  is  placed  in  position 
and  secured  to  the  disc  by  means  of  wax. 

"This  done,  the  pivot,  disc,  and  the  plate  tooth  are  carefully  re- 
moved and  invested  in  plaster  and  asbestos,  in  order  that  a  backing 
of  gold  may  be  made,  and  the  tooth  soldered  to  it  and  the  disc.  The 
tooth  is  now  ready  to  be  inserted,  and  by  slightly  separating  the  two 
parts  which  form  the  pivot,  at  its  apex  or  free  extremity,  it  will  tightly 


CROWN    AND    BRIDGE-WORK. 


689 


fit  the  cylinder,  the  two  halves  acting  as  springs,  and  pressing  against 
the  walls  of  the  square  cylinder  inserted  in  the  root." 

The  late  Dr.  M.  H.  Webb  suggested  several  methods  of  pivoting 
by  which  gold  crowns  with  porcelain  faces  made  of  plain  plate  teeth 
are  attached  to  natural  roots. 

One  of  these  methods  consists  in  soldering  to  a  plain  plate  tooth 
with  straight  pins  a  narrow  strip  of  heavy  gold  plate  beveled  on  its 
sides  toward  the  tooth,  and  long  enough  to  form  the  pivot  extending 
into  the  root. 


Fig.  629. 

When  ready  for  insertion,  gold  is  packed  around  the  pivot  (being 
anchored  in  the  roots  by  means  of  undercuts)  and  behind  the  beveled 
edges  of  the  backing,  and  so  built  up  as  to  form  a  contour  palatine 
surface  on  the  crown  (Fig.  629). 

Another  method  of  Dr.  Webb's  is  to  back  with  gold  plate  a  plain 
plate  tooth  with  straight  pins,  the  sides  of  the  backing  being  bent  to 
form  a  tube  or  cannula.     Through  this  tube  a  gold  pivot  passes  into 


Fig.  630. 


Fig.  631. 


Fig.  632. 


the  root,  and  cohesive  gold  is  employed  to  secure  the  pivot  to  both 
crown  and  root,  by  packing  it  around  the  pivot  in  the  root,  around 
the  tube  on  the  backing,  and  into  the  dovetailed  grooves  in  the  crown 
(Fig.  630).  This  plan  is  a  modification  of  that  suggested  by  Dr.  W. 
H.  Dwindle,  to  be  used  in  connection  with  crystal  gold. 

A  method  of  no  recent  date  is,  to  take  an  impression  of  the  root 
surface  and  adjoining  teeth,  and  to  drill  a  hole  in  the  plaster  model 
thus  obtained,  to  correspond  to  the  canal  or  canals  of  bicuspids  and 
44 


690 


MECHANICS — DENTAL    PROSTHESIS. 


molars.  Into  these  holes  gold,  platinum,  or  platinum-and-iridium 
alloy  pins  are  inserted,  and  to  these  a  disc  covering  the  exposed 
surface  of  the  root  is  soldered.  A  plate  tooth  is  then  adapted  by 
grinding  and  soldered  to  the  disc,  the  plaster  model  serving  as  a 
guide  for  the  adaptation  of  both  pins  and  crown.  Fig.  631  repre- 
sents the  tooth  prepared  for  insertion  into  the  root  by  means  of 
gutta-percha  or  zinc  preparations,  the  pins  being  roughened  or 
barbed,  being  made  square  for  the  latter  purpose.  When  the  roots 
are  filled  with  gutta-percha,  tKe  pins  and  crown  are  warmed  and 
pressed  into  place. 

Dr.  J.  F.  Flagg  suggests  the  following  method  of  pivoting,  shown 
in  Fig.  632,  and  described  by  him  as  follows  :  "  Select  plate  tooth,  fit 
it  to  root,  and  bevel  it  from  near  the  pin — cervical — or  pins,  if  cross- 
pins,  to  the  labio-cervical  edge.  Solder  a  platinum  pin  to  it  as  a 
backstay  and  pivot  combined,  leaving  it  rough  or  grooved  on  both 
sides  of  the  pin  for  a  retaining  hold  to  the  finishing  palatal  amalgam. 
"  Fill  the  root  ....  I  prefer  to  give  this  ('  cement ')  a  day  to 
harden  thoroughly.  In  the  root  filling  drill  a  hole  larger  than  the 
platinum  pin,  as  near  to  the  palatal  portion  of  the  filling  as  possible, 
and  directed  slantwise  to  the  apical  center  of  root-filling ;  then  fissure- 
drill  the  hole  toward  the  labial  side  of  the  now 
oval  pivot  hole.  By  this  method  the  tooth  is  ac- 
curately placed  in  position,  and  easily  held  firmly 
in  place  while  the  pin  is  secured  by  filling  the 
pivot  hole  with  amalgam.  Let  this  harden  for 
half  an  hour,  and  then  add  amalgam  in  contour 
to  the  root-filling  and  palatal  face  of  the  porcelain 
tooth.  It  is  at  this  point  of  the  operation  that 
the  need  for  '  beveling  '  the  cervical  portion  of 
the  tooth  is  demonstrated,  for  by  this  bevel  one 
is  enabled  to  make,  by  filling,  a  perfectly  tight 
joint  at  the  labio-cervical  junction  of  tooth  with 
root,  and  also  to  secure  a  strength  of  amalgam 
equal  to  the  entire  surface  of  root-filling." 

Dr.  Boice  modifies  Dr.  Flagg's  method  by  cut- 
ting a  groove  across  the  tooth  between  the  pins 
before  attaching  the  platinum  pivot,  for  the  purpose  of  leaving  a  space 
behind  the  pivot  for  the  better  support  of  the  amalgam  with  which  it 
is  filled. 

Dr.  H.  Weston's  method  consist  of  a  special  crown  with  a  depres- 
sion on  its  palatal  surface,  within  which  are  the  tooth-pins  and  a  spear- 
shaped  pivot  of  hard  platinum,  or  platinum-andlridium  alloy,  notched 
on  both  edges,  to  the  crown  end  of  which  a  backing  of  the  same  metal 


Fig.  633. 


CROWN    AND    BRIDGE-WORK. 


691 


is  soldered,  giving  the  pivot  with  the  backing  (which  is  to  be  soldered 
to  it)  a  T-shape  (Fig.  6^;^).  The  root  canal  being  enlarged  and 
undercut  with  a  wheel-drill,  and  the  crown  fitted  to  the  root  and  pivot, 
the  latter  is  secured  in  the  root  by  the  packing  around  it,  either  amal- 
gam, gold,  or  zinc  preparation. 

Dr.  E.  L.  Hunter's  method  consists  in  making  a  pivot  of  gold 
alloyed  with  platinum,  with  a  thread  cut  on  one  end,  by  means  of 
which  it  is  screwed  into  the  root  canal,  the  other  end  of  the  pivot 
being  split.  Several  screws  are  inserted  into  the  root  around  the 
pulp  canal,  to  afford  anchorage  to  the  gold  which  is  packed  about 
them  and  the  pivot  projecting  from  the  canal.  A  pivot  crown  being 
adapted  to  the  root  surface,  the  split  end  of  the  pivot  is  sprung  open 
and  the  crown  forced  to  its  place,  being  firmly  held  by  the  split  end 
of  the  pivot 

Dr.  G.  P.  Carman  modifies  Dr.  Hunter's  method  by  using  an  ordi- 
nary pivot  crown,  with  the  hole  drilled  completely  through  it  (Fig.  634). 


Fig.  634. 


Fig.  635. 


The  split  or  cleft  end  of  the  pivot  is  made  to  fit  loosely  in  the  hole 
in  the  crown,  so  that  gold  may  be  packed  around  it  to  hold  the  crown 
firmly. 

A  method  of  pivoting  devised  by  Dr.  H.  K.  Leech  (Fig.  635)  is 
described  also  by  Dr.  Dexter,  as  follows:  The  root  is  drilled  out  to 
a  depth  of  about  three  eighths  of  an  inch,  to  a  diameter  of  No.  16 
standard  American  wire  gauge,  the  bottom  of  the  hole  being  flared 
or  enlarged  and  the  canal  above  filled  with  gutta-percha.  A  gold 
tube  is  made  to  fit  the  hole  accurately  and  project  sufficiently  for  con- 
venience of  handling,  and  is  soldered  through  a  hole  in  a  gold  base 
struck  to  the  root,  projecting  through  the  plate  some  distance.  A 
plate-tooth  is  fitted  to  the  root  and  plate  and  soldered  to  the  latter, 
gold  being  flowed  on  to  the  plate  and  backing  and  around  the  project- 
ing tube,  to  form  the  palatal  contour,  and  the  tube  cut  off  flush  with 
the  latter.    We  now  have  a  plate  tooth,  gold  backed,  with  a  tube  pivot. 


692 


MECHANICS — DENTAL   PROSTHESIS. 


the  orifice  of  which  opens  on  the  palatal  aspect  of  our  tooth.  The 
root  end  of  the  tube  is  now  slit  perpendicularly  in  three  or  four  places, 
for  about  two-thirds  of  its  length,  a  thin  sheet  of  warm  gutta-percha 
is  placed  on  the  base  of  the  crown  around  the  tube,  and  the  whole  is 
pushed  securely  to  place.  Now  pack  gold  or  tin  into  the  tube,  con- 
densing the  bottom  portions  so  that  the  slit  end  will  spread  and  tightly 
fill  the  flared  end  of  the  hole  in  the  root,  and  the  operation  is  complete. 
Dr.  Dexter  suggests  that  tin  be  used  to  fill  the  tube,  so  that  the  tooth 
may  be  easily  removed  in  case  of  trouble. 

Dr.  W.  G.  A.  Bonwill,  the  inventor  of  the  "  Bonwill  crowns,"  has 
suggested  several  methods  of  pivoting,  but  the  latest,  consisting  of  an 
all-porcelain  crown,  he  considers  to  be  the  best.  These  teeth  are 
made  in  special  molds,  and  the  incisor  crowns  are  so  shaped  as  to 

form  a  dovetail,  which  allows  the  strain 
outward  to  come  high  up  near  the  cutting 
edge,  and  not  to  depend  upon  the  palatal 
wall  for  support.  The  bicuspid  and  molar 
crowns  are  cut  out  at  the  base,  leaving 
little  more  than  a  shell  with  undercuts 
for  the  amalgam,  to  act  as  dovetails,  the 
operation  being  an  amalgam  filling  capped 
with  porcelain.  The  hollow  crowns  en- 
able the  operator  to  fit  them  to  the  natural 
roots  very  readily,  as  there  is  little  material 
to  arrind  off. 


Mounted  Crown. 


Fig.  636. 


After  the  crown  is  fitted  to  the  root  the  pulp  canal  is  filled  with 
amalgam  in  a  plastic  condition,  and  the  triangular  barbed  metal  pin 
is  forced  into  it.  The  crown  is  then  filled  with  the  same  substance, 
placed  over  the  pin,  and  forced  to  its  place,  the  pin  resting  in  the 
hole  in  the  crown.  Several  modifications  of  this  method  are  suggested 
by  the  inventor,  such  as  a  nut  on  the  end  of  the  pin,  and  a  gas  vent 
formed  by  allowing  a  flat  side  of  the  pin  to  rest  against  one  wall  of  the 
canal,  and  the  space  kept  free  of  amalgam  when  it  is  packed  about 
the  pin.  Retaining  points  are  made  in  the  root  with  a  wheel  bur, 
and  the  amalgam  is  packed  in  the  countersunk  base  of  the  crown,  and 


CROWN    AND    BRIDGE-WORK.  693 

the  surplus  escapes  by  the  opening  on  the  palatal  surface  in  the  case 
of  an  incisor  crown.  When  the  crown  is  well  pressed  into  its  place 
on  the  root,  the  amalgam  can  be  packed  in  around  the  pin.  The  too 
free  escape  of  the  amalgam  through  the  palatal  opening  in  the  crown 
can  be  prevented  by  placing  the  thumb  and  index  finger  on  the  orifice 
when  pressing  up  the  crown.  The  tooth  should  be  kept  at  rest  until 
the  amalgam  has  hardened.     Fig.  637  represents  the  Gates-Bonwill 


Fig.  637. 

crowns,  which  are  inserted  on  the  triangular  pins  in  the  same  manner 
as  the  crowns  just  described. 

Dr.  S.  Davis's  method  (Fig.  638)  is  to  prepare  the  root  as  usual, 
and  ream  out  the  chamber  in  a  funnel  shape,  and  cut  anchorages  in 
the  sides  of  the  reamed  surface.  A  plate-tooth  is  then  fitted,  by  grind- 
ing it,  to  the  labio-cervical  edge  of  the  root,  and  backed  with  gold 
plate,  when  the  sides  of  the  tooth  and  backing  are  ground  to  bevel 
sharply  inward,  leaving  the  labial  surface  untouched.  A  gold  pivot 
is  then  soldered  to  the  backing,  of  such  a  length  that  when  it  is  placed 
in  position  a  narrow  space  is  left  between  the  crown  and  root.  The 
pivot  and  backing  are  then  roughened,  the  latter  being  barbed  and 
fastened  into  the  root  with  oxychlorid  or  oxyphosphate  of  zinc. 
Gold  is  then  packed  in  the  retaining  points,  the  pulp  chamber  and 
around  the  pivot,  and  built  upon  the  backing  to  give  a  proper  form  to 
the  inner  surface  of  the  crown  of  the  tooth. 

The  four-pin  crowns,  invented  by  Dr.  W.  Storer  How,  are  among 
the  more  recent  methods  of  pivot  work,  and  the  following  description 
of  the  successive  steps  to  be  taken  in  mounting  these  crowns,  with  the 
necessary  appliances,  was  prepared  for  the  present  edition  of  this 
work  by  Dr.  How. 

1.  When  the  root  is  in  proper  condition  for  mounting,  measure  the 
depth  of  the  canal  by  means  of  the  canal  plugger  (Fig.  640)  and  its 
flexible  gauge  (Fig.  639),  and  fill  the  canal  at  and  a  short  distance 
from  the  apex  of  the  root,  keeping  the  gauge  at  position  to  show  the 
length  of  the  canal,  and  also  the  distance  to  which  it  has  been  filled. 

2.  Cut  off  the  root  crown,  with  the  excising  forceps  and  a  round 
file,  down  to  the  gum  margin,  and  with  the  barrel  bur,  No.  241,  cut 
the  labial  part  of  the  root  fairly  under  the  gum  without  wounding  it. 

3.  Set  gauge  (Fig.  639)  on  a  Gates  drill  (Fig.  644),  to  one-half  the 
gauged  depth  of  the  canal,  and  drill  to  that  depth. 


694  MECHANICS — DENTAL    PROSTHESIS. 

4.  Set  the  twist  drill  (Fig.  643)  in  its  chuck  (Fig.  647),  to  project 
the  same  length  as  the  Gates  drill,  and,  turning  the  chuck  with  thumb 
and  finger,  drill  the  root  to  exactly  that  depth. 


Fig.  638. 


Fig.  641. 


Fig.  642.  Fig.  643. 


: 


Fig.  639. 


Fig.  645.    Fig.  646.    /  Fig.  647. 


Fig.  640. 


Fig.  644. 


5.  Enlarge  the  mouth  of  the  canal,  one-sixteenth  of  an  inch  deep 
all  around  to  near  the  margin  of  the  root,  using  the  square-end  fissure 


CROWN    AND    BRIDGE-WORK. 


695 


bur,  No.  59,  and  then  with  the  oval,  No.  94,  under-cut  a  groove  at 
the  sides  and  lingually,  as  shown  in  Fig.  645. 

6.  If  the  rubber  dam  is  to  be  used  for  a  gold  or  plastic  backing,  put 
it  now  over  the  root  with  Hunter's  root-clamp,  also  over  the  adjacent 
teeth,  and  thoroughly  dry  the  canal. 

7.  Set  the  tap  (Fig.  646)  in  its  chuck  (Fig.  647),  a  trifle  less  in 
length  than  the  drill ;  oil  the  tap  and  carefully  tap  to  the  gauge 
depth. 

S.  Insert  the  post  in  its  chuck  (Fig.  647)  to  the  exact  gauge  of  the 
tap,  and  turn  the  thumb  screw  down  hard  on  the  end  of  the  post; 
then  screw  the  post  into  the  root ;  release  the  thumb-screw ;  unscrew 
the  chuck  a  half  turn  ;  bend  the  post  until  the  chuck  stands  in  center 
line  with  the  adjoining  teeth,  and  unscrew  the  chuck. 

9.  Slit  the  rubber  back  from  adjacent  teeth,  tucking  the  flaps  out 


Fig.  648. 


Fig.  649. 


Fig.  650. 


Fig.  651. 


Fig.  652.       Fig.  654. 


of  the  way,  so  that  occlusion  may  be  tried,  and  the  post  excised  and 
ground  off,  until  the  teeth  close  clear  of  the  post. 

10.  Try  the  crown  on  the  post,  and  with  an  F  disc,  dry,  grind  the 
rib  between  the  neck-pins  until  the  crown  is  labially  flush  with  the  root 
margin,  cutting  a  little  at  a  time  until  exactly  flush. 

11.  Take  the  crown  and  place  the  mandrel  (Fig.  648)  between  the 
pins  just  as  the  post  is  to  be,  and,  with  the  pliers  (Fig.  649),  bend  the 
pins  carefully  over  the  mandrel,  cutting  off"  the  pins  if  too  long  to  be 
pinched  in  on  the  mandrel  at  the  sides,  observing  that  the  pin  nearest 
the  cutting  edge  is  first  to  be  bent  (Fig.  651),  and  the  opposite  pin 
bent  below  it  on  the  mandrel,  and  so  with  the  others  (Fig.  652). 


696 


MECHANICS — DENTAL   PROSTHESIS. 


12.  Slip  the  crown  over  the  post,  try  occlusion,  and  with  the  post- 
chuck  bend  the  post  until  the  crown  is  properly  aligned  with  the 
teeth  ;  then  with  a  stump  corundum  wheel  No.  3  grind  the  neck  of 
the  crown  to  a  close  labial  fit  with  the  root,  fitting  only  the  portion  to 
be  concealed  by  the  gum,  leaving  narrow  gaps  at  the  sides  to  be  filled 
by  the  backing  between  crown  and  root  (Fig.  653). 

13.  Grind  the  cutting  edge  for  relation  to  the  other  teeth,  being  sure 
that  the  opposing  tooth  does  not  strike  crown,  or  post,  or  pins. 

14.  Fix  the  crown  on  post  by  pinching  the  pins  into  the  screw 
threads  of  the  post  with  special  pliers  (Figs.  649  or  650). 

15.  Finally,  pack  the  backing  of  gold,  or  cement,  or  amalgam,  or 
Wood's  metal,  or — for  temporary  backing  while  treating  abscess — 
gutta-percha,  into  all  the  crevices  around  the  post  and  behind  and 
under  the  pins,  and  between  the  crown  and  the  root ;  contour  and 
finish  thoroughly,  so  that  no  ledge  or  other  imperfection  can  be  found. 

Fig.  654  shows  in  vertical  mid-section  an  incisor  crown  mounted ; 
the  blackened  portions  of  the  backing  defining  the  locking-hold  of 
the  backing  on  the  post,  the  crown-pins,  and  the  root  recess. 


Fig.  655. 


Fig.  656. 


Fig.  655  shows  in  perspective  a  cuspid  crown  ready  to  be  slipped 
over  its  post,  and  also  a  cuspid  crown  ready  for  its  post  in  the  bicuspid 
root,  which  has  its  lingual  cusp  remaining,  and  Fig.  656  shows  the 
crowns  on  their  posts  awaiting  the  contour-backing. 

In  mounting  a  crown  on  the  bicuspid  root  (Fig.  655)  the  chucks 
will  not  usually  pass  the  natural  cusp,  and  hence  the  drill  and  the  tap 
must  project  the  cusp's  length  in  addition  to  the  gauge  length.  Ob- 
serve also  if  the  space  between  the  tap  and  the  cusp  is  wider  than 
the  thickness  of  a  crown-pin,  and,  if  not,  cut  the  cusp  vertically 
with  a  large  fissure-bur,  so  that  the  space  shall  be  wide  enough, 
before  setting  the  post,  else  the  bent  pins  will  not  pass  between  the 
post  and  cusp.  Grind  the  rib — see  step  ro — quite  down  to  the  floor 
of  the  crown;  take  steps  11,  12,  and  13,  and,  if  the  occasion  neces- 
sitates grinding  the  crown  so  as  to  destroy  one  pair  of  pins,  invest  the 
crown,  and    older  the  pins  at  the  lap,  taking  step  15  for  completion. 

When  it  is  desired  to  contour  the  backing  of  a  cuspid  crown  to 


CROWN    AND    BRIDGE-WORK. 


697 


form  an  inner  cusp,  or  to  adapt  a  cuspid  or  incisor  crown  for  masti- 
cating uses,  the  pins  may  be  twisted  together  over  the  mandrel,  and 
again  twisted  tightly  over  the  post,  as  in  Fig.  657;  but  in  some  cases 
it  may  be  better  to  bend  the  neck-pins,  as  in  Fig.  658,  instead  of 
twisting  them.  In  all  cases  the  bent  pins  are  to  be  pinched  quite 
hard  over  the  mandrel  and  post,  so  that  the  serrations  of  the  pliers  will 
roughen  the  pins  to  prevent  their  being  pulled  through  the  backing, 
which  should  also  be  condensed  around  the  pins  and  post. 

If  the  root  is  not  ready  for  permanent  mounting,  use  a  tubular  post, 
or,  in  the  absence  of  a  threaded  tube,  take  the  successive  steps  up  to 
13  ;  then  back  temporarily  with  wax,  rubber,  or  gutta-percha,  await- 
ing the  next  sitting,  when  the  crown  may  be  taken  off,  the  post  un- 
screwed, and  the  remedy  applied.  Thus  the  root  may  be  alternately 
medicated  and  itiounted  until  ready  for  the  permanent  crown. 

When  the  root   is   much  decayed,  the  bottom  of  a   cone-shaped 


Fig.  657. 


Fig.  658. 


Fig.  659, 


Fig.  660. 


cavity  may  be  drilled  and  tapped  to  the  depth  of  a  sixteenth  of  an 
inch,  and  the  post,  thus  anchored,  may  be  further  secured  by 
cement  in  the  grooved  walls  of  the  cavity  and  around  the  post 
(Fig.  659). 

These  crowns  afford  unusual  facility  for  mounting  by  any  of  the 
well-known  methods  of  inserting  the  post  after  soldering  it  to  the 
crown.  They  are  also  adapted  for  use  in  celluloid  and  rubber  work, 
especially  in  cases  of  single  teeth.  The  several  long  pins,  having 
their  ends  bent  with  pliers  at  a  sharp  angle  (Fig.  660),  may  be  so 
arranged  as  to  both  strengthen  the  shank  of  the  plate  and  hold  the 
crown  very  firmly  in  position. 

The  screw-posts  are  made  of  crown  metal,  an  alloy  devised  for  the 
purpose,  in  order  to  obtain  a  stiff  post  that  will  permit  the  cutting  of 
the  peculiar  and  extremely  accurate  thread  formed  upon  it,  and  which 
will  not  amalgamate  or  be  otherwise  affected  by  any  backing  material 
that  may  be  used.      Of  course,   platinum   or  platinum  alloyed  with 


MECHANICS DENTAL    PROSTHESIS. 


iridium  may  be  employed  for  posts,  but  the  crown  metal  is  in  every 
way  superior. 

There  are  some  cases  of  a  class  which  has  hitherto  presented  diffi- 
culties that  may  now  be  easily  overcome  by  grinding  the  post  flat  on 
the  crown  side  after  it  has  been  set  and  bent  in  the  root  (Fig.  66 1), 


Fig.  66i. 


Fig.  662. 


Fig.  663. 


Fig.  664. 


so  as  to  be  clear  of  the  occluding  tooth  ;  and  then  the 
crown-pins  may  be  bent  over  the  reduced  post,  the 
crown  fitted  and  ground  to  clear  the  opposite  tooth 
(Fig.  662),  and  the  backing  added. 

A  similar  case,  in  which  the  opposing  tooth  and  a 
proper  alignment  require  an  oblique  bending  of  the 
pins,  is  seen  in  Fig.  663,  while  the  reverse  arrangement 
of  parts  is  shown  in  Fig.  664.  The  crown  is  thus  seen 
to  be  adapted  to  a  wide  range  of  adjustments  because 
its  point  of  contact  with  the  root  is  at  the  labial  portion  of  the 
neck,  on  which,  as  on  a  hinge,  the  crown  may  be  swung  out  or  in 
(Fig.  665,  dotted  lines),  over  an  arc  of  at  least  sixty  degrees,  at  any 
point  of  which  it  may  be  quickly  and  firmly  fixed.     The  labio-cervical 


Fig.  665. 


junction  is  made  just  under  the  gingival  margin,  with  a  thin  layer  of 
cement,  amalgam,  or  gutta-percha,  or  a  narrow  ribbon  or  several  large 
blocks  of  soft  gold  interposed ;  the  joint  always  to  be  made  smooth, 
and  hid  from  view  under  the  free  margins  of  the  gums. 


CROWN    AND    BRIDGE-WORK. 


699 


Dr.  M.  L.  Logan  has  devised  a  porcelain  crown,  with  a  metal  pin 
placed  in  position  before  burning  the  tooth  (Fig.  666).  The  pin 
extends  three-eighths  of  an  inch  outside  the  crown,  which  is  provided 
with  a  basal  cavity  intended  to  be  filled  with  a  cement  or  other 
retaining  material,  to  afford  additional  support. 

Fig.  667  represents  posterior  Logan  crowns,  where  the  pin,  in  the 
incisors,  cuspids,  and  bicuspids,  is  a  stout,  tapering,  double-T-shaped 
platinum  post,  which  extends 
outside  of  the  crown  three- 
eighths  of  an  inch.  It  can  be 
split,  as  shown,  for  two-rooted 
bicuspids,  or  shortened  when 
necessary.  The  molars  are  made 
with  two  square  pins,  grooved 
on  all  four  sides.  One  of  these 
is  for  the  palatal  root,  the  other 
for  either  of  the  buccal  roots,  as 
may  be  most  convenient.  The  posts  can  be  filed  smaller  for  special 
cases,  or  nicked,  if  desired,  to  afford  a  stronger  hold  in  the  retaining 
material,  though  this  will  usually  be  unnecessary,  as  their  shape  was 
designed  specially  to  give  the  strongest  hold  possible.  It  can  be  used 
with  the  seamless  gold  collars  when  desired. 

For  reaming  out  and  grooving  the  walls  of  the  root-canals,  Fig.  668 


Fig.  667. 


Fig.  668. 


Fig.  669. 


represents  what  is  known  as  the  "grooving  bur  engine-bit."  This 
bur  is  intended  for  cutting  grooves  in  the  walls  of  root-canals  to  pro- 
vide retaining-points  for  plastic  materials  in  setting  porcelain  crowns. 
The  grooves  are  made  by  sweeping  the  bur,  while  in  motion,  around 
the  walls  of  the  canal,  which  should  be  made  large  enough  to  permit 
the  bur  end  to  reach  the  bottom  of  the  cavity.     Two  or  three  grooves, 


700 


MECHANICS DENTAL    PROSTHESIS. 


as  may  be  desired,  can  be  cut  in  thin  roots  with  safety,  one  size  of  the 
bur  answering  for  all  cavities.  The  canal  is  then  filled  with  gutta- 
percha, oxychlorid,  amalgam,  or  other  plastic,  and  before  it  sets  the 
barbed  pin  of  the  crown  is  inserted,  with  the  effect  of  forcing  the 
material  into  the  grooves,  thus  adding  greatly  to  the  strength  of  the 
operation. 

Fig.  669  represents  twist  drills  and  root-reamers. 

Fig.  670  represents  Dr.  Ottolengui's  root-facers,  and  Fig.  671 
represents  corundum  points  for  dressing  and  beveling  roots. 

The  root-reamers  are  of  the  size  and  taper  of  the  I>ogan  crown-pins 
Nos.  I,  2,  3,  and  have  corresponding  numbers.  With  a  drill  just  the 
diameter  of  the  smooth  end  of  the  reamer,  the  root  should  be  drilled 
to  the  proper  measured  depth  and  the  bored  canal  be  then  enlarged 


ROOT-FACERS. 


ROOT-DRESSERS. 


Fig.  670. 


Fig.  671. 


Fig.  672.  Fig.  673. 


with  a  suitably  numbered  root-reamer,  which,  having  a  smooth  end, 
cannot  be  forced  beyond  the  end  of  the  drilled  hole.  There  are  five 
sizes  of  the  root-facers,  so  that  one  may  be  chosen  of  such  width  that 
the  root  end  can  be  smoothly,  quickly,  and  safely  faced  to  fit  the  crown. 
Dr.  R.  Ottolengui's  method  of  mounting  the  Logan  crown  is  as  fol- 
lows :  "The  canal  of  the  root  to  be  crowned  is  opened  up  to  the 
proper  depth  with  a  twist  drill,  and  then  with  a  root-reamer  corre- 
sponding to  the  size  of  the  pin,  is  enlarged  to  fit  the  pin  along  its 
whole  length,  and  so  hold  the  crown  firmly  itidepetidently  of  the 
cement.  With  a  root-facer  a  labial  slope  is  given  to  the  root-end,  so 
that  the  crown  neck  shall  fit  under  the  edge  of  the  gum.  The  cuts 
(Fig.  674)  show  the  method  and  its  result,  and  the  cross-section  shows 
how  the  cement  encases  the  pin. 


CROWN    AND    BRIDGE-WORK. 


701 


"The  distinguishing  excellences  of  this  crown  are  the  ease  with 
which  it  can  be  set  and  the  naturalness  and  strength  of  operations 
made  with  it.  The  crown  is  hollowed  out  around  the  pin  so  that 
when  mounted  the  retaining  material  extends  inside  of 
the  crown  instead  of  forming  a  joint  at  its  junction  with 
the  root,  thus  carrying  the  line  upon  which  the  leverage 
is  exerted  nearer  to  the  point  upon  which  the  biting 
force  is  applied,  and  providing  room  for  a  considerable 
body  of  the  retaining  material  instead  of  a  thin  disc  as 


Fig.  674. 


in  ordinary  crowns,  reducing  the  liability  to    fracture  to  the  mini- 
mum." 

Fig.  675  shows  an  enlarged  platinum  pin,  and  also  a  cross-section 
of  a  central  incisor,  giving  the  position  of  the  pin  in  the  root. 

Dr.  Gordon  White's  method  of  adjusting  a  Logan 
crown  to  a  natural  root  is  as  follows  :  — 

'•By  making  a  considerable  change  in  the  present 
form  of  the  Logan  crown,  as  shown  in  Fig.  676,  A  and 
B,  we  have  a  crown  that  can  be  adjusted  in  a  few  min- 
utes, and  with  a  degree  of  perfectness  not  yet  obtainable 
by  any  crown  on  the  market,  nor,  within  my  knowledge, 
by  any  so  far  suggested  method. 

"  The  manner  of  making  the  adjustment  is  certainly 
as  simple  as  could  be  desired. 

"After  preparing  the  canal  for  the  reception  of  the 
*  Logan-pin'  select  a  tooth  in  the  usual   way,  having 
regard  to  correct  length,  width  and  color,  and  if  care 
has  been  exercised  to  select  one  as  near  the  right  length  as  possible  it 
will  only  be  necessary  to  touch  the  buccal  or  labial  point  of  the  neck 
of  the  crown  a  few  times  with  the  corundum  wheel,  and  the  proper 
length  or  bite  will  be  obtained.     Next  take  a  disc,  or  small  piece  of 


Fig.  675. 


702  MECHANICS — DENTAL    PROSTHESIS. 

thin  platinum  foil,  about  No.  50,  and  push  through  this  the  pin  of  the 
tooth,  carrying  the  disc  up  against  the  porcelain,  as  represented  in  Fig. 
677.  With  a  little  drop  of  Parr's  fluxed  wax  dropped  in  the  triangle, 
as  it  were,  formed  by  the  backing  and  the  pin,  the  disc  is  held  securely 
in  place,  and  the  platinum  is  trimmed  around  with  small  scissors,  that 
there  may  not  be  any  overlapping.  Now  place  around  the  pin  on  the 
platinum  a  ball  of  Parr's  wax,  stick  the  pin  through  the  second  disc  of 
the  foil,  and  rub  the  platinum  with  a  hot  instrument,  that  the  wax  and 
disc  may  be  sealed  together,  as  shown  in  Fig.  678.  Place  this  in  ice- 
water  to  harden  the  wax,  so  as  to  resist  pressure.  It  is  now  ready  to 
insert,  and  by  pressing  the  tooth  up  until  the  labial  surface  strikes  the 
end  of  the  root,  and  having  the  patient  to  close  the  jaws,  the  correct 
bite  will  be  secured  with  the  opposite  tooth.  It  will  be  found  on  the 
removal  of  the  crown,  that  the  platinum  next  the  root  has  been  per- 
fectly swaged  to  the  root-end.  The  second  disc  is  now  trimmed 
according  to  the  outlines  of  the  root.  When  it  is  so  desired,  the  pala- 
tine side  of  the  root  having  been  left  a  little  high,  or  just  above  the 


Fig.  676.  Fig.  677.       Fig.  678.    Fig.  679.  Fig.  680. 

gum,  the  platinum  can  be  split  with  scissors,  lapped,  and  burnished 
around  the  exposed  side  of  the  root,  to  form  a  partial  band  (Fig.  679). 

"After  having  dried  the  wax  with  bibulous  paper,  and  shaped  up  the 
approximal  sides,  these  sides  are  covered  with  small,  triangular  pieces 
of  platinum  (Fig.  680),  by  laying  the  platinum  on  the  wax  and  rubbing 
over  it  a  hot  burnisher.  The  crown  is  now  ready  to  invest,  and  the 
investing  mixture  is  poured  on  a  small  piece  of  wire  netting,  which 
will  prevent  its  cracking  during  the  soldering  operation.  The  wax 
having  been  burned  out,  this  triangular  box  is  filled  flush  with  solder 
in  the  usual  way  and  polished.  The  result  is  a  beautiful  and  perfect 
crown,  in  every  respect  the  most  substantial  porcelain  crown  we  have." 

Dr.  E.  C.  Kirk's  method  of  fitting  the  same  style  of  crown  is  as 
follows : — 

"The  following  method  will  in  the  majority  of  cases  enable  a  per- 
fectly close  joint  to  be  made  between  the  crown  and  root-end.  Cut 
several  small  pieces,  about  one-quarter  inch  square,  from  a  strip  of 
thin  articulating  paper.  In  the  center  of  each  punch  a  hole  with  the 
tool  shown  in  the  margin.     Having  prepared  the  root-end,  slip  the 


CROWN    AND    BRIDGE-WORK. 


703 


perforated  piece  of  articulating  paper  over  the  pin  of  the  Logan  crown 
and  press  it  firmly  into  position,  in  contact  with  the  root.  Upon 
withdrawing  the  crown  and  removing  the  articulating  paper,  the 
points  of  contact  will  be  found  to  be  marked  black.  Grind  these  off 
carefully,  readjust  on  the  root  as  before,  grind  again,  and  continue 
the  operation  of  fitting  and  grinding  until  the  mark  made  by  the 
articulating  paper  on  the  contact  surface  of  the  crown  presents  as  a 
uniformly  unbroken  black  ring.  When  this  has  been  accomplished, 
the  crown  will  be  found  to  fit  the  root-end  with  the  utmost  accuracy. 
The  advantages  of  fitting  a  crown  directly  to  the  root  are,  it  would 


Fig.  681. — Prepared  Articulating  Paper. 


Fig.  682.— The  above  figure  shows 
the  Operation  of  grinding  the 
Crown  to  fit  the  Root. 


seem,  self-evident  from  the  mechanical  standpoint,  and  involve  beside 
the  least  expenditure  of  time." 

Another  method  of  fitting  the  same  crown  is  as  follows: — 
"  After  preparing  the  root  for  the  reception  of  the  Logan  crown  in 
the  usual  manner  (Fig.  683),  take  an  impression  of  the  end  of  the  root 
and  surrounding  parts  with  the  proper  quantity  of  moldine  in  a  partial 
impression  tray  (Fig.  685).  Remove  the  impression  carefully  and  fill  it 
with  Melotte's  metal.  The  location  of  the  root  canal  will  be  clearly 
indicated  by  a  small  hole  in  the  metallic  model  (Fig.  684),  and  this  hole 
may  be  deepened  with  a  twist  drill  and  slotted  or  elongated  for  the 
reception  of  the  crown  pin  with  an  Ottolengui  reamer.  This  gives  a 
metal  root, — the  exact  counterpart  of  the  natural  one  and  adjacent 
teeth, ^by  which  the  crown  may  be  fitted." 

Dr.  T.  P.  Hinman's  method  is  as  follows  (Fig.  686)  : — 
"  First  prepare  the  face  of  the  root  to  be  crowned  as  desired  (Fig. 
A),  and  having  selected  a  suitable  crown  (Fig.  B)  bend  the  pin,  if 
necessary,  so  as  to  make  a  proper  alignment. 


704 


MECHANICS — DENTAL   PROSTHESIS. 


''Next  place  a  piece  of  paraffin  wax  around  the  pin  next  to  the 
porcelain  (Fig.  C),  then  take  No.  60  tin  foil  and  trim  a  disc  a  little 
larger  than  the  abutment  (Fig.  D),  pierce  the  center  of  disc  with  the 
crown-pin  or  instrument  shown  in  margin  (Fig.  E),  pushing  disc  down 
until  it  touches  the  wax,  place  crown  on  the  root,  and  force  it  to  place 
(Fig.  F),  the  wax  driving  the  tin-foil  disc  to  a  perfect  apposition  with 
the  abutment  of  the  root. 

"Remove  crown  with  the  wax  holding  the  tin-foil  disc  in  position, 
and  with  a  pair  of  sharp-pointed  scissors  snip  the  edges  of  disc  slightly 
all  around.  Place  a  small  pellet  of  wax  on  end  of  pin  (Fig.  H),  then 
insert  pin  up  to  the  porcelain  in  quick-setting  plaster  (Fig.  I);  after 
plaster  hardens  warm  crown  and  remove  it,  the  snipped  edges  of  disc 


Fig.  683. 


Fig.  684. 


Fig.  685. 


serving  to  hold  it  in  position ;  clean  off  wax  and  replace  crown  on 
model,  and  you  have  a  perfect  metallic-surfaced  model  of  the  abutment 
of  the  root  to  which  to  grind  with  a  perfect  view  of  every  surface 
of  the  root,  the  wax  which  was  on  the  end  of  the  pin  allowing  it 
to  penetrate  the  plaster  as  the  porcelain  is  ground  away.  By  this 
method  a  Logan  crown  can  be  made  to  fit  perfectly  in  ten  minutes 
and  no  guesswork  (Fig.  K).     It  is  also  applicable  to  bicuspids." 

To  mount  a  Logan  crown  with  gutta-percha,  the  following  is  the 
method  (Fig.  687)  : — 

"First  prepare  and  treat  the  pulp-canal  of  the  natural  tooth-root  in 
the  ordinary  way,  the  canal  being  provided  with  undercuts  or  retain- 
ing points,  and  fit  the  crown  in  proper  alignment  with  adjacent  teeth 
as  usual.     Fill  the  cup  or  recess  in  the  neck  of  the  porcelain  crown 


CROWN   AND    BRIDGE-WORK. 


705 


with  gutta-percha,   which  can   best  be  accomplished   by  slipping   a 
washer  or  perforated  disc  of  gutta-percha,  cut  to  correspond  approxi- 


FlG.  686. 


No.  2. 


Fig.  687. 


mately  with  the  size  of  the  neck  of  the  crown,  over  the  crown-pin,  and 
after  softening  by  holding  it  in  the  flame  of  a  burner,  press  the  crown 
45 


7o6  MECHANICS — DENTAL   PROSTHESIS. 

to  its  place  upon  the  root.  After  it  has  been  held  in  position  until 
the  gutta-percha  has  cooled,  remove  the  crown  from  the  root  and  trim 
off  any  surplus  gutta-percha.  Now  coat  the  end  of  the  root  with 
shellac  varnish,  fill  the  root-canal  with  a  suitable  amalgam  or  cement, 
or  if  preferred  pack  it  with  prepared  gutta-percha  points,  using  such 
an  amount  of  points  as  will  allow  the  crown-pin  to  enter  the  canal 
quite  the  full  length  of  the  pin.  The  opening  for  the  pin  in  the  gutta- 
percha in  the  canal  may  be  made  with  a  heated  instrument  having  a 
tapered  point.  Having  packed  the  crown-recess  with  the  proper 
quantity  of  gutta-percha,  as  above  explained,  place  the  crown  in  posi- 
tion in  the  mouth,  heat  the  copper  end  of  a  crown-setter  sufficiently 
to  soften  gutta-percha,  and  place  the  grooved  end  of  the  setter  over 
the  crown  with  the  heated  copper  in  contact  with  the  porcelain.  Hold 
the  setter  against  the  crown  until  the  gutta-percha  becomes  soft,  when 
pressure  should  be  applied  to  the  setter  and  the  crown  with  its  pin 
forced  to  its  proper  position.  After  the  gutta-percha  becomes  cool, 
which  can  be  hastened  by  dipping  the  crown-setter  in  a  tumbler  of 
ice-water  and  holding  it  against  the  tooth  until  it  is  cold,  cut  off  any 
surplus  that  may  be  squeezed  out  from  between  the  crown  and  root, 
with  a  sharp  knife,  and  then  with  a  hot  tool  smooth  the  edge  of  the 
gutta-percha  between  crown  and  root.  If  the  cutting  is  attempted 
while  the  gutta-percha  is  soft,  it  will  be  dragged  out  of  place. 

"  The  use  of  gutta-percha  for  packing  the  root-canal,  thus  making  the 
entire  attachment  with  this  material,  possesses  the  advantage  over  the 
use  of  cement  or  amalgam,  in  that,  should  the  root  become  abscessed, 
the  crown  may  be  removed  with  a  pair  of  forceps  after  first  heating  it 
with  the  setter,  the  root-canal  treated  until  the  disease  is  cured,  and 
the  crown  reset.     Heating  the  porcelain  crown  when  a  cement  is  used 

to  fill  the  root  around  the  pin  hastens  its 
setting.  Do  not  heat  the  crown  if  amal- 
gam has  been  used. 

"A  bridge  made  with  Logan  crowns 
instead  of  plain  teeth  is  simple  of  con- 
struction as  well  as  strong  (Fig.  688) 
Each  crown  is  prepared  by  cutting  oiT 
the  cervico-lingual  wall  of  the  basal 
cavity,  and  placing  a  packing  soldered  to 
the  pin  over  the  entire  cervical  end. 
P     gg^  They  are  then  assembled  as  a  bridge,  in- 

vested in  plaster  and  sand,  the  backings 
soldered  together,  and  the  pins,  except  those  used  for  anchorages,  cut 
off.  A  root  for  anchorage  is  banded  and  its  end  is  covered  with  a 
plate  with  a  hole  through  it  for  the  passage  of  the  pin." 


CROWN   AND    BRIDGE-WORK. 


707 


To  grind  the  Logan  crown  it  is  suggested  to  take  a  hollow  mandrel 
and,  while  in  a  hand-piece,  heat  the  end  and  mount  on  it  a  corundum 
or  carborundum  wheel,  such  as  No.  00,  being  careful  to  make  its  outer 
face  true,  and  to  leave  the  hole  in  the  end  of  the  mandrel  free  for  the 
post  of  the  crown  to  enter.  The  neck  of  the  Logan  crown  can  then 
be  ground  without  the  risk  of  grinding  the  post,  which  enters  the  socket 
of  the  mandrel  and  is  protected. 

A  crown  has  been  invented  by  Dr.  Richmond,  and  the  mode  of 
mounting  it  is  described  by  Dr.  How  as  follows  : — 

"  A  superior  central  incisor  root  will  serve  as  a  typical  case,  and  its 
projecting  end  is  to  be  shaped  as  seen  in  Figs.  689  and  690.  This  can 
be  rapidly  done  with  a  narrow,  safe-sided,  flat,  or  square  file,  the 
angles  of  the  slopes  being  such  that  the  gum  on  the  labial  and  palatal 
aspects  will  not  interfere  with  nor  be  disturbed  by  the  operator  in  this 
preliminary  work,  for  the  root-end  is  not  at  this  time  to  be  cut  quite 
down  to  the  gum.  A  root-reamer  is  then  employed  to 
bore  out  the  root  to  receive  the  crown-post,  which  is  of  the 
same  size  and  shape  as  the  Logan  crown-post  for  a  central 


Fig.  6S9. 


P'iG.  690. 


Fig.  69X. 


incisor.  Fig.  691  shows  in  section  the  relation  of  the  reamer  to  the 
root.  The  Richmond  crown,  Fig.  692,  is  then  put  on  the  root  (see 
Fig.  693),  and  its  position  relative  to  the  adjacent  and  occluding  teeth 
noted.  If  the  cutting-edge  of  the  crown  is  to  be  brought  out  for 
alignment  with  its  neighbors,  the  root  can  be  drilled  a  little  deeper 
and  the  reamer  pressed  outward  as  it  revolves  to  cut  the  labial  wall  of 
the  cavity.  The  palatal  root-slope  must  then  be  filed  to  make  the  V 
correspond  to  the  changed  inclination  of  the  crown. 

"Thus,  by  alternate  trial,  and  reaming,  and  filing,  the  crown  may 
be  fitted  to  the  root  and  adjusted  in  its  relations  until  the  post  has  a 
close,  solid  bearing  against  the  labial  and  palatal  walls  of  the  enlarged 
pulp-cavity,  and  the  crown-slopes  separated  from  the  root-slopes  by  the 
thickness  of  a  sheet  of  heavy  writing-paper.  This  space  can  be  accu- 
rately gauged,  and  the  root-slopes  conformed  to  the  crown-slopes  by 
warming  the  crown  and  putting  on  its  slopes  a  little  gutta-percha,  so 
that  an  impression  of  the  root-end  may  be  taken,  and  the  root-slopes 
dressed  with  a  file  until  the  film  of  gutta-percha  proves  to  be  of  equal 


•joS  MECHANICS — DENTAL    PROSTHESIS. 

thinness  on  both  slopes.  After  thus  completing  the  adjustment,  with 
due  attention  to  the  alignment  and  occlusion,  the  crown  and  the  root 
are  to  be  dried  as  thoroughly  as  possible. 

"  To  do  this  effectively  in  the  root,  it  should  first  be  swabbed  and 
washed  out  with  absolute  alcohol,  and  then  continuously  flooded  with 
warm  air,  until  the  root  is  not  merely  dry,  but  dried  throughout  as  far 
as  possible,  and  made  so  warm  as  to  render  the  patient  conscious  of 
its  heat.  A  little  gutta-percha  is  then  put  on  the  sides  of  the  post  and 
over  the  slopes  of  the  crown,  which  is  then  pushed  into  place,  the 
exuding  gutta-percha  cut  away,  and  the  joint  smoothed  with  a  warm 
burnisher.  The  film  of  gutta-percha  should  be  very  thin.  The  crown 
and  root  may  be  quickly  cooled  by  the  use  of  the  syringe  with  cold 
water,  and  the  patient  then  enjoined  to  let  the  crown  rest  for  a  few 
hours  in  order  that  the  gutta-percha  may  become  quite  set.  Fig.  694 
shows  the  completed  crown. 

"Dr.    Richmond  usually  takes  a  thin,    perforated  disc  of  gutta- 


,'-"^ 


Fig.  692. 


Fig.  693. 


Fig.  694. 


Fig.  695. 


percha,  pushes  the  post  through  it,  warms  the  crown,  presses  it  into 
place,  and  when  cooled  removes  the  crown,  and  with  a  sharp  knife 
trims  away  the  gutta-percha  close  to  the  crown-neck.  He  then  warms 
the  crown,  puts  a  very  little  oxyphosphate  cement  on  the  post,  and 
presses  the  crown  home. 

"The  obvious  advantages  of  the  device  are:  the  readiness  with 
which  the  slopes  of  the  root  end  may  be  shaped  with  a  file  ;  the  facil- 
ity with  which  these  slopes  may  be  given  any  angle  to  set  the  crown 
out  or  in  at  the  base  or  at  the  cutting  edge,  or  to  give  it  a  twist  on  its 
axis;  the  certainty  that,  once  adjusted,  the  final  setting  will  exactly 
reproduce  the  adjustment ;  the  assurance  that  in  use  the  crown  will  not 
be  turned  on  its  axis, — a  most  common  cause  of  the  loosening  of  arti- 
ficial crowns  ;  the  firmness  of  its  resistance  to  outward  thrust  in  the  act 
of  biting.  This  fact  is  made  apparent  by  Fig.  695,  wherein  it  will  be 
seen  that  in  an  outward  movement  the  crown  B  would  rock  upon  A  as 
a  pivot,  and  the  dotted  line  D  shows  how  the  crown  slope  is  resisted 
by  the  root-slope,  which  extends  so  far  toward  the  incisive  edge  that  a 


CROWN    AND    BRIDGE-WORK. 


709 


much  firmer  support  is  given  to  the  crown  than  if  the  resistance  should 
be,  as  it  usually  is,  on  the  line  of  the  gingival  margin  C. 

"The  cases  for  which  the  new  crown  seems  specially  adapted  are 
such  as  have  some  considerable  portion  of  the  natural  crown  remain- 
ing, and  for  these  it  would  seem  that  no  better  artificial  substitute  has- 
yet  been  made  accessible  to  the  profession. 

"  For  roots  that  have  become  wasted  below  the  gum-surface  the  new 
crown  is  not  suitable,  except  in  such  cases  as  are  decayed  under  the 
labial  or  palatal  gum-margin  only,  but  have  yet  projecting  the  approx- 
imal  portions  of  the  crown  (see  Fig.  696). 

"The  sectional  view  (Fig.  697)  and  the  perspective  plan  views 
(Fig.  698)  illustrate  the  manner  of  mounting  these  crowns  on  this 
class  of  roots.     The  finished  crown  appears  as  in  Fig.  698." 

Fig.  699  represents  different  forms  of  crowns,  and  the  nut-driver 
and  screw-nut  for  setting  porcelain  crowns  on  natural  roots. 

The  all-porcelain  crowns,  such  as  the  Foster,  Gates-Bonwill,  dove- 


FlG.  696. 


Fig.  697. 


Fig.  698. 


tail  crown,  and  others,  have  been  set  in  various  ways,  prominent 
among  which  has  been  the  use  of  solid-headed  screws ;  but  we  find 
that  much  more  satisfactory  and  firmer  work  can  be  done  by  first  fixing 
the  screw-post  in  the  root,  thus  permitting  the  crown  to  be  slipped 
over  the  end  of  the  post  and  properly  adjusted  to  the  root,  after  which 
the  cavities  in  both  root  and  crown  may  be  partly  filled  and  a  nut 
screwed  on  the  end  of  the  post  to  condense  the  filling  and  firmly 
secure  the  crown  in  its  place.  These  appliances  are  very  simple. 
They  consist  of  a  nut-driver,  over  which  is  placed  a  split  tube  for 
carrying  the  nut  (see  sectional  view).  The  sole  object  of  this  tube 
is  to  hold  the  nut  and  prevent  its  falling  into  the  mouth  or  on 
the  floor  during  the  process  of  attaching  or  detaching  it  from  the 
post. 

The  substitution  of  pieces  of  porcelain  for  the  portions  of  crowns 
of  teeth  destroyed  by  caries,  by  a  process  of  inlaying,  was  suggested 
many  years  ago  by  Dr.  Edw.  Maynard,  and  successfully  practiced  by 


7IO 


MECHANICS — DENTAL   PROSTHESIS. 


Dr.  A.  J.  Volck,  of  Baltimore,  and  also  by  Dr.  B.  Wood.  Dr.  W. 
Storer  How  describes  a  method  as  follows  :* — 

"  One  of  the  chief  obstacles  to  success  in  many  of  these  operations 
has  been  the  difficulty  of  exactly  fitting  the  inlay  to  the  tooth.  There 
is,  however,  a  class  of  cases  which,  by  methods  that  will  be  now  de- 
scribed, may  be  repaired  with  the  certainty  of  gratifying  results. 

"A  typical  instance  is  that  illustrated  in  Fig.  700;  the  filling 
of  gold  usually  inserted  in  such  a  cavity  is  a  glaring  disfigurement, 


Foster  Crown. 


Gates-Bonwill  Crown. 


Dove-tailed  Crown. 


How  Screw  Posts 
(b  with  nut). 


Headed  Screws. 


Nut-Driver  with  Split  Tube. 
Fig.  699. 

endurable  only  by  reason  of  the  necessity  of  preserving  the  life  and 
usefulness  of  the  tooth.  Fig.  700  also  shows  the  oval-shaped  cavity 
about  to  be  converted  into  a  circular  one  by  means  of  a  wheel  bur, 
as,  say,  No.  208.  A  fine-cut  bur  is  essential  for  this  work,  which 
requires  skill  and  delicacy  with  firmness  of  touch  in  order  to  the 
making  of  a  truly  circular  cavity  of  the  smallest  diameter  consistent 
with  the  inclusion  of  all  the  borders  of  the  original   cavity.     When 


*  Dental  Cosmos,  August  No.,  if 


CROWN    AND    BRIDGE-WORK. 


711 


this  has  been  nearly  done,  and  the  cavity  suitably  deepened  by  an  exca- 
vating wheel-bur,  as  No.  22,  the  barrel-bur,  say  No.  239,  is  to  be 
used  with  steadiness  and  due  attention  to  the  holding  of  it,  so  that 
when  pressed  quite  to  the  bottom  of  the  cavity  the  margin  will  be 
exactly  circular,  whenever  that  is  possible.  (See  Fig.  701.)  In  some 
cases  the  differences  between  the  diameters  of  the  successive  or  even 
the  same  numbers  of  the  finishing  burs  will  be  found  too  great,  so  that 
while  one  size  is  not  quite  large  enough,  the  next  size  is  much  too 
large.     It  is  best,  therefore,  to  be   prepared   with   some   hard-wood 


Fig.  700. 


Fig.  701. 


Fig.  702. 


points,  in  shape  like  the  wood  polishing-points  No.  3,  and  of  closely 
graded  sizes,  to  be  used  in  the  porte-polisher  No.  307.  A  thin  strip 
of  bone  or  ebony  or  vulcanite  should  also  be  at  hand  having  a  series  of 
holes  that  may  be  made  with  the  barrel  burs,  each  of  which  will  make 
three  different  sizes,  and  the  strip  serves  as  a  very  useful  gauge.  Select- 
ing then  a  hard-wood  point  (one  made  of  copper  or  of  tin-solder  would 
be  even  better)  a  very  little  larger  than  the  cavity,  put  in  it  some  corun- 
dum polishing-paste  and  carefully  grind  the  cavity  larger,  circular,  and 
true  down  to  the  bottom.  Of  course,  it  is  next  to  be  thoroughly 
washed  out  with  alcohol  and  dried  with  warm  air.  With  a  wheel  bur 
No.  15,  or  oval  No.  91,  cut  small 
grooves  in  the  upper  and  lower  walls,  but 
not  on  the  thin  side-walls,  which  would 
thus  be  needlessly  weakened.  Select 
from  the  stock  of  broken  or  whole 
porcelain  teeth,  whether  plain-plate, 
vulcanite,  or  gum  teeth,  one  which  will 
match  the  color  of  the  natural  tooth, 
and,  with  a  corundum  disc  or  other 
wheel,  cut  out  a  section  somewhat  larger 
than  the  cavity.  But  when  a  stock  of 
cavity-stoppers  is  accessible,  one  of  these  will  be  preferable  because 
made  wholly  of  enamel,  and  therefore  likely  to  take  a  better  polish  in 
the  process  of  finishing. 

Fig.  703  represents  a  set  of  diamond  trephines  for  cutting  inlays 
from  porcelain  teeth.  They  are  made  of  copper,  charged  with  dia- 
mond, exactly  like  the  diamond  discs. 


Fig.  703. 


712  MECHANICS DENTAL    PROSTHESIS. 

"It  is  worth  while  to  spare  no  trouble  or  time  or  expense  in  match- 
ing as  nearly  as  possible  the  exact  shade  of  the  tooth  to  be  inlaid, 
because  the  success  of  the  substitution  will  greatly  depend  upon  the 
closeness  of  its  resemblance  to  the  natural  tooth.  In  an  emergency 
choose  the  lighter  rather  than  the  darker  shade.  When  the  suitable 
tooth  has  been  found,  and  ground  to  an  approximate  diameter  and 
thickness,  cleanse  thoroughly  its  enamel  face  with  alcohol,  and  then 
with  shellac  melted  but  not  burned,  stick  the  face  of  the  porcelain 
to  the  flat-faced  end  of  a  wood-point  in  the  porte-polisher.  After 
the  porcelain  has  become  quite  cool,  try  it  severely  to  be  sure  that  it 
has  stuck  fast,  because  it  will  be  annoying  and  cost  valuable  time  if  it 
shall  be  dislodged  and  need  to  be  reset  when  nearly  finished.  For 
the  purpose  of  illustration,  a  cavity-stopper  is  selected,  and  is  shown 
mounted  with  shellac  on  a  wood-point.  The  porte-polisher  is  put  in 
the  engine  hand-piece  and  rotated  in  contact  with  a  corundum  wheel 
or  slab,  Fig.  702.  For  more  rapid  grinding  it  may  be  rotated  in  con- 
tact with  a  revolving  corundum  wheel.  The  gauge  previously  men- 
tioned will  serve  for  frequent  trials  in  the  successive  holes  until  the 
inlay  fits  the  hole  next  larger  than  the  cavity.  Then  the  successive 
trials  must  be  made  in  the  cavity  itself  until,  after  grinding  on  a  piece 
of  Arkansas  stone,  the  inlay  exactly  fits  the  cavity.  In  some  instances 
it  will  be  best  to  wet  the  inlay  with  a  very  fine  polishing  paste  and 
grind  it  in  the  cavity.  This  is,  however,  somewhat  hazardous,  because 
of  the  liability  of  the  inlay  to  get  stuck  fast  in  the  cavity,  and  so  en- 
danger the  cavity-walls.  It  is  then  best  to  grind  on  the  corundum 
slab  the  bottom  of  the  inlay,  to  allow  it  to  settle  in  the  cavity  and  take 
up  the  space  previously  occupied  by  the  paste  between  it  and  the 
cavity-walls.  A  fitted  inlay  will  resemble  Fig.  704,  and  for  greater 
security  after  it  shall  have  been  mounted,  it  will  be  necessary  to  cut 
with  a  sharp  corundum  disc  notches  on  opposite  sides  of  the  inlay; 
and  to  insure  the  coaptation  of  these  notches  with  the  grooves  in 
the  cavity,  and  at  the  same  time  be  sure  that  the  inlay  shall  shade 
properly  with  the  tooth,  it  will  be  best  to  detach  the  inlay  from  the 
wood  before  cutting  the  notches  (Fig.  705).  Both  the  cavity  and 
inlay  must  be  perfectly  clean  and  dry  before  the  inlay  is  lightly  placed 
in  the  cavity,  to  determine  which  is  its  upper  and  which  its  under 
edge,  so  that  the  notches  may  be  correspondingly  cut  with  a  clean, 
sharp,  dry  disc.  Another  reason  for  so  cutting  the  notches  is  found 
in  the  fact  that  sometimes  the  lateral  curve  of  the  surface  of  the  tooth 
will  be  so  great  that  a  groove  on  the  lateral  wall  of  the  inlay  would 
jeopardize  the  closeness  of  the  joint  on  the  surface  at  that  point. 

"  It  will,  of  course,  be  understood  that  the  process  described  with 
reference  to  the  porcelain  cavity  stopper  is  applicable  to  the  prepara- 


CROWN    AND    BRIDGE-WORK.  713 

tion  of  any  section  from  a  porcelain  tooth,  and  at  this  stage  of  the  pro- 
ceedings it  is  assumed  that  the  clean,  dry,  notched  porcelain  inlay 
closely  fits  the  clean,  dry,  grooved  cavity.  These  are  to  be  fastened 
to  each  other  mainly  by  a  locking-bit  of  cement  or  gutta-percha  in 
each  of  the  notches  and  grooves,  in  addition  to  a  mere  film  of  such 
plastic  material  between  the  cavity  and  inlay  walls.  This  is  the  criti- 
cal period  of  the  operation,  because  of  the  extreme  difficulty  of  so 
nicely  proportioning  and  evenly  distributing  the  cement  or  gutta- 
percha that  the  joining  of  inlay  and  tooth  shall  be  complete  in  the 
actual  contact  of  the  marginal  walls,  excepting  only  the  interstitial 
porosities,  which  are  to  be  filled  with  the  cement  or  gutta-percha. 

"It  is  probable  that  the  generality  of  operators  will  do  best  with 
the  phosphate  of  zinc  cement,  but  in  any  case,  whatever  the  material 
of  union  is  to  be,  the  invariable  prerequisites  are — perfect  dryness  of 
both  the  cavity  and  the  inlay,  and  some  degree  of  warmth  in  each  of 
them.  These  conditions  may  be  best  accomplished  by  a  thorough 
washing  of  both  with  absolute  alcohol,  and  the  use  of  the  hot-air 
syringe  immediately  preceding  the  mixing  of  the  cement.    This  should 


Fig.  704.         Fig.  705.  Fig.  706.  Fig.  707.  Fig.  708. 


be  mixed  quickly  and  thin,  and  a  mustard-seed  bit  of  it  taken  on  the 
blade  of  a  small  excavator  and  placed  in  the  two  grooves  of  the  cavity, 
as  also  in  the  two  grooves  of  the  inlay  ;  to  be  instantly  followed  by  the 
rubbing  of  the  walls  of  the  inlay  all  over  with  the  least  possible  cement 
on  the  tip  of  the  finger.  The  inlay  is  then  at  once  seated  in  the  cavity 
and  with  a  quick  back-and-forth  grinding  motion  pressed  firmly  into 
place  (taking  care  that  the  notches  are  in  right  relations  lo  the  cavity- 
grooves),  and  held  under  pressure  fully  five  minutes.  In  cases  wherein 
the  inlay  has  been  ground  into  the  cavity,  it  may  be  better  not  to 
remove  the  inlay  from  the  mandrel,  but  to  thinly  coat  its  walls  with 
cement,  and  using  the  porte-polisher  as  a  handle,  turn  the  inlay  into 
its  seat  (as  a  ground  stopper  into  its  bottle)  with  such  firmness  as  to 
detach  the  inlay  from  its  shellac  attachment  to  the  wood-point,  and 
leave  the  inlay  stuck  fast  in  the  tooth.  A  little  white  wax  is  then 
melted  around  the  joint  with  a  hot  burnisher,  and  the  patient  dis- 
missed for  a  subsequent  sitting,  at  least  five  or  six  hours  later ;  for  it  is 
of  great  importance  that  the  cement  be  allowed  to  get  hard  before  any 
strain  is  put  upon  the  inlay.  It  is  also  essential  to  the  proper  seating 
of  the  inlay  that  no  cement  be  allowed  on  the  floor  of  the  cavity  or 


714 


MECHANICS — DENTAL    PROSTHESIS. 


the  bottom  of  the  inlay,  because  no  amount  of  pressure  will  bring  the 
walls  into  contact  if  there  is  a  body  of  cement  between  those  two  flat 
surfaces ;  and  continued  pressure  for  a  short  time  after  the  seating  is 
necessary  lest  the  elasticity  of  possibly  occluded  air  lift  the  inlay  from 
its  seat  before  the  cement  or  gutta-percha  shall  have  stiffened  suffici- 
ently to  hold  it  in  place. 

"  The  rough  grinding  of  the  protruding  portion  of  the  inlay  I  Fig. 
706)  may  be  done  with  a  stump  or  crown  corundum  wheel,  until  the 
margins  are  nearly  flush  with  the  tooth-surface,  and  then  a  beveled 
corundum  point  like  No.  7  or  No.  12  may  be  used,  as  shown  in  Fig. 
707,  to  make  the  inlay  conform  closely  to  the  contour  of  the  tooth, 
and  the  final  finish  will  best  be  given  by  an  engine  Arkansas  stone 
beveled  like  '  R  '  or  'T,'  and  used  with  its  further  side  in  contact  with 
the  inlay  or  tooth,  or  both,  as  the  case  may  be  (Fig.  707).  Such  use 
of  the  side  of  a  grinding  or  polishing  wheel  avoids  the  hollowing  or 
wavy  lines  which  commonly  result  from  the  peripheral  contact  of 
wheels  or  points  with  the  convex  surfaces  of  the  tooth.  Indeed,  the 
preferable  polishing  instrument  would  be  a  device  like  the  old  engine 


Fig.  710. 


reciprocating  porte-polisher,  if  it  could  be  given  power  enough  to  be 
effective.  A  magnifying-glass  will  aid  in  making  sure  that  the  finish 
leaves  the  inlay  border  quite  flush  with  the  enamel  at  every  point. 

"  Previous^  to  attempting  this  method  of  repair,  it  is  advisable  that 
there  should  be  some  preliminary  practice  in  setting  inlays  in  teeth 
which  have  been  extracted,  or  in  pieces  of  ivory  or  bone  ;  because 
there  will  thus  be  developed  practical  points  which  cannot  be  here 
described  and  yet  are  essential  to  the  proper  performance  of  the 
operation. 

"  The  completed  inlay,  Fig.  708,  when  suitably  adapted  and  finely 
finished,  may  well  be  considered  as  exemplifying  the  nearest  approach 
to  perfection  in  the  accomplishment  of  dental  repair  that  has  as  yet 
been  achieved." 

A  method  of  applying  hard  or  vulcanized  rubber  to  pivot  work  has 
been  suggested  by  Dr.  J.  Richardson,  and  is  briefly  described  by  Dr. 
J.  E.  Dexter,  as  follows:  "An  ordinary  pivot  crown  is  loosely  fitted 
up  with  a  wood  peg,  which  also  fits  loosely  the  canal  in  the  roor.  The 


CROWN    AND    BRIDGE-WORK.  715 

crown  15  groand  from  before  backward  so  as  to  leave  a  space  between 
the  posterior  portions  of  root  and  crown.  Wax  applied  to  the  root 
and  crown  at  once  holds  the  crown  and  pivot  in  proper  relative  posi- 
tion and  gives  an  impression  of  the  root  end.  The  whole  is  withdrawn, 
and  so  invested  in  plaster  that  the  crown,  peg,  and  wax  may  be  removed, 
and  the  crown  be  capable  of  accurate  replacement  on  the  model.  The 
hole  in  the  root  and  root  model  are  now  properly  drilled  by  the  same 
drill  to  receive  a  gold  wire  pivot,  the  latter  being  long  enough  to  pro- 
ject above  the  root  into  the  crown,  and  being  smaller  than  the  holes 
in  both  root  and  crown,  to  allow  of  vulcanite  enwrapping  it  within 
these  spaces.  Now  the  hole  in  the  root  model  is  packed  with  \Tilcan- 
ite  gum,  the  gold  pivot  heated  and  pushed -through  the  gum  to  its  place, 
the  hole  in  the  crown  also  packed,  and  the  crown  forced  to  its  position 
on  the  model  over  the  projecting  end  of  the  gold  pivot.  More  gum  is 
packed  in  the  palatal  groove  between  root  and  crown,  the  whole  flasked 
and  vulcanized,  and  the  finished  cro\vn  forced  to  its  place  on  the  root, 
a  few  folds  of  gold  foil  being  interposed  to  fill  the  joint  tightly. 

'•'Dr.  Richardson  also  made  vulcanite  tubes  for  pivot  sockets,  to 
replace  those  of  gold  commonly  used,  by  vulcanizing  a  layer  of  gum 
around  a  gold  wire,  which  should  afterward  form  the  pivot.  The 
wire,  being  wrapped  in  a  single  layer  of  tin  foil,  was  readily  drawn 
from  the  tube  after  \-ulcanizing,  the  tin  being  removed  with  muriatic 
acid.  A  proper  length  of  the  %-ulcanite  tube  was  inserted  in  the  root, 
either  by  force  and  a  tight  fit  or  by  aid  of  plastic  cements,  aixi  the 
pivot,  \iilcanized  to  a  porcelain  crown,  was  made  to  take  up  the  extra 
space  in  the  tube  caused  by  the  removal  of  the  tin  foil  by  bending,  or 
by  splitting  and  springing  it  open." 

Also,  Dr.  H.  C.  Register's  variation  of  this  method,  which  '•'  is  to 
use  an  ordinary  plain  rubber  tooth,  and  form  its  palatal  contour  with 
\-ulcanite.  Through  this  a  hole  is  drilled  in  line  with  that  in  the  root, 
the  latter  being  filled  with  hickory  wood.  The  crown  now  being  held 
in  position,  a  drill  is  passed  through  the  hole  in  the  vulcanite  into  the 
wood  in  the  root,  and  a  gold  screw  pivot  is  passed  through  the  crown 
into  the  wood  root  socket,  holding  the  two  firmly  together.  The 
details  need  no  further  description." 

A  method  of  pivoting  a  bicuspid  is  suggested  by  Dr.  Bishop  and 
described  as  follows  by  Dr.  Dexter :  "  The  root  being  a  first  bicuspid, 
both  canals  were  opened,  and  a  thin  wire  set  loosely  in  each,  the  pro- 
jecting ends  being  bent  together  like  a  staple  over  the  root  face. 
Gutta-percha  was  then  packed  upon  the  root  face,  around  and  under 
the  wire  staple.  A  plain  rubber  tooth  was  now  ground  to  fit,  and  held 
in  place  while  the  gutta-p)ercha  was  continued  over  its  pins  and  shaped 
to  contour. 


7l6  MECHANICS — DENTAL    PROSTHESIS. 

"The  whole  was  now  removed  together,  invested,  vulcanite  gum 
substituted  for  the  gutta-percha,  and  vulcanized.  The  tooth  was  set 
in  place  with  plastics  in  the  canals  around  the  pins. 

"  This  method  appears  to  have  much  value  for  certain  cases.  Varia- 
tions of  it  may  be  noted ;  for  instance,  using  oxyphosphate,  oxychlo-- 
rid,  or  fossiline,  in  place  of  the  gutta-percha,  and  leaving  the  tooth 
in  place,  for  a  temporary  purpose,  instead  of  removing  and  vulcaniz- 
ing. Also,  using  heavier  wires  of  platinum  and  iridium  alloy  for  the 
pivots,  and  springing  them  apart,  after  vulcanizing,  so  as  to  obtain 
their  spring  pressure  in  maintaining  the  tooth  in  place." 

Banded  or  Collar  Crown. — Gold  Collar  Crowns  consist  of  porcelain 
crowns  with  gold  collars  or  bands  hermetically  inclosing  the  base  of 
the  crown  and  the  neck  and  exposed  portion  of  the  natural  root,  in 
order  to  secure  stability,  and  to  prevent  decay,  and  thus  permanently 
preserve  the  natural  root.  Dr.  W.  H.  Dwindle,  in  the  Ameri- 
can Journal  of  Dental  Science,  April,  1855,  '^^^  the  first  to 
suggest  the  banded  or  collar  crown  in  connection  with  crys- 
tal gold,  for  restoring  lost  or  fractured  crowns.  Fig.  711 
represents  the  shape  or  mold  into  which  crystal  gold  was 
packed,  a  plate  tooth  being  first  backed  with  gold,  to  which 
Fig  ^ii  ^^^^  soldered  a  band.  The  tooth  was  fastened  to  the  root  by 
a  screw  passing  through  a  horizontal  plate  at  the  base  of  the 
backing  into  the  dentine,  and  a  somewhat  larger  screw  was  placed  and 
secured  in  the  pulp  canal,  with  the  free  end  projecting  into  the  capon 
the  crown,  and  gold  was  built  around  this  end  and  the  cap  filled. 

What  may  be  more  properly  termed  a  "cap  crown,"  or  collar 
crown,  was  suggested  by  Dr.  Wm.  N.  Morrison,  in  the  Missouri 
Dental  Jou7-nal,  May,  1869.  No  screws  or  pivots  were  used  in  his 
method,  but  a  cap  of  gold  was  made  in  the  form  of  a  tooth  crown  by 
being  swaged  on  a  model  or  die  of  a  natural  tooth,  its  sides  encircling 
the  root,  and  extending  under  the  gum  to  the  edge  of  the  alveolar 
process.  A  bar  was  soldered  across  the  inside  of  the  cap  to  afford  a 
support  for  the  oxychlorid  of  zinc  (the  oxyphosphate  will  answer 
also).  The  root  was  then  prepared  for  the  reception  of  the  cap, 
which  was  filled  with  the  zinc  preparation  and  pressed  into  place  on 
the  root.  Dr.  B.  Beers,  in  1873,  suggested  a  method  of  forming  a 
gold  crown  from  a  flat  strip  of  gold  by  stamping  it  in  the  center  on  a 
block  of  lead  with  a  punch.  The  gold  was  then  annealed,  and  the 
two  ends  bent  around  the  tooth  (the  stamped  surface  representing  the 
labial  surface  of  a  front  tooth),  and  these  ends  soldered  together. 
The  "  bite  "  was  then  adjusted  by  means  of  a  half-round  file,  so  that 
the  tooth  articulated  properly  with  its  antagonists.  A  thick  flat  piece 
of  gold  was  then  bent  to  suit  the  form  of  tooth  required  and  soldered 


CROWN   AND    BRIDGE-WORK. 


717 


on  the  top  of  the  gold  crown,  which  was  fastened  to  the  root  by  insert- 
ing headed  gold  screws  into  the  canal  and  then  filling  the  cap  with 
oxychlorid  of  zinc,  when  it  was  forced  over  the  root  to  its  proper 
place.  Fig.  712  represents  Dr.  Beers'  crowns  and  method  of  attach- 
ment to  the  roots  of  teeth. 

Dr.  E.  S.  Talbot  improved  upon  the  method  of  Dr.  Beers  by  a  band 
fitted  to  the  root  and  extending  to  the  alveolus,  across  the  inside  of 


Fig.  712. 


which  a  partition  or  floor  of  gold  is  soldered.  In  this  floor  holes  are 
made  opposite  the  pulp  canals  underneath.  Wires  are  loosely  inserted 
in  these  canals,  and  the  space  in  the  band  beneath  the  floor  is  filled 
with  gutta-percha  or  one  of  the  zinc  preparations,  and  the  band  or 
collars  forced  into  position  on  the  root,  the  wires  projecting  through 
the  holes  in  the  floor.  After  the  gutta-percha  or  cement  has  become 
hard,  the  wires  are  drawn   out,  and  headed  screws  are   substituted, 


Fig.  713. 


Fig.  715. 


which  fasten  the  band  or  crown  to  the  root.  The  work  is  completed 
by  filling  the  band  with  gold  or  by  swaging  a  gold  crown  or  cap,  which 
is  slipped  over  or  within  the  edge  of  the  band  encircling  the  root,  the 
cap  being  previously  filled  with  cement. 

Fig.  713  represents  Dr.  Talbot's  method. 

The  collar  of  such  crowns,  as  now  made,  consists  of  22  to  23  carat 


7i8 


MECHANICS — DENTAL   PROSTHESIS. 


gold  plate,  or  pure  gold  lined  with  platinum,  or  iridio-platinum  alloy. 
The  coronal  portion  of  the  natural  root  is  prepared  by  first  grinding 
the  occluding  surface  with  a  properly  adapted  stump  corundum  or 
carborundum  wheel  (Fig.  716),  and  finishing  with  the  corundum 
points.  The  approximal  surfaces  are  removed  by  means  of  cutting 
discs  and  thin  safe-sided  separating  files  (Fig.  335,  page  428), 
and  the  corners  rounded.  The  exposed  or  cervical  portion  of  the 
natural  root  is  trimmed  until  it  is  brought  to  the  shape  represented 
by  Fig.  715  b,  in  which  the  sides  are  parallel  with  the  line  of 
the  root,  and  the  cut  surface  extends  as  deep  as  the  collar  is  to 
be  placed.  Fig.  714  illustrates  the  root-trimmers  for  shaping  the 
cervical  portion  of  the  root.  Where  a  large  portion  of  the  crown 
of  the  tooth  is  to  be  removed  in  preparing  the  root,  a  succession 
of  holes  may  be  drilled  across  such  a  portion,  and  the  partitions 
removed  by  a  fissure-bar  or  corundum  disc.  As  much  of  the  natural 
crowns  of  bicuspids  and  molars  as  possible  should  be  preserved  for  the 
stability  of  the  artificial  crown  when  such  is  of  all  gold  or  a  porcelain 


Fig.  71b. 

facing  is  employed  in  connection  with  gold  to  form  the  crown.  The 
preparation  of  the  root  canals  is  the  same  as  before  described.  The 
root  trimmers  or  reducers  devised  by  Dr.  R.  W.  Starr  are  intended  for 
trimming  the  edges  or  reducing  the  diameters  of  roots  over  which 
collars  are  to  be  placed.  The  shoulder  keeps  the  instrument  on  the  root 
and  limits  the  penetration  of  the  spur,  which,  by  its  knife  edge,  scrapes 
the  side  of  the  root  (Fig.  715  a)^  so  that  it  may  easily  and  quickly 
be  given  the  shape  of  Fig.  715  b,  or  any  similar  form.  They  are 
made  right  and  left  (Fig.  714)  ;  the  straight  pair  (Nos.  i  and  2)  for 
use  on  the  superior  roots  anterior  to  the  molars,  and  the  curved  pair 
(Nos.  3  and  4)  for  use  in  all  the  other  natural  roots. 

Dr.  C.  M.  Richmond's  method  of  making  what  are  known  as  the 
"Richmond  Crowns"  is  as  follows:  This  crown  consists  of  a  close- 
fitting  band  or  ferrule  of  coin-gold  plate,  to  which  a  cap  or  surface, 
corresponding  to  the  grinding  surface  of  the  class  of  tooth  it  is  de- 
signed to  crown,  is  soldered.  The  root  is  prepared  by  making  the 
exposed  surface  flat  by  means  of  the  file  or  corundum  disc.     A  strip 


CROWN    AND    BRIDGE-WORK.  719 

of  gold  plate,  about  No.  27  American  gauge,  is  then  cut,  of  such  a 
width  as  will  extend  from  the  alveolar  process  to  a  height  sufficient  to 
give  the  proper  length  of  gold  crown.  To  determine  the  proper 
width  of  the  strip  or  ferrule,  a  pattern  of  tin  or  sheet  lead,  adapted  to 
the  tooth,  may  be  used.  The  strip  of  gold  plate  is  then  bent  with  the 
pliers  and  filed  to  the  proper  form,  and  the  overlapping  ends  soldered 
together,  the  ferrule  being  made  slightly  smaller  than  the  root  it  is  to 
encircle,  so  as  to  secure  a  tight  fit.  After  the  band  or  ferrule  is  com- 
pleted, it  is  capped  by  a  piece  of  plate  large  enough  to  cover  the  crown 
end,  and  the  two  soldered  together,  and  properly  finished  by  smooth- 
ing the  sharp  edges  with  a  file  and  burnisher.  The  cap  or  crown  is 
then  adapted  to  the  festooned  margin  of  the  gum  and  septa  by  filing 
the  approximal  edges  concave.  The  margin  of  the  gold  crown,  where 
it  comes  in  contact  with  the  neck  of  the  root,  is  slightly  beveled  from 
the  outside,  in  order  to  make  a  thin  edge  which  will  adapt  itself  to 
the  surface  of  the  neck  under  the  pressure  necessary  to  force  the  crown 
to  its  place  on  the  root.  The  crown  is  then  forced  over  the  root,  and 
the  position  of  the  artificial  cusps  yet  to  be  made  determined  by  the 
antagonism  of  the  opposing  teeth.  Small,  flattened  buttons,  made  by 
melting  scraps  of  plate  and  slightly  flattening  them  by  blows  with  a 
hammer,  are  soldered  on  the  grinding  surface  of  the  gold  crown,  which 
is  filled  and  invested  during  the  soldering  process  with  moistened 
sand,  to  which  is  added  a  little  plaster.  After  thus  attaching  the 
cusps  and  contouring  the  grinding  surface,  the  gold  crown  is  ready  to 
be  adjusted  to  the  root.  A  small  hole  is  first  drilled  through  the  side 
or  top  of  the  crown,  to  allow  the  surplus  cement,  by  which  the  crown 
is  secured,  to  escape.  The  concavity  of  the  crown  is  then  filled  with 
either  the  oxychlorid  or  oxyphosphate  of  zinc,  mixed  somewhat  thinner 
than  for  a  temporary  filling,  and  the  crown  forced  over  the  root  and 
the  patient  directed  to  bite  upon  it,  in  order  to  secure  the  proper 
occlusion  of  the  teeth.  The  crown  is  then  firmly  held  in  place  until 
the  cement  has  hardened,  when  the  small  hole  through  which  the  sur- 
plus has  escaped  can  be  filled  with  gold.  Any  slight  defect  in  the 
articulation  can  be  remedied  by  grinding  with  corundum  points. 

The  method  of  Dr.  H.  W.  F.  Buttner  is  a  combination  of  the 
ferrule,  or  band  encircling  the  root,  and  a  central  pivot,  and  is 
described  as  follows  by  Dr.  J.  E.  Dexter:  — 

'*  A  special  set  of  instruments  is  used  in  this  process.  Those  for 
preparing  the  root  are  drills,  reamers,  and  trephines  (Fig.  717,  h  c  ii~). 
The  drill  bores  out  the  root  canal.  The  reamer  cuts  the  face  of  the 
root  level,  being  guided  by  a  central  pin.  The  trephine  turns  the 
neck  truly  cylindrical  for  a  certain  distance  up  or  down  its  sides, 
being  also  guided  by  a  center  pin.     The  root,  thus  prepared,  is  shown 


720 


MECHANICS — DENTAL   PROSTHESIS. 


in  Fig.    718.      The  drill,  reamer,   and  trephiiie  are  in  various  and 
exactly  corresponding  sizes. 

"  A  steel  wire  is  now  placed  in  the  root,  projecting  half  an  inch. 
An  impression  is  now  taken,  the  wire  projecting  through  it,  a  cup 
with  an  opening  over  the  root  being  used  for  that  purpose.  The  wire 
is  withdrawn  carefully  before  removal  of  the  impression  from  the 
mouth,  but  is  afterward  replaced.  Over  it,  on  the  impression,  is 
now  slipped  that  one  of  a  set  of  brass  root  models  which  corre- 
sponds to  a  drill  and  trephine  used,  and  the  model  is  then  made,  and 
holds  the  brass  root  model  in  its  place,  with  the  wire  projecting. 
The  latter  is  now  removed,  and  plaster  cut  from  around  the  root 
model  to  a  depth  sufficient  to  accommodate  the  cap  which  is  to  follow. 
This  is  of  gold,  struck  out  of  the  solid,  on  that  one  of  the  accompany- 
ing steel  dies  which  accords  with  the  trephine  and  root  model  used. 

It  also  has  a  central  pin,  to  correspond 
be  d         with  the   drill  which   enlarged  the   root 

canal  (Fig.  718).     This  cap  is  set  on  the 
root   model,    and    a    plain   plate   tooth, 


'  B   B 


Fig.  717. 


Fig.  71S. 


Fig.  719. 


ground  hollow  on  the  inner  surface,  to  cover  the  outer  wall  of  the  gold 
cap,  is  backed,  and  soldered  in  place  on  the  cap — of  course,  after 
removal  from  the  brass  root  model — the  solder  forming  the  palatal 
contour.  The  whole  is  now  polished,  placed  on  the  root,  and  driven 
home  with  a  mallet  (Fig.  719). 

"  The  perfectly  accurate  fitting  of  this  operation  is  secured,  beyond 
cavil,  by  the  set  of  drills,  reamers,  trephines,  dies,  and  root  models 
with  which  it  is  performed.  Probably — indeed,  almost  certainly — 
this  is  the  strongest  method  of  attachment  of  artificial  crowns  to  nat- 
ural roots  which"  can  be  devised.  Indeed,  the  only  thing  breakable 
about  any  given  case  of  this  method  seems  to  be  the  porcelain  crown 
or  face.  The  end  and  interior  of  the  root,  also,  are  absolutely  pre- 
served from  moisture  for,  at  least,  a  very  long  time." 

Another  method  of  forming  collar-crowns  is  described  as  follows  by 


CROWN   AND    BRIDGE-WORK. 


721 


Dr.  C.  S.  W.  Baldwin  :  *  "  Select  a  Logan  crown  slightly  shorter  than 
would  be  used  for  setting  without  a  ferrule.  Countersink  and  prepare 
the  inside  of  a  root  as  for  a  Bonwill  or  any  ordinary  crown.  If  the 
outside  of  the  root  at  the  margin  of  the  gum  presents  an  irregular 
surface,  then  with  Dr.  Starr's  reducers  (Fig.  714)  shape  it  to  such  a 
size  that  the  ferrule  may  be  perfectly  adapted  to  all  parts.  Take  an 
impression,  and  produce  in  zinc  or  Babbitt's  metal  a  die,  to  form 
which  take  a  plaster  model  of  the  root-end,  an  eighth  of  an  inch  long, 
and  shellac  it  to  the  point  of  a  cone,  which  can  be  easily  made  by 
turning  down  a  large  spool,  thus  making  the  deep  mold  in  sand  into 
which  the  metal  is  poured.  With  this  die  strike  the  gold  (22-carat, 
No.  30  gauge,  is  most  commonly  in  use),  laid  upon  soft  lead.  A  few 
blows  will  produce  a  seamless  and  perfectly-fitting  cover  and  ferrule. 
After  trimming  this  to  fit  the  festoon  of  the  gum,  drill  in  it 
from  the  lower  side  a  hole  for  the  pin  of  the  crown,  leaving 
the  ragged  edge  produced  by  the  drill.  Then  fill  the  coun- 
tersunk portion  in  the  porcelain  crown  with  oxyphosphate 
of  zinc,  and  with  the  gold  ferrule  or  cap  in  place,  adjust  the 
crown  as  you  would  wish  it  when 
completed.  When  the  oxyphosphate 
is  hard,  you  will  find  the  ragged  edge 
on  the  upper  side  of  the  cover  will 
materially  aid  in  removing  and  keep- 
ing the  cap  where  it  belongs.  Unite 
the  cover  to  the  platinum  pin  in  the 
crown  with  a  small  amount  of  soft 
solder — tin  and  lead — using  muriate  pic.  720. 
of  zinc  as  a  flux,  a  few  blasts  from  the 

blowpipe  being  all  the  heat  required.  Then  fill  the  root  with  oxy- 
phosphate and  firmly  press  to  place.  These  caps  might  be  made 
up  at  leisure,  providing  a  few  variations  for  double  and  single  rooted 
teeth.  When  a  case  is  met  that  you  cannot  fit  from  your  stock, 
choose  a  cap  larger  than  the  end  of  the  root,  and  with  a  single  clip 
of  the  shears  cut  to  the  center  of  the  cap,  and  with  pliers  spring 
together,  lapping  the  edges  until  the  size  required  is  obtained. 
Solder  with  gold  solder  by  holding  over  the  spirit-lamp,  and  proceed 
as  before. 

"  Fig.  722  shows  a  root,  cover,  and  Logan  crown  ready  to  be  assem- 
bled for  the  soldering  of  the  crown-pin  to  the  cover  ;  Fig.  720  shows 
the  cap  cemented  and  soldered  to  the  crown,  and  Fig.  721  the  com- 
pletely crowned  root." 


Fig.  721. 


Fig.  722. 


*  Dental  Cosmos,  vol.  xxviii. 


46 


722 


MECHANICS DENTAL    PROSTHESIS. 


Dr.  H.  C.  Merriam  describes  a  form  of  artificial  crowns  as  fol- 
lows :* — 

"  We  need  a  crown  that  can  be  ground  on  its  sides  as  well  as  against 
the  root,  with  a  straight  hole  through  it,  similar  to  that  of  the  English 
tube  teeth,  excepting  that  the  hole  should  come  out  at  a  greater  dis- 
tance from  the  cutting  edge  in  the  incisors  and  cuspids.  After  the 
crown  is  ground,  to  place  the  hole  through,  it  may  be  formed  as  we 
desire  with  a  copper  drill  and  corundum,  or  with  hard-rubbef  points 
dipped  in  corundum, 

"There  are  now  made,  for  use  in  machine-shops,  wheels  the  cor- 
undum of  which  is  united  with  a  flux,  and  baked  at  a  temperature  of 
nearly  three  thousand  degrees.  These  wheels  hold  a  true  edge,  and 
when  made  small  enough  will  be  a  great  step  in  advance  of  what  we 
have.  I  have  had  small  points  made  in  this  way,  with  which  I  can 
grind  out  a  crown  to  any  of  the  forms  illus- 
trated in  Fig.  723." 

"I  now  show  you  some  of  the  different 

Fig.  724. 


Fig.  723. 


Fig.  725. 


varieties  that  can  be  made  by  grinding  the  crown  just  referred  to 
(Fig.  724),  the  advantages  of  which  have  already  been  stated.  With 
these  crowns  it  is  expected  that  dowels  will  be  used,  set  in  either 
cement  or  gutta-percha. 

"  We  will  now  pass  to  forms  which  are  to  be  secured  by  metal  bands 
fitted  either  to  the  root  or  to  the  crown  itself  (the  strongest,  of  course, 
being  held  at  their  periphery),  and  I  will  detail  my  method  of  applying 
the  same,  for  it  enables  me  to  avoid  the  trouble  and  delay  of  investing 
or  soldering.  For  these  the  crowns  given  in  Fig.  723  may  be  used,  as 
well  as  those  shown  in  Fig.  724. 

"  The  band  is  fitted  to  the  root,  and  the  crown  ground  into  the  band 
after  proper  occlusion  with  its  antagonist  has  been  obtained.     If  a 


Dental  Cosmos,  January,  1887. 


CROWN    AND    BRIDGE-WORK. 


-'3 


molar,  a  fine  groove  is  ground  around  it,  and  the  band,  after  being 
corrugated  on  its  inner  surface  with  a  small  lining  bur,  is  placed  on  a 
lead  anvil  and  the  tooth  driven  into  it,  thus  partially  securing  the 
advantage  of  union  by  gomphosis.  The  common  glass  stopper  is  a 
good  illustration  of  how  little  more  than  its  fit  would  be  required  to 
retain  it  firmly  in  place.  For  this  little  I  have  drawn  on  the  tube- 
teeth  workers  of  England.  A  few  small  pieces  of  sulphur  are  then 
placed  inside  the  band,  and  all  held  over  a  small  flame  until  the  sul- 
phur melts  and  flows  into  the  groove  between  the  band  and  the  crown. 
Zinc  phosphate  may  be  used  before  the  crown  is  forced  in,  or  some 
flux — borax,  for  instance,  which  melts  at  a  low  temperature,  though 
this  would  probably  require  investing.  We  then  have  a  crown  which, 
if  a  molar,  I  do  not  fear  to  attach  with  gutta-percha  without  dowels; 
but  others  may  not  have  this  confidence,  and  dowels  may  either  be  put 
into  the  roots  or  set  in  the  crown  with  cement,  and  afterward  secured 
to  their  places  in  the  root  as  usual  TFig.  725).     It  is  evident  that  if 


Fig.  726. 


Fig.  727. 


Fig.  728. 


Fig.  729. 


cement  is  strong  enough  to  hold  a  dowel  in  the  root  it  must  be  equally 
serviceable  in  securing  the  crown  to  the  dowel.  Some  like  the  hardest 
way  best.  These  may  fit  a  fine  platinum  or  pure  gold  wire  into  the 
groove  around- the  crown  (Fig.  726).  Drive  in  as  before;  invest  and 
solder  (Fig.  727).  A  gold  amalgam  may  be  used,  such  as  was  em- 
ployed by  old  plate-workers  for  banding  a  plate  over  the  teeth.  I 
have  not  tried  this,  but  suggest  it  as  of  possible  use,  the  dowels  being 
put  in  as  before.  For  the  incisors  the  groove  should  not  run  around 
the  anterior  face  of  the  crown,  and  I  have  not  soldered  these  teeth  in 
(Fig.  728).  I  have  entire  confidence  in  any  form  for  the  incisors 
and  bicuspids  where  the  root  is  well  banded,  the  dowel  put  into  the 
center,  and  the  crown  forced  to  place  in  gutta-percha  (Fig.  729); 
while  for  the  molars,  if  quite  short,  I  do  not  care  for  the  dowels. 
You  will  notice  that  this  method  does  away  with  much  of  the  showing 
of  gold  in  molars,  where  such  a  result  is  desired  (Fig.  730). 


724 


MECHANICS DENTAL    PROSTHESIS. 


"  When  cohesive  gold  was  first  used  we  thought  nothing  could  be 
more  beautiful — the  more  conspicuous  the  better — but  we  gradually 
learned  that  the  perfection  of  art  was  to  conceal  art.  So  it  is  with 
tooth-crowns,  and  we  shall  learn  soon  to  omit  great  backings,  etc., 
wherever  possible ;  not  only  because  they  are  conspicuous,  but  because 
a  tooth  backed  up  by  any  substance  is  no  longer  translucent. 

"I  will  present  one  more  form  for  molars,  and  although  it  shows 
more  gold  than  any  of  the  others,  it  is  perhaps  the  strongest  of  all. 
The  band  is  made  full  width  down  to  occlusion,  and  any  large,  strong 
tooth  is  ground  to  fit  the  space  to  be  filled  in  the  arch.  This  is 
driven  into  the  band  so  as  to  be  even  with  its  edge ;  cemented  with 


Fig.  731. 


Fig.  732. 


sulphur  as  before,  and  I  think  we  have  a  crown  that  is  made  for  all 
time  (Fig.  731). 

'^Setting. — I  first  varnish  the  band  inside  with  Canada  balsam  dis- 
solved in  ether;  then  fill  the  crown  with  gutta-percha  and  crowd  it 
up  against  the  root  several  times,  to  get  an  impression.  When  sure 
that  I  have  the  right  amount  of  gutta-percha,  I  place  the  dowels  in  the 
root  (if  I  am  to  use  them)  ;  heat  the  crown  ;  dip  it  into  cajeput  or  any 
essential  oil,  and  crowd  it  to  place.  The  dowels  I  fit  in  the  same  way, 
wrapping  them  with  gutta-percha  and  working  up  and  down  in  the 
root  until  I  get  the  impression,  before  the  final  forcing  to  place.  I 
thus  have  the  advantage  of  the  dowel  and  hard  center  of  gutta-percha 
to  act  as  a  plunger,  and  the  soft,  semi -dissolved  gutta-percha  comes 
back  on  the  outside  of  the  mass,  forming,  I  think,  the  tightest  root- 
filling  known.  I  fill  roots  in  this  way  with  gutta-percha  points  when 
I  do  not  use  a  dowel.     The  dowels  used  are  made  by  wrapping  a  piece 


CROWN   AND    BRIDGE-WORK. 


725 


of  platinum  and  iridium  wire  with  about  one-third  of  a  sheet  of  gold 
foil,  which  is  melted  on  and  the  combination  made  true  by  being  drawn 
once  through  a  wire  gauge.  A  piece  of  piano  wire  is  then  wound 
around  it  three  or  four  times,  to  serve  as  a  guide,  and  a  line  platinum 
wire,  previously  drawn  square,  is  caught  and  turned  through  the  wire 
guide  a  few  times,  when  the  winding  may  either  be  finished  by  hand, 
or  the  end,  after  being  started,  may  be  placed  in  a  lathe-chuck  and 
wound  up  at  once  (Fig.  732).  A  piece  of  gold  foil  is  then  wrapped 
around  the  whole  and  the  fine  wire  soldered  on.  A  dowel  made  in 
this  manner  is  not  strained  by  having  its  thread  cut,  and  the  thread, 
being  square  and  coarse  or  fine,  as  you  wish,  is  strong  and  possesses 
plenty  of  grip. 

"  Should  these  forms  prove  as  valuable  as  I  hope,  those  at  a  distance 
from  the  cities,  without  gas,  will  find  that  the  labor  of  crowning  roots 
has  been  much  lessened. 

"  When  a  root  has  broken  off  far  under  the  gum  it  should  be  filled 
with  gutta-percha  and  a  temporary  plate  worn — if  the  loss  be  in  the 
front  of  the  mouth — until  the  root  works  down,  when  it  may  be 
crowned  and  the  plate  given  up. 

' '  In  preparing  roots  after  a  large  portion  of  the  crown  is  broken 
away,  I  enlarge  the  pulp-chamber  with  a  large,  round  bur,  and,  when 
even  with  the  gum,  follow  with  the  revolving  saw  here  shown  (Fig.  733). 
With  this  saw  I  often  cut  off  the  remnants  of 
a  crown   from   the  inside  without  wounding     ^^ 
the  gum  or  drawing  a  drop  of  blood,  and  am 
saved  the  unpleasantness  of  running  a  stump 
corundum  wheel  in  the  mouth.     The  outside 
of  the  root  can  sometimes  be  formed  with  the 
instrument  here  shown  (Fig.  734)." 

Fig.  735  represents  porcelain  cusp-crowns. 

These  porcelain  cusps  are  designed  for  use 
with  a  gold  band  representing  the  body  of  the 
tooth.  The  band  or  collar  is  first  fitted  to  the 
suitably  prepared  root,  and  the  cusp-crown  is 
then  fitted  in  the  collar.  The  collar  is  then 
filled  with  gutta-percha,  cement,  or  amalgam, 
and  the  crown  pressed  into  place,  i  shows 
in  section  a  molar  root,  collar,  and  cusp-crown, 
mounted. 

In  cases  where  it  is  desirable  to  show  as  little  of  the  gold  collar  as 
possible,  the  forms  indicated  in  3  and  4  may  be  employed,  the  gold 
band  being  cut  away  on  the  buccal  side,  as  shown  in  the  cuts. 

Dr.  E.  T.  Starr,  in  the  Denial  Cosmos,  describes  an  improved  "  die- 


FlG.  733- 


Fig.  734- 


2  shows  the  same 


726 


MECHANICS DENTAL    PROSTHESIS. 


plate"  and  "hubs"   for  shaping  metal  cap-crowns,  of  his  own  sug- 
gestion :  — 

"  In  the  construction  of  metal  cap-crowns  to  cover  natural  teeth  or 
teeth- roots  there  are  many  methods  which  result  in  good  work,  but  in 
most  cases  the  caps  do  not  articulate  as  well  as  they  might,  for  the 
reason  that  means  for  embossing  the  bicuspid  and  molar  cusps  are  not 
at  hand  or  available  within  the  short  time  at  the  disposal  of  either  the 
patient  or  the  dentist.  With  the  object  of  providing  an  easy  and 
quick  way  of  working  under  such  circumstances,  I  have  made  a  single 


Fig.  735. 


plate  (Fig.  736)  in  which  are  four  groups  of  intaglio  dies  representing 
with  distinctive  correctness  the  peculiar  cusps  of  the  upper  and  lower 
right  and  left  bicuspids  and  molars.  These  are  indicated  by  the  Hil- 
lischer  notation,  so  that  each  form  may  be  easily  identified  in  practice. 
"  The  hubs  A,  B  (Fig.  737)  are  of  the  sizes  shown,  and  are  made  of 
an  alloy  composed  of  tin  one  part,  lead  four  parts,  melted  together. 
The  mold  C  should  be  warmed,  the  melted  alloy  poured  in  every  hole, 
and  the  overflow  wiped  off  just  before  the  metal  stiffens.  This  will 
make  the  butts  of  the  hubs  smooth  and  flat.  After  a  minute  or  two 
the  mold  may  be  reversed,  the  hubs  shaken  out,  and  the  casting  pro- 
cess continued  until  a  considerable  number  of  hubs  shall  have  been 
cast. 


CROWN   AND    BRIDGE-WORK. 


727 


''  In  Fig.  738  a  molar  hub  is  shown  in  place  on  a  piece  of  No.  32 
gold  plate,  which  lies  over  the  6.  (upper  right  first  molar)  die.     A 


Fig.  736. 


succession  of  blows  on  the  hub,  with  a  four-pound  smooth-faced  ham- 
mer, will  drive  the  plate  into  the  die,  and  at  the  same  time  spread  the 


Fig.  737. 


hub  metal  from  the  die  center  to  its  circumference  in  such  a  manner 
that  the  plate  will  be  perfectly  struck-up  with  the  least  possible  risk  of 
being  cracked.     The  flattened   hub  is  seen  in  Fig.  739,  which  also 


728 


MECHANICS DENTAL    PROSTHESIS. 


shows  at  D  the  obverse  of  the  struck-up  hub,  and  at  E  the  cameo  of 
the  struck-up  plate,  having  every  cusp  and  depression  of  6.  sharply 
defined. 

"The  counter-die  plate   (Fig.  736)   is  made  of  a  very  hard   cast 
metal,  which  will  admit  of  the  striking  up  of  many  crown-plates  by 

the  means  and  methods  de- 
scribed, if  the  crown-plates  be 
not  too  thick  and  stiff.  Of 
course  they  should  be  annealed 
before  they  are  placed  over  the 
die.  In  careful  hands,  the  die- 
plate  should  give  clear  cusp 
definitions  after  years  of  use. 

' '  For  the  reason  that  the 
counter-die  plate  is  in  some 
respects  similar  to  a  stereotype 
plate  for  printing,  the  struck 
impressions  on  two  strips  of 
thin  plate  will  appear  as  in  Fig.  740,  wherein  their  regular  order  is 
noticeable  as  seen  from  the  cameo  surface  of  the  struck  plates.  The 
peculiar  action  of  the  hub  in  forming  first  the  center  of  the  crown 
plate,  and  spreading  from  the  center  outward,  as  the  hub  is  shortened 
under  the  hammer,  until  the  die  is  overspread  by  the  plate  and 
hub,  with  the  result  shown   in   Fig.  739,  is  an  essential   feature  of 


Fig.  738. 


Fig.  739. 


this  process  for  obtaining  easily  and  quickly  the  superior  styles 
of  coronal  cameos  shown.  If  a  cusp  or  fissure  should  chance  to 
crack  in  hubbing,  a  small  piece  of  plate  may  be  struck  over  it,  or 
another  crown  plate  be  struck  over  the  first  and  the  two  soldered 
together. 

"  The  depressions  in  the  struck  plate  can  be  partly  or  wholly  filled 


CROWN    AND    BRIDGE-WORK.  729 

with  scraps  of  plate  or  solder,  and  the  surplus  plate  cut  away  from  the 
cameo. 

"The  fact  is  noteworthy  that,  by  means  of  the  Knapp  blowpipe, 
the  coronal  intaglio  may  even  be  filled  with  melted  scraps  cut  from 
the  identical  plate  out  of  which  the  cameo  was  struck.  The  better 
way,  however,  is  to  fill,  say  a  twenty-carat  cameo  with  eighteen-carat 
plate  scraps.  The  fitting  and  soldering  of  the  doubled  or  filled  cameos 
to  suitable  collars  is  a  simple  matter,  and  need  not  be  described. 

"It  only  remains  to  add  the  statement  that,  by  this  counter  die 
and  hub  process,  gold,  platinum,  silver,  or  other  metallic  cap-crowns, 
having  finely-formed  and  solid  cusps  for  proper  occlusion  and  re- 


*  Fig.  740. 

sistance  to  wear,  can  be  made  with  little  trouble  and  in  a  very  short 
time." 

All-Metal  Crowns. — Entire  crowns  of  either  gold  or  aluminum  are 
employed  for  capping  badly  decayed  or  fractured  posterior  teeth. 
These  crowns  may  be  made  either  in  sections,  composed  of  a  collar  or 
ferrule  and  grinding  surface,  or  as  seamless  contour  crowns  by  a  stamp- 
ing process.  In  constructing  a  crown  in  sections  the  collar  of  23-carat 
gold  may  be  first  formed  on  a  mandrel,  and  then  placed  in  a  die 
obtained  from  a  model  of  a  natural  crown,  and  burnished  to  the  sides, 
or  stamped  between  a  die  and  counter-die  representing  the  crown  of  a 
natural  tooth.  After  the  collar,  which  may  be  seamless,  or  its  ends 
soldered  together,  is  contoured,  the  cap  or  grinding  surface,  of  a  size 


730  MECHANICS — DENTAL    PROSTHESIS. 

suitable  to  adjust  to  the  collar,  is  stamped  with  a  die  (Fig.  741)  and 
'   _^  adjusted  and  soldered  to  the  collar.     Having  the  collar 

r  Z*^^  1  part  of  the  crown  a  little  smaller  or  contracted  than  the 
ft|^^^^  cervical  part  of  the  prepared  root  which  it  is  to  cover,  will 
:i  permit  of  a  nice  adjustment,  as  the  gold,  especially  in  the 
II  case  of  a  seamless  crown,  will  expand  when  forced  or 
ll  slipped  over  the  end  of  the  natural  root,  and  can  be 
'!|i  trimmed  with  curved  scissors  or  shears,  and  closely  adapted 
to  the  root  and  gum.  Stamped  seamless  aluminum  crowns 
are  made  in  the  same  manner  as  the  gold  seamless  crown, 
the  construction  of  which  is  described  by  Dr.  George  Evans  in  his 
work  as  follows  :  "A  contour  crown  can  be  made  by  placing  a  seam- 
less cap  on  a  sectional  die  or  mandrel  of  the  shape  of  the  tooth,  first 
swaging  the  grinding  surface  on  the  mandrel  and  then  stamping  down- 
ward on  the  straight  sides  of  the  crown  with  a  cap  fitted  to  the  shank 
part  of  the  mandrel."  A  sectional  mold  method  is,  however,  more 
simple  and  practical,  and  is  described  by  the  same  author  for  a  molar 
crown,  as  follows:  "A  natural  tooth,  or  one  made  of  plaster,  is  used 
as  a  model.  From  this  a  sectional  mold  is  made  in  Babbitt's  metal, 
zinc,  or  fusible  alloy.  Into  the  mold  a  cap  of  gold  23  to  24  carats 
fine,  30  to  32  gauge,  is  adjusted,  fitting  tightly  the  orifice  of  the  closed 
mold.  The  mold  is  placed  in  a  vise,  the  cap  expanded  to  the 
general  form  of  the  mold  by  hammering  into  it  a  mass  of  cotton, 
and  then  swaged  more  in  detail  to  the  form,  and  with  a  wood  point  or 
burnisher  revolved  by  the  dental  engine  burnished  into  every  part  of 
the  mold.  To  facilitate  the  process,  the  mold  should  be  frequently 
opened  and  the  gold  annealed."  "Another  method  is  to  form  a 
fusible-metal  die  of  the  tooth  to  be  crowned,  and,  after  having  stamped 
the  grinding  surface  of  the  crown,  to  reverse  and  swage  the  sides  close 
to  the  die  ;  the  crown  is  then  relieved  of  the  core  (die)  b)y  heating  to 
the  melting  point  of  the  fusible  metal  and  pouring  it  out." 

Figs.  742  and  743  represent  solid  gold  cusps  for  crown  and  bridge- 
work. 

Gold  cap-crowns  can  be  rendered  more  durable  by  filling  in  the 
under  surface  of  occluding  portion  of  the  crown  with  gold  solder. 

Fig.  744  represents  the  Evans  Gold  Seamless  Contour  crowns  for 
bicuspids  and  molars. 

The  Hollingsworth  system  for  crown  and  bridge-work  is  described 
by  its  author  as  follows  : — 

"This  system  supplies,  in  the  first  place,  a  variety  of  forms  for  the 
various  teeth,  great  enough  to  cover  almost  any  case,  and  for  the  rare 
cases  which  cannot  be  suited  direct  it  affords  a  ready  means  of 
making  the  exact  form  required.     There  are  in  the  set  204  forms  of 


CROWN    AND    BRIDGE-WORK. 


731 


cusps  and  36  of  facings  for  bicuspids  and  molars,  and  40  forms  for 
incisors  and  cuspids.  These  last  give  both  the  labial  and  lingual 
faces.     All  the  forms  are  exact  fac-similes  from  nature,  selected  with 


Fig.  742. 


I'\ 


:'%' 


Fig.  743. 


great  care  to  cover  the  widest  range  possible.  They  are  made  of 
metal,  and  are  used  as  patterns  from  which  to  make  dies  or  molds,  as 
may  be  required,  for  the  swaging  of  gold  cusps,  or  crowns.     There  is 


Fig.  744. 


therefore,  no  wear  upon  them,  and  they  retain  their  shapes  and  sizes 
unaltered. 

"  The  outfit  for  working  these  forms  consists  of  a  molding-plate,  three 
rubber  rings,  a  sheet  of  asbestos  10x7  inches,  a  carbon  stick  for  use 


732 


MECHANICS — DENTAL    PROSTHESIS. 


in  casting,  and  a  box  of  Hollingsworth's  annealed  copper  strips  for 
measuring  roots. 

"  This  system  permits  cusps  to  be  made  either  hoilow  or  solid.  Scrap 
gold  can  be  used  for  casting  solid  cusps,  and  porcelain  facings  can 
be  quickly  inserted  in  crowns  without  investing ;  but  perhaps  its  most 


Fig.  745. 


Fig.  746. 


Fig.  747. 


important  advantage  is  the  exactness  with  which  the  fit  and  articula- 
tion of  bridges  are  obtained  and  maintained." 

To  Make  a  Gold  Croivii  {^Bicuspid  or-  Molar^. — Make  a  band  to  fit 
the  root  in  the  ordinary  way.     Place  the  band  in  the  mouth  (see  Fig. 


Fig.  748. 


Fig.  749 


Fig.  751. 


Fig.  750. 


Fig.  752. 


745),  and  cut  off  on  a  line  where  the  adjoining  teeth  begin  to  turn  to 
form  the  cusp  (see  c.  Fig.  745).  Place  a  small  piece  of  wax  inside  the 
band  to  assist  in  holding  the  cusp-button,  which  should  be  selected  to 
fit  the  circumference  of  the  band,  to  articulate  properly,  and  to  corre- 
spond in  shape  with  the  other  teeth  (see  b,  Fig.  745).     Remove  the 


CROWN    AND    BRIDGE-WORK. 


*7   ■»  '» 


button,  and  place  it  on  the  molding-plate  with  the  grinding-surface 
up  (see  Fig.  746).  Place  the  small  rubber  ring  di' around  it,  pour  in  a 
sufficient  quantity  of  Melotte's  metal  to  nearly  fill  the  ring  (Fig.  747). 
As  soon  as  the  metal  sets,  chill  the  surface  by  dipping  in  water  for  a 
moment,  and  then  remove  the  rubber  ring.  When  the  heat  begins  to 
return  to  the  surface,  a  quick  rap  of  the  die  on  the  bench  will  cause 
the  cusp-button  to  drop  out  and  leave  the  mold  ready  to  form  the  gold 
cusp.  Now  take  a  piece  of  lead,  such  as  our  lead  hubs,  and  with  a 
hammer  drive  into  the  Melotte-metal  die  (Fig.  748)  to  form  the 
counter-die  (Fig.  749,  d). 

Anneal  the  gold  plate,  and  start  the  swaging  process  by  coaxing  the 
plate  into  the  die  by  hand-pressure  (Fig.  750),  using  a  piece  of  wood, 
which  makes  a  depression  for  the  lead  counter-die  to  rest  in.  Then 
place  the  counter-die  on  the  gold  plate  (Fig.  751),  and  drive  to  a  fit. 
Cut  the  surplus  metal  from  the  hollow  cusp  with  shears  (Fig.  752), 
filing  up  the  edges  when  necessary,  and  rub  down  the  under  surface 
on  a  smooth  file  until  it  fits  the  band  made  for  it  (Fig.  752).  Wire  the 
cusp  and  crown  together,  place  flux  and  solder  in  the  cap,  and  hold 
over  a  lamp  until  soldered  (Fig.  753).  Then  finish  in  the  usual  way. 
If  the  forms  of  cusp-buttons  do  not  afford  one 
which  articulates  perfectly,  the  difficulty  is  easily 
remedied  by  taking  the  button  which  most  nearly 
answers,  and  building  up  the  cusps  with  Melotte's 
moldine  (Fig,  754).  If  a  band  is  accidentally  cut 
too  short,  it  can  still  be  utilized.  Place  moldine 
upon  the  molding-plate,  put  the  cusp-button  upon 
it,  press  down  and  adjust  to  make  up  the  deficiency 
of  the   band,    cutting   away   the   surplus    moldine. 


Fig.  753- 


Fig.  754. 


Fig.  755. 


This  will  of  course  throw  the  soldering  line  a  little  further  upon  the 
crown  (Fig.  755). 

Scrap  gold  can  be  utilized  for  making  a  solid  gold  cusp  by  casting 
in  asbestos  by  the  following  method  :  — 

After  selecting  the  desired  cusp-button,  instead  of  making  a  mold  in 
Melotte's  metal,  as  before  described,  take  a  piece  of  asbestos  board 


734 


MECHANICS — DENTAL    PROSTHESIS. 


about  one  inch  square  and  one-fourth  inch  thick,  moisten  it,  and  with 
a  hammer  drive  the  cusp-button  into  it,  flush  with  the  surface  of  the 
button.  (See  Fig.  757.)  Remove  the  button,  and  dry  the  asbestos 
in  a  flame  (Fig.  756).  When  perfectly  dry,  place  a  suflicient  quantity 
of  gold  scraps  in  the  die  made  in  the  asbestos,  and  direct  the  blow- 
pipe flame  upon  it  until  melted,  inclining  the  carbon  stick,  as  shown, 
against  the  die  for  the  double  purpose  of  confining  the  heat  and  warm- 
ing up  the  carbon  stick.     When  the  gold  is  fused  into  a  button,  press 

it   into    the   die  with   the  carbon  stick   (Fig. 

758).       Avoid  the   use  of  flux  when   working 

with  asbestos. 


Fig.  757. 


Fig.  758. 


To  build  up  a  cusp  to  make  a  perfect  articulation,  in  this  method, 
sealing-wax  must  be  used  instead  of  moldine,  as  in  the  method  of 
swaging  the  cusp.  Warm  the  button  before  applying  the  wax,  and 
with  a  warm  instrument  shape  the  cusp  as  desired. 

To  Make  Gold  Crowns  (^Centrals,  Laterals,  and  Cuspids^. — Select 
from  the  forty  different  forms  in  the  set  that  which  is  most  suitable  to 


Fig.  759- 


a 


Fig.  760. 


Fig.  ;'6i. 


Fig.  762. 


the  case  in  hand  (Fig.  759).  (The  forms  are  in  pairs,  showing  labial 
and  lingual  surfaces.)  Take  the  measurement  of  the  root  to  be 
crowned  with  one  of  the  annealed  copper  strips,  binding  the  strip 
around  the  tooth  with  pliers  ''Fig.  760  a^.     Take  this  measurement 


CROWN    riiNU    BRIDGE-WORK. 


735 


and  cut  it  through  the  center  (Fig.  760  b),  then  bend  the  respective 
halves  over  the  lingual  and  labial  forms  selected,  at  the  necks,  with  the 
cut  ends  of  the  strips  resting  on  the  flat  of  the  plate  (Fig.  761).  If 
the  measurement  is  larger  than  the  form  selected,  build  the  latter  up 
with  moldine  until  the  space  between  the  form  and  strip  is  filled  (Fig. 
761  F).  Avoid  getting  moldine  on  the  approximal  surface.  Remove 
the  strips,  dry  out  the  moldine  by  passing  through  a  flame  a  few 
times,  then  place  the  form  on  the  molding-plate  with  a  rubber  ring 

around  it.  Pour  Melotte's  metal 
into  the  ring'  as  in  forming  the 
molar  or  bicuspid  cusp,  which 
makes  a  die  of  the  two  sections, 
lingual  and  labial.  Make  a  lead 
counter-die  and  proceed  as  directed 
in  the  making  of  a  molar  cusp, 
swaging  both  sections  (Fig.  762). 
Trim  off  the  surplus  plate  (Fig. 
763),  and  square  the  opposing 
edges  of  the  two  sections  by  rub- 
bing  them  over  a   dead  smooth 


Fig.  764. 


Fig.  765. 


Fig.  766. 


file.  Bind  the  two  sections  together  with  wire  with  sufficient  solder 
and  flux  inside  (Fig.  764,  and  Fig.  765),  and  proceed  as  in  soldering  an 
ordinary  band.  With  a  small  mechanical  saw  cut  off"  the  upper  por- 
tion where  the  tooth  begins  to  slope  back  (about  the  dotted  lines  in 
Fig.  765).  This  leaves  the  crown  as  shown  in  Fig.  766,  approximal 
and  labial  views.  Drive  on  the  root.  If  too  small,  place  on  the  horn 
of  an  anvil  and  enlarge  by  hammering  ;  if  too  large,  band  the  root  in 
the  same  manner  as  for  a  Richmond  crown,  grinding  the  tooth  to  fit. 
To  Insert  a  Porcelain  Facing. — Make  the  gold  crown  as  described. 
Select  a  porcelain  facing  suitable  for  the  case  (Fig.  767).  Place  the 
crown  on  the  root  in  the  mouth,  and  with  an  excavator  mark  on  the 
face  where  the  porcelain  is  to  appear.  Remove  the  crown  and  saw 
out,  so  that  the  facing  will  fit  loosely.  With  a  knife  bevel  the  inner 
edge  or  seat  for  the  facing  (Fig.  768).  Grind  the  facing  to  fit  (Fig. 
769).  Back  up  the  facing  with  No.  34  or  36  gauge  pure  gold,  punch- 
ing holes  in  the  backing  for  pins,  annealing  as  required  to  readily 
conform  it  to  the  tooth  (Fig.  770  and  Fig.  771).     With  a  sharp  knife 


736 


MECHANICS  —  DENTAL   PROSTHESIS. 


cut  a  barb  on  each  side  of  the  pins  in  the  facing,  and  press  the  barbs 
against  the  backing  (Fig.  772),  which  keeps  the  backing  in  place. 
Burnish  down  the  edges  well,  being  careful  not  to  let  the  backing 
overlap  the  facing. 

Place  the  facing  in  the  space  prepared  for  it  in  the  crown  (Fig.  773), 
and  bind  the  two  together  (not  too  tight)  with  wire,  wrapping  the 
wire  directly  over  the  facing  with  asbestos  to  prevent  discoloration  of 
the  porcelain.  Flux  and  solder  by  holding  over  a  lamp  as  in  the  case 
of  a  band  (Fig.  774).     Then  finish  in  the  usual  way. 

If  it  is  desired  to  use  a  platinum  pin  for  anchorage,  as,  for  instance, 
a  Logan  pin,  bf-nd  the  pins  in  the  facing  sufficiently  to  clamp  the 
anchorage  pin,  -^rid  insert  the  pin  through  the  gold  crown  (Fig.  775), 


F^C.  767. 


Fig.  768. 


Fig.  769. 


FiQ,  770.  Fig.  771. 


Fig.  772. 


Fig.  773. 


Fig.  774. 


Fig.  775. 


Fig.  775. 


finishing  as  before  described.     Fig.  776  shows  a  finished  crown  so 
made. 

To  Make  the  Grinding  Surface  of  a  Bridge  in  One  Continuous  Piece. 
— After  having  crowned  the  teeth  for  the  attachment  of  the  bridge, 
take  a  bite  in  modeling  compound,  remove  the  compound,  place  the 
crowns  in  their  impressions,  make  a  cast  of  sand  and  plaster,  and  place 
on  an  articulator ;  now  put  moldine  between  the  abutments  instead  of 
wax,  and  get  the  articulation  with  cusp-buttons  the  same  as  you  would 
for  plate  teeth  (Fig.  777).  Then  to  remove  the  buttons  without 
destroying  the  articulation,  make  a  cup  by  pouring  Melotte's  metal,  as 
cool  as  it  will  flow,  on  the  face  of  the  cusp-buttons.  Heat  the  pouring 
lip  of  the  ladle  and  use  it  to  smooth  out  the  half-congealed  metal, 


CROWN   AND    BRIDGE-WORK. 


737 


much  as  you  would  a  soldering  iron  (Fig.  778).     Then  place  a  thin 
coating  of  moldine  upon  the  molding-plate.     Remove  the  cup  from 
the  articulator  with  the  cusp- 
buttons    in    place    (Fig.    778). 
Transfer  the  cusps  by  inverting 
the  molding-plate  (Fig.   779), 
and  turn  the  cusp-buttons  out 
upon  the  moldine  on  the  plate 
with   the   grinding-surface    up 
(Fig.  780),   and  they  will  oc- 
cupy the  same  relative  positions  fig.  777. 
as  when  on  the  articulator. 

Now  place  the  large  rubber  ring  around  the  buttons  on  the  plate, 
and  proceed  to  make  a  die  with  Melotte's  metal,  as  before  described 
(Fig.  781).  When  cool,  remove  the  buttons  and  coat  the  face  of  the 
die  with  whiting.     Invert  the  die  and  raise  the  rubber  ring  sufficiently 


Fig.  778. 


Fig.  782. 


Fig.  783. 


Fig.  784. 


high  on  it,  and  make  a  counter-die  with  the  same  metal  by  pouring 
as  cool  as  possible  (Fig.  782).  This  gives  the  male  and  female  dies 
with  which  to  swage  the  continuous  grinding-surfaces.  Then  proceed 
to  swage  the  gold  plate  in  one  piece  (Fig.  783),  annealing  as  often  as 
47 


738 


MECHANICS — DENTAL   PROSTHESIS. 


necessary.  Trim  off  the  surplus  plate  (Fig.  783),  and  place  in 
position  on  the  articulator.  Cut  the  cusps  out  on  the  buccal  face  to 
avoid  showing  the  gold  (Fig.  784),  grind  the  porcelain  facings  to  fit 
the  cusps,  and  back  with  gold,  No.  34  or  ^6,  letting  the  gold  come  to 
the  cutting-edge,  the  same  as  in  a  single  crown  as  before  described. 

If  there  is  a  space  between  the  cutting-edge  and  the  porcelain,  place 
a  little  wax  in  the  joint  to  keep  out  the  plaster  investment,  invest, 
remove  the  wax  from  between  the  joints,  flux,  and  solder. 

If  it  is  desired  to  make  an  all-gold  bridge,  select  the  proper  facings 
from  the  set,  make  a  die  of  Melott'e's  metal,  and  swage  up,  the  same 


Fig.  785. 


as  in  the  continuous  bridge  before  described,  and  mount  gold  facings 
in  place  of  porcelain. 

Note. — In  case  it  is  desired  to  mount  a  gold  tooth  on  a  vulcanite 
plate,  select  the  proper  form  from  the  set,  and  make  the  crown  as 
described.  Solder  pins  on  the  back,  and  vulcanize  to  the  plate  in 
the  usual  way. 

These  strips  will  be  found  more  desirable  and  practical  than  the 
ordinary  binding-wire  for  taking  measurements  of  roots,  especially  of 
badly  decayed  teeth.     To  use  them,  the  strip  is  passed  around  the 


CROWN    AND    BRIDGE-WORK. 


739 


tooth,  and  the  joint  pinched  firmly  with  a  pair  of  pliers.  Where  the 
decay  runs  under  the  gum,  tack  the  ends  of  the  strip  together  with  soft 
solder,  and  with  an  excavator  carry  it  well  up  under  the  gum. 

Fig.  785  represents  Dr.  Melotte's  moldine,  impression  cup,  rubber 
ring,  and  fusible  metal  for  crown  dies  and  counter-dies.  Moldine 
(molding  sand  and  glycerin)  is  an  impression  material  into  which  the 
metal  can  be  poured  as  soon  as  the  impression  of  the  crown  of  a  tooth 
is  obtained. 

Bridge  Work. — Artificial  Crowns  Attached  to  Natural  Teeth  without 
Plates  or  Clasps. — These  operations  are  generally  known  as  "  bridge- 
work,"  which  is  simply  an  extension  of  artificial  crowns  over  the 
spaces  made  by  the  loss  of  natural  teeth.  The  credit  of  first  inserting 
artificial  crowns  to  adjoining  natural  teeth,  by  fillings  of  cohesive  gold 
foil,  is  due  to  Dr.  B.  J.  Bing,  who  describes  his  method  as  follows: — 


Fig.  786. 


Fig.  787. 


Fig.  789. 


"In  the  case  of  inserting  a  central  incisor,  a  cavity  must  be  made 
in  the  palatine  depression  of  the  adjoining  central,  and  also  the  lateral, 
and  one  in  the  approximal  surface  of  either  of  these  teeth,  about  the 
place  where  we  usually  find  decay  on  these  surfaces.  An  impression 
is  then  taken  which  will  show  these  cavities,  and  a  gum  or  plain  plate 
tooth  carefully  fitted  and  backed  with  gold,  observing  the  precaution 
of  allowing  a  small  point  of  the  backing  to  extend  into  the  approximal 
cavity.  Two  little  griffes  (bars)  are  then  soldered  to  the  base  of  the 
backing,  the  ends  of  which  are  carefully  plugged  into  the  palatine 
cavities  with  gold  foil,  in  such  a  manner  as  will  tend  to  draw  these 
teeth  very  slightly  together. ' ' 

Figs.  787,  788,  789,  790,  and  791  represent  Dr.  Bing's  bridge-teeth. 

Fig.   789  represents  porcelain  crowns  having  two  strong   pins  of 


74° 


MECHANICS — DENTAL   PROSTHESIS. 


platinum  baked  in  each  side,  the  pairs  of  pins  being  so  placed  that 
the  tooth  when  fixed  in  position  is  held  firmly  in  proper  relations  to 
the  adjacent  teeth.  Fig.  788  shows  the  supporting  teeth  prepared  to 
receive  a  lateral  incisor.  Fig.  790  is  a  face  view  of  the  same  in  posi- 
tion. Figs.  789  and  791  show  the  same  in  the  case  of  a  bicuspid  crown. 
These  crowns  may  be  soldered  to  each  other,  or  to  collars  and  to 
cap-crowns,  in  the  construction  of  every  form  of  bridge  denture. 


Fig.  790. 


Fig.  791. 


Dr.  W.  F.  Litch  has  modified  Dr.  Bing's  method,  an  abridged  de- 
scription of  which,  by  Dr.  Dexter,  is  as  follows  : — 

"Supposing  a  left  upper  lateral  to  be  inserted:  Take  an  accurate 
impression  of  the  parts  (canine  and  central,  and  gum  between),  and 
make  metallic  dies  from  the  model.  Swage  gold  or  platinum  plates 
to  very  exactly  fit  the  palato-approximal  surfaces  of  the  canine  and 
central.  Fit  into  the  interspace  a  plain  plate  lateral  incisor,  slightly 
wider  than  the  space  to  be  filled,  beveling  and  grinding  the  sides 


Fig.  792. 


Fig.  793- 


posteriorly,  so  that  the  tooth  cannot  be  forced  backward  between  its 
neighbors ;  the  neck  fitting  accurately,  but  lightly,  upon  the  gum. 
Back  the  tooth  with  gold.  Place  the  prepared  tooth  and  the  struck 
plates  upon  a  perfect  model  of  the  parts,  and  adjust  the  tooth  backing 
accurately  to  the  plates  on  each  side.  Cement  together  with  shellac 
or  other  resinous  cement ;  remove  and  complete  the  final  adjustment 
in  the  mouth.  Invest,  and  solder  the  tooth  and  plates  together  in 
their  exact  relative  positions,  observing  to  accumulate  a  large  portion 
of  solder  over  the  joints  (Fig.  792).  The  apparatus,  if  now  placed  in 
the  mouth,  will  be  found  self-supporting  against  any  force  except  the 


CROWN    AND    BRIDGE-WORK. 


741 


perpendicular;  for  it  cannot  be  forced  backward  into  the  mouth, 
owing  to  the  extra  width  of  the  lateral ;  nor  forward  out  of  the  mouth, 
owing  to  the  wings  or  plates  extending  over  the  backs  of  the  neighbor- 
ing teeth ;  nor  upward  toward  the  gum,  owing  both  to  the  porcelain 
tooth  resting  thereon,  and  to  the  converging  planes  of  the  plates  or 
wings  and  the  postero-approximal  surfaces  of  the  artificial  tooth. 

"  The  methods  of  final  attachment  are  two,  depending  upon  the 
case:  i.  If  one  of  the  neighboring  teeth  is  devitalized,  attaching  a 
pivot  to  the  plate  on  that  tooth  and  inserting  it  with  gutta-percha,  the 
plates  themselves  being  covered  with  a  film  of  the  same  substance  on 
their  dental  aspects  (Fig.  793).  If  the  teeth  are  both  alive,  a  modifi- 
cation of  Bing's  plan  of  filling,  performed  as  follows:  — 

"The  denture  being  constructed  as  before  described,  and  polished, 

drill  a  cavity  in  the  center  of  the  palatal  face  of  each  tooth  covered 

by  the  plates,  slightly  larger  in  diameter  than  the  head  of  the  pin  in 

an  ordinary  rubber  tooth,  no  deeper  than  the  enamel,  and  undercut 

(Fig.  794  b).     To  each  of  these  openings  fit    a 

platinum  one-headed  rivet,  the  head  being  very 

thin  and  perfectly  flat  on  each  side.     Split  the 

a  -         -  -^ 

-A 


Fig.  794 


Fig.  796. 


shanks  of  the  rivets  nearly  to  the  head  (Fig.  794  a).  Make  open- 
ings in  the  plates  to  exactly  correspond  with  those  in  the  teeth,  and 
countersink  them  deeply  on  their  palatal  aspect.  Place  the  gutta- 
percha on  the  dental  surfaces  of  the  plates,  as  described,  and  press  the 
denture  to  its  place  in  the  mouth.  When  the  cement  is  cooled  and 
hard,  remove  that  portion  pressed  into  the  holes  in  the  plates  and 
teeth,  pass  the  rivet  heads  through  the  holes  in  the  plates  to  their  seats 
in  the  tooth  cavities,  and  fill  them  in  position  with  gold.  When  the 
fillings  have  reached  the  level  of  the  tooth  surfaces,  spring  open  the 
split  riret  shanks  and  continue  packing  gold  around  and  between  the 
separated  parts  and  into  the  countersinks  in  the  plates  until  flush  with  the 
plate  surfaces.  Cut  off"  the  surplus  pivot  shanks  and  finish  (Fig.  794)-" 
Dr.  Litch's  method  can  also  be  adapted  to  the  restoration  of  frac- 
tured angles  of  incisor  teeth,  as  shown  in  Figs.  795  and  796,  and 
which  need  no  further  description. 


742 


MECHANICS — DENTAL   PROSTHESIS. 


Fig.  797  represents  a  case  of  two  bicuspid  crowns  secured  to  one 
root  and  two  adjoining  teeth. 

The  late  Dr.  M.  W.  Webb  also  modified  the  methods  of  Dr.  Bing 
by  forming  an  undercut  groove  in  the  porcelain  crown  in  each  side 
and  along  the  cutting-edge,  and  filling  gold  foil  solidly  in  the  groove 
and  slightly  over  the  cutting-edge,  to  make  the  porcelain  crown  more 
secure  than  the  platinum  pins  hold  it,  and  to  protect  the  edge  from  the 
occlusion  of  the  lower  teeth  ;  also  to  build  the  crown  into  the  approx- 
imal  surfaces  only. 

Dr.  Webb  also  described  a  method  by  which  a  crown  without  plate 
or  clasps  and  where  no  root  remains  can  be  inserted  :  "  After  suitably 
forming  the  cavities  in  the  proximate  wall  of  each  tooth  next  the  space 
left  by  the  loss  of  the  one  that  had  been  extracted,  a  plain  porcelain 
crown  was  fitted  to  the  place  and  backed  with  gold  plate.     A  portion 


Fig.  797 


of  the  backing  extended  about  one  and  a  half  lines  from  each  side  of 
the  crown  for  insertion  in  the  cavities  prepared  in  the  adjoining  teeth, 
and  to  these  parts  a  gold  wire  was  soldered  to  fit  into  the  pulp-cham- 
bers of  the  adjoining  teeth.  A  small  gold  plate  was  then  formed  to 
fit  upon  the  gum,  covering  as  much  space  as  was  taken  up  by  the  neck 
of  the  natural  tooth.  When  the  backing  was  riveted  to  the  pins  in  the 
crown  and  this  placed  in  position,  and  while  the  whole  rested  on  the 
small  plate  upon  the  gum,  the  backing  and  plate  were  so  secured  by 
wax  that  they  could  be  removed  intact  and  soldered.  Each  extended 
side  of  the  backing  and  the  surface  of  the  wire  was  barbed,  so  that  the 
gold  foil  would  the  better  secure  the  crown  when  filled  into  every 
part.  The  crown  with  the  gold  attachments  being  ready  for  inser- 
tion, oxychlorid  of  zinc  (or  oxyphosphate)  was  placed  in  the  pulp- 


CROWN    AND    BRIDGE-WORK. 


743 


chambers  of  the  adjoining  teeth  and  the  crown  at  once  pressed  to 
place.  When  the  cement  had  hardened,  a  portion  of  it  was  cut  away, 
so  as  to  make  proper  anchorage  for  light,  cohesive  gold  foil,  which 
was  impacted  in  small  pieces  around  part  of  the  wire  and  that  por- 
tion of  the  plate  extending  into  the  cavities,  and  the  crown  was  then 
secured." 

To  avoid  any  danger  of  the  porcelain  crown  being  broken  from  the 
platinum  pins,  Dr.  Webb  suggested  that  a  groove  be  cut  in  each  side, 
and  along  the  cutting-edge  of  this  crown  (Fig.  798  ^),  so  that  gold 
foil  may  be  impacted  into  it  by  means  of  a  fine-edged  corundum  disc, 
after  a  heavy  backing  of  gold  plate  and  the  wire  have  been  fixed  in 
place  and  soldered  (Fig.  799  a).  Into  this  groove  the  wire  to  connect 
the  artificial  crown  with  the  natural  teeth  is  to  be  placed  (Fig.  798  a). 
When  the  operation  of  contouring  the  palatal  surface  of  the  crown 


Fig.  799. 


Fig.  800. 


with  gold  foil  is  completed,  the  case  presents  the  appearance  shown 
by  Fig.  800. 

Dr.  Webb  also  made  use  of  a  stout  wire  (No.  13),  with  a  screw 
thread  cut  upon  one  end,  for  insertion  into  a  devitalized  tooth,  and 
bent  to  receive  the  porcelain  crown  which  was  soldered  to  its  free  end, 
the  wire  being  secured  in  place  in  the  natural  tooth  by  filling  around 
it  with  gold  foil  (Fig.  801). 

Figs.  802,  803,  and  804  show  an  extensive  operation  performed  by 
Dr.  M.  W.  Webb,  in  which  he  made  use  of  gold  wire  (No.  13)  for 
bridging  a  lateral  incisor,  the  natural  tooth  having  been  lost,  and  also 
the  crown  of  the  left  cuspid,  and  disintegration  having  taken  place  in 
many  of  the  teeth,  and  the  front  teeth  abraded  to  the  dentine.  Fig. 
802  shows  the  cases  as  prepared  for  filling,  with  the  artificial  crown 
attached  to  the  gold  wire  in  position,  and  gold  screws  inserted  in  the 
pulp-chambers  of  the  cuspid  and  bicuspid  teeth. 

Fig.  803  shows  the  labial  contour  of  each  crown  after  the  lost  por- 
tions were  restored  with  gold  foil.     Fig.  804  shows  the  finished  case. 


744 


MECHANICS DENTAL    PROSTHESIS. 


Fig.  802. 


Fig.  803. 


Fig.  804. 
Finished  case— a,  b,  d,/,  g,  and  h,  pulpless  teeth  ;  g,  whole  crown  restored  with  gold  ;  a,f, 
and  h,  almost  entire  gold  crowns ;  the  teeth  b  and  d  support  the  gold  crown  faced  with  porce- 
lain, c,  and  fully  one-fourth  of  the  crown  of  each  of  these  is  restored  with  gold,  as  is  also 
that  of  e,  the  pulp  of  which  is  living. 


CROWN    AND    BRIDGE-WORK.  745 

What  is  known  as  the  "  mandrel  system"  of  bridge-denture  is  de- 
scribed as  follows :  * — 

In  all  of  the  various  systems  of  crown  and  bridge-work  which  have 
been  brought  to  the  attention  of  the  dental  profession,  one  very  im- 
portant point  seems  to  have  been  overlooked,  viz.,  the  comparative 
conformation  of  the  necks  of  different  classes.  The  general  forms  of 
the  crowns  of  teeth  have  long  been  well-known,  but  so  far  as  we  are 
informed  no  systematic  classification  of  the  shapes  of  the  necks  has 
heretofore  been  made.  It  would  appear  that  such  a  classification 
ought  to  form  the  basis  of  any  system  of  crown  and  bridge-work  claim- 
ing a  scientific  foundation.  To  lay  the  groundwork  of  the  system 
here  described  a  large  number  of  human  teeth  of  the  various  classes 
were  secured,  their  crowns  cut  off,  and  the  shapes  of  the  stumps  accu- 
rately determined;  thereby  developing  the  fact  that,  no  matter  hov/ 
great  differences  may  exist  in  the  apparent  shapes  of  the  crowns  of 
individual  teeth  of  a  given  class,  there  is  a  remarkable  uniformity  in 
the  configuration  of  their  necks.  That  is,  the  necks  of  upper  cuspids, 
for  instance,  were  found  to  have  a  fixed  type,  from  which  the  varia- 
tions were  very  slight  as  to  shape,  though  there  appeared  to  be  no 
exact  standard  of  size.  So  of  the  other  classes,  with  the  single  excep- 
tion of  the  superior  molars,  in  which  two  distinct  forms  were  found, 
the  first  being  those  in  which  the  buccal  roots  were  wider  than  the 
palatal ;  the  second,  those  in  which  the  reverse  condition  was  found, 
the  single  palatal  root  being  wider  at  its  junction  with  the  crown  than 
the  two  buccal  roots.  The  occurrence  of  roots  of  the  second  class 
being  rather  exceptional,  the  first  class  was  accepted  as  the  type. 

The  configuration  of  the  necks  of  all  the  teeth  having  been  deter- 
mined, a  set  of  mandrels  for  shaping  collars  to  fit  them  was  devised. 
The  set  (Fig.  805)  consists  of  seven  mandrels,  six  of  which  are  double- 
end.  Their  shapes  are  modeled  upon  the  general  typal  forms  of  the 
necks  of  the  teeth  which  they  represent,  and  they  are  made  tapering 
to  provide  for  all  required  variations  in  size.  The  illustrations  are 
about  two-thirds  actual  size,  the  longest  instruments  being  nine  inches 
in  length.  The  cross-sections  show  the  shapes  and  proportionate  sizes 
at  the  greatest  and  least  diameters.  The  long  taper  permits  the  most 
minutely  accurate  adjustment  of  the  collar. 

No.  I  is  a  double-end  mandrel,  for  superior  molars,  right  and  left ; 
No.  2  is  a  single  mandrel,  for  superior  bicuspids,  right  and  left ;  No.  3 
is  a  double-end,  for  superior  cuspids,  right  and  left ;  No.  4,  double- 
end,  for  superior  centrals,  right  and  left;  No.  5,  double-end,  for 
inferior  molars,  right  and  left ;    No.  6,  double-end,  for  the  inferior 

*  Dental  Cosmos,  Aug.,  1886. 


746 


MECHANICS — DENTAL    PROSTHESIS. 


t3 


« 


M 


•G 


a, 

3 


'2 
■ft, 

m 
3 
o 

'S 


Ho.  L 


HO.S. 


No.  8. 


ir«,4. 


Ka  \ 


Ho.  0. 


Ho.  T. 


CROWN    AND    BRIDGE-WORK. 


747 


centrals,  laterals,  cuspids,  and 
first  bicuspids,  right  and  left ; 
No.  7,  double-end,  one  end  for 
the  superior  lateral  incisors,  the 
other  for  those  bicuspids  in  which 
a  bifurcation  of  the  roots,  or  a 
tendency  in  that  direction,  ex- 
tends across  the  neck  to  the 
crown,  in  the  form  of  a  depres- 
sion on  one  or  both  approximal 
surfaces.  The  foregoing  scheme 
comprehends  all  the  teeth  of  the 
permanent  set  except  the  second 
inferior  bicuspids.  The  necks  of 
these  approximate  those  of  the 
superior  central  incisors  so  closely 
in  shape  that  it  was  deemed  inex- 
pedient to  make  a  separate  man- 
drel, as  the  No.  4  mandrel  will 
serve  for  both. 

The  collars  or  bands  are  made 
seamless,  of  No.  30  (American 
gauge)  gold  plate,  22  carats  fine. 
Fifteen  sizes,  each  of  three  widths 
(tV'  t^H'  ^^^  TIT  inch)  are  made 
(Fig.  806),  which  it  is  believed 
will  cover  all  requirements.  These 
collars,  although  devised  as  a  part 
of  the  system,  can  be  used  in  all 
methods  of  crown  and  bridge- 
work  which  require  bands,  and 
possess  many  advantages  over  any 
others.  They  are  really  labor- 
saving  devices,  as  their  use  saves 
the  time  and  trouble  of  making, 
and  there  is  no  danger  of  their 
coming  unsoldered  when  the  pins 
or  the  backing  of  the  crown  is 
being'  soldered  ;  and  there  are  no 
hard  spots  to  give  trouble  in  bur- 
nishing, as,  for  instance,  close  to 
the  root,  after  the  collar  has  been 
shaped  and  placed  in  position,  the 
whole  surface  being  uniformlysoft. 


so 


"o 

O 

in 


o 

(O 


748 


MECHANICS — DENTAL    PROSTHESIS. 


The  seamless  collars  are  also  especially  adapted  to  removal  or 
detachable  bridge-work.  They  are  so  constructed  that  Nos.  i,  i6, 
and  31  exactly  fit  into  or  telescope  with  Nos.  2,  17,  and  32,  and  so  on 
through  the  entire  set,  each  collar  fits  into  the  series  next  higher ;  so 
that  a  root  may  be  banded  with  one  size  and  the  size  next  larger  used 
to  form  the  tube  for  the  telescoping  crown.  Their  advantages  for 
the  construction  of  cap  crowns  are  obvious. 

The  other  appliances  specially  devised  for  this  system  are,  a  reduc- 
ing-plate  or  contractor,  a  pair  of  collar  pliers,  and  a  hammer. 

The  contractor  (Fig.  807)  contains  holes  which  are  complementary 
in  shape  to  the  mandrels.  The  mandrels  being  applied  to  the  inner 
circumferences  of  the  collars,  while  the  contractor  must  admit  the 
collars  themselves,  the  short  taper  of  the  holes  in  the  contractor  neces- 


FiG.  807. 

sarily  covers  a  somewhat  greater  range  of  size  than  is  shown  in  the 
mandrels.  With  this  appliance  collars  can  be  evenly  and  accurately 
reduced  in  size  at  the  edges,  without  burring  or  buckling.  The  illus- 
tration is  actual  size. 

The  collar  pliers  (Fig.  808)  are  for  contouring  the  collars  to  shape, 
one  beak  being  made  convex  and  the  other  concave  to  correspond. 
With  this  appliance  the  slightest  changes  required  in  the  contour  of 
the  collars  are  easily  made.  About  a  half  inch  from  the  extremity  of 
the  concave  beak  a  small  bar  of  flat  steel  is  attached  to  it  by  means  of 
a  screw.  The  free  end  of  the  bar  has  a  minute  projection  upon  one 
face,  the  other  being  reinforced  to  fit  into  the  concavity  of  the  beak. 
In  the  center  of  the  face  of  the  convex  beak  is  a  depression,  into 
which  the  projection  on  the  steel  bar  strikes,  making  a  very  efficient 
punch  for  forming  guards  or  stops  to  prevent  the  collars  from  being 


CROWN   AND    BRIDGE-WORK. 


749 


forced  too  far  under  the  gum.  The  depression  in  the  convex  beak 
being  slightly  larger  than  the  projection  or  punch,  the  metal  is  not 
cut  through,  but  merely  raised  on  the  side  opposite  to  the  punch. 
The  punch  attachment,  being  pivoted,  can  be 
swung  to  one  side  when  not  in  use. 

Fig.  809  is  a  mallet  or  hammer,  with  steel  face 
and  horn  peen.     The  handle  is  9  inches  long. 

One  of  the  appliances  required  is  a  lead  anvil, 


Fig. 


Fig.  800. 


which,  being  only  a  piece  of  soft  lead,  say  2x3  inches  and  an  inch 
thick,  is  not  illustrated.  The  female  die  of  an  ordinary  case  will 
answer  very  well. 

To  illustrate  the  uses  of  these  appliances,  take  a  case  in  which  two 


75° 


MECHANICS — DENTAL   PROSTHESIS. 


inferior  bicuspids  of  the  left  side  are  missing,  and  the  crowns  of  the 
cuspid  and  first  molar  so  badly  decayed  that  the  probabilities  are  that 
they  will  soon  fall  victims  to  the  forceps.  The  old-time  way  would 
have  been  to  extract  the  molar  and  cuspids,  and  make  a  partial  plate. 
Examination,  however,  shows  that  the  roots  of  these  two  teeth  are  in 
good  condition,  affording  an  excellent  opportunity  for  the  construc- 
tion of  a  piece  of  bridge-work. 

With  a  corundum  point  or  rotary  file,  cut  off  the  remaining  portions 
of  the  crowns  level  with  the  gum  margins.  Prepare  the  roots  in  any 
of  the  well-known  ways,  thoroughly  cleansing  the  apical  portions  and 
filling  them  with  whatever  material  is  desired,  being  careful  only  that 
the  work  is  well  done.  For  the  better  retention  of  the  filling  material 
to  be  placed  in  the  pulp-chamber,  retaining-grooves  can  be  made  or 
retaining-posts  inserted.  Take  a  piece  of  binding-wire  (No.  26, 
American  gauge),  say  2^^  inches  long,  pass  it  around  the  neck  of  the 
molar  stump,  cross  the  free  ends,  and,  holding  the  wire  in  place  with 
one  finger,  twist  the  ends  with  a  pair  of  flat-nose  pliers  until  the  wire 
clasps  the  neck  closely  at  every  point  (Fig.  810).     Where  there  are 


Fig.  810. 


Fig.  811. 


irregularities  in  the  contour  of  the  tooth,  it  is  necessary  to  press  the 
wire  into  them  with  an  approximal  burnisher.  It  is  obvious  that  the 
ring  thus  formed  will  show  the  exact  size  and  shape  of  the  neck  of  the 
tooth.  Remove  the  ring  carefully,  lay  it  on  the  lead  anvil,  put  over 
it  a  piece  of  flat  metal,  and  with  a  smart  blow  from  a  hammer  drive 
the  wire  into  the  lead  (Fig.  811).  Upon  removing  the  wire  an  exact 
impression  of  the  ring  will  be  left  in  the  lead  anvil.  (This  part  of  the 
work,  as,  indeed,  all  others,  should  be  done  carefully  as  described. 
The  wire  ring  may  be  driven  into  the  lead  by  a  direct  blow  of  the 
hammer  face,  but  the  blow  might  not  strike  equally,  and  the  interpo- 
sition of  the  flat  metal  held  level  insures  an  even  impression.  A  piece 
of  an  old  file  is  best,  as  the  file-cuts  keep  the  wire  from  slipping.) 

Next,  cut  the  wire  ring  at  the  lap,  straighten  out  the  wire,  and 
select  a  suitable  collar  by  comparing  the  length  of  the  wire  with  the 
straight  lines,  which  correspond  in  length  to  the  inside  diameters  of  the 
various  sizes.     Should  none  of  these  correspond  exactly,  take  prefer- 


CROWN    AND    BRIDGE-WORK. 


751 


ably  the  next  size  smaller.  It  will  be  remembered  that  the  collars  are 
No.  30  in  thickness,  while  the  wire  with  which  the  conformation  is 
secured  is  No.  26.  This  difference  permits  the  collar  when  contoured 
to  shape  to  enter  the  lead  impression  readily,  a  decided  advantage  in 
fitting.  Having  selected  the  collar,  fit  it  to  mandrel  No.  5,  with  the 
peen  of  the  hammer,  holding  it  upon  the  lead  anvil,  and  using  a  slight 
pushing  force  to  help  in  stretching  and  forming  it  (Fig.  812).  Having 
driven  the  collar  to  form,  remove  it  from  the  mandrel  and  try  in  the 
lead  impression.  If  it  does  not  fit  exactly,  return  it  to  the  mandrel 
and  stretch  it  a  little,  when  it  will  usually  fit  perfectly,  as  the  mandrels 
have  been  designed  carefully  to  the  average  shapes  which  obtain  in 
the  great  majority  of  tooth-necks.     In  the  exceptional  cases  where  the 

collar  does  not  fit  it  can  be  readily 
contoured  to  the  exact  shape  with  a 
pair  of  flat-nose  pliers.  Of  course,  if 
it  fits  the  impression  in  the  lead,  it 
will  fit  the  neck  of  the  tooth,  always 
provided  the  measurement  and  the 
impression  have  been  carefully  made. 
If  the  collar  or  band  has  been 
accidentally  stretched  too  much,  or 
if  for  any  reason  when  brought  to 
shape   it   is   too    large,    its   root   end 


Fig.  812. 


Fig.  S13. 


can  easily  be  reduced  to  the  proper  size  by  the  use  of  the  contractor. 
Place  the  edge  of  the  collar  which  is  to  fit  the  root  in  the  proper  hole ; 
hold  it  level  with  a  piece  of  file  as  in  taking  the  lead  impression  of  the 
ring,  and  tapping  lightly  on  the  file  drive  the  collar  into  the  plate 
(Fig.  813)  until  the  proper  reduction  is  made.  The  collar  is  next 
"festooned"  to  correspond  to  the  shape  of  the  "maxillary"  ridge. 
Lay  it,  gum  edge  up,  on  the  lead  anvil,  and  with  the  piece  of  flat  file 
and  the  hammer  drive  it  into  the  lead.  A  few  cuts  with  a  fine  half- 
round  file  across  the  approximal  diameter  will  confirm  the  edges  to 
the  surface  of  the  ridge  (Fig.  814).  Then  place  the  .collar  in  position, 
and,  having  ascertained  just  how  far  it  should  go  down  on  the  root, 
remove  it,  and  with  the  small  spring  punch  in  the  collar  pliers  form 
projections  on  the  inside  of  the  band  at  the  proper  points  to  serve 
as   stops,  which,  resting   on  the  top  of  the   root,  will    prevent   the 


752 


MECHANICS DENTAL    PROSTHESIS. 


collar  from   being   forced    further    down  upon    it    than    is   desirable 

(Fig-  815). 

A  collar  for  the  cuspid  is  then  fitted  in  the  same  manner,  using 
mandrel  No.  6  for  shaping,  after  which  the  case  is  ready  for  the  build- 
ing of  the  bridge. 

Place  both  collars  in  position  and  take  an  impression  of  the  parts, 
including  the  interiors  of  the  excavated  pulp-chambers,  from  which 
make  a  cast  in  the  usual  way.  Bend  a  short  piece  of  half-round  gold 
or  platinum  wire  into  the  form  of  a  horse-shoe,  the  two  extremities 
of  which  shall  fit  into  the  roots  of  the  molar.  Then  take  a  longer 
piece  of  the  same  wire,  somewhat  more  than  enough  to  extend  from 


Fig.  S14. 


Fig.  815. 


Fig.  817. 


the  toe  of  the  horse-shoe  when  in  position  to  the  cuspid  root ;  bend 
one  end  of  it  at  a  right  angle,  or  nearly  so,  to  fit  the  root  of  the 
cuspid,  and  (cutting  off  any  excess  of  length)  solder  the  other  end  to 
the  toe  of  the  horse-shoe.  The  bar  extending  between  the  two  roots 
is  the  truss  of  the  bridge.  Next,  place  the  appliance  on  the  cast  (Fig. 
816),  holding  it  in  position  with  wax,  and  select  the  teeth  to  take  the 
place  of  the  missing  bicuspids  and  molar.  The  best  form  for  this  pur- 
pose is  a  tooth  having  holes  extending  through  it  vertically  from  the 
neck  to  the  grinding  surface,  similar  to  the  well-known  Bonwill  crown. 
The  crowns  used  should  be  large  enough  to  fill  the  space  rather 
tightly,  even  if  their  sides  have  to  be  flattened  slightly  to  let  them  in. 


CROWN    AND    BRIDGE-WORK. 


753 


If  the  teeth  do  not  fill  the  space  tightly,  a  small  portion  of  plastic 
filling  material  crowded  between  them,  as  mortar  between  the  granite 
blocks  in  the  arch  of  a  railway  bridge,  will  greatly  increase  the 
strength  of  the  work. 

After  the  teeth  are  ground  to  fit  and  the  proper  length  for  occlusion 
is  ascertained,  the  truss  is  covered  with  a  thin  film  of  wax,  upon  which 
the  crowns  are  again  pressed  to  their  positions.  Upon  the  removal 
of  the  crowns  the  impression  of  the  holes  running  through  them  will 
be  found  in  the  Avax.  At  these  points  drill  holes  through  the  bar  with 
a  small  twist  drill  run  by  the  engine,  and  into  these  fit  and  solder  the 
pins  for  the  support  of  the  crowns. 

The  bridge  is  now  ready  to  be  attached  permanently.  Set  the 
crowns  in  position  upon  their  supporting  pins  to  secure  the  proper 
alignment.  (If  the  operation  were  upon  the  upper  jaw  they  would 
have  to  be  held  with  wax).  Put  into  the  canals  of  the  supporting 
roots  (the  cuspid  and  first  molar)  a  sufficient  quantity  of  some  quick- 
setting  plastic,  as  oxyphosphate,  to  about  half  fill  the  pulp-chamber, 
but  not  enough  to  prevent  the  supports  of  the  truss  from  being  forced 
home.  Force  the  bridge  supports  to  place,  and  after  allowing  the 
filling  material  to  become  set  remove  the  crowns.  Fill  the  remainder 
of  the  pulp-chamber  and  the  whole  of  the  collar  with  gold  or  with 
amalgam,  gutta-percha,  oxyphosphate,  or  any  suitable  plastic  (Fig. 
817).  Set  the  crowns  permanently,  the  molar  and  cuspid  first,  as  this 
affords  greater  facility  for  the  trimming  off  of  any  excess  of  the  filling 
material  used  in  the  attachment.  For  attachment  of  the  crowns^ 
gutta-percha  is  probably  the  best  material,  as  crowns  set  with  it  are 
readily  removed  for  the  correction  of  any  inaccuracies  of  occlusion  or 
alignment,  by  grasping  them  between  the  beaks,  previously  warmed, 
of  a  pair  of  universal  lower 
molar  forceps.  The  heat 
warms  the  gutta-percha 
and  releases  the  tooth, 
which  can  then  be  re-set 
properly.  In  attaching 
crowns  with  gutta-percha 
the  holes  in  the  crowns 
are  first  filled  with  the 
material,  after  which  the 
crown  is  warmed  and 
forced  to  place.  Any  of  the  other  plastics  ordinarily  used  in  setting 
Bonwill  crowns  can  be  employed  at  the  discretion  of  the  operator. 
Fig.  81 S  shows  the  case  completed. 

In  securing  the  occlusion  of  a  piece  of  bridge-work  it  is  well  to 
48 


Fig.  818. 


754 


MECHANICS — DENTAL   PROSTHESIS. 


make  th'e  artificial  teeth  a  little  short,  so  that  the  natural  teeth  on  both 
sides  will  meet  the  first  shock  of  mastication.  Nature  will  correct  the 
occlusion  in  time  by  slightly  elongating  the  roots  supporting  the 
bridge.  If  the  artificial  crowns  are  permitted  to  strike  the  natural 
teeth  from  the  first,  the  undue  strain  upon  the  two  supporting  roots 
may  cause  soreness  and  perhaps  more  serious  consequences. 

When  a  sound  tooth  is  to  be  used  as  one  of  the  supports  of  the 
bridge,  a  modification  of  the  method  just  described  is  necessary. 
Take  a  case  where  it  is  desired  to  bridge  the  space  caused  by  the  loss 
of  the  right  inferior  bicuspids  and  first  molar.  The  crown  of  the  right 
cuspid  is  nearly  gone,  but  the  root  is  sound  and  capable  of  supporting 
one  end  of  the  bridge.  The  other  end  will  be  attached  to  the  second 
molar,  which  is  a  sound  tooth.  Prepare  and  band  the  cuspid  root  as 
before  ;  dress  off  the  second  molar  crown  until  it  is  slightly  smaller 
than  the  neck,  so  as  to  permit  a  cap  to  be  telescoped  over  it,  and  take 
the  measure  of  the  crown  with  the  binding-wire.  Select  a  suitable 
seamless  collar  of  sufficient  width  to  extend  from  the  neck  to  a  little 
beyond  the  grinding  surface,  and  drive  it  up  on  the  proper  mandrel 
to  get  the  general  shape,  but  not  the  full  size  required  to  fit  the  tooth, 
leaving  it  so  that  the  edge  having  the  larger  circumference  will  just 
pass  over  the  end  of  the  crown  ;  place  the  collar  on  the  tooth,  and 
with  a  block  of  wood  and  the  mallet  tap  it  to  place  just  beyond  the 
free  margin  of  the  gum.  This  method  will  make  a  close  fit,  as  the 
collar  will  readily  stretch  all  that  is  necessary.  With  a  sharp  pointed 
instrument  mark  the  length  of  the  crown,  remove  the  collar,  and  cut 
it  to  the  proper  width  as  indicated.  Then  in  a  piece  of  gold  plate  of 
the  thickness  used  for  caps  form  four  little  depressions  of  the  general 

character  of  an  impression 
of  the  molar  cusps.  An 
easy  way  to  do  this  is  to 
lay  the  plate  on  the  lead 
anvil ;  then  with  the  ball 
on  the  end  of  an  ordinary 
socket-handle  and  the  ham- 
mer the  depressions  are 
made  in  a  moment.  Set 
the  collar  on  the  plate, 
borax  it,  charge  with  sol- 
der, and  heat  till  the  solder  flows.  Cut  off  the  surplus  plate,  and  a 
perfect  cap  for  the  molar  is  made.  Place  it  on  the  tooth  and  take  an 
impression,  and  thereafter  proceed  as  before  directed  to  make  the 
truss  of  the  bridge  and  mount  the  teeth,  except  that  in  this  case  the 
posterior  end  of  the  truss  is  to  be  soldered  to  the  molar  cap.     For  the 


Fig.  819. 


CROWN    AND    BRIDGE-WORK. 


755 


final  attachment  place  a  little  oxyphosphate  or  any  other  plastic  filling 
material  in  the  cap  to  secure  it  firmly  (Fig.  819),  first  cutting  a  slot  in 
the  crown  end  of  the  cap  for  the  escape  of  the  excess  of  material. 
Pressure  upon  the  filling  material  hastens  its  hardening. 

Detachable  Bridge-work. 

A  description  of  two  or  three  methods  of  constructing  detachable 
bridges  will  suffice  to  indicate  the  general  principles  involved.  Hav- 
ing these,  each  operator  will  find  it  an  easy  task  to  devise  the  modifi- 
cations necessary  to  adapt  a  method  to  individual  cases. 

The  first  method  is  especially  applicable  to  cases  where  both  ends 
of  the  bridge  are  attached  to  roots — as,  for  example,  the  inferior 
cuspid  and  second  molar  roots  of  the  right  side,  the  intervening  teeth 
having  been  lost.  The  operation  is  conducted  as  described  in  the 
first  case  of  fixed  bridge-work  down  to  the  construction  of  the  truss, 
for  which  in  this  method  square  gold  wire  is  used.  Having  cut  the 
wire  of  the  proper  length,  lay  it  upon  a  piece  of  gold  plate  (about 
No.  29,  American  gauge)  of  the  same  length  and  full  three  times  as 
wide,  and  placing  the  two  upon  the  lead  anvil,  with  a  hammer  and 
the  piece  of  file  before  used  drive  them  into  the  lead.  This  will  form 
the  plate  into  what  we  may  call  an  open  trunk,  which  fits  the  square 
wire.  Remove  the  two  from  the  lead  together,  and,  without  separating 
them,  curve  to  the  proper 
shape  to  form  the  truss. 
Grind  crowns  having  ver- 
tical holes,  like  the  Bon- 
will,  to  fit,  and  having  de- 
termined the  proper  points 
for  the  supporting  pins,  by 
the  method  already  de- 
scribed, drill  through  both 
trunk  and  bar  at  these 
points.  Separate  the  bar 
from  the  trunk,  and  fit  and 
solder  pins  to  the  bar. 
Construct   small    tubes    to 

fit  the  pins,  ream  out  the  holes  through  the  trunk  to  admit  them,  and 
set  the  tubes  with  solder  in  the  enlarged  holes  (Fig.  820).  Fix  the 
crowns  permanently  upon  the  tubes.  They  may  be  mounted  in  any 
of  the  approved  ways,  by  vulcanizing  or  by  the  use  of  a  plastic  filling 
material.  When  they  are  firmly  set,  place  the  trunk  with  the  teeth 
upon  the  bar,  and  anchor  permanently  as  already  described.  Fig. 
821  shows  the  completed  work. 


756 


MECHANICS — DENTAL    PROSTHESIS. 


In  this  method  the  truss  consists  of  the  bar  and  the  open  trunk 
which  covers  three  sides  of  it.  The  bar  is,  of  course,  permanently 
attached  to  the  roots  of  the  molar  and  cuspid,  but  the  trunk  with  the 
teeth  can  be  removed  at  any  time. 

The  second  method  of  constructing  a  detachable  bridge  is  applica- 
ble to  cases  where  one  or  both  of  the  supports  or  piers  are  sound  teeth. 

In  the  case  adduced  for 
illustration  the  right  infe- 
rior cuspid  crown  was  de- 
cayed, and  both  of  the 
bicuspids  and  the  first 
molar  were  absent.  The 
supports  for  the  bridge 
were  the  sound  second 
molar  and  the  cuspid  root. 
After  the  cuspid  root  was 
prepared. and  banded,  the 
crown  of  the  molar  was  re- 
duced very  slightly, — not  sufficient  to  destroy  the  enamel,  but  just 
enough  to  permit  a  collar  properly  fitted  to  pass  over  it.  A  collar  some- 
what wider  than  the  length  of  the  crown  from  grinding  surface  to  neck 
was  fitted  and  cut  to  the  proper  width.  Two  lugs  were  then  soldered 
upon  the  anterior  and  posterior  sides  and  bent  to  fit  into  the  approxi- 
mal  fissures  which  were  slightly  cut  out  to  admit  them.  An  impres- 
sion was  taken,  the  collar  coming  away  in  the  plaster,  and  a  cast  was 
made  with  the  collar  in  position.  A  coned  tube  was  then  made  for 
the  root  of  the  cuspid  and  a  coned  pin  fitted  into  it.  A  truss  of  half- 
round  wire  was  made,  to  which  the  coned  pin  and  the  molar  collar 
were  soldered  (Fig.  822).  A  half-clasp  to  grasp  the  lateral  was  next 
soldered  to  the  end  of  the  truss  to  be  supported  by  the  cuspid.  The 
object  of  this  clasp  was  to  guard  against  the  teeth  being  thrown  out  of 
proper  alignment  by  the  force  of  mastication.  Bonwill  crowns  were  then 
vulcanized  to  the  truss,  after  their  supporting  pins  had  been  fitted  and 
soldered  to  it.  (Countersunk  crowns  can  be  used  as  well  in  the  same 
way.  Plain  plate  teeth  may  also  be  used  in  this  style  of  work,  in  which 
event  they  are  to  be  soldered  to  the  truss.)  The  bridge  was  then  ready 
to  be  set,  which  was  accomplished  in  the  following  manner :  The 
cuspid  root  was  nearly  filled  with  oxyphosphate,  and  the  coned  tube 
was  placed  upon  the  pin.  The  band  was  put  on  the  molar,  and  the 
coned  pin  with  the  tube  upon  it  was  forced  into  the  plastic  in  the 
cuspid.  As  soon  as  this  became  set,  the  tube  was  held  permanently, 
while  the  bridge  itself  could  be  removed  whenever  desired  (Fig.  823). 
This  method  of  fixing  the  tube  allows  considerable  range  in  its 


CROWN    AND    BRIDGE-WORK. 


757 


adjustment.  In  soldering  the  coned  pin  to  the  truss,  care  should  be 
taken  to  set  it  at  an  angle  exactly  parallel  to  the  axis  of  the  molar ; 
otherwise  there  will  be  difficulty  in  removing  the  bridge. 

The  third  style  of  detachable  bridge-work  to  be  described  involves 
the  use  of  cusp  crowns  (Fig.  824)  for  supporting  posts  and  piers. 
Suppose  a  case  where  both  ends  of  t?ie  bridge  are  to  be  attached  to 
inferior  cuspid  and  second  molar  roots,  the  intervening  teeth  having 
been  lost ;   the  bridge  is,  therefore,  required  to  extend  from  the  right 


Fig.  822. 


Fig.  S23 


inferior  cuspid  to  the  right  inferior  second  molar,  with  only  the  roots 
of  the  two  teeth  named  as  supports.  Prepare  the  roots  and  pulp- 
chambers.  Set  screw-posts  into  the  dentine  for  anchorage  or  as  retain- 
ing-pins,  and  fit  the  collars,  using  sizes  wide  enough  to  form  the  walls 
of  the  crowns.  Fill  the  pulp-chamber  and  about  two-thirds  of  the 
depth  of  the  collars  with  a  plastic  filling  material,  packing  it  well 
around  the  retaining  posts.  Select  suitable  cusp  crowns  for  the  molar 
and  cuspid  and  place  them  in  the  ends  of  the  bands  to  ascertain  the 


■^^pr^  ^ry  ^y  %Y 


/"•"VN 


Fig.  824. 


occlusion.  If  too  long,  shorten  the  cusps  or  reduce  the  bands  with 
engine  corundums  or  rotary  files,  and  when  the  correct  articulation  is 
found  form  a  small,  square  shoulder  in  the  lingual  edge  of  the  cuspid 
and  in  the  posterior  grinding  surface  of  the  molar.  Fill  the  remain- 
ing portion  of  the  collars  with  plastic  mixed  somewhat  thinner  than 
the  first  lot,  and  set  the  cusp  crowns  in  position.  If  there  are  antago- 
nizing teeth  the  mere  closing  of  the  patient's  jaws  will  force  the 
crowns  to  place.      If  there  are  no  antagonizing  teeth  the  crowns  -■■an 


758 


MECHANICS DENTAL    PROSTHESIS. 


be  readily  tapped  to  place  with  the  mallet,  using  a  piece  of  wood  as  a 
driver.  Allow  the  filling  material  to  set  firmly,  trimming  off  any  excess 
which  may  exude  around  the  collars. 

Bridge  supports  or  piers  constructed  on  this  plan  are  strong  and 
durable,  and  likely  to  withstand  any  strain.  Take  an  impression,  and 
proceed  to  fit  seamless  collars  to  telescope  over  those  already  set  upon 
the  cuspid  and  second  molar  roots.  It  will  be  remembered  that  these 
collars  are  so  made  that  each  size  telescopes  into  the  next  higher 
series.  If  the  proper  sizes  are  selected  for  the  outside  or  female  bands, 
the  work  of  fitting  is  readily  and  quickly  accomplished,  forming  tubes 
which  slide  easily  over  the  supporting  piers,  and  at  the  same  time  fit 
closely.  It  is  only  necessary  to  take  care  in  shaping  the  tubes  not  to 
drive  them  too  far  up  on  the  mandrels,  and  thus  stretch  them  so  as  to 
destroy  the  fit.     To  the  outer  end  of  each  of  the  tubes  solder  a  small 


Fig.    825. 


Fig.  826. 


piece  of  gold  plate,  forming  partial  caps  so  placed  as  to  rest  when  in 
position  upon  the  shoulders  previously  cut  in  the  cusp  crowns.  Adjust 
a  truss  bar  of  half  round  gold  wire,  to  the  ends  of  which  solder  the 
tubes  (Fig.  825).  The  truss  is  now  ready  for  the  teeth,  which  may  be 
of  any  of  the  forms  used  for  this  purpose,  and  they  may  be  attached 
to  the  bar  in  any  way  desired.  One  of  the  strongest  attachments  is 
vulcanite. 

An  easy  modification  of  the  plan  just  described  is  readily  adapted 
to  cases  where  only  a  small  space  is  to  be  filled  and  one  end  of  the 
bridge  is  to  be  supported  by  a  sound  tooth.  Thus,  suppose  it  is  de- 
sired to  bridge  a  space  formerly  occupied  by  the  two  inferior  left 
bicuspids,  the  crown  of  the  first  molar  being  a  mere  shell.  The  oper- 
ation would  be  essentially  the  same  as  in  the  previous  case,  except 
that  the  sound  cuspid  would  be  utilized  for  one  of  the  piers  as  follows : 


CROWN    AND    BRIDGE-WORK.  759 

Fit  a  seamless  collar,  cut  out  a  portion  of  it  so  that  it  will  embrace 
only  about  two-thirds  of  the  cuspid  crown,  and  solder  a  partial  cap  or 
cover  to  it,  as  illustrated  in  Fig.  826.  Or,  if  deemed  preferable,  the 
cuspid  may  be  separated  from  the  lateral  incisor  with  the  corundum 
disc  and  the  collar  allowed  to  embrace  the  whole  crown. 

The  great  desideratum  in  constructing  a  piece  of  bridge-work  is, 
of  course,  the  securing  of  perfect  usefulness  in  mastication  and  sj^eech, 
combined  with  absolute  comfort  and  cleanliness.  The  closer  a  bridge 
approaches  that  condition  where  its  wearer  loses  consciousness  of  its 
presence  in  his  mouth,  the  nearer  perfection  it  is.  Scarcely  less  im- 
portant, however,  is  the  necessity  of  providing  for  repair.  Accidents 
will  occur,  and  the  system  which  superadds  to  usefulness,  comfort  and 
beauty,  ready  facilities  for  repairing  breakages,  is  by  so  much  superior 
to  those  which  make  no  such  provision.  A  crown  broken  from  a 
bridge  constructed  by  any  of  the  methods  above  described  can  be 
easily  substituted,  and  the  piece  when  repaired  will  be  as  strong  and 
serviceable  as  it  was  originally. 

It  has  not  been  deemed  necessary  to  detail  the  construction  of  a 
single  crown  separately,  as  all  the  steps  are  included  in  the  building  of 
bridges,  which  have  been  described  minutely.  Porcelain  cusps  of  the 
general  form  illustrated  in  Fig.  827  have  been  designed  specially  for 
these  cases.  In  mounting  them  the  gold  band  is  cut  away  on  the 
buccal  side  as  shown  in  Fig.  828  to  permit  the  porcelain  to  show. 

Dr.  C.  M.  Richmond,  of  New  York  City,  in  making  removable 
dentures  of  the  entirely  soldered  kind,  employs  a  zinc  die  made  from 
a  cast  of  the  anchor  tooth  with  its  cap  on.  He  makes  of  crown  metal 
(platinum  faced  with  gold)  a  collar  somewhat  smaller  than  the  tooth- 
ca}),  and  deep  enough  to  reach  from  the  gum  to  about  a  sixteenth  of 
an  inch  above  the  cap.  He  then  drives  the  die  into  the  collar  so  far 
that  the  extra  sixteenth  of  an  inch  can  be  hammered  over  and  bur- 
nished down  on  the  die-end  to  form  a  flanged  collar.  Outside  of  this, 
in  the  same  manner,  he  forms  another 
flanged  collar,  and  then  solders  the 
two  together,  thus  obtaining  a  close- 
fitting  stiff  collar,  that  will  not  stretch 
in  being  telescoped  on  and  off  the 
anchorage,  and  is  kept  by  the  flange  Fig.  827. 

from  being  forced  too  far  over  the 

tooth-cap.  A  denture  of  this  kind  is  illustrated  in  Fig.  829,  which 
also  shows  his  post  and  roof  device  in  another  form  than  that  previ- 
ously described. 

It  may  be  well  to  add  that,  in  the  use  of  an  impression  cup  for  hold- 
ing the  plaster  and  sand  around  the  parts  to  be  subsequently  removed 


760 


MECHANICS — DENTAL    PROSTHESIS. 


from  the  mouth,  the  inside  of  the  cup  should  first  be  slightly  oiled,  to 
allow  a  separation  of  the  cup  when  the  mass  is  being  prepared  for  the 
soldering. 

A  removable  bridge-work  is  suggested  by  Dr.  T.  S.  Waters,  which 
is  described  as  follows:  "The  natural  molars  and  bicuspids,  one  or 
more  of  each  class,  are  capped  with  gold  crowns,  each  molar  being 
double  capped,  and  the  outer  cap  containing  two  small  springs  con- 
structed of  small  strips  of  elastic  metal  (gold  and  platinum),  one  end 
of  each  spring  being  soldered  to  the  inner  surface  of  the  cap  near  its 
base  at  the  neck  of  the  crown,  and  the  other  end  free  to  press  on  the 
side  of  the  inner  cap.  Such  springs  retain  the  outer  cap  fitting  over 
the  inner  one  on  the  prepared  natural  crowns  by  their  pressure  on  the 
sides  of  the  inner  caps,  the  latter  being  cemented  to  the  natural 
crowns. 

"The  band  for  the  natural  bicuspid  crowns  has  two  shoulders  on 


Fig.  828. 


Fig.  829. 


the  inside  which  fit  into  grooves  cut  in  the  mesial  and  distal  surfaces 
of  the  gold  forming  the  crown." 

Dr.  James  W.  Low,  the  inventor  of  what  is  known  as  the  "Low 
method  of  bridge-denture,"  describes  it  as  follows: — 

"  My  experience  has  convinced  me  that,  as  a  rule,  a  tooth  firm  in 
the  jaw  need  not  be  extracted.  There  are  but  few  exceptions.  When 
the  treatment  is  followed  persistently,  and  proper  judgment  used, 
nearly  all  the  partial  loss  of  the  teeth  can  be  restored  without  covering 
the  roof  of  the  mouth,  and  made  as  valuable  for  masticating  food  as 
the  natural  teeth,  I  am  positive,  and  with  less  injury  to  the  remaining 
teeth,  than  by  any  other  method.  The  method  referred  to  is  that 
known  as  the  '  Low  method,'  or  bridge-work. 

"  Bridge-work  consists  in  supplying  vacancies  between  teeth  or  roots 
with  artificial  teeth,  attached  to  the  adjoining  natural  teeth  or  roots 
by  means  of  bands  or  crowns,  and  held  in  such  position  that  there  is 
no  contact  with  or  pressure  on  the  gums  beneath,  and  thus  no  oppor- 
tunity for  secretions  or  other  foreign  matter  to  be  held  there  and 
thereby  become  offensive. 

"There  is  really  but  one  kind  of  bridge-work,  and  but  one  way  to 


CROWN    AND    BRIDGE-WORK. 


761 


make  bridge-work  to  insure  success.  There  are  many  ways  of  making 
teeth  without  plate,  but  this  is  not  bridge-work.  I  will  here  try  to 
explain  in  detail  my  manner  of  making  and  adjusting  bridge-work. 

"  For  the  first  illustration,  as  seen  in  Fig.  830,  we  have  a  case  where 
all  the  teeth  have  been  extracted,  except  the  two  cuspids  and  two 
second  molar  roots. 

"We  first  proceed  to  prepare  the  roots  by  crowning.  I  use  gold 
crowns  on  the  molar  teeth,  and  what  is  known  as  the  Low  crown  on 
the  two  cuspids. 

"  The  preparation  of  the  two  cuspids  consists  in  making  the  crown 
ready  for  adjustment.  I  always  measure  the  tooth  to  be  crowned  with 
gold  with  a  strip  of  block  tin,  35-thick  stub  gauge  or  thereabouts. 
Place  the  tin  around  the  tooth,  and  with  pliers  carefully  measure  the 
full  size  of  the  same. 


Fig.  830. 

"  Should  you  be  measuring  a  tooth,  or  part  of  a  tooth,  on  which 
there  are  projections,  take  the  engine,  and  with  a  stone  grind  off  the 
same,  making  a  smooth  surface,  so  there  will  be  nothing  to  interfere 
with  the  fitting  of  the  bands  properly.  After  cutting  the  tin  measures 
by  the  marks  made  by  the  pliers  you  have  the  measures  ready  to  make 
the  gold  bands  by.  Cut  the  bands  and  bevel  the  edges,  and  solder 
together,  and  you  are  ready  to  fit.  After  fitting  all  the  bands,  and 
finishing  the  crowns  in  the  usual  way,  I  place  each  in  position  in  the 
mouth,  having  previously  regulated  the  articulation  of  each  crown  as 
desired,  in  the  process  of  making.  We  now^  take  a  deep  articulation 
in  wax,  and  impression  in  plaster  of  Paris ;  remove  before  it  gets  too 
hard,  and  place  all  the  crowns  in  their  positions  in  the  impression; 
varnish,  oil  and  pour  in  the  usual  way  ;  separate  the  cast  from  the 
impression  and  place  in  the  articulator.     Then  pour  plaster.    After  the 


762  MECHANICS — DENTAL    PROSTHESIS. 

plaster  has  hardened,  remove  the  wax  and  we  have  the  articulation 
proper,  and  are  ready  to  select  and  grind  our  teeth,  having  previously- 
selected  our  shade.  My  experience  has  long  ago  taught  me  that  no 
porcelain  teeth  can  stand  the  pressure  for  bridge-work,  the  strain  on 
them  being  twice  as  great  as  with  teeth  on  plates,  which  rest  on  the  gums 
that  give  to  pressure.  In  order  to  prevent  breakage  of  teeth  and  give 
strength,  I  have  for  many  years  been  making  a  tooth  with  gold  cusps. 
I  will  here  describe  my  manner  of  doing  so.  I  had  some  shells  of  bi- 
cuspids and  molars  made,  or  rather  teeth,  without  the  crown.  They 
can  now  be  found  in  some  of  the  depots. 

"  For  the  first  step,  I  use  28-gauge  platinum  for  a  covering  of  the 
inside  of  the  shell,  or  just  where  you  wish  gold  to  flow.  Then  I  bend 
the  pins  down  to  hold  the  platinum  in  position,  and  with  a  file  remove 
all  overlapping  platinum  to  prevent  breaking  of  our  tooth  in  heating. 
The  tooth  is  made  flat  on  the  crown  surface  with  the  express  intention 
of  restoring  with  a  gold  crown.  This  crown  need  not  be  very  thick, 
but  should  perfectly  resemble  the  cusps  on  the  natural  tooth,  for  the 
purpose  of  mastication.  As  these  cusps  are  not  on  the  market,  and 
every  dentist  making  bridge-work  cannot  make  it  in  a  way  to  stand, 
without  putting  gold  cusps  on  the  grinding  surface  of  the  bicuspids 
and  molars,  I  will  here  describe,  for  the  benefit  of  those  who  do  not 
know  how  to  make  them,  how  they  can  be  made  with  very  little  trouble. 
Pick  out  a  natural  tooth  with  cusps  the  exact  shape  you  wish  to  have 
your  gold  cusps,  mix  some  fire-clay  in  a  thick  paste,  then  press  your 
tooth  into  it  a  little  deeper  than  you  wish  the  cusps.  Having  made 
the  proper  impression,  remove  the  tooth,  and  set  the  impression  over 
the  gas  stove  to  dry.  After  it  is  dried  and  reasonably  hot,  lay  your 
pieces  of  gold  in  the  impression  and,  with  a  blowpipe,  melt  them. 
When  melted,  press  with  a  piece  of  steel  on  the  gold  till  cool.  This 
mold  will  do  to  make  many  from.  If  you  have  not  the  fire-clay  and 
can  get  charcoal  that  is  burned  from  fine-grained  wood,  and  is  soft, 
you  can  simply  press  your  tooth  into  the  charcoal  and  melt  in  the  same 
way,  or  you  can  carve  your  teeth  as  you  desire  in  a  block  of  carbon. 
Of  course  the  little  steel  dies  are  handier,  as  we  can  swedge  up  our 
gold  cusps'in  them,  either  solid  or  thin. 

"Having  described  our  manner  of  making  the  cusps,  we  will  now 
return  to  the  manner  of  finishing  our  tooth.  We  left  off  by  saying 
we  covered  the  inside  and  bent  down  the  pins  and  filed  ofi"  the  over- 
lapping platinum.  We  now  place  the  cusp  on  the  top  of  the  tooth, 
and  place  in  the  position  desired,  holding  it  there  with  wax,  and  with 
a  spatula  trim  the  wax  the  exact  shape  we  wish  our  tooth  to  be,  V- 
shape,  tapering  from  the  crown  down.  We  now  encase  in  plaster  and 
sand,  vvhich  gives  us  a  box.     When  hard,  remove  the  wax  and  place 


CROWN    AND    BRIDGE-WORK. 


■63 


over  the  stove,  and  when  sufficiently  dry  fill  in  with  coin  gold,  using 
the  blowpipe  to  melt  it  in  a  solid  mass,  and  then  our  tooth  is  ready  to 
file  up  and  place  in  position  on  the  articulator.  Fig.  831  shows  the 
tooth  in  this  condition. 

"  After  our  teeth  are  all  arranged  we  hold  the  same  in  position  with 
wax,  remove  from  the  articulator,  encase  with  plaster  and  sand  or 
asbestos  in  the  usual  way.  That  we  may  have  a  strong  case,  I  always 
use  platinum  wire  between  each  tooth,  and  then  proceed  to  heat  and 
solder.     Be  sure  that  all  the  gold  cusps  are  so  arranged  that  you  can 


Fig.  831. 


Fig.  832. 


get  all  soldered  together,  as  this  gives  us  great  strength.  My  formula 
for  solder,  which  I  have  used  for  many  years  and  which  will  be  found 
very  easy-flowing  and  almost  the  exact  color  of  the  gold  you  are 
using,  is  as  follows :  Always  figure  from  the  carat  of  gold  you  are 
working.  Take  one  pennyweight  coin  gold,  two  grains  of  copper, 
and  four  of  silver.  We  now  have  our  case  soldered ;  after  filing  as 
desired,  commence  to  finish  with  felt  wheels  and  pumice  stone,  after 
which  we  use  rough  buff  wheels.  We  are  now  ready  to  adjust  in  the 
mouth.     In  Fig.  832  we  see  the  case  ready  for  adjustment. 

"  Have  the  assistant  dry 
all  the  teeth  or  roots  to  be 
operated  upon  while  you 
are  mixing  the  cement.  Be 
sure  and  use  a  kind  which 
does  not  harden  very  rapid- 
ly, or  your  cement  will  set 
before  you  get  your  teeth 
adjusted.  Use  sufficient 
cement  to  fill  all  the  gold 
crowns  perfectly  when  the 
case  is  driven  to  place.  Moisten  the  step  plugs  and  cap  with  cement, 
touching  every  portion,  and  with  an  instrument  place  a  little  cement 
in  the  bottom  of  the  cavity.  We  now  adjust  our  case,  using  the  little 
rotor  for  the  low  crowns,  and  a  piece  of  ivory  for  driving  on  the  gold 
crowns.     Fig.  833  represents  the  case  when  in  position. 


Fig.  833. 


764 


MECHANICS DENTAL    PROSTHESIS. 


"It  will  be  seen  by  looking  at  the  previous  cut  (Fig.  832)  that  the 
teeth,  after  having  been  soldered,  are  all  spaced  fully  one-third  of  the 
distance  from  the  place  of  contact  with  the  gums  and  the  grinding 
surface  of  the  teeth,  so  that  secretions  could  not  possibly  lodge  there. 
I  have  given  you  a  description  of  my  manner  of  making  a  full  upper 
case  of  bridge-work  where  there  are  roots  to  be  crowned  to  support  the 
bridge.  I  will  now  describe  my  manner  of  operating  upon  a  case 
where  the  four  centrals  are  missing,  as  seen  in  Fig.  834.  To  supply 
these  four  teeth  where  the  cuspids  are  intact,  I  use  a  gold  band. 

"I  first  measure  the  tooth  with  strips  of  tin  and  make  the  gold 
bands  as  before  described,  cut  out  the  outside  lower  portion  of  the 
band  before  beginning  to  fit.  In  fitting,  as  the  band  is  being  driven 
down,   cut  away  any  of  the  band  that  touches  the  gum   before  all 

touches  ;  never  drive  the  band 
under  the  gum,  as  inflamma- 
tion would  probably  follow. 

"I  mention  this,  as  I  have 
seen  many  attempts  to  get  rid 
of  the  band  by  driving  up 
under  the  gums  and  cutting 
them  out  on  the  front,  until 


Fig.  834. 


Fig.  835. 


they  were  too  narrow  for  strength.  It  is  hard  work  to  make  some- 
thing out  of  nothing.  The  bands  should  be  heavy  and  strong,  and 
the  patient  made  to  understand  that  if  he  expects  to  get  rid  of  the 
annoyance  of  the  plate  he  must  sacrifice  his  dislike  to  showing  gold. 
After  driving  the  bands  up  close  to  the  margin  of  the  gums,  as  the 
cuspid  teeth  are  very  tapering,  the  bands  will  have  to  be  taken  in  at 
the  bottom.  To  do  this  I  slit  the  band  about  a  third  of  its  length  up, 
then  place  it  on  the  tooth  again,  lap  it  over  enough  to  bring  it  to  a 
close  fit,  and  then  take  it  off  and  solder. 

"  Continue  taking  it  in  wherever  it  does  not  perfectly  fit  the  tooth, 
and  after  a  good  fit  is  obtained  proceed  as  before  described  by  taking 
an  articulation  and  impression.  In  adjusting  first  try  the  case  on  to 
see  that  it  fits  and  that  the  articulation  is  all  right.  Fig.  835  shows 
the  case  ready  for  adjustment. 

"Next,  have  the  assistant  dry  the  teeth  upon  which  the  bands  are 
going,  and  then  mix  your  cement.     This  should  be  mixed  to  about 


CROWN    AND    BRIDGE-WORK. 


765 


the  consistency  of  thick  cream.  It  must  be  neither  too  thick  nor  too 
thin,  or  the  adhesion  will  not  be  strong  enough  to  hold.  Cover  your 
teeth  with  cement  and  then  the  inside  of  the  bands.  Place  these  on 
the  teeth  and  carefully  mallet  up  into  position.  For  this  purpose  I 
use  a  steel  instrument  with  a  crease  or  groove  in  the  end.  The  teeth 
must  be  kept  dry  after  the  case  is  in  position  until  the  cement  is  well 
set.  After  this  is  done  bevel  the  edges  of  the  bands  and  burnish  close 
to  the  teeth,  and  if  properly  done  they  will  be  made  to  resemble  gold 
fillings. 

"  In  Fig.  836  we  have  the  case  completed. 

"  I  am  aware  that  in  a  case  like  this,  porcelain  crowns  instead  of 
gold  bands  could  be  used,  and  I  should  consider  it  much  preferable  to 
do  so  where  we  have  roots  or  unsound  teeth  to  operate  upon,  but  do 
not  advise  the  destroying  of  nerves  where  the  teeth  are  intact  to  supply 
such  a  case  with  crowns,  as  the  bands  will  answer  every  purpose  for 
many  years. 

"If  they  should  give  out  in  after  years,  the  roots  can  then  be 
crowned.  I  have  many  of  these  cases  that  have  been  in  use  seven  and 
eight  years,  some  of  which  have  never  loosened,  and  some  I  have  reset 
nearly  every  year.  I  always 
impress  upon  the  patient  the 
necessity  of  having  them  re- 
set immediately,  should  they 
become  loose,  and  .advise 
them  to  have  their  cases  ex- 
amined at  least  once  a  year. 
Should  parties  insist  upon 
having  crowns  used  to  supply 
a  case  like  the  one  just  de- 
scribed on  perfectly  sound 
teeth,  I  should  begin  by  using 
an  aluminum  disc,  with  corun- 
dum, cutting  deep  as  possible, 
both  on  the  labial  and  lingual  sides.  Then  use  the  excising  forceps. 
This  can  be  done  under  the  influence  of  an  anesthetic  or  otherwise. 
It  is  not  by  any  means  so  painful  an  operation  as  one  would  think.  If 
the  nerve  does  not  come  out  with  the  piece  of  tooth  cut  off,  I  take  a 
piece  of  orange  wood  which  I  have  previously  cut  the  proper  shape  to 
drive  into  the  nerve  canal.  I  place  it  in  creosote  and  let  it  soak  a  few 
minutes  before  beginning  to  operate.  Immediately  after  severing  the 
tooth,  drive  this  into  the  canal,  then  remove,  and  dip  in  creosote  and 
drive  in  again.  This  will  perfectly  fill  the  nerve  canal ;  all  sensitive- 
ness will  disappear,  and  you  can  begin  to  operate  at  once.     I  do  not 


Fig.  836. 


766 


MECHANICS — DENTAL    PROSTHESIS. 


recommend  this  treatment  for  sound  teeth,  but  I  have  treated  many 
exposed  nerves  in  this  way  ;  also  many  teeth  broken  by  accident,  and 
think  this  the  most  satisfactory  way  to  dispose  of  such  cases.  I  have 
never  had  any  unfavorable  results  follow  after  operating  upon  teeth  in 

this  way,  and  I  can  hardly 
say  as  much  in  favor  of 
any  other  treatment.  I 
speak  of  this  manner  of 
treating  exposed  nerves 
as  one  of  the  operations 
that  sometimes  become 
necessary  in  adjusting  a 
bridge  properly.  I  do 
not  claim  any  originality 
i  n  this  mode  of  treatment. 
I  know  several  dentists 
who  use  this  method,  all 
of  whom  report  satisfac- 
tory results.  We  now  have  Fig.  837,  showing  the  roots  prepared  to 
receive  the  case. 

"  I  have  many  of  these  cases  in  use  that  are  giving  entire  satisfaction. 
The  instrument  selected  for  preparing  these  roots  should  be  one  with 
small  inside  cutters  and  large  bevelers,  so  as  not  to  cut  away  any  more 
tooth-substance  than  pos- 
sible. 

"  Fig.  838  represents 
the  case  ready  for  adjust- 
ment. 

''Fig.  839  represents 
the  case  after  adjustment. 


Fig.  837. 


Fig.  838. 


Fig.  839. 


"  In  this  article  I  have  described  my  manner  of  making  teeth  for 
bridge-work,  and  I  am  now  using  a  tooth  made  expressly  for  this 
work. 

"The  following,  Fig.  840,  shows  us  a  socket.  These  are  ready 
made  in  various  sizes  in  bicuspids  and  molars  with  corresponding 
shells. 


CROWN    AND    BRIDGE -WORK. 


707 


**  Figs.  841  and  842  represent  the  shells  placed  in  sockets.  Fig. 
841  is  a  molar  tooth  showing  the  shell  in  position,  and  842  is  a  cen- 
tral reversed. 

"Fig.  843  represents  the  socket  as  made  for  the  four  central  and 
two  cuspid  teeth.  The  advantage  of  these  teeth  can  readily  be  seen, 
not  only  for  bridge-work  but  all  gold  plates.  A  tooth,  if  broken,  can 
readily  be  replaced  without  removing  the  bridge  or  cracking  by 
soldering,  and  with  only  a  small  expense. 

"  Fig.  844  represents  the  shell  placed   in   position  in   the  socket, 


Fig.  840. 


Fig.  S42. 


Fig.  S43. 


which  can  be  used  for  bridge-  or  crown-work,  and  will  greatly  reduce 
the  labor  in  making  either." 

Dr.  G.  W.  Melotte  describes  his  system  of  bridge-denture  as  fol- 
lows :  — * 

"  Fig.  845  illustrates  a  case  for  the  supply  of  a  lateral  and  a  bicuspid. 
In  this  instance  the  cuspid  could  be  cut  off,  and  the  root  collared  and 
capped  in  combination  with  a  pin  entering  the  enlarged  pulp-canal ; 
but,  as  there  may  be  grounds  for  objection  to  cutting  off  sound  teeth, 
I  obviate  the  necessity  by  cutting  a  shoulder  on  the  lingual  portion  of 
the  cuspid,  and  suitably  shap- 
ing its  sides  to  permit  a  close- 
fitting  collar  just  under  the  free 
margin  of  the  gum.  A  narrow 
strip  of  pure  pattern  tin,  bent 
tight  around  the  tooth-neck, 
and  cut  through  with  a  knife  at 
the  lap  on  the  labial  surface,  will  serve  as  a  measure  for  the  length  of  a 
strip  of  22-carat  gold  plate.  No.  29  thick,  and  as  wide  as  the  length  of 
the  distal  side  of  the  cuspid  The  ends  of  the  gold  are  then  squared, 
and  with  round-nosed  pliers  brought  evenly  together,  to  be  held  in  flush 
contact  by  the  soldering-clamp  shown  in  Fig.  846.  The  soldered 
collar,  with  its  joint  side  inward,  is  then  adjusted  on  the  tooth  as 
accurately  as  possible,  giving  slight  blows  with  a  mallet  until  the  col- 
lar touches  the  gum,  when  it  should  be  marked  to  indicate  the  neces- 
sary trimming  to  conform  it  to  the  gum  contour.     After  it  has  been 


Fig.  S45. 


*  Dental  Cosmos,  Decern.  No.,  1886. 


768 


MECHANICS — DENTAL    PROSTHESIS. 


thus  trimmed,  the  edges  beveled,  the  labial  part  swelled  with  contour- 
ing pliers,  and  the  lingual  part  cut  down  to  about  one-tenth  of  an 
inch  in  width,  the  collar  is  again  driven  on,  and  will  appear  as  seen 
in  Fig.  845.  A  stump  corundum  wheel  is  then  used  to  grind  a 
shoulder  on  the  lingual  surface  of  the  tooth,  grinding  also  the  edges 
of  the  collar  flush  with  the  shoulder.  The  collar  is  again  removed, 
and  a  piece  of  thin  platinum  plate,  about  No.  32,  sufficient  to  cover 
the  lingual  surface  of  the  tooth,  is  caught  on  the  lingual  edge  of  the 
collar  by  the  least  bit  of  solder,  and  all  put  in  place  on  the  cuspid 
(see  Fig.  847).  The  platinum  should  now  be  burnished  on  to  the 
shoulder,  and  over  the  tooth  and  collar  to  the  extent  shown  by  the 
lines  in  Fig.  847.  After  trimming  to  those  lines,  and  careful  replace- 
ment and  burnishing  on  the  tooth,  the  collar  and  half  cap  are 
removed,  filled  Avith  wet  plaster  and  sand,  and  the  platinum  soldered 
to  the  gold.  It  is  then  placed  on  the  tooth,  burnished  into  all  the 
inequalities  of  the  tooth,  very  carefully  removed,  invested,  and  enough 


Fig.  846. 


solder  flowed  over  the  platinum  to  cover  and  give  it  strength.  Fig. 
848  shows  it  complete  on  the  cuspid. 

"I  have  feared  that  a  detailed  statement  would  imply  a  long  and 
tedious  process,  but  I  have  often  made  such  collars  in  less  than  an 
hour,  and  in  any  case  time  must  be  made  subservient  to  exactness  of 
fit  and  adaptation  to  the  end  in  view. 

"In  the  preparation  for  fitting  a  collar  on  the  first  molar  (Fig.  845), 
I  should  have  wedged  or  otherwise  separated  it  from  the  second 
molar,  so  that  a  piece  of  sheet  brass  might  be  put  in  place,  as  shown 
by  Fig.  849,  and  an  impression  taken  in  plaster,  which  if  allowed  to 
get  hard  would  bring  away  the  metal.  If  not,  it  could  be  replaced  in 
the  plaster.  Melted  fusible  metal,  when  near  the  cooling  point,  is 
then  poured  into  the  impression,  and  when  cold  will  allow  the  safe 
removal  of  both  the  plaster  and  the  metal  strip.  On  this  metal  model 
a  collar  can  be  formed  that  will  accurately  fit  the  molar,  as  seen  in 
Fig.  845.  If  the  molar  has  no  antagonist,  a  cap  may  at  once  be 
struck  up  on  the  model,  but  if  there  be  an  antagonist  the  cusps  of 


CROWN    AND    BRIDGE-WORK. 


769 


the  natural  molar  should  be  removed  by  grinding  at  points  where  the 
occluding  tooth  will  admit  of  sufificient  thickness  of  the  gold  cap. 
An  exact  copy  of  the  ground  cusps  can  then  be  made  in  less  than  five 
minutes,  by  the  use  of  moldine  with  its  accessories,  and  the  process  is 
as  follows :  Make  the  tooth  perfectly  dry.  Put  the  collar  on  it. 
Nearly  fill  the  cup  (Fig.  851)  with  moldine,  and  coat  it  with  soap- 
stone  powder.     Press  the  compound  on  the  tooth  and  collar  firmly  to 


Fig.  847.     Fig. 


Fig.  849. 


Fig.  850. 


about  one-fourth  the  depth  of  the  tooth.  Carefully  remove  the  cup ; 
trim  off  any  overhanging  material,  and  place  the  rubber  ring  over  the 
cup  to  about  one-half  the  depth  of  the  ring.  Melt  the  fusible  metal 
and  pour  it,  as  cool  as  it  will  run  from  the  iron  ladle.  As  soon  as  the 
metal  is  hard,  remove  it  with  the  ring  (Fig.  852),  taking  care  not  to 
impair  the  impression,  which  can  be  used  again  if  the  die  is  found 
imperfect  or  gets  injured  in  use.  Place  the  die  and  ring  in  cold 
water,  to  remain  until  quite  cooled.  While  the  die  is  wet  and  held 
over  a  basin  of  water,  pour  into  the  ring  fusible  metal  which  has  been 


Fig.  851. 


Fig.  852. 


Stirred  until  it  begins  to  granulate,  and  quickly  immerse  all  in  the 
water.  The  die  and  counter-die  should  separate  readily  by  tapping 
them  with  a  hammer,  but  if  they  stick,  others  can  be  quickly  made 
from  the  same  impression,  by  the  same  method,  using  more  care. 
With  this  die  and  its  counter-die,  a  piece  of  No.  29  or  30  gold  plate 
is  swaged  to  fit  perfectly  the  cusps  and  collar,  which,  when  removed, 
can  be  held  to  its  place  on  the  cap  by  the  soldering-clamp,  using 
spring  pressure  enough  merely  to  hold  them  together  for  careful 
49 


77°  MECHANICS — DENTAL    PROSTHESIS. 

soldering  with  the  pointed  flame  so  as  not  to  unsolder  the  collar. 
The  seamless  collars  are  excellent  when  care  is  used  in  selecting  the 
proper  size,  as  directed  on  the  diagram. 

"The  caps  being  in  place  on  the  cuspid  and  molar,  an  impression 
is  taken  with  plaster;  the  caps  accurately  set  in  the  impression,  and 
hard  wax  melted  with  a  hot  spatula  around  the  edges  of  the  caps. 
The  impression  is  then  thoroughly  coated  with  sandarac  varnish,  after 
which  it  is  dipped  for  a  moment  in  water,  and  filled  with  a  wet  mix- 
ture of  one  part  marble-dust  with  two  parts  of  plaster  ;  using  great 
care  to  perfectly  fill  the  caps  and  molds  of  the  teeth.  Wait  until  this 
mixture  has  become  quite  hard  ;  remove  the  cup,  and  with  a  suitable 
knife  chip  off  the  plaster  without  marring  the  cast ;  secure  a  good 
articulating  impression,  and  transfer  it  to  the  cast  to  obtain  an  exact 
reproduction  of  the  relative  occlusions  of  all  the  teeth  involved. 
With  such  an  articulation  in  hand,  and  with  the  means  already 
described  for  swaging  gold  or  platinum  plate  to  fit  the  cusps  and 
articulating  surfaces  of  either  the  natural  or  artificial  teeth,  it  should 
be  within  the  capacity  of  any  competent  dentist  to  complete  a 
suitable  bridge ;  although  there  are  practical  points  that  can  only  be 
imparted  by  clinical  instruction  and  actual  demonstration  in  the 
mouth.     Such  a  bridge  is  shown  in  position  by  Fig.  850." 

Dr.  R.  Walter  Starr  describes  a  bridge-denture  which  can  be  re- 
moved for  repair  in  case  of  injury,  as  follows: — * 

"  It  will  doubtless  be  admitted  that  in  some  cases  bridge-work  has 
advantages  over  the  ordinary  plates  for  partial  dentures.  It  will  also 
be  conceded  that  the  security  and  permanence  of  the  fixture  enhances 
its  practical  value  to  the  patient  so  long  as  all  goes  well.  But  if  for 
any  reason  it  shall  become  necessary  to  remove  the  bridge,  for  repairs 
or  treatment  of  the  roots  used  as  anchorage,  its  fixedness  proves  a 
serious  objection. 

"In  the  endeavor  to  provide  a  remedy  for  this  defect,  the  structures 
now  to  be  described  originated,  and  will,  it  is  hoped,  be  found  applica- 
ble in  many  instances  in  such  cases  as  are  typified  by  the  accompany- 
ing illustrations. 

"In  the  construction  of  such  bridges  the  first  thing  to  be  done  is 
to  grind  with  engine-corundums  the  overhanging  edges  and  sides  of 
the  teeth  which  are  to  serve  as  abutments,  so  that  the  crown-ends 
shall  be  slightly  smaller  but  of  the  same  shape  as  their  necks.  This 
can  be  demonstrated  by  bending  a  piece  of  fine  binding-wire  around 
the  tooth-neck,  and  twisting  the  free  ends  together  to  form  a  close- 
fitting  loop,  which,  if  the  tooth  has  been  suitably  shaped,  may  be 

*  Dental  Cosmos,  vol.  xxviii. 


CROWN    AND    BRIDGE-WORK. 


771 


slipped  from  the  tooth  without  changing  the  form  of  the  loop,  thus 
giving  an  exact  outline  of  its  form  and  size.  Such  a  loop  is  shown 
in  Fig.  853.  The  loop  is  then  laid  upon  an  anvil,  and  the  squared 
end  of  a  short  piece  of  wood  placed  over  the  wire,  and  a  blow  struck 
to  drive  the  loop  into  the  wood  as  a  guide  in  shaping  the  wood  to  the 
precise  size  and  form  of  the  inside  of  the  loop,  as  in  Fig.  854.  The 
free  end  of  this  wooden  mandrel  must  subsequently  be  slightly  re- 
duced so  as  to  conform  exactly  to  the  natural  crown.  In  lieu  of  this 
method  an  exact  impression  of  the  tooth  may  be  taken  in  plaster  to 
serve  as  a  mandrel.  About  a  sixteenth  of  an  inch  is  then  ground 
from  the  occluding  cusps  of  the  abutment  teeth,  and  an  impression 
taken  of  the  teeth  and  surrounding  parts,  to  obtain  a  model,  as  shown 
in  Fig.  857.  A  piece  of  gold  plate,  say  22-carat  fine,  number  30 
gauge,  is  cut  and  fitted  closely  around  the  mandrel,  and  its  ends 
soldered  to  make  a  collar,  as  in  Fig.  855.  This 
is  laid  with  the  crown  end  upon  a  piece  of 
lead,  and  a  piece  of  wood  or  metal  laid  over  it 
and  struck  with  a  hammer  to  drive  the  collar 


Fig.  853. 


Fig.  8s4. 


Fig.  855. 


Fig.  856. 


Fig.  S57. 


into  the  lead  so  as  to  hold  it  securely  and  maintain  its  form,  while  with 
a  smooth,  half-round  file  the  neck  end  is  shaped  as  seen  in  Fig.  856. 
The  other  end  of  the  collar  is  then  cut  so  that  the  depth  of  the  collar 
shall  a  little  exceed  the  visible  length  of  the  tooth,  thus  allowing  the 
neck  end  when  placed  upon  the  tooth  to  pass  beneath  the  free  edge  of 
the  gum.  A  piece  of  gold  plate,  either  plain  or  struck  up  in  cusp  form, 
is  then  soldered  to  the  crown  end  of  the  collar.  If  a  seamless  collar  is 
used  it  can  be  laid  upon  the  plate  for  soldering  without  an  investment 
or  a  clamping  wire.  A  piece  of  thin  platinum  plate.  No.  T)^  gauge,  a 
little  wider  than  the  space  to  be  covered  with  the  teeth,  is  fitted  and 
burnished  over  the  space  between  the  abutment  teeth,  which  have 
been  so  trimmed  that  the  caps  described  will  slide  on  and  off  easily. 
These  caps  are  now  cemented  to  the  platinum  plate,  and  collars  made 
and  fitted  to  properly  fill  the  space  between  the  abutment  teeth. 
They  are  held  in  contact  with  each  other  and  with  the  platinum  plate 


77^ 


MECHANICS DENTAL    PROSTHESIS. 


by  running  melted  white  wax  in  and  between  them.  The  whole  piece 
may  then  be  transferred  from  the  model  to  the  mouth,  and  stiff  mixed 
plaster  and  sand  pressed  into  and  over  the  collars  and  caps.  When 
the  plaster  has  set  the  mass  may  be  removed,  trimmed,  and  the  wax 
melted  away  with  a  result  as  shown  in  Fig.  858.  The  lines  of  con- 
tact of  the  collars  with  each  other,  with  the  caps,  and  with  the  plate 
are  to  be  neatly  soldered,  when  the  investment  may  be  removed, 
leaving  the  bridge  as  shown  by  Fig.  859.  The  free  edges  of  the 
plate  may  then  be  trimmed  to  the  margins  of  the  collars  or  caps,  and 
the  whole  denture  polished.     The  bridge  may  now  be  slipped  on  and 


Fig.  858. 


Fig.  859. 


Fig.  S60. 


off  the  natural  abutment  teeth  with  just  enough  of  friction  to  retain 
the  denture  in  position  and  yet  allow  of  its  ready  removal. 

"Suitable  cusp-crowns  (see  Fig.  860)  are  now  selected,  the  cups 
partly  filled  with  wax,  and  the  cusps  placed  in  position.  The  den- 
ture is  then  tried  in  the  mouth  and  the  proper  occlusion  obtained  by 
grinding  or  filing  the  edges  of  the  cups.  The  piece  is  now  to  be 
thoroughly  cleansed  and  dried;  the  cups  nearly  filled  with  insoluble 
cement,  or  hot  gutta-percha ;  the  cusp  crowns  set  in  the  cups  ;  the 
bridge  put  quickly  in  place,  and  the  patient  directed  to  firmly  and 
repeatedly  close  the  jaws  to  properly  determine  the  occlusion.       It 

will  be  found  best  to 
place  a  piece  of  paper 
the  thickness  of  a  postal 
card  over  the  porcelain 
cusps  when  forcing  the 
denture  to  place,  so  as 
to  insure  that  they  shall 
be  a  little  short,  and 
thus  avoid  irritation  of 
the  anchorage  teeth  in 
mastication.  These  anchorage  teeth  or  roots  will  in  time  elongate 
and  form  a  close  occlusion. 

"  When  the  cement  is  properly  hardened  the  piece  may  be  removed. 
A  hole  should  now  be  drilled  through  the  metal  caps  to  allow  escape 
of  surplus  filling  material.    A  small  quantity  of  gutta-percha  thoroughly 


Fig.  501. 


CROWN    AND    BRIDGE-WORK. 


773 


warmed  should  now  be  placed  in  the  caps,  and  with  a  piece  of  card 
placed  between  them  and  the  occluding  teeth,  the  caps  should  be 
forced  home. 

"  The  complete  case  is  represented  in  Fig.  86 1. 

"The  bridge  may  at 
any  time  be  removed  with 
warmed  forceps  beaks 
held  long  enough  on  the 
caps  to  soften  the  gutta- 
percha. The  cusp  crowns 
may  be  removed,  if  de- 
sired, by  the  same  method 
and  replaced  without  de- 
taching the  bridge. 

"A  modified  bridge  is 
shown  in  Fig.  862.  It 
will  be  observed  that  col- 
lars have  been  firmly  fixed  with  cement  or  gutta-percha  on  the  abut- 
ment teeth,  which  have  their  occluding  surfaces  ground  flat  on  their 
inner  aspects,  so  that  the  partial  cap  shown  may  thus  prevent  the 
telescoping  collars  from  being  forced  too  far  down  on  the  teeth.  By 
means  of  a  frame  saw  a  narrow  tongue  is  cut  on  the  outer  face  of  each 
telescoping  collar,  the  free  portion  serving  as  a  spring  clasp  to  hold 
the  bridge  securely  on  the  abutment  teeth  and  still  allow  the  removal 
of  the  piece  whenever  so  desired.     Fig.  863  shows  such  a  bridge  in 


Fig.  862. 


Fig.  864. 


Fig.  865. 


place.  It  is  obvious  that  if  in  this  instance  the  roots  only  of  the 
cuspid  and  second  molar  had  been  present,  they  could,  by  means  of 
the  collar  and  cusp  crown  devices,  have  been  put  in  shape  to  serve 
as  abutment  teeth  for  the  telescoping  bridge  shown  in  Figs.  862  and 
863.  The  second  molar  roots  so  crowned  are  seen  in  Fig.  864. 
When  it  is  desirable  to  show  the  faces  of  the  porcelains  to  a  greater 
degree,  the  collars  may  be  cut  away  on   the  buccal   sides  and  the 


7U 


MECHANICS — DENTAL    PROSTHESIS. 


countersunk  crowns  be  used  as  illustrated  by  Fig.  865.  The  platinum 
base  may  either  rest  broadly  upon  the  gums  or  be  sloped  so  that  only 
the  buccal  border  shall  touch  the  gums,  or  it  may  be  so  shaped  as  to 
be  entirely  free  from  the  gum.  This  is  done  by  building  upon  the 
plaster  cast,  and  bending  the  platinum  plate  and  shaping  the  gold 
tubes  to  the  surface  so  made,  depending  wholly  for  support  on  the 
abutment  teeth  or  roots. 

"  Briefly  stated,  the  points  of  excellence  in  this  bridge  are  strength, 
lightness,  avoidance  of  liability  to  breakage  of  the  porcelain  in  sol- 
dering, ease  of  construction  and  adaptation,  and  the  facility  with 
which  it  may  be  reorganized,  or  for  any  reason  be  removed  and  re- 
placed. This  last  feature  is  of  special  value  in  the  not  infrequent 
event  of  subsequent  alveolar  abscess,  for  in  cases  such  as  are  shown  in 
Fig.  861  the  bridge  may  be  removed,  the  involved  teeth  drilled, 
medicaments  applied,  the  bridge  replaced,  and  this  process  repeated 
without  depriving  the  patient  of  the  use  of  the  denture." 

In  the  Dental  Cos?nos,  Dr.  Dexter  describes  a  removable-bridge 
denture  or  "cap-plate,'"  as  follows:  — 

"Take  a  case  where,  on  the  lower  jaw,  there  are  standing  in  the 
mouth  a  third  molar,  a  canine,  and  first  bicuspid  on  each  side — six 
teeth  in  all.  These  teeth  are  shortened  by  breakage  and  mastication, 
so  that  the  upper  incisors  close  to  within  an  eighth  of  an  inch  of  the 
gum  line  between  the  canines;  added  to  this,  they  are  so  tipped  and 
twisted  in  their  places  as  to  make  it  very  difficult  to  properly  adapt 
an  ordinary  denture  to  the  spaces  between  them  ;  and,  lastly,  let  the 
patient  evince  entire  abhorrence  of,  and  a  fixed  resolution  not  to 
permit,  the  resting  or  pressure  of  any  appliance  upon  his  gum  tissue. 

Such  a  case  is  the  one  for 
which  I  have  constructed  this 
cap-plate.  Such  cases  are  often 
treated  by  building  up  or  down 
the  natural  teeth  with  gold,  in 
/       jg^  order   to  open    the   bite,   and 

1/7"^  ^^       then  replacing  lost  teeth  with 

an  ordinary  plate.     My  appa- 
ratus,   however,    accomplishes 
both  these  desiderata   in    one 
operation,  while  simultaneously 
avoiding  any  and  all  pressure 
upon  or  irritation  of  the  gum. 
"The  appliance  which   I  show  you  (Fig.   866)  is  constructed  as 
follows:    Caps  of  gold  and  platinum  alloy,  of  about   26  to  28  U.  S. 
standard  gauge,  are  struck  up  to  fit  over  and  down  the  sides  of  the 


Fig.  866. 


CROWN    AND    BRIDGE-WORK.  775 

natural  teeth  selected  for  the  piers,  fitting  closely.  If  all  the  support- 
ing teeth  stand  perpendicularly  and  parallel  with  each  other,  thus 
creating  no  '  undercut '  (so  to  say),  the  sides  of  the  caps  may  encircle 
the  teeth  as  far  as  possible  {not,  however,  impinging  upon  the  gum- 
line),  and  be  simply  slit  (in  two  or  more  places  on  each  tooth) 
perpendicularly,  so  as  to  spring  apart  and  allow  of  sliding  the  whole 
over  the  natural  convexities  of  the  teeth,  the  sides  coming  together 
again  when  in  place  and  thus  holding  the  whole  apparatus  firmly. 
But  should  the  teeth  be  tipped  or  leaning,  and  not  parallel,  the  sides 
of  the  caps  must  then  extend  over  only  such  parts  as  can  be  closely 
fitted  and  yet  be  sufficiently  perpendicular  and  parallel  to  allow  of 
removal  and  replacing  of  the  appliance.  Of  such  a  character  is 
the  case  now  shown  you,  there  being  only  one  place  on  the  six 
caps  where  a  slit  is  of  value ;  the  sides  of  the  caps  being  so  fitted 
as  to  hold  partly  by  their  own  elasticity,  and  partly  by  that  of 
the  whole  apparatus.  Such  a  case,  of  course,  will  most  severely  try 
the  capabilities  of  any  artificial  denture ;  and  not  the  least  merit  of 
the  present  piece  is  its  triumph  over,  and  perfect  and  practical  adap- 
tation to,  the  obstacles  of  an  exceptionally  difficult  case. 

"The  caps,  when  struck  up,  will  not  cling  to  the  teeth  when  in 
place  ;  nor  should  they,  for  they  must  be  capable  of  easy  removal 
during  succeeding  processes.  But  when  the  piece  is  ready  for  final 
insertion,  the  sides  of  the  caps  must  be  sprung  inward  sufficiently  to 
hold  to  their  supports  with  firmness. 

**  The  caps  being  now  made,  it  is  in  order  to  determine  the  length 
of  '  bite '  needed.  Place  the  caps  in  position  in  the  mouth,  and 
build  wax  on  their  grinding  surfaces  to  a  proper  length  and  contour, 
both  side  and  grinding.  Invest,  remove  wax,  and  flow  into  its  place 
eighteen -carat  gold.  Shape  the  grinding  surfaces,  by  trial  in  an 
articulator  or  the  mouth,  to  the  proper  occlusion.  Next,  take  an 
impression  with  the  caps  in  place,  pour  the  model,  select  and  back 
plain  plate-teeth,  and  wax  them  in  place.  Invest  the  whole,  remove 
the  wax  from  the  backs  of  the  teeth,  and  fit  in  the  spaces  between  the 
caps,  bands,  or  bars  of  irido-platinum  alloy  (or  gold,  as  circumstances 
may  determine),  being  careful  that  the  bars  fit  accurately  to  the  back- 
ings of  the  porcelain  teeth  and  to  the  caps  at  each  end.  In  fitting 
the  bars  to  the  caps,  select  such  points  of  attachment  as  will  not  in- 
terfere with  the  spring  of  the  slit  sides  of  the  caps.  If  necessary,  let 
the  bars  avoid  the  sides  of  the  caps,  and  reach,  by  curving,  to  the 
tops  or  grinding  surfaces.  Should  you  desire  to  arrange  the  porcelain 
teeth  irregularly,  you  need  not  hesitate  to  do  so.  Set  them  just  as 
you  would  for  rubber  or  celluloid,  and  then,  simply  taking  a  '  finger 
impression  '  of  their  backs  with  modeling  composition  or  wax,  when 


776  MECHANICS — DENTAL   PROSTHESIS. 

invested  as  above  stated,  and  making  dies,  you  can  readily  '  strike 
up  '  your  bars  to  fit  the  irregular  positions  of  the  backings.  But 
should  this  be  difficult  on  account  of  great  irregularity  or  stiffness  of 
bars,  then  construct  the  bars  of  two  or  three  thicknesses  of  metal, 
each  struck  up  separately,  and  then  '  sweated  '  into  one.  Next,  solder 
the  bars  to  the  backed  teeth,  but  not  to  the  caps,  as  yet.  The  reason 
is  that /^?7^r/ adaptation  of  the  bars  to  the  caps  is  absolutely  necessary 
to  the  success  of  the  piece.  Therefore,  now  place  the  caps  in  place 
in  the  mouth,  and  wax  the  bars  with  their  attached  teeth  in  the  spaces 
between  them  ;  filling,  grinding,  and  adjusting  until  all  is  exactly  as 
required.  Then  (and  not  until  then)  take  an  impression  of  the 
whole  in  place,  the  apparatus  coming  away  with  the  plaster.  Pour 
the  impression  with  plaster  and  pumice,  sand  or  asbestos  (sand  is 
best),  carefully  remove  the  impression  plaster,  invest  outside  the 
model  with  its  sustained  apparatus,  and  then  solder  the  caps  and  bars 
together.  In  doing  this  as  little  solder  as  possible  should  be  used,  to 
prevent  warping  of  the  whole.  The  bars  should  have  a  broad,  firm 
hold  on  the  caps ;  but  the  contour  of  their  union  should  be 
made  on  the  bars  before  they  are  united  to  the  caps,  and  not  by  flow- 
ing on  a  body  of  gold  while  uniting  the  bars  and  caps  sufficient  to 
attain  the  desired  hold  and  shape  of  union.  On  the  contrary,  the 
bars  should  be  properly  shaped  at  their  ends,  and  carefully  fitted  to 
the  surfaces  to  which  they  will  be  attached,  when  a  small  amount  of 
solder  flowed  into  the  joint  will  make  a  perfect  union  and  give  all  the 
strength  possible.  This  is  7iot  plumbing  work.  All  that  now  remains 
to  do  is  to  spring  or  bend  slightly  inward,  as  before  directed,  the  sides 
of  the  caps  so  that  they  may  grasp  their  supporting  teeth  firmly,  yet 
not  so  much  as  to  create  difficulty  in  removal  or  insertion  \  then 
finish  and  polish.  Burnishing  is  generally  objectionable,  since  it 
gives,  in  some  lights,  a  black  shine  to  the  piece,  adding  greatly  to  the 
prominence  of  the  appliance  as  a  part  of  the  view  whenever  the 
wearer  opens  his  mouth. 

"  Should  it  be  desired  to  produce  the  best  possible  results  with  the 
piece,  the  interstices  between  the  artificial  teeth  and  any  other  crev- 
ices to  be  found  may  be  filled  with  gold  or  amalgam,  —  I  prefer  the 
former;  or  vulcanite  may  be  packed  in  such  places  (which  may  be,  if 
necessary,  cut  out  to  proper  dimensions  by  burring),  and  finished  up 
smoothly.  The  piece  shown  you  contains  no  less  than  seventeen  gold 
fillings,  which  signifies  that  no  debris,  or  even  moisture,  has  any  foot- 
hold of  concealment  about  it,  and  that  it  is,  therefore,  as  clean  in 
itself  as  is  possible  for  any  artificial  denture  to  be.  This,  you  will 
say,  is  rather  expensive  work.  Very  true.  The  whole  method  is  ex- 
pensive in  both  money  and  labor.     But  I  am  quite  consoled  for  this 


CROWN    AND    BRIDGE-WORK. 


777 


fact  by  the  thought  that  it  will  not,  therefore,  be  likely  to  do  much 
harm  to  the  public,  since  the  '  cheap-jacks '  and  '  incompetents  '  will 
probably  let  it  alone. 

"  In  the  piece  shown  there  are  six  caps,  three  on  a  side.  There  are 
five  incisor  teeth  placed  between  the  canines,  two  of  which  are  capped 
with  gold  to  break  up  the  uniformity  of  porcelain  in  front,  as  con- 
trasted with  the  uniformity  of  gold  behind,  and  thus  help  to  evade 
artificiality  of  appearance.  Between  the  molar  caps  and  the  double 
caps  for  canine  and  bicuspid,  the  connecting  bar  is  horizontally 
placed,  dipping  downward  to  parallel  the  gum  line,  as  well  as  to  evade 
an  encroaching  molar  above.  When  necessary,  an  artificial  tooth  or 
teeth  can  be  ground  and  soldered  to  these  bars.  Generally,  however, 
the  connecting-bars  should  be  perpendicularly  placed,  to  insure  resist- 
ing strength  in  the  line  of  the  attacking  force." 

Dr.  R.  Walter  Starr,  in  the  same  journal,  describes  the  following 
case  of  removable  bridge-denture: — 

"The  case  of  Mr.  W.  presented  difficulties  of  an  unusual  charac- 
ter, as  may  be  seen  by  inspecting  the  illustration,  Fig.  867,  which 
renders  detailed  description  unnecessary. 

"It  will  be  observed  that  the  molars  and  the  left  second  bicuspid 
overhang  to  a  degree  that  would  make  the  taking  of  an  accurate  im- 
pression by  ordinary  methods  well-nigh  impossible.  After  a  careful 
study  of  the  case  it  was 
decided  that  two  separ- 
ate pieces  of  removable 
bridge-work  should  be 
attempted,  and,  as  an 
essential  preliminary 
step,  the  overhanging 
sides  of  the  molars  and 
bicuspids  were  ground 
with  engine  corundum 
wheels  and  points  un- 
til those  sides  were 
made  much  less  in- 
clined, when  plaster  im- 
pressions were  taken, 
first  of  one-half,  and 
then  of  the  other  half, 
of  the  jaw.  Gold  cap- 
crowns  were  closely  fitted  over  the  molars,  left  second  bicuspid,  right 
first  bicuspid,  and  cuspid  stump.  Gold  crowns  were  made  to  tele- 
scope over  all  the  caps,  which  were  then,  by  means  of  oxyphosphate 


Fig.  867. 


778 


MECHANICS DENTAL    PROSTHESIS. 


cement,  fixed  firmly  on  the  teeth.  Suitable  plate-teeth  were  selected, 
fitted,  backed,  and  hard-waxed  in  place  between  the  telescoping 
crowns.  After  hardening  the  wax  with  cold  water  from  a  tooth- 
syringe,  the  pieces  were  carefully  removed,  invested  and  soldered. 
The  two  completed  bridges  were  easily  replaced  on  or  removed  from 
the  supporting  capped  teeth,  and  their  appearance  when  detached  is 
correctly  shown  by  the  illustration,  Fig.  868,  which  also  shows  the 
capped  teeth  and  stumps.  This  figure  likewise  shows  the  results  of 
the  novel  method  employed  in  crowning  the  incisors.     Gold  collars 

were  fitted  tight  on  the 
necks  of  the  incisor 
stumps,  and  the  new- 
style  porcelain  caps  ad- 
justed in  the  collars, 
^^  and  set  in  the  oxyphos- 

ll^ifl'lf'     ^-v^^^s^*.^  phate     cement     which 

had  been  packed  into 
the  collars ;  thus  at  the 
same  time  fastening  the 
collars  on  the  stumps 
and  the  caps  in  the 
collars,  as  shown  com- 
pleted in  Figs.  868  and 
869. 

"  Fig.  S69  illustrates 
the  finished  crowns  and 
bridges,    which     latter 
were   secured    in    posi- 
tion by  placing  a  small 
piece    of    gutta-percha 
in  each  of  the  telescop- 
ing cap- crowns,  which  were  then  warmed   and  carefully  pressed    in 
place — the  gutta-percha  filling  only  the  spaces  between  the  flat  tops 
of  the  caps  of  the  natural  teeth  and  cusped  caps  of  the  bridges. 

"Whenever  for  repair,  or  for  any  other  purpose,  it  shall  become 
desirable  to  remove  one  of  the  bridges,  that  may  readily  be  done  by 
applying  a  hot  instrument  or  hot  air  to  the  caps,  to  soften  the  gutta- 
percha sufficiently  to  permit  the  telescoping  bridge  to  be  taken  off. 

"A  full  upper  vulcanite  denture  was  made  to  replace  the  old  one, 
which,  by  improper  occlusion,  had  thrown  the  full  force  of  mastication 
on  the  anterior  teeth  of  the  lower  jaw,  and  produced  the  destructive 
action  that  resulted  in  the  deplorable  loss  of  tooth  substance  shown  in 
Fig.  867. 


CROWN    AND    BRIDGE-WORK. 


779 


"  The  prosthetic  devices  thus  briefly  described  have  so  far  proved 
perfectly  satisfactory  to  both  patient  and  dentist.  The  obvious  diffi- 
culties of  the  case, 
and  the  somewhat  novel 
means  employed  in  sup- 
plying useful  and  secure 
dental  substitutes,  seem 
to  justify  the  writer  in 
bringing  the  case  to 
the  attention  of  the 
profession." 

A  bridge  of  this  form 
can  also  be  made  re- 
movable by  cementing 
it  on  the  natural  crowns 
or  roots  with  gutta- 
percha, and  by  still 
further  securing  it  by 
screws  entering  the 
body  of  the  crowns  or 
roots  through  the  gold 
forming  the  occluding  or  grinding  surface  portion. 

Dr.  H.  C.  Register  has  devised  the  following  method,  which,  in  the 
event  of  a  porcelain  crown  being  broken,  possesses  the  advantage  of 
allowing  the  place  to  be  filled  by  a  new  crown  without  disturbing  the 
main  appliance.  The  following  concise  description  of  this  method  is 
by  Dr.  Dexter  :  — 

"  Taking  a  typical  case  (Fig.  870),  a  rim  or  saddle  of  gold,  plati- 
num, or  iridinized  platinum  is  struck  to  fit  the  spaces  between  the 
teeth  A  and  b.  To  this  are  attached  bars,  x.  Fig.  872,  to  enter  the 
fillings  at  z,  z  (Fig.  871).  Posts  or  pivots  (d.  Fig.  872)  are  soldered 
upon  this  saddle  where  the  artificial  teeth  are  to  be  placed,  their 
free  ends  being  threaded  to  carry  the  nut  E.  Hollow  crowns,  counter- 
sunk for  the  nut  at  g,  and  having  the  necks  ground  to  reach  over  the 
saddle  and  press  upon  the  gum,  are  fitted  over  each  post.  Amalgam 
is  used  to  fill  in  the  space  between  the  post  and  the  tooth-wall,  as 
in  a  Bonwill  setting,  and  the  crowns  are  drawn  to  place  and  held 
with  the  nut.  The  saddle  is  fixed  in  its  place  in  the  mouth,  before 
the  crowns  are  finally  attached,  by  filling  into  the  cavities  z  the 
bars  XX." 

Dr.  J.  Iv.  Williams  suggests  the  following  methods  for  the  single 
crown  and  for  "  bridge-work,"  which  he  describes  as  follows  ;  — 

"It  consists  essentially  of  three  parts:  a  square  pin  of  platinum 


ySo 


MECHANICS — DENTAL   PROSTHESIS. 


and  iridium  which  enters  the  enlarged  pulp-canal,  a  cap  of  gold,  and 
the  porcelain  face,  which  is  the  ordinary  plate  tooth. 

**  This  crown  is  made  in  the  following  manner  :  After  the  end  of 


Fig.  870. 


the  root  is  made  perfectly  smooth  with  corundum  wheels  and  properly 
shaped  scalers,  a  gold  ferrule  or  band  is  fitted  around  it.  If  it  is 
desirable  that  this  band  should  be  entirely  concealed,  the  labial  sur- 
face of  the  root  should  be  beveled  a  little  above  the  margin  of  the 


Fig.  871. 


Fig.  872. 


gum,  and  after  the  band  has  been  soldered  it  may  be  placed  in  posi- 
tion, and  the  line  of  contour  of  the  margin  of  the  gum  marked  upon 
the  front  of  the  band.     The  proper  bevel  can  then  be  cut  and  the 


CROWN   AND    BRIDGE-WORK. 


781 


Fig.  873. 


edges  squared  upon  a  corundum  wheel,  leaving  the  lingual  portion  of 
the  band  a  little  longer  than  the  front.  Pure  gold,  rolled  to  No.  34 
of  the  standard  gauge 
(American),  is  used  for 
soldering  upon  the  bev- 
eled surfaces,  thus  mak- 
ing a  closed  cap  for  the 
end  of  the  root.  A 
suitable  tooth  is  now 
selected  and  backed 
with  pure  platinum  or 
pure  gold.  The  cervi- 
cal end  of  the  tooth  is  then  ground  to  the  proper  position  on  the  front 
bevel  of  the  cap,  all  of  the  fitting  being  done  while  the  cap  is  in 
position  on  the  root. 

''After  the  fitting  is  completed  the  cap  is  removed  and  the  tooth 
attached  by  strong  resin  wax  and  again  placed  in  position  while  the 
wax  is  warm.  Any  slight  change  in  position  which  is  necessary  can 
then  be  easily  made.  The  tooth  and  cap  are  now  removed  together, 
invested,  and  united  at  the  back  by  solder.  It  is  well  to  use  a  solder 
for  the  cap  with  a  higher  melting  point  than  that  used  for  the  backing, 
as  it  obviates  the  danger  of  unsoldering  the  band  when  the  backing  is 
flowed  on.  After  finishing  and  polishing  the  work,  the  end  of  the 
root  is  made  perfectly  dry,  a  sufficient  quantity  of  oxyphosphate 
cement,  mixed  somewhat  thinner  than  for  filling  purposes,  is  placed 
in  the  enlarged  pulp  canal  and  also  in  the  cap.  The  crown  is  then 
carried  to  place  with  firm,  steady  pressure,  held  a  few  minutes  until 
the  cement  is  sufficiently  hard  to  prevent  displacement.  The  surplus 
cement  v/hich  has  oozed  out  around  the  band  should  be  carefully 
removed,  and  the  work  is  then  completed." 

Dr.  Williams's  method  can  be  applied  to  "bridge-work,"  as  the 
following  Figs.  874,  875,  and  876  will  show. 


Fig.  874. 


Fig.  875. 


In  this  method,  special  crowns.  Figs.  877  and  878,  for  molars  and 
bicuspids,  with  porcelain  faces,  are  made,  which  are  backed  with 
gold  or  platinum  and  the  tips  ground  squarely  off.  Zinc  pattern 
dies  are  made  from  the  grinding  surfaces  of  molars  and  bicuspids, 


782 


MECHANICS — DENTAL   PROSTHESIS. 


to  be  used  for  swaging  from  pure  gold  a  tip  or  cap  for  the  protec- 
tion of  the  porcelain  face.  The  concave  surface  of  these  tips  is 
filled  by  melting  coin  gold  into  them,  and  this  surface  is  then  ground 
smooth  and  fitted  to  the  squared  surface  of  the  porcelain  face  and 
waxed  into  position.  Triangular  pieces  of  platinum  are  then  cut 
of  the  proper  size  to  fit  the  sides  of  the  tooth,  waxed  in  position. 


Fig.  876. 


o 

Fig.  877. 


and  the  whole  invested,  leaving  the  back  open,  which  is  filled  with 
coin  gold. 

Dr.  Williams  also  describes  other  forms  of  bridge-denture,  in  one 
of  which  there  are  no  supporting  roots,  and  in  the  other  the  sections 
are  united  by  bands  of  gold.* 


*  Dental  Cosmos,  December,  1885. 


CROWN    AND    BRIDGE-WORK. 


7«3 


"  Figs.  879  and  880  illustrate  a  method  of  inserting  extensive  pieces 
of  bridge-work  in  cases  where  there  are  no  natural  teeth  or  roots  for 
supporting  one  end  of  the 
bridge.  The  work  from  which 
these  drawings  were  made  was 
constructed  by  Dr.  H.  A. 
Parr.  By  this  method  bridges 
may  be  inserted  in  cases  where 
all  of  the  teeth  on  one  side  of 
the  mouth  have  been  lost,  or 
where  all  the  teeth  anterior  to 
the  molars  on  both  sides  are 
wanting.  Crowns  are  first 
fitted  to  the  teeth  which  re- 
main. These  crowns  being 
in  position,  an  impression  is 
taken.     From   this  a  cast  is 

obtained  with  the  crowns  in  their  proper  positions.  A  second  impres- 
sion is  also  taken  of  that  portion  of  the  mouth  where  there  is  no 
natural  support  for  the  bridge.  From  this  impression  metallic  dies  and 
counter-dies  are  obtained,  from  which  is  'struck'  a  small  gold  plate 
about  three-fourths  of  an  inch  in  length  and  width,  the  size  of  the 
plate  varying  according  to  position  and  other  conditions.  After  this 
little  plate  or  '  saddle '  has  been  perfectly  fitted,  it  is  waxed  in  the 


Fig.  879. 


Fig.  880, 


proper  position  on  the  model,  with  the  crowns.  The  intervening 
teeth  are  now  placed  in  position,  and  the  work  invested  and  soldered. 
To  provide  for  the  possibility  of  shrinkage  or  absorption  at  the 
point  where  the  plate  or  saddle  rests,  it  is  suggested  that  it  be  not 
soldered  to  the  bridge,  but  attached  by  means  of  an  adjustable 
screw. 

"Fig.  881  illustrates  another  device  for  obviating  the  necessity  for 


784 


MECHANICS — DENTAL    PROSTHESIS. 


Fig.  882. 


removing  the  crowns  of   natural  teeth  in  preparing  the  mouth  for 

bridge-work.  Crowns 
are  fitted  in  the  mouth 
to  the  points  of  attach- 
ment in  the  usual 
manner.  An  impres- 
sion is  taken,  bringing 
the  crowns  away  in 
their  proper  positions. 
From  this  the  cast  or 
model  is  obtained. 
Heavy  bands  of  half- 
round  gold  or  plati- 
num bars  are  now 
fitted  around  the  necks 
of  the  natural  teeth, 
on  their  lingual  sur- 
faces. These  bands,  being  waxed  in  position,  serve  to  connect  the 
different  parts  of  the  bridge,  uniting  them  in  one  piece  without  the 
loss  of  any  of  the  natural  crowns.  I  have  found  this  a  highly  satisfac- 
tory method  of  inserting  extensive  pieces  of  the  work.  Fig.  882  shows 
the  mouth  as  presented,  for 
which  the  piece  shown  in  Fig. 
881  was  constructed.  Fig.  883 
shows  the  piece  in  position. 

"  Fig.  884  illustrates  a 
case  which  is  a  type  of  a 
class  of  frequent  occurrence. 
Alternate  molars  and  bicus- 
pids in  the  upper  and  lower 
jaws  are  lost  until  the  occlu- 
sion is  somewhat  changed, 
and  the  force  of  mastication 
is  gradually  brought  upon  the  front  teeth.  Rapid  wearing  of  these 
teeth  results.  These  cases  are  among  the  most  difficult  that  the  opera- 
tor is  called  upon  to  treat  by  the  ordinary  methods.  In  the  case 
herewith  illustrated,  the  lower  bicuspids  with  a  molar  on  one  side 
were  in  good  condition,  but  the  loss  of  the  upper  bicuspids  and 
molars  made  them  useless.  As  usually  happens,  the  upper  incisors  had 
suffered  most.  The  lower  incisors  were  restored  by  capping  them 
with  cohesive  foil.  The  bridge  shown  at  Fig.  885  was  constructed 
for  the  right  side  of  the  upper  jaw,  while  the  teeth  on  the  left  side 
were  restored  bv  contour  work,  as  shown  at  Fig.  886. 


Fig.  S83. 


CROWN    AND    BRIDGE-WORK.  785 

"  The  superiority  of  the  condition  of  this  patient's  mouth,  which 
resulted  from  this  work,  over  anything  which  could  have  been  accom- 
plished by  plate  work,  is  almost  inconceivable  to  one  not  familiar  with 
these  methods. 

"The  only  annoyance  which  bridge-work  is  likely  to  cause  patient 
or  operator  is  the  occasional  breaking  of  a  porcelain,  an  accident  of 


not  frequent  occurrence.  While  the  replacing  of  a  broken  porcelain 
has  never  been  a  matter  of  extreme  difficulty,  yet  I  have  always 
regarded  the  methods  hitherto  employed  as  more  or  less  imperfect  and 
uncertain  in  their  results.  This  led  me  to  devise  a  method  of  replac- 
ing broken  porcelains  which  leaves  the  work  fully  as  strong  as  before; 
a  method  which  makes  the  operation  a  very  simple  one,  requiring  less 


Fig.  887. 

than  an  hour  for  its  performance  ;  and  after  the  porcelain  has  been 
replaced,  an  expert  would  not  discover  any  traces  of  an  accident. 
After  removing  all  traces  of  the  broken  porcelain,  the  projecting  pins 
are  cut  off,  and  two  holes  drilled  through  the  backing  in  the  exact 
position  occupied  by  the  pins.  The  narrow  space  of  metal  now  in- 
50 


786 


MECHANICS — DENTAL   PROSTHESIS. 


tervening  between  these  two  holes  is  cut  out  with  a  fissure-bur. 
This  leaves  a  groove  which  should  not  be  wider  than  the  diameter  of 
the  pins.  The  length  of  this  groove  should  now  be  increased  on  the 
lingual  surface,  but  not  on  the  front.  The  object  of  this  is  to  give  a 
dove-tail  shape  to  the  groove,  which  is  easily  effected  by  the  use  of  the 
same  fissure-bur  above  referred  to.  The  lingual  appearance  of  this 
groove  when  properly  shaped  is  shown  in  Fig.  887.  The  proper  tooth 
is  selected,  the  pin  passed  through  this  hole  and  bent  outward  into  the 
dove-tail  groove.  It  now  remains  but  to  fill  the  space  between  the 
pins  with  any  form  of  cohesive  gold  (I  use  crystal  gold),  and  with 
corundum,  Arkansas,  and  rubber  points  in  the  engine  the  surface  is 
finished  and  polished.     The  wedge-shaped  filling  of  crystal  gold  acts 

as  a  keystone  between  the  pins,  and 
makes  a  most  perfect  method  of 
repair." 

Porcelain  veneers  or  facings  for 
bridge-work  are  represented  by 
Fig.  888. 

These  facings  of  molar  and  bi- 
cuspid forms  have  two  long  platinum 
pins  (cross-wise)  for  attachment. 
They  are  specially  designed  for  use 
in  bridge-work  operations.  The 
long  pins  afford  facility  of  repair 
when  a  tooth  has  been  broken  in 
use.  Incisor  facings  of  the  same 
character  are  also  employed. 

Dr.  H.W.  Howe  recommends  the 
following  flux  that  is  exceedingly 
useful  in  bridge-work  and  is  prepared  as  follows.     Put  in  a  cup  : — 

Boracic  acid, I  oz. 

Ammonia, i  oz. 

Carbonate  of  ammonia, ^  dwt. 

Bicarbonate  of  soda, 2  dwt. 

Water, 4  ozs. 

Boil  until  the  fumes  of  ammonia  are  no  longer  given  off.  Coat  the 
bridge  or  other  work  all  over  the  gold  with  the  flux.  Heat  it  over  a 
spirit-lamp  to  dry  it  on.  Give  it  another  coat,  if  needed,  leaving  no 
part  exposed.  Then  scrape  off  where  it  is  desired  that  the  solder  shall 
flow,  and  it  will  go  nowhere  else.  The  work  will  come  out  of  the  heat- 
ing as  bright  as  when  it  went  in,  and  the  solder  will  be  smooth.  The 
polished  surfaces  will  not  be  corroded  or  blackened. 


CROWN    AND    BRIDGE-WORK.  787 

Dr.  A.  S.  Condit  has  devised  a  combination  of  plate-  and  bridge- 
work,  and  describes  his  method  as  follows  : — * 

"  How  well  do  bridge-workmen  know  the  difficulties  incurred  in 
preparing  a  case  for  a  piece  of  bridge-work  when  the  teeth  on  each 
side  of  the  case  converge  or  diverge  !  My  object  in  devising  the  new 
method  was  to  avoid  the  above  mentioned  difficulties.  It  is  sometimes 
almost  necessary  to  expose  the  pulp,  to  make  the  sides  parallel.  By 
the  new  method  it  is  only  necessary  to  dress  the  tooth  until  the  band 
or  crown  can  be  nicely  adjusted,  the  same  as  would  be  done  to  nicely 
cap  the  tooth  for  its  preservation. 

"The  attachment  tubes  or  sockets  are  placed  upon  the  bands  or 
crowns  parallel  to  each  other,  regardless  of  the  position  the  teeth  may 
occupy  in  the  arch. 

"  Fig.  889  represents  a  case  where  all  the  teeth  posterior  to  the  cuspid 
on  the  right  side  of  a  lower  jaw  are  lost,  a  case  which  could  not  be 
retained  by  a  clasp,  and  the  only  method  known  to  the  profession  is  to 
couple  the  teeth  on  both  sides  with  a  plate,  permitting  all  the  pressure 
of  mastication  to  come  on  the  gums  and  alveolar  process,  causing  con- 
tinued absorption  and  the  usual  tilting  of  one  side  while  biting  upon 
the  opposite  side.  In  following  the  new  method  a  band  or  crown  is 
first  made  for  the  tooth  adjacent  to  the  space  to  be  filled,  then  a  tube 
or  socket  is  made  of  gold  or  any  suitable  metal  and  soldered  to  the 
band  or  crown  on  the  side  next  to  the  space  on  a  line  parallel  to  the 
lingual  side  of  the  tooth.  The  length  of  the  tube  is  governed  by  the 
amount  of  space  between  the  tooth  so  attached  and  the  tooth  in  the 
opposite  jaw.  The  longer  the  tube  the  better,  yet  when  two  attach- 
ments can  be  made  the  tube  can  be  very  short,  for  the  solidity  of  the 
work  depends  almost  entirely  upon  the  lock-pin.  By  this  method  no 
undue  pressure  is  placed  upon  the  gums,  as  the  resistance  in  mastication 
is  partly  taken  up  by  the  tooth  or  teeth  to  which  attachment  is  made. 
The  tube  or  socket  referred  to,  which,  as  previously  mentioned,  is 
soldered  to  the  band  or  crown,  has  placed  on  the  lower  end  an  annular 
flange,  making  the  opening  at  the  lower  end  of  the  tube  a  trifle  smaller 
than  at  the  upper  end.  To  this  tube  is  fitted  what  is  termed  the  cap 
and  shield.  The  shield  part  is  also  a  tube  just  large  enough  to  fit  over 
the  one  fastened  to  the  band  or  crown  and  encircle  it  except  at  the  side 
which  is  soldered.  The  cap  covers  the  upper  end  of  the  large  tube  or 
shield  and  has  a  thread-hole  through  the  center  into  which  is  screwed 
the  lock-pin.  The  lower  end  of  the  lock-pin  is  split  and  surrounded 
by  an  annular  groove  which  corresponds  with  flange  in  tube  upon  band 
or  crown,  so  that  when  lock-pin  passes  into  the  tube  it  is  compressed 

*  Ohio  Dental  Journal. 


788 


MECHANICS — DENTAL    PROSTHESIS. 


by  the  flange  until  it  reaches  the  groove  upon  the  pin  when  the  spread- 
ing out  of  the  pin  locks  it  firmly  in  place  and  it  cannot  be  detached 


In  upper  portion  of  above  illustration  is  represented  the  device  in  sections,  viz : 
I  represents  the  exact  size  of  split  pin. 

2,  the  same  magnified,  of  which  A  represents  the  split. 
B,  the  annular  groove,  and  C  the  screw. 

3,  the  exact  size  of  the  tube  or  socket. 

4,  a  magnified  view  of  same. 

5,  shows  the  different  parts  of  device  put  together. 

6,  illustrates  a  band  with  tube  4  attached. 

D,  represents  the  device  placed  in  the  work,  and  E  the  tube  or  band  ready  for 
adjustment. 


CROWN    AND    BRIDGE-WORK. 


789 


except  by  a  straight  up  or  down  pull.     The  cap  and  shield  also  has  a 
projecting  ear,  the  purpose  of  which  is  to  firmly  hold  it  to  the  plate. 

"  Fig.  890  represents  a  case  attached  to  central  incisor  and  second 
molar  on  the  right  side  of  lower  jaw.  This  is  a  case  which  would 
be  considered  impracticable  for  any  other  kind  of  work  and  right  here 


ai«te:r[or 

ATTACHMENT. 


Fig.  890. 

In  Figs.  890  to  894,  X  represents  the  work  ready  for  adjustment.  Y  casts  of  the 
mouth  with  bands  and  crowns  in  position  and  tubes  in  proper  place  for  the  insertion 
of  the  work.  Z  the  work  in  position  on  the  cast.  A  represents  the  device  as  placed 
in  the  work.  B  the  tube  placed  on  band.  C  the  split  pin  in  position  in  the  device, 
and  D  the  tube  as  placed  on  crown. 


790 


MECHANICS DENTAL    PROSTHESIS. 


it  might  be  said  that  it  was  the  difficulties  presented  by  this  case  of 
making  anything  satisfactory  or  permanent  by  any  former  method, 


Showing  mode  of  attachment. 


Showing  bridge-plate  in  position. 

Figs.  891,  892. 


CROWN    AND    BRIDGE-WORK. 


791 


that  caused  the  devising  of  "The  New  Method."  On  the  left  side 
of  the  jaw  was  a  piece  of  bridge-work  which  forbade  any  attachment 
of  plate  to  that  side  and  it  was  certainly  not  advisable  to  use  the  incisor 
as  one  of  the  piers  for  a  piece  of  bridge-work,  for  it  would  soon  be 


Showing  mode  of  attachment. 


Showing  plate  in  position. 

Figs.  893,  894. 


moved  from  position  and  lose  its  efficiency  if  suspended  from  the  gum; 
nor  was  there  any  more  encouragement  of  retaining  the  plate  by  clasp- 
ing one  or  both  teeth.  It  was  quite  a  puzzle  to  know  just  what  was 
the  best  thing  to  do.     It  was  certain  if  satisfaction  was  attained  some- 


792  MECHANICS DENTAL    PROSTHESIS. 

thing  new  must  be  adopted  and  the  solving  of  the  problem  brought  to 
life  'The  New  Method.' 

"Figs.  891,  892  represent  the  upper  jaw  of  the  case  above  cited. 
With  molars  and  bicuspids  gone  on  the  left  side,  the  cuspids  and  bicus- 
pids gone  on  the  right,  in  this  case  we  find  it  necessary  to  connect  the 
teeth  on  both  sides,  that  the  strain  occasioned  by  the  weight  on  cuspid 
may  be  relieved  somewhat  by  the  molar.  No  one  rule  can  be  applicable 
in  all  cases,  but  the  general  principles  are  so  familiar  that  they  need  no 
description  and  with  slight  modifications  they  may  apply  in  most  cases. 
In  this  case  an  attachment  was  made  to  cuspid  and  molar,  connecting 
the  two  by  a  narrow  strip  of  plate,  thus  avoiding  the  covering  of  the 
entire  palate,  and  when  the  work  was  in  place  it  was  equally  as  strong 
for  mastication  as  bridge- work  could  be. 

"  Figs.  893,  894  represent  an  upper  case  with  only  the  second  molars 
remaining.  The  attachments  are  sufficiently  secured  for  comfort  in 
masticating  with  but  very  little  if  any  strain  upon  the  natural  teeth. 

"  One  of  the  strong  features  of  this  method  and  one  that  cannot  be 
attained  by  any  other  class  of  work  in  cases  of  absorption  of  the  gums 
and  alveolar  process,  which  is  not  apt  to  occur  as  there  is  no  undue 
pressure,  is  that  the  tube  and  lock-pin  can  be  shortened  and  the  plate 
brought  as  close  to  the  gum  as  desired." 

Dr.  George  Evans  describes  his  method  of  forming  hollow  gold 
molar  and  bicuspid  dummies  for  bridge-work,  and  also  of  making 
collar  or  ferrule  crowns,  in  which  no  gold  is  exposed  at  the  cervico- 
labial  portion,  as  follows  :  *  — 

"  Practical  experience  in  bridge-work  evidences  the  advantages  of 
all-gold  bicuspid  and  molar  dummies  in  cases  which  properly  admit 
of  their  use ;  but  where  they  are  long  or  large,  the  weight  and  ex- 
pense, owing  to  the  amount  of  gold  required  to  fill  them,  are  at  times 
objections  to  their  use.  To  overcome  these  objections  and  lessen  the 
labor  of  construction,  he  had  lately  devised  a  method  of  making  all- 
gold  dummies  hollow,  as  follows :  Take  a  contour  gold  crown  of 
suitable  size,  with  a  thick  grinding-surface,  or  one  which  has  been 
thickened  with  solder  and  the  flux  removed,  and  cut  away  the  gold 
forming  the  palatal  section  of  the  collar  to  the  form  termed  self- 
cleansing,  or  shape  the  neck  of  the  crown  to  the  exact  contour  of  the 
portion  of  the  gum  the  dummy  is  to  rest  on,  and  scrape  a  little  from 
the  surface  of  the  model  to  cause  pressure  and  insure  closeness  of  fit. 
Melt  a  small  quantity  of  solder  with  flux  to  a  ball  form.  Fit  a  piece 
of  platinum  plate,  about  No.  32  gauge,  over  the  aperture;  place  the 
ball  of  solder  on  the  platinum  within  the  gold  cap  (see  Fig.   895). 

*  Dental  Cosmos. 


CROWN    AND    BRIDGE-WORK.  793 

Hold  cap  and  platinum  in  a  Bunsen  flame,  and  heat  slowly  until  the 
solder  melts  and  appears  under  the  edge  of  the  cap,  then  instantly 
remove  from  the  flame,  trim  the  platinum,  and  stone  the  edges.  This 
gives  you  a  hermetically  inclosed  dummy-tooth  of  gold,  from  the 
interior  of  which  the  air  has  been  exhausted  by  the  heat.  The 
dummy  can  then  be  placed  in  its  position  on  the  bridge  and  soldered 
in  the  usual  manner.  Fig.  896  gives  the  palatal  aspect  of  a  bridge 
the  dummies  of  which  were  constructed  in  the  manner  described. 
The  bicuspid  dummy  is  given  a  self-cleansing  form,  and  the  molar  is 
shaped  to  rest  on  the  gum. 

"  The  advantage  of  a  collar  or  ferrule  on  crowns  for  the  front  teeth 
as  affording  additional  security  of  attachment  and  insuring  against  all 
possibility  of  longitudinal  fracture  of  the  root,  is  generally  accepted. 

"  The  objectionable  features  of  collar  crowns  are  the  exposure  of  the 
collar  at  the  cervico-labial  section,  which  is  difficult  to  avoid,  and  the 
irritation  its  presence  there  is  apt  to  cause  the  peridental  membranes, 
which  it  is  more  liable  to  do  at  this  point  than  at  the  other  sides  of 
the  root.  The  collar,  to  be  invisible,  has  to  be  fitted  well  under  the 
gum-margin.       This  requires  extensive  removal  of  the  periphery  of 


Fig.  895.  Fig.  S96. 

the  cervico-labial  section  of  the  end  of  the  root,  rendering  adapta- 
tion of  the  collar  at  this  point  an,  operation  few  practitioners  succeed 
in  accomplishing  perfectly.  An  examination  of  collar  crowns  in  the 
mouths  of  patients  frequently  results  in  showing  a  condition,  as  regards 
construction  and  adaptation,  such  as  is  shown  in  Fig.  897,  at  either 
of  the  points  A  or  B,  or  both.  At  A,  the  edge  of  the  collar,  owing  to 
the  inward  slant  of  the  root,  protrudes  slightly,  and  at  B  the  porcelain 
is  projected  beyond  the  line  of  the  collar  for  position  or  to  hide  the 
metal.  Either  or  both  in  time  produce  and  maintain  an  unclean  con- 
dition, worse  than  a  deep-seated  line  of  cervical  decay  in  a  natural 
crown,  causing  irritation  and  gradual  absorption  of  the  adjacent 
investing  membranes. 

"  The  form  of  crown  about  to  be  presented  is  not  new  in  principle, 
neither  is  it  off'ered  as  a  universal  substitute  for  the  ordinary  collar 
crown,  but  as  embodying  features  which  are  advantageous,  and  without 
some  of  those  found  objectionable  in  the  ordinarily  used  collar  crowns. 
The  method  will  greatly  simplify  and  facilitate  the  operation,  and  it 
is  one  which  can  be  accomplished  by  those  of  only  ordinary  skill. 


794 


MECHANICS DENTAL    PROSTHESIS. 


"Take,  for  example,  the  right  superior  incisor  illustrated  in  Fig. 
898.  A  shows  the  line  of  trimmed  root;  B,  point  at  cervico-labial 
section  which  may  be  removed  if  it  is  desirable  to  have  only  the  porce- 
lain front  cover  that  part.  In  Fig.  899  an  enlarged  outline  of  the 
surface  of  the   prepared  end  of  the  root  is  presented,  A  being  the 


B — ^^ 


Fig.  S97. 


Fig. 


Fig.  899. 


labial  and  B  the  palatal  side.  The  dotted  line  is  intended  to  indicate 
the  original  form.  The  shaping  is  done  in  the  usual  manner  with 
discs  and  trimmers.  It  will  be  seen  that  the  line  of  the  labial  portion 
is  left  intact. 

''The  root-canal  is  next  enlarged  with  an  Ottolengui  root-canal 
reamer  (see  Fig.  900). 

"  The  size  and  condition  of  the  root  and  the  judgment 
*      *     *      of  the  operator  should  determine  the  number  or  size  of 
reamer  to  be  used  and  the  depth  to  which  the  canal 
should  be  reamed.     To  the  reamed  canal  is  fitted  a  pre- 
pared iridio-platinum  post,  as  illustrated  in  Fig.  901,  cor- 


FiG.  900. 


Fig.  901. 


Fig.  902. 


Fig.  903. 


Fig.  904. 


responding  in  size  by  number  to  the  reamer  used.  These  posts  have 
a  screw-thread  cut  on  the  sides,  tapering  downward  to  the  point,  so 
that  they  can  be  screwed  just  where  wanted  and  soldered  in  an  instant. 
Next  take  a  prepared  disc  of  platinum  plate,  having  a  perforated 
concave  depression  as  seen  in  Fig.  902.  This  depression  fits  in  the 
orifice  of  the  root  canal.  If  necessary,  the  orifice  may  be  slightly 
enlarged  with  a  round-headed  bur.  This  disc  of  platinum  plate, 
which  is  about  No.  35  gauge,  is  made  by  stamping  with  a  punch  01 


CROWN    AND    BRIDGE-WORK.  795 

die.  In  the  depression  in  the  disc,  as  shown  in  section  in  Fig.  903, 
pure  gold  with  a  little  flux  is  melted,  and  in  the  center  of  this  gold  a 
hole  is  punched  through  the  disc.  The  post  when  fitted  to  the  canal 
is  grasped  at  the  line  of  the  orifice  of  the  canal  with  small  pliers, 
the  post  removed,  and  without  moving  the  position  of  the  pliers  it  is 
screwed  into  the  disc  up  to  the  points  of  the  pliers,  thus  giving  the 
post  its  position  in  the  disc.  The  sides  of  the  disc  are  bent  on  ac- 
count of  the  approximal  teeth,  as  shown  in  Fig.  904,  and  the  relative 
positions  of  the  post  and  disc  on  the  root  are  determined. 

"  The  disc  should  fit  in  the  orifice  of  the  canal  when  the  post  is  in 
position.  By  twisting  the  post  in  the  disc,  change  of  position  is  in- 
stantly effected.  Both  post  and  disc  are  next  removed,  and  the  post 
secured  in  position  in  the  disc  by  being  held  in  a  Bunsen  flame,  and 
heated  to  a  point  that  fuses  the  pure  gold  in  the  depression.  No  flux 
is  necessary,  as  sufficient  remains  from  the  first  fusing  of  the  gold. 
The  post  with  the  disc  is  next  inserted  on  the  root,  the  platinum 
pressed  with  a  large  flat  plugger,  and  malleted  so  that  the  line  of  the 
edge  of  the  end  of  the  root  will  be  impressed  upon  it.  The  platinum 
is  next  removed,  and  slit  at  the  two  points  between  the  palatal  and 
approximal  sides  shown  at  A  and  B,  Fig.  905,  and  guided  by  the  mark 
of  the  end  of  the  root  on  the  platinum  the  approximal  portions  are  bent 
over  with  small-pointed  pliers  to  embrace  the  sides  of  the  root.  The 
post  and  cap  are  then  placed  on  the  root,  and  the  side  flaps,  with  the 
aid  of  foot-shaped  condensers  and  burnishers,  are  closely  fitted.  The 
palatal  flap  is  next  brought  down  to  position.  Frequent  removals  and 
annealings  are  necessary  during  the  process,  which  should  include 
finally  trimming  the  edge  of  the  platinum,  smoothing  with  a  corun- 
dum point,  and  then  annealing  and  all-around  burnishing  of  the  cap 
to  the  root. 

"  At  the  cervico-labial  section  the  porcelain  can  rest  on  the  platinum, 
or  the  platinum  can  be  trimmed  so  that  the  front  edge  of  the  porcelain 
may  be  fitted  against  the  root,  covering  it  (see  Fig.  905).  The  pro- 
iecting  end  of  the  post  should  also  be  removed,  leaving  it  a  little  flush 
at  the  palatal  side.  The  porcelain  front,  which  should  be  a  cross-pin 
plate  tooth,  is  ground  and  closely  fitted  to  the  surface  of  the  root  or 
metal,  as  may  be,  at  the  cervico-labial  section  under  the  edge  of  the 
gum,  but  a  properly  shaped  space  opening  toward  the  palatal  side  is 
left  between  it  and  the  surface  of  the  cap.  To  so  shape  the  porcelain 
simplifies  the  fitting  of  the  cervical  section.  The  space  between  the 
cap  and  the  porcelain  is  also  easier  filled  in  the  soldering.  To  the 
porcelain  front  at  the  part  B  (Fig.  906)  a  piece  of  very  thin  platinum 
foil  is  shaped,  the  porcelain  heated,  the  part  veneered  with  a  mere 
film  of  gum-shellac,  and  by  pressure  with  a  napkin   or  cotton    the 


796 


MECHANICS DENTAL    PROSTHESIS. 


platinum  foil  is  attached  thereto.  The  rest  of  the  porcelain  is  then 
backed  with  thin  platinum  plate  (about  No.  35  gauge).  The  platinum 
is  left  slightly  extending  over  the  incisor  edge,  and  the  porcelain  front 
is  waxed  in  position  on  the  cap. 

"  Fig.  907  shows  the  crown  waxed  up  ready  for  investment.  Wax  in 
full  amount  must  be  extended  over  the  collar  to  its  edge,  in  the  seams, 
and  between  the  porcelain  and  the  cap  at  every  point  solder  is  to 
flow.  (Dr.  Evans  generally  uses  Parr's  fluxed  wax.)  Fig.  908  shows 
the  invested  crown  with  the  wax  removed.  In  trimming  the  invest- 
ment, the  material  must  not  be  removed  from  over  the  collar  lower 
than  the  line  of  the  surface  of  the  cap,  or  in  such  a  manner  that  the 
platinum  turn-over  edges  are  exposed  to  the  direct  force  of  the  flame. 
If  the  collar  is  not  exposed,  the  solder  will  flow  over  the  outer  surface 
of  the  platinum  just  where  it  is  wanted  and  where  wax  has  been 
applied,  and  all  the  parts  will  become  united. 

"  The  investment  must  be  slightly  raised  at  one  end,  and  heated  up 
at  its  base  with  the  full  flame  of  a  gas  blowpipe  thrown  in  the  direc- 


FlG.  905. 


-W 


Fig.  907. 


Fig.  90S. 


tion  indicated  by  the  arrow  in  Fig.  908.  Heat  thus  applied  will  cause 
the  solder  to  flow  downward  and  fill  the  interstices  in  all  parts  of  the 
investment  as  though  it  were  an  ingot.  The  best  way  is  to  apply  a 
little  solder  at  a  time  until  the  deep  parts  are  filled.  The  flame  is 
then  withdrawn  for  an  instant'  and  with  a  small  pointed  flame  and 
more  solder  the  backing  can  be  contoured.  As  platinum  forms  the 
cap  and  backing,  the  soldering  can  be  conducted  without  fear  of 
accidentally  fusing  those  parts. 

"The  form  of  crown  described,  as  well  as  the  ordinary  collar  crown, 
he  usually  cements  in  the  following  manner  :  Having  the  root  and 
crown  ready,  he  warms  the  crown  and  applies  a  thin  coating  of 
chloro-gutta-percha  to  the  post.  The  chloroform,  instantly  evapor- 
ating, leaves  a  film  of  heated  gutta-percha.  Immediately  the  crown 
is  adjusted  to  the  root  and  removed.  This  shapes  the  gutta-percha 
on  the  post.  The  crown  is  then  allowed  to  cool,  and  is  cemented  on 
as  though  no  gutta-percha  was  used  on  post.  A  crown  so  cemented 
can  be  removed  at  any  time  by  repeated  applications  of  the  thick  part 


CROWN    AND    BRIDGE-WORK. 


797 


of  a  heated  root-canal  drier  to  the  metallic  portion  of  the  crown, 
which  communicates  the  heat  to  the  post.  In  a  short  time  the  sheath 
of  gutta-percha  around  the  post  is  softened,  and  the  crown  can  usually 
be  removed  without  difficulty.  He  also  attaches  ordinary  bridge-work 
in  this  way,  having  abandoned  the  use  of  methods  classed  as  '  detach- 
able,' which  only  allow  the  bridge  to  be  removed  by  the  dentist. 

"  Porcelain  can  be  used  in  the  construction  of  the  crown  described 
instead  of  gold  solder.  In  such  a  case,  the  porcelain  front  should  be 
attached  to  the  end  of  the  post.  This  can  be  done  by  flattening  the 
end  of  the  post  and  riveting  the  pins,  or  by  soldering  them. 

"  Fig.  909  represents  a  removable  pin  crown.  It  consists  of  a 
crown  having  a  threaded  socket,  I,  to  which  is  fitted  a  correspondingly 
threaded  silver  pin,  II,  which  admits  of  freedom  in  grinding  and  fitting 
the  crown  to  the  root  without  the  interference  of  the  stationary  pin. 

"Another  crown,  known  as  the  Downie  Crown,  is  designed  to  obtain 
a  perfect  adaptation  to  the  root  by  means  of  a  platinum  band  or  cap, 
which  not  only  prevents  the  splitting  of  the  root,  but  protects  the 
joint  from  decay  and  the  washing  out  of  the  cement,  and  materially 


Fig.  909. 

Strengthens  the  attachment  of  the  crown  ;  the  anterior  portion  of  the 
band  is  covered  with  porcelain  of  the  same  color  as  the  facing,  so  there 
is  no  metal  showing  whatever,  and  no  necessity  of  cutting  the  root  off 
far  above  the  gingival  margin  and  lacerating  the  gums;  it  is  made 
with  the  teeth  used  for  other  work,  so  that  no  special  tooth  is  required ; 
the  backing  is  fused  on  to  the  facing,  making  a  perfect  union,  so  we 
do  not  need  any  metal  to  protect  the  point  to  keep  the  facing  from 
being  broken  off;  the  laborious  work  of  grinding  away  the  back  of 
the  tooth,  and  the  always  unsatisfactory  guesswork  in  setting  the  fac- 
ing, which  are  necessary  in  some  other  porcelain  processes,  are  entirely 
obviated. 

"  Fig.  910  represents  the  Downie  Crown,  the  directions  for  construct- 
ing it  by  the  use  of  the  Downie  Porcelain  Crown  Furnace,  represented 
by  Fig.  912,  being  given  as  follows  :  — 

"  Dress  up  the  root  even  with  the  gums,  and  prepare  it  in  the  usual 
manner  for  crowning.  Take  measure  with  small  wire,  cut  the  wire  on 
the  opposite  side  from  the  twist,  and  straighten  it  out.  Take  a  strip 
of  platinum,  about  30  gauge,  of  sufficient  width  for  the  band,  lay 


798  MECHANICS DENTAL    PROSTHESIS, 

the  wire  on  the  platinum  and  mark  the  length.  Cut  -^j  of  an  inch 
longer  than  the  mark,  bevel  both  ends,  lap  to  the  mark,  and  solder 
together  with  pure  gold.  In  this  case,  as  in  all  others  in  porcelain 
work,  the  soldering  should  be  done  with  as  small  an  amount  of  gold 
as  possible,  and  then  the  joint  dressed  off  so  that  there  is  no  gold  left 
showing.  Fit  the  band  to  the  root,  letting  it  extend  nicely  under 
the  free  margin  of  the  gums.  If  the  band  is  now  nearly  even  with 
the  root,  grind  it  off  flush.  If  it  extends  much  beyond  the  surface 
of  the  root,  it  should  be  marked  and  removed  to  be  clipped  off,  then 
replaced  and  ground  perfectly  even.  It  is  again  removed,  and  a  piece 
of  platinum  fitted  and  soldered  over  the  top,  using  pure  gold  as  a 
solder.  The  overhanging  edge  of  the  top  is  now  clipped  off  and 
filled  up,  and  the  sharp  edge  of  the  cap  dressed  off,  also  the  edge  of 
the  band.  The  cap  is  now  completed  as  shown  in  Fig.  910,  i,  except 
that  it  has  now  to  be  placed  in  position  on  the  root  and  a  hole 
punched  through  the  top  to  correspond  with  the  canal,  for  the  inser- 
tion of  the  post.  The  material  most  suitable  for  making  the  post  is 
square  iridio-platinum  wire,  but  it  may  be  made  of  platinum  wire. 


either  round,  square,  or  three-cornered.  The  wire  is  flattened  out  on 
one  end  so  that  it  is  broader  than  the  space  between  the  pins  of  tooth 
selected,  and  a  notch  filed  in  each  side,  corresponding  with  pins,  so 
that  it  will  slip  in  between  them.  After  measuring  root  canal  to  see 
the  length  of  pin  required,  the  wire  is  cut  off  and  the  end  tapered, 
making  a  finished  post  as  shown  in  Fig.  910,  2.  It  is  now  placed  be- 
tween the  pins,  which  are  bent  over  as  shown  in  Fig.  910,  3. 

"The  ordinary  plate  teeth  are  used  in  making  these  crowns,  as  will 
be  seen  by  the  cuts,  but  they  may  also  be  made  with  the  plain  teeth 
used  for  vulcanite  work,  and  sometimes  to  good  advantage.  When 
this  kind  of  a  tooth  is  used,  however,  the  post  should  be  soldered  be- 
tween the  pins  with  pure  gold,  as  the  back  is  not  flat  like  the  back  of 
a  plate  tooth,  and  it  will  not  be  held  firmly  enough  to  the  post  by 
simply  bending  the  pins  over.  The  tooth  is  now  fitted  to  the  proper 
position  by  bending  the  post  if  necessary,  or  grinding  the  base  to  let 
it  up  if  too  long  ;  this  should  be  done  with  the  cap  in  place.  The 
position  of  the  tooth  on  the  cap  should  now  be  noted  and  both  re- 


CROWN    AND    BRIDGE-WORK.  799 

moved  and  well  dried.  Placing  them  in  their  relative  position  as  near 
as  can  be  judged  while  out  of  the  mouth,  back  the  tooth  up  to  the 
cap  with  hard,  sticky  wax  prepared  especially  for  the  purpose.  While 
the  wax  is  still  soft,  it  is  set  on  in  position  in  the  mouth  to  get  the 
articulation  exact.  The  wax  is  hardened  by  dropping  on  to  it  a 
little  cold  water  with  the  mouth  syringe,  and  the  crown  can  then  be 
removed  with  the  cap,  without  shifting  the  relative  position  of  cap 
and  tooth.  This  part  of  the  operation  may  also  be  done  as  follows : 
After  a  tooth  is  fitted  and  both  it  and  the  cap  removed  and  dried, 
place  a  napkin  in  the  mouth  and  dry  the  root  and  adjacent  parts. 
Place  cap  in  position,  and  taking  a  piece  of  sticky  wax  previously  pre- 
pared, about  the  size  of  a  pea,  warm  it  and  place  it  directly  on  top 
of  the  cap  ;  then  stick  post  of  tooth  through  the  wax,  and  press  it  up 
to  position.  Whichever  of  these  methods  is  employed  to  set  the 
tooth  on  with  wax,  it  is  necessary  to  see  that  the  palatine  side  of  the 
cap  is  down  in  its  proper  position  before  removing  it,  as  the  pressure 
brought  to  bear  on  the  anterior  side  by  pressing  the  tooth  up  to  posi- 
tion will  tend  to  tip  off  the  posterior  side,  especially  if  the  cap  is 
shallow.  The  wax  may  now  be  chilled,  and  the  case  removed  for 
investment.  In  removing,  it  is  best  to  hook  the  cap  off  with  a  hoe- 
shaped  excavator,  instead  of  removing  the  tooth  with  the  fingers  and 
depending  on  the  wax  to  draw  off  the  cap.  If  the  cap  should  be 
loose  after  the  piece  is  removed,  which  will  be  the  case  if  there  has 
been  any  moisture  on  the  cap  when  the  wax  was  pressed  on,  take  a 
wax  spatula  and  melt  the  wax  on  the  cap,  and  replace  in  the  mouth 
to  be  certain  the  articulation  is  correct,  and  remove  again.  The  case 
will  now  appear  as  in  Fig.  910,  4.  Remove  from  around  the  post,  with 
small  knife  blade  or  other  instrument,  any  wax  which  may  have  been 
drawn  down  into  the  canal  while  pressing  the  tooth  into  position. 

"  Mix  up  equal  parts  of  silex  and  plaster,  and  fill  the  cap,  building 
it  up,  crowning  around  the  post.  After  the  investment  sets,  boiling 
water  is  poured  on  the  case  to  remove  the  wax.  Fig.  910,  5,  shows  the 
silex  and  plaster  in  the  cap  and  the  wax  boiled  out.  As  will  be  seen, 
the  investment  is  put  in  the  cap  for  the  purpose  of  retaining  it  in  posi- 
tion on  the  post  after  the  wax  is  removed.  If  desired,  the  tooth  may 
be  entirely  invested  and  the  cap  soldered  to  the  post,  but  this  is  not 
necessary  unless  it  is  to  be  used  for  the  support  of  bridge  teeth.  The 
next  step  is  to  build  on  the  porcelain  body.  This  is  in  the  form  of  a 
powder,  and  is  mixed  up  with  water  and  applied  with  a  small  camel's 
hair  artist's  pencil.  A  color  should  be  selected  several  shades  darker 
than  the  base  of  the  tooth,  as  it  requires  a  darker  shade  to  cover  the 
band  and  not  appear  lighter  than  the  tooth,  while  it  is  sufficiently 
translucent  so  that  the  thin  portion  which  overlaps  the  tooth  will  not 


8oO  MECHANICS — DENTAL    PROSTHESIS. 

make  it  look  perceptibly  darker.  It  should  be  mixed  as  stiff  as  can 
be  handled  with  the  brush.  The  post  is  held  with  a  pair  of  pliers  while 
the  body  is  applied  with  the  brush,  tapping  the  pliers  with  the  brush 
handle  to  jar  the  body  down  into  the  crevices,  and  smooth  off  the  sur- 
face. If  it  does  not  run  down  well  between  the  tooth  and  cap,  wet 
the  brush  slightly  and  apply  a  little  more  water,  but  always  work  it 
as  dry  as  possible  and  still  have  the  surface  smooth  down  when  the 
pliers  are  tapped  with  the  brush  handle.  Build  out  well  on  the  cap 
and  around  the  front  to  conceal  the  band,  but  do  not  build  down  over 
the  pins  of  the  tooth  the  first  time.  The  piece  is  now  ready  for  the 
first  fusing.  In  baking,  the  crown  is  placed  in  the  tray  of  the  fur- 
nace, which  is  made  of  platinum  and  has  a  hole  through  the  posterior 
edge  through  which  to  place  the  post,  the  tooth  being  placed  face  up, 
resting  on  the  back  of  the  band  as  shown  in  Fig.  911.  This  prevents 
the  piece  being  fused  on  to  the  tray,  as  the  body 
is  not  built  over  the  back  of  the  band.  The 
furnace  should  be  heated  up  very  slowly,  so  as 
not  to  check  the  tooth  or  throw  off  the  porcelain 
Pj^    jj  body  by  drying  it  out  too  quickly.      However 

careful  the  operator  may  be,  there  is  always  a 
slight  amount  of  wax  left  on  to  the  tooth  around  the  pins,  which  on 
heating  up  will  burn  out,  making  the  body  black  until  it  is  all  burned 
out.  If  the  case  is  heated  up  too  rapidly,  this  will  sometimes  separate 
the  body  from  the  tooth  so  that  it  will  not  fuse  on,  especially  down 
near  the  pins,  or  it  may  throw  the  body  off  entirely.  Great  care 
should  be  taken,  however,  to  remove  all  traces  of  wax  before  building 
in  any  body,  and  the  greatest  cleanliness  should  be  observed  through 
the  whole  process.  The  pins  and  post  at  the  place  of  attachment  are 
now  filed  or  ground  off  so  as  not  to  interfere  with  the  bite.  If  the 
bite  is  very  close  the  back  of  the  tooth  may  be  ground  away  at  the 
point  of  contact,  so  that  it  will  not  strike. 

"  During  the  first  baking  the  body  has  shrunken  considerably,  but  it 
is  now  built  up  again,  shaped  as  desired,  and  fused,  making  a  finished 
crown,  as  seen  in  Fig.  910,  6.  In  the  case  of  bicuspids  and  molars, 
especially  when  the  bite  is  short,  it  is  often  better  to  build  them  up 
entirely  with  the  body,  not  using  any  tooth  or  facing. 

"  In  making  these  crowns  with  the  ordinary  porcelain  body,  the 
facing  will  become  etched,  or  rough  and  pitted,  and  on  being  handled 
will  have  black  specks  over  its  surface,  thus  marring  its  appearance. 
This  is  entirely  overcome  by  using  Downie's  Porcelain  Body,  which 
fuses  at  a  temperature  so  much  below  the  fusing  point  of  the  enamel 
on  the  teeth  that  they  come  out  of  the  furnace  as  smooth  and  perfect 
as  they  were  before  baking. 


CROWN   AND    BRIDGE-WORK.  8oi 

"Another  valuable  point  gained  in  using  this  low-fusing  body  is 
that  one  can  easily  determine  when  it  is  sufficiently  fused.  The  white 
heat  required  for  the  high  fusing  body  makes  it  extremely  difficult  to 
see  when  it  is  properly  glazed  ;  but  as  this  fuses  at  a  red  heat,  the 
gloss  on  the  piece  can  be  watched  closely,  and  when  it  is  seen  to  shine 
it  is  done. 

"  The  color  of  the  teeth  can  also  be  matched  to  almost  a  certainty 
with  our  latest  improved  body.  It  may  be  fused  just  to  a  glaze,  or 
considerably  above,  and  still  be  the  same  color,  as  the  coloring 
materials  are  not  so  fugitive  as  they  are  at  the  higher  heats. 

"It  is  the  next  thing  to  an  impossibility  to  bake  two  pieces  of  the 
high  fusing  body  at  different  times  and  have  them  come  out  the  same 
shade  ;  so  there  is  positively  no  certainty  whatever  in  matching  colors 
with  it.  A  slight  difference  in  the  fusing  may  bleach  out  the  colors 
so  as  to  ruin  the  case.  Often  when  the  darkest  shades  of  yellow  are 
used,  the  thin  portion  around  the  neck  of  the  tooth  in  front  will 
bleach  out  almost  white  in  trying  to  get  a  good  glaze.  No  troubles 
of  this  kind  are  encountered  if  the  new  low-fusing  body  is  used. 
Although  it  was  imperfect  when  put  on  the  market,  it  has  been  im- 
proved until  it  has  been  brought  to  a  remarkable  degree  of  per- 
fection." 

The  Downie  Porcelain  Gas  Furnace  (Fig.  912)  will,  it  is  claimed, 
fuse  the  Downie  body  in  one  and  a  half  minutes,  or  even  less  time, 
and  the  following  directions  for  using  this  furnace  are  given  : — 

"  If  properly  set  up  and  operated,  the  porcelain  will  be  fused  in  the 
Crowning  Furnace,  in  inlay  work,  in  less  than  one  minute,  and  crowns 
in  from  one  and  a  half  to  two  minutes.  This  is  counting  from  the 
time  the  blast  is  turned  on.  Bridges  or  sections  take  a  proportion- 
ately longer  time,  as  they  take  longer  to  heat  through. 

"The  body  is  handled  with  a  brush  adapted  for  that  purpose,  and 
mixed  up  with  sufficient  water  so  it  can  be  built  on  where  desired,  care 
being  taken  not  to  get  it  so  wet  that  it  will  run  after  it  is  built  on. 
The  crown  or  matrix,  on  to  which  the  body  is  added,  should  be  held 
with  a  pair  of  tweezers  while  the  body  is  being  built  on,  and  the 
tweezers  should  be  tapped  with  the  brush  handle  to  settle  the  body 
down  and  bring  the  water  to  the  surface. 

"The  fresh  body  should  be  built  the  shape  desired,  and  well 
smoothed  over,  as  it  keeps  its  shape  pretty  well  and  will  show  rough 
places  after  firing  if  care  is  not  taken  to  smooth  down  by  jarring  while 
wet. 

"The  tray  is  then  filled  with  silex  and  work  set  upon  it  in  such  a 
manner  that  the  face  of  the  work  does  not  come  in  contact  with  the 
silex,  as  it  would  be  fused  on  and  destroy  the  appearance  of  the  piece. 
51 


802 


MECHANICS — DENTAL   PROSTHESIS. 


The  tray  is  then  put  into  the  mufifle,  the  furnace  lighted  and  very  grad- 
ually heated  up  to  drive  off  the  water,  and  if  there  is  a  veneer  or  block 
in  to  heat  it  up  gradually  and  not  crack  it.  This  takes  but  a  short 
time,  however,  from  a  half  minute  for  inlays  or  small  crowns,  to  a 


Fig.  912. 

minute  or  minute  and  a  half  for  large  crowns  or  blocks.  Then  run  the 
furnace  to  its  full  capacity  until  work  is  fused.  The  body  should  not 
be  baked  until  it  is  thoroughly  glazed  the  first  time,  but  merely  bis- 
cuited,  or  baked  until  it  is  well  fused  together.  Leave  in  the  muffle 
until  it  is  no  longer  red,  then  remove  and  set  in  tempering  oven,  and 


CROWN   AND    BRIDGE-WORK.  803 

let  it  remain  until  well  cooled  down.  Add  more  body  to  give  the  re- 
quired contour  and  bake  until  well  glazed,  letting  it  cool  off  gradually. 

"  In  making  the  Downie  Crown,  however,  do  not  put  any  silex  in 
the  tray,  but  stick  the  pin  of  the  crown  through  a  hole  in  the  back 
end  of  the  tray,  as  shown  in  Fig.  911  on  page  800,  letting  it  rest  on 
the  pin  and  the  band  resting  on  the  bottom  of  the  tray. 

"  Care  should  be  taken  not  to  let  any  body  or  any  fusible  material 
get  on  to  the  interior  of  the  muffle,  as  it  will  fuse  the  tray  to  the 
muffle  and  injure  it  in  removing  the  tray.  Should  such  a  thing  hap- 
pen, put  some  silex  on  the  bottom  of  the  muffle. 

"  Care  should  also  be  taken  to  prevent  the  contact  of  any  metal  with 
the  platinum  muffle,  as  it  is  likely  to  make  a  hole  after  heating  up." 

A  larger  furnace  of  the  same  style  is  used  for  porcelain  bridge-work, 
gum  sections,  etc. 

Porcelain  Bridge-  Work. — This  style  of  bridge-work  has  no  joints  to 
retain  the  secretions,  and  the  gold  of  other  forms  of  this  work  may  be 
dispensed  with  in  all  places  except  where  it  is  necessary  to  make  an 
attachment  to  a  gold  cap ;  and  with  this  exception  the  natural  ap- 
pearance can  be  almost  perfectly  restored.  "  No  gold  caps  or  cutting 
edges  are  required  to  protect  the  bridge  teeth,  for  precisely  the  same 
reason  that  they  are  not  needed  in  the  crown-work.  The  crown  al- 
ready described  is  used  as  a  support  for  these  bridges,  the  only  differ- 
ence in  its  construction  being  that  when  intended  for  bridge-work, 
after  setting  it  up  in  wax  it  is  invested  and  the  cap  and  pins  soldered. 
This  allows  the  crown  to  be  set  in  position  without  the  porcelain  back- 
ing, and  an  impression  to  be  taken  with  modeling  compound.  A 
model  is  run,  the  bridge  teeth  are  waxed  in,  and  the  case  invested. 
After  removing  the  wax  a  bar  of  iridioplatinum  is  fitted  from  the  posts 
of  the  supporting  teeth  across  under  the  pins  of  the  bridge  teeth  and 
soldered  in  position.  The  case  may  then  be  removed  from  the  invest- 
ment and  the  porcelain  backing  added  and  fused  on  ;  when  it  is  ne- 
cessary to  use  a  gold  cap  for  the  support  of  a  bridge,  it  is  made  of  an 
alloy  of  gold  and  platinum  (22  kt.  gold);  this  admits  of  being  sol- 
dered with  pure  gold,  is  quite  hard,  so  that  its  wearing  qualities  are 
excellent,  and  goes  through  the  heat  of  the  furnace  without  oxidation. 
The  bar  is  soldered  to  the  cap,  th^ porcelain  added  and  fused,  and  the 
case  handled  in  every  respect  as  when  porcelain  crowns  are  used  as 
supports." 

Porcelain  Inlaying. — One  of  the  best  methods  for  making  them  is 
to  burnish  platinum  foil  over  and  into  the  cavity,  thus  forming  a 
matrix,  into  which  the  porcelain  is  built  and  fused.  Body  may  be 
added  and  fused  two  or  three  times  until  the  required  contour  is  ob- 
tained.    The  platinum    is  then   peeled   off  and  retaining   points   or 


8o4  MECHANICS — DENTAL   PROSTHESIS. 

grooves  cut  into  the  porcelain  with  the  edge  of  a  diamond  disc  ;  also 
undercuts  made  in  the  cavity,  when  the  piece  is  ready  for  cementing 
on.  The  mistake  is  often  made  of  taking  too  small  a  piece  of  foil 
with  which  to  make  the  matrix.  This  should  be  large  enough  to  be 
held  easily  in  position  with  the  thumb  and  finger  of  the  left  hand, 
while  it  is  being  burnished  into  the  cavity  with  the  right.  This  over- 
lapping foil,  by  which  the  matrix  is  handled,  is  left  on  during  the  pro- 
cess of  baking.  There  are  two  principal  points  wherein  lie  the  secret 
of  obtaining  a  good  fit  with  an  inlay  :  First,  in  making  the  walls  of 
the  cavity  beveled  outward  for  a  little  way  from  the  margin,  so  that 
when  the  platinum  is  removed  the  plug  will  fit  tightly  on  the  margin 
as  it  bevels  out,  and  will  set  in  the  thickness  of  the  platinum  removed, 
thus  taking  up  the  space  occupied  by  it,  and  making  a  perfect  fit  at 
the  margin  ;  second,  in  only  partially  filling  the  matrix  with  body  the 
first  time  it  is  baked,  then  replacing  in  the  cavity  and  burnishing  down 
the  edge  again  ;  this  corrects  any  springing  of  the  matrix.  For  labial 
cavities,  where  there  is  no  force  to  be  exerted  which  will  tend  to 
loosen  the  filling,  they  may  be  set  with  Hill's  Stopping,  using  a  warm 
instrument  handle  to  press  them  into  place.  This  is  perhaps  more 
reliable  as  to  lasting  qualities  than  any  cement  which  we  have  at  the 
present  day. 

The  Jacket  Crown. — "This  is  a  platinum  cap  with  a  porcelain 
facing,  and  is  in  certain  cases  very  valuable ;  its  use  is  indicated  for 
undeveloped  teeth,  usually  called  rice  or  peg  teeth.  These  may  be  built 
out  and  the  normal  appearance  fully  obtained.  It  is  also  of  use  in 
cases  of  badly  decayed  teeth  where  the  pulp  has  receded  considerably 
and  is  in  a  healthy  condition  ;  it  is  of  no  use  for  decayed  teeth  of 
normal  size  if  the  nerve  has  not  receded  and  they  set  in  their  proper 
position  in  the  arch,  because  they  must  be  ground  so  near  to  the  pulp 
in  order  to  get  the  facing  on  without  its  being  too  prominent  that  the 
death  of  that  organ  is  almost  sure  to  result.  There  is  no  good  reason 
why  they  should  ever  be  used  in  any  case  where  the  pulp  is  not  alive. 

"  To  construct  this  crown,  make  a  deep  band  or  ferrule  of  platinum 
to  fit  the  tooth,  which  has  previously  been  ground  slightly  tapering 
on  its  sides  and  lingual  surface,  and  flat  (receding  considerably)  on  the 
labial  surface.  The  inner  portion  of  the  band,  which  stands  up  from 
the  tooth,  is  clipped  off  and  a  flat  piece  soldered  on  to  make  the  sloping 
lingual  surface  (supposing  the  crown  to  be  an  incisor  or  cuspid),  and 
the  anterior  portion  of  the  band  ground  very  thin,  except  around  the 
gum  margin.  This  thin  anterior  portion  is  malleted  down  against  the 
tooth,  using  a  large  foot  plugger,  and  folding  down  the  upper  corners 
when  necessary.  A  tooth  is  selected,  either  a  flat  back  or  a  plain  tooth 
for  rubber  work ;  it  is  ground  away  flat  at  the  back,  tapering  down  to 


CROWN    AND    BRIDGE-WORK. 


80s 


as  thin  an  edge  as  possible  at  the  base  ;  after  grinding  until  it  will  set 
in  the  proper  position,  the  cap  is  removed  and  the  facing  stuck  on  with 
a  little  porcelain  body.  The  piece  is  then  set  on  a  tray  in  which  is  a 
little  ground  silex  to  keep  it  from  shifting  around  while  in  the  furnace. 
It  should  be  very  carefully  heated  up,  in  order  that  the  facing  may 
not  be  thrown  off.  When  cool,  more  porcelain  is  added  around  the 
edges  to  securely  attach  the  facing,  and,  after  fusing,  the  crown  is 
ready  to  be  cemented  in  place.  All  these  operations  in  porcelain 
are  made  infinitely  more  practical  by  the  use  of  the  low-fusing  porce- 
lain body,  which  enables  us  to  bake  crowns  without  etching  the  face 
of  the  tooth,  to  fuse  on  to  a  bridge  which  is  soldered  to  a  gold  cap,  and 
to  match  the  colors  almost  perfectly." 

Dr.  C.  H.  Land  has  devised  what  he  calls  "  metallic  enamel  coat- 
ings and  sections,"  which  he  describes  as  follows  : — * 

"  The  accompanying  engravings,  Figs.  913  and  914,  are  taken  from 


Fig.  913. 


Fig.  914. 


practical  cases  that  have  at  this  date  been  in  use  for  one  year.  In  the 
case  represented  by  Fig.  913,  the  patient  was  about  sixty  years  of  age. 
The  right  lateral  incisor  was  prepared  with  a  Howe  post,  shown  in  its 
relative  position.  The  five  remaining  teeth,  after  the  cavities  were 
prepared,  contained  tooth  substance  as  represented  by  the  dark  sur- 
faces, the  white  representing  the  lost  portion  of  each  tooth,  restored 
with  sections  of  porcelain  made  to  imitate  the  exact  color  and  contour 
of  the  original  tooth  substance.  The  cavities  are  prepared  as  for  gold 
filling,  when  a  thin  piece  of  annealed  platinum  plate.  No.  35  standard 
gauge,  is  placed  over  the  tooth,  and  by  means  of  burnishers  made  to 
take  a  perfect  impression  of  the  outer  rim  of  the  cavity,  after  which 
platinum  pins  are  attached,  as  shown  at  A.  The  object  of  the  pins  is 
to  serve  as  a  fastening,  both  for  the  porcelain  paste  or  body  and  as  re- 
tainers to  hold  the  completed  section  in  the  cavity  of  the  tooth.     The 


*  Independent  Practitioner. 


8o6  MECHANICS — DENTAL    PROSTHESIS. 

porcelain  paste  or  body  is  built  upon  the  platinum  disc  and  made  to 
imitate  the  lost  portion  of  the  tooth.  It  is  then  baked  in  a  gas  fur- 
nace, requiring  but  twenty  minutes  for  the  first  biscuit  and  fifteen  for 
the  second,  and  when  finished  appears  as  shown  at  B,  ready  to  be 
cemented  with  oxyphosphate.  C  and  D  are  modifications  for  the  other 
teeth,  and  Fig.  914  illustrates  porcelain  facings  for  molars. 

"  The  especial  feature  of  this  system  is  the  large  amount  of  tooth 
substance  preserved  above  the  gum,  there  being  no  necessity  for  tele- 
scoping the  root  so  far  below  as  to  sever  the  tissues.  This  mode  of 
practice  also  dispenses  with  the  long  operations  and  protracted  use  of 
the  rubber  dam  ;  it  almost  entirely  obviates  the  use  of  amalgam,  and 
saves  the  necessity  for  large  gold  fillings;  there  is  no  malleting,  no  long 
and  tedious  operation  either  for  the  patient  or  dentist,  while  at  the 
same  time  teeth  are  perfectly  restored,  both  in  appearance  and  use- 
fulness. 

"There  is  another  advantage  in  the  use  of  the  enamel  coatings 
which  is  not,  in  my  opinion,  a  trivial  matter.  When  large  metallic 
fillings  are  inserted,  the  constant  thermal  changes  consequent  upon 
their  alternate  heating  and  cooling  must  exercise  an  unfavorable  in- 
fluence upon  the  tissues  about  the  tooth.  Even  if  the  pulp  be  dead 
and  the  root  be  filled,  there  will  be  a  checking  and  fracture  of  the 
tooth  in  time  from  the  continually  varying  changes  of  temperature. 
An  inflammation  of  the  membranes  will  also  be  likely  to  occur  from 
the  same  cause,  and  thus  the  tooth  will  in  time  be  lost,  from  the  mere 
influence  of  the  presence  of  a  large  mass  of  metal. 

"  It  is  also  a  fact  that  large  gold  fillings  cannot  be  inserted  with- 
out so  much  malleting  that  the  strength  of  the  tooth  is  gone,  and  frail 
walls  are  cracked  beyond  the  possibility  of  repair.  These  dangers  are 
all  obviated  by  the  use  of  the  porcelain  facings,  while  teeth  so  restored 
are  much  more  natural  in  feeling  and  more  grateful  to  the  touch  of  the 
tongue  than  any  metallic  filling  can  be." 

Dr.  Land  describes  his  metallic  enamel  sections  as  follows  : — 

"  By  reference  to  Fig.  915,  Nos.  2,  7,  10,  12,  and  15,  there  will  be 
seen  characteristic  conditions  of  decay  suitable  for  this  class  of  work. 
2  and  7  are  the  prepared  cavities  on  anterior  sides  of  molars.  The 
manner  of  procedure  is  to  burnish  a  thin  i)iece  of  annealed  platinum 
plate  into  the  cavity.  This  takes  a  perfect  impression  of  its  outlines. 
The  surplus  edges  are  trimmed  off  and  platinum  pins  attached,  using 
pure  gold  leaf  for  solder.  (See  3  and  4.)  The  pins  serve  as  a  fasten- 
ing, both  to  secure  the  completed  section  in  place  and  as  retainers  for 
the  porcelain  body.  5  and  8  illustrate  the  completed  sections,  show- 
ing the  contour  of  the  original  shape  of  the  lost  portion  of  the  natuial 
tooth.     Nos.  I  and  6  are  prepared  sections  cemented  in  place. 


CROWN    AND    BRIDGE-WORK. 


867 


"Having  secured  the  prepared  sections  as  shown  in  3  and  4,  porce- 
lain paste  or  body  is  built  upon  them  and  carved  so  as  to  imitate 


Fig.  915. 


the  original  contour  of  the  lost  portion  of  the  tooth,  as  shown  in  5 
and  8.     They  are  then  placed  on  a  bed  of  silex  and  fused  in  a  gas 


So8  MECHANICS — DENTAL    PROSTHESIS. 

furnace.  This  requires  twenty  minutes  for  the  first  biscuit  and  fifteen 
for  the  second.  When  completed,  they  will  be  a  reproduction  in 
porcelain  of  the  lost  parts  of  the  natural  organs,  resembling  nature  per- 
fectly, both  in  color  and  shape.  They  are  then  cemented  in  the 
cavity,  either  with  gutta-percha  filling  or  oxyphosphate  cement.  When 
the  anterior  side  of  a  molar  or  bicuspid  is  decayed,  as  shown  in  ii 
and  15,  the  enamel  front  or  veneer,  13,  is  added  to  the  porcelain  body, 
and  when  completed  it  will  appear  as  shown  in  14.  This  veneer  serves 
as  a  ready  and  efficient  means  of  securing  the  proper  shape  and  con- 
tour of  each  class  of  teeth.  To  those  who  are  not  familiar  with  the 
use  of  a  gas  furnace  this  class  of  work  may  seem  difficult,  but  a  little 
experience  with  the  modern  appliances  now  within  the  reach  of  every 
dentist  makes  the  operation  a  comparatively  simple  and  easy  one.  17, 
18,  19,  and  20  are  a  modification.  17  represents  a  tooth  filled  with 
gold,  having  two  pins  attached.  18  is  a  platinum  disc,  with  tubes  ad- 
justed to  correspond  to  the  position  of  the  pins  in  17.  Porcelain  body 
is  built  about  the  tubes,  and  when  fused  in  the  furnace  the  whole  will 
form  a  porcelain  crown,  as  shown  in  19.  20  illustrates  the  relative 
position  of  the  tubes,  which  are  designed  to  form  countersinks  for  the 
pins  in  17.  When  cemented  in  place,  it  makes  a  very  durable  and 
beautiful  piece  of  work.  16  is  an  incisor  constructed  in  a  similar 
manner.  From  this  will  be  seen  the  great  advantage  of  being  able 
to  have  the  porcelain  in  a  plastic  state,  as  it  enables  the  dentist  to  per- 
fectly adapt  the  form  of  each  peculiar  case  with  the  utmost  precision, 
and  this  could  not  be  so  admirably  done  with  manufactured  crowns. 

"I  wish  to  call  especial  attention   to  the  large  amount  of  tooth- 
substance  preserved.     In  nearly  all  the  modern  systems  of  crown-work 

there  seems  to  be  too  much  good  tooth- 
material  cut  away,  and  I  think  a  care- 
ful investigation  will  demonstrate  this 
new  process  to  be  far  superior,  mak- 
ing it  possible  to  save  the  greater  por- 
tion of  the  crown,  it  not  being  neces- 
,  sary  to  cut  beneath  the  gum.  In  nearly 

every  case,  sufficient  tooth-substance 
can  be  retained  to  preserve  the  pulp  alive,  and  when  the  teeth  are  de- 
vitalized the  major  portions  of  the  crown  can  be  left  intact,  serving 
for  retaining  purposes  and  making  it  unnecessary,  in  the  majority  of 
cases,  to  resort  to  screws  or  posts.  16  illustrates  a  section  of  porcelain 
adjusted  to  a  central  incisor,  which,  when  carefully  done,  makes  a  very 
acceptable  piece  of  work.  Although  the  joint  may  sometimes  be 
conspicuous,  it  is  not  nearly  as  much  so  as  a  glaring  piece  of  gold." 
Fig.  916  represents  a  practical  case  for  the  insertion  of  the  sections. 


REFINING    AND    ALLOYING    GOLD.  8og 

In  concluding  the  subject  of  artificial  crowns  attached  to  natural 
roots  and  teeth,  it  remains  only  to  briefly  refer  to  the  advantages  and 
disadvantages  of  each  method.  As  regards  what  is  strictly  pivot  work, 
all  methods  are  objectionable  in  which  the  exposed  surface  of  the  root 
is  not  protected  from  such  agents  as  disintegrate  tooth  structure  ;  as  re- 
gards the  collar  or  ferrule  crown,  such  work  is  objectionable  where  it 
causes  irritation  of  the  gum  and  periosteal  tissues,  or  permits  of  the 
disintegration  of  the  supporting  roots  or  teeth,  or  is  temporary  in  its 
nature,  on  account  of  the  use  of  the  plastic  preparations  in  connec- 
tion with  it ;  and  lastly,  all  "  bridge  "  or  crown-work  is  objectionable 
where  it  cannot  be  kept  perfectly  clean  and  free  from  accumulations 
of  fluid  and  other  substances  beneath  it,  and  where  it  cannot  be  re- 
paired in  case  of  accident  without  breaking  up  the  entire  appliance. 
The  effects  of  thermal  changes  on  tooth  tissues  when  brought  directly 
in  contact  with  large  masses  of  metal,  and  the  exceedingly  frail  nature 
of  many  of  the  porcelain  crowns  and  facings  required  by  some  of  the 
methods  in  use,  should  also  be  considered. 

To  grind  the  Logan  tooth-crown,  it  has  been  suggested  to  take  a 
hollow  mandrel  and,  while  in  a  hand-piece,  heat  the  end  and  mount 
on  it  a  corundum  wheel,  such  as  No.  oo,  being  careful  to  make  its 
outer  face  true  and  leave  the  hole  in  the  end  of  the  mandrel  free  for 
the  pivot  or  post  of  the  tooth-crown  to  enter.  The  neck  of  the  Logan 
crown  can  then  be  ground  without  the  risk  of  grinding  the  post  or 
pivot,  which  enters  the  socket  of  the  mandrel  and  is  protected. 

Solid  gold  cusps  made  of  twenty-two  carat  gold  and  designed  to 
be  soldered  to  gold  bands  fitted  to  natural  roots,  and  also  for  forming 
the  masticating  surfaces  of  porcelain  crowns  in  bridge-work,  can  be 
obtained  at  the  dental  depots  or  be  made  by  stamping  thick  gold  plate 
with  hard  metal  dies. 


CHAPTER  VL 


MANNER  OF   REFINING   AND    ALLOYING   GOLD,  AND   CALCU- 
LATING ITS  FINENESS. 

Gold  is  the  best  metal,  and  for  general  use  the  best  material,  that 
can  be  used  for  the  attachment  of  artificial  teeth.  When  used  of  proper 
fineness  it  resists  the  most  acrid  secretions  of  the  mouth,  and  under- 
goes, during  the  long  years  of  use,  no  change  in  its  strength,  form,  or 
texture.  Other  metals  and  materials  have  a  special  utility,  but  none 
have  so  wide  a  range  of  usefulness,  and  none  can  take  the  place  which 
this  royal  metal  holds  in  dental  prosthetics. 


8lO  MECHANICS — DENTAL    PROSTHESIS. 

Gold  in  its  pure  state,  free  from  alloy,  is  too  soft  and  yielding  to 
serve  as  a  suitable  support  for  artificial  teeth ;  and,  on  the  other  hand, 
if  it  contains  too  much  or  an  improper  alloy,  it  will  become  tarnished 
by  the  secretions  of  the  mouth,  rendered  too  brittle  for  service,  through 
those  molecular  changes  which  take  place,  with  greater  or  less  rapidity, 
if  the  plate  is  less  than  twenty  carats  fine.  It  is,  therefore,  of  the 
utmost  importance  that  the  gold  used  in  connection  with  artificial 
teeth  should  be  of  the  proper  fineness  and  possessed  of  the  requisite 
malleability.  To  secure  these  qualities,  it  is  necessary  to  know  the 
kind  and  quantity  of  metal  with  which  to  alloy  it  before  it  is  made 
into  plate  or  other  forms  necessary  for  the  purposes  for  which  it  is  to 
be  employed. 

Gold  clippings,  filings,  and  scraps  generally,  if  free  from  admix- 
ture with  base  metals,  only  require  to  be  remelted  if  of  a  required 
fineness  ;  but  gold  clippings,  filings,  and  other  scraps  and  parts  of  old 
gold  plate  or  bridge-work,  as  found  in  the  laboratory,  are  apt  to 
become  mixed  with  base  metals,  such  as  iron  from  the  wearing  of 
files,  and  occasionally  small  particles  of  lead,  tin,  zinc,  or  fragments 
containing  solder  If  these  are  melted  with  and  permitted  to  remain 
in  the  gold,  they  will  destroy  its  ductility  and  render  it  unfit  for  use. 
Iron,  less  objectionable  than  the  lead  or  tin,  may  be  removed  with  a 
magnet  before  the  gold  is  melted  ;  but  to  free  it  perfectly  from  the 
others,  it  will  sometimes  be  necessary  to  refine  it  by  roasting,  or  to 
reduce  it  to  pure  gold  by  the  humid  process  in  the  manner  presently 
to  be  described.  A  two-thousandth  part  of  tin  or  lead  destroys  the 
ductility  of  gold,  and  even  exposure  to  the  fumes  of  red-hot  tin  or 
lead  renders  it  exceedingly  hard  and  brittle. 

The  sweepings  of  a  laboratory  contain  many  impurities,  both  earthy 
and  metallic,  and  they  should  be  treated  by  either  first  washing 
thoroughly  to  remove  the  earthy  matter,  and  the  remaining  metal 
refined  separately.  A  better  process,  however,  is  to  burn  out  the  com- 
bustible substances,  and  then  mix  the  residue  with  the  following 
substances  :  to  every  eighth  part  of  the  sweepings  add  carbonate  of 
potassa  four  parts,  chlorid  of  sodium  four  parts,  supertartrate  of 
potassa  one  jjart,  and  nitrate  of  potassa  half  part;  place  in  a  crucible 
and  subject  the  contents  to  the  fire  for  some  time  after  fusing  occurs. 
As  different  aiifinities  exist  between  metals,  the  selection  of  a  reagent 
is  governed  by  the  nature  of  the  alloy  in  the  process  of  separating 
gold  from  foreign  metals.  Zinc  or  iron,  or  both  of  these  metals,  if 
present  in  gold  in  small  quantities,  may  be  separated  by  nitrate  of 
potassa,  as  it  yields  oxygen,  which  has  an  affinity  for  such  metals  and 
converts  them  into  oxids.  Tin  is  more  readily  separated  from  gold 
by  chlorid  of  mercury,  for  the  reason  that  oxygen  has  a  feeble  affinity 


REFINING    AND    ALLOYING    GOLD.  8ll 

for  tin,  whereas  chlorin  in  the  act  of  decomposition  separates  the  tin 
from  the  gold  very  readily.  When  gold  is  contaminated  with  a  num- 
ber of  these  metals,  which  render  it  very  coarse,  the  most  powerful 
and  efficient  reagent  is  sulphuret  of  antimony,  or  resort  may  be  had 
to  the  humid  process  and  the  alloy  thereby  reduced  to  pure  gold. 
Antimony  or  bismuth,  when  mixed  with  gold,  also  renders  gold  hard 
and  brittle.  So  marked  is  the  influence  of  antimony  in  injuring  one 
of  the  most  valuable  properties  of  gold,  that  its  original  name, 
regiilus  (little  king),  by  which  it  is  best  known  in  commerce,  was 
given  in  view  of  this  controlling  effect  upon  the  king  of  metals.  It 
is  of  the  utmost  importance  to  bear  in  mind  the  action  of  minute 
quantities  of  these  four  metals,  so  much  used  in  the  laboratory,  upon 
gold,  platina,  and  silver. 

Platina,  united  with  gold  in  certain  proportions,  has  the  effect  of 
hardening  the  latter  metal  and  making  it  very  elastic,  but  does  not 
materially  affect  its  ductility.  The  affinity  of  the  alloy  for  oxygen, 
however,  is  so  great  that  it  is  readily  acted  on  by  nitric  acid.  The 
acids  of  the  mouth  will  often  make  this  alloy  very  brittle.  But  for 
this,  the  two  metals,  combined  in  the  proportion  of  the  fifteen  parts 
of  gold  to  one  of  platina,  would  form  an  exceedingly  useful  alloy  for 
the  construction  of  spiral  springs.  That  a  combination  of  two  metals 
should  be  thus  easily  acted  on  by  an  agent  incapable  of  acting  on 
either  when  in  a  separate  state  may  appear  somewhat  remarkable, 
but  it  is,  nevertheless,  true.  We  have  in  the  effect  of  platina  upon 
steel  an  analogous  case.  It  makes  the  steel  exceedingly  hard  and 
fine-grained  ;  but  although  itself  totally  insensible  to  the  action  of 
oxygen,  when  alloyed  in  minute  quantity  with  steel  it  causes  this 
latter  metal  to  oxidize  with  such  readiness  as  to  make  it  unfit  for 
use. 

Hence  may  be  seen  the  fallacy  of  the  idea,  entertained  by  many, 
that  because  platina  is  a  more  indestructible  metal  than  silver  or  copper 
it  must  necessarily  make  a  purer  plate.  The  properties  of  alloys  are, 
in  fact,  so  often  and  so  widely  different  from  those  of  their  com- 
ponent metals  that  they  can  be  ascertained  only  by  experiment.  Of 
the  three  metals,  platina,  silver,  and  copper,  speculative  theory  might 
select  the  first  and  purest  as  the  best  alloy  for  gold ;  whereas,  actual 
experience  demonstrates  that  copper,  itself  the  most  injurious  to  the 
mouth,  imparts  most  perfectly  to  gold,  if  kept  within  proper  limits, 
those  qualities  which  are  required  in  a  dental  plate. 

In  view,  then,  of  the  importance  of  having  gold  which  is  to  be 
placed  in  the  mouth  of  the  right  quality,  every  dentist  who  has  con- 
nected with  his  practice  a  mechanical  laboratory  should  have  the 
necessary  fixtures  for  melting  and  working  this  metal  into  the  various 


8l2  MECHANICS — DENTAL    PROSTHESIS. 

forms  required  for  dental  purposes.  The  principal  of  these  are,  a 
small  furnace,  with  crucibles  and  tongs,  ingot-molds,  an  anvil  and 
hammers,  and  a  rolling  mill ;  a  plate  gauge,  draw  plate,  and  bench 
vise  ;  fluxing  and  refining  chemicals,  etc. 

REFINING   GOLD. 

It  is  not  our  intention,  in  describing  the  manner  of  refining  gold, 
to  enter  into  a  minute  detail  of  the  various  methods  employed  for 
assaying  or  refining  this  metal,  but  to  point  out  as  briefly  as  possible 
the  manner  of  separating  it  from  the  several  metals  with  which  it  is 
most  frequently  combined  in  the  dentist's  laboratory.  The  two 
methods  generally  employed  for  separating  gold  from  foreign  metals 
are  the  "dry"  and  the  *' humid"  processes,  the  former  being  a 
"roasting  "  process  effected  by  the  action  on  the  alloy  in  a  molten 
condition  of  either  oxygen,  chlorin,  or  sulphur;  while  the  latter 
process  (humid)  reduces  the  alloy  to  pure  gold  by  the  solvent  action 
of  either  nitric,  sulphuric,  and  nitro-muriatic  or  hydrochloric  acid. 

The  method  usually  employed  by  assayers  for  separating  gold  from 
silver  is  to  roll  the  alloy  out  into  very  thin  plates,  and  put  it  in  nitric 
acid  ;  this  will  dissolve  most  of  the  silver,  and  leave  the  gold  behind 
in  the  form  of  brown  plates,  scales,  or  powder,  which,  after  being 
thoroughly  washed,  is  put  into  a  crucible  with  borax  and  melted 
down  into  an  ingot  of  pure  gold.  But  this  method  will  not  succeed 
unless  the  quantity  of  silver  be  equal  to  two  or  three  times  that  of  the 
gold ;  for  the  nitric  acid,  which  acts  only  upon  the  silver  (and  copper), 
cannot  eat  out  all  the  alloy  if  its  particles  are  too  much  surrounded 
with  the  particles  of  gold.  From  the  old  rule — one-fourth  gold, 
three-fourths  alloy — came  the  name  given  to  this  process,  quartation  ; 
it  is  also  known  as  the  nitric  acid  process.  It  is  well  adapted  to  the 
purification  of  gold  upon  a  large  scale,  and  is  the  process  used  in  the 
U.  S.  Mint.  But  it  does  not  remove  the  platina  so  generally  found  in 
dentists'  scrap ;  and  it  is  not  so  well  adapted  for  gold  of  i8-carat  fine- 
ness and  upward  as  the  next  process. 

The  nitro-muriatic  or  aqua  regia  process  dissolves  all  the  metals  of 
the  alloy,  but  immediately  precipitates  the  silver.  The  gold  is  subse- 
quently precipitated  in  a  state  of  purity,  thoroughly  washed,  dried, 
and  melted  down  with  borax.  The  process  is,  briefly,  as  follows : 
Melt  the  scrap  to  be  refined  ;  roll  into  a  thin  strip  and  curl  it  up  into 
what  is  technically  termed  a  cornet;  place  in  a  porcelain  vessel  and 
pour  on  the  aqua  regia,  three  or  four  ounces  to  the  ounce  of  alloy, 
which  must  be  mixed  at  the  moment  of  using  in  the  proportion  of 
one  part  of  pure  nitric  acid  to  two,  two  and  a  half,  or  three  parts  of 
hydrochloric  acid;  quicken  the  solution  by  heat  from  a  spirit-lamp. 


REFINING   AND   ALLOYING   GOLD.  813 

setting  the  vessel  where  the  nitrous  fumes  can  escape  from  the  room  ; 
decant  or  filter  the  solution  so  as  to  separate  the  precipitated  silver ; 
evaporate  the  clear  solution  over  a  spirit-lamp,  nearly  to  dryness,  add 
hydrochloric  acid,  and  evaporate  a  second  time,  so  as  to  get  rid  of 
all  nitric  acid. 

The  concentrated  orange-colored  solution  is  the  chlorid  of  gold 
together  with  the  chlorid  of  platina  and  other  metals,  from  which  it 
must  be  separated  by  precipitation.  Dilute  largely  with  water,  and 
add,  little  by  little,  a  solution  of  the  protosulphate  of  iron  (green- 
vitriol),  until  the  dark  olive-brown  precipitate,  which  instantly  appears, 
ceases  to  form.  Pour  on  this  precipitate  some  sulphuric  acid,  to 
remove  all  traces  of  iron,  and  then  wash  several  times  with  hot  water, 
dry  it,  and  melt  with  borax  in  a  crucible. 

Another  method  of  refining  is  the  sulphuric  acid  process,  which  it 
is  unnecessary  to  describe  further  than  to  say  that  it  resembles  the 
quartation  process.  Gold  is  melted  with  five  to  seven  times  as  much 
silver,  granulated,  and  then  boiled  three  or  four  hours  in  a  platina  or 
iron  retort  with  sulphuric  acid. 

The  late  Prof.  George  Watts'  process  of  refining  gold  by  the 
"humid"  or  "wet"  process,  the  solvent  being  nitro-muriatic  or 
hydrochloric  acid,  which  appears  to  give  the  most  convenient  results, 
is  as  follows  : — * 

"Let  us  then  suppose  that  our  gold  alloy  has  become  contaminated 
with  platinum  to  such  an  extent  that  the  color  and  elasticity  of  the 
plate  are  objectionable.  The  alloy  should  be  dissolved  in  nitro- 
muriatic  or  hydrochloric  acid,  called  aqua  regia,  the  best  proportions 
of  which  are  three  parts  of  hydrochloric  to  one  of  nitric  acid.  Four 
ounces  of  the  aqua  regia  will  be  an  abundance  for  an  ounce  of  the 
alloy.  If  the  acids  be  '  chemically  pure,'  four  parts  of  the  hydro- 
chloric to  one  of  the  nitric  produces  still  better  results. 

"  By  this  process  the  metals  are  converted  into  chlorids ;  and  as  the 
chlorid  of  silver  is  insoluble,  and  has  a  greater  specific  gravity  than 
the  liquid,  it  is  found  as  a  grayish-white  powder  at  the  bottom  of  the 
vessel.  The  chlorids  of  the  other  metals,  being  soluble,  remain  in 
solution.  By  washing  and  pouring  off,  allowing  the  chlorid  of  silver 
time  to  settle  to  the  bottom,  the  solution  may  be  entirely  separated 
from  it.  The  object  is  now  to  precipitate  the  gold  while  the  others 
remain  in  solution.  This  precipitation  may  be  effected  by  any  one 
of  the  several  different  agents,  but  we  will  mention  only  the  proto- 
sulphate of  iron. 

"  This  salt  is  the  common  green  copperas  of  the  shops,  and  as  it  is 

*  Denial  Register. 


8l4  MECHANICS — DENTAL   PROSTHESIS. 

always  cheap  and  readily  obtained,  we  need  look  no  further.  It 
should  be  dissolved  in  clean  rain-water,  and  the  solution  should  be 
filtered,  and  allowed  to  settle  until  perfectly  clear.  Then  it  is  to  be 
added  gradually  to  the  gold  solution  as  long  as  a  precipitate  is  formed, 
and  even  longer,  as  an  excess  will  the  better  insure  the  precipitation 
of  all  the  gold.  The  gold  thus  precipitated  is  a  brown  powder,  hav- 
ing none  of  the  appearances  of  gold  in  its  ordinary  state.  The 
solution  should  now  be  filtered,  or  the  gold  should  be  allowed  to 
settle  to  the  bottom,  where  it  may  be  washed  after  pouring  off  the 
solution.  It  is  better  to  filter  than  decant  in  this  case,  as,  frequently, 
particles  of  the  gold  float  on  the  surface,  and  would  be  lost  in  the 
washings  by  the  latter  process. 

"Minute  traces  of  iron  may  adhere  to  the  gold  thus  precipitated. 
These  can  be  removed  by  digesting  the  gold  in  dilute  sulphuric  acid, 
and,  when  the  process  is  properly  conducted  thus  far,  the  result  is 
pure  gold,  which  may  be  melted,  under  carbonate  of  potash,  in  a 
crucible  lined  with  borax  and  reduced  to  the  required  carat." 

By  any  of  these  processes,  but  most  conveniently  by  the  second, 
dental  scrap  may  be  refined  to  a  purity  sufficient  for  every  practical 
purpose. 

The  Dry  Process. — The  form  of  furnace  for  melting  gold  depends 
much  upon  the  kind  of  fuel.  Charcoal,  coke,  and  anthracite  are  the 
three  kinds  used ;  bituminous  coal  is  inadmissible  until  converted 
into  coke.  The  plumbing  stores  and  stove  factories  now  furnish  so 
many  convenient  forms  for  the  use  of  gas  and  many  of  these  fuels 
that  we  shall  not  occupy  time  or  space  in  their  detailed  description. 
A  pipe  six  feet  high  will  give  to  the  ordinary  "  preserving  furnace"  a 
draft  sufficient  to  melt  gold  with  charcoal ;  coke  gives  a  very  intense 
heat,  but  needs  a  stronger  draft ;  anthracite  requires  a  powerful  draft, 
but  gives  a  more  steady  heat,  needs  less  frequent  renewal,  and  hence 
is  better  for  long-continued  heats. 

As  regards  the  shape  and  size  of  the  furnace,  the  following  points 
should  be  attended  to  :  convenience  of  access  to  the  crucible ;  suffi- 
cient depth  and  width  to  surround  the  crucible  with  a  good  body  of 
fuel,  without  unnecessary  waste  of  material. 

Fletcher's  small  and  convenient  blast  crucible  furnaces,  for  melting 
gold  by  the  use  of  gas  and  refined  petroleum,  are  very  serviceable  in 
laboratory  work. 

Downie's  crucible  gas  furnace  (Fig.  917)  is  especially  designed  for 
melting  metals,  such  as  gold  and  silver,  making  alloys  for  amalgam, 
experimental  work,  etc.  It  is  also  very  useful  for  brazing,  soldering, 
heating  up  bridge  cases  or  metal  plates  to  solder,  etc. 

It  has  two  removable  rings  of  different  widths,  which  set  on  above 


REFINING    AND    ALLOYING    GOLD. 


815 


the  flaring  base  to  carry  the  heat  up  around  the  crucible,  the  wide  or 
narrow  ring  to  be  used,  according  to  the  size  of  the  crucible,  or  both 
rings  may  be  put  on  at  the  same  time. 

It  also  has  a  conical-shaped  top  which  can  be  set  on  above  the 
rings  to  confine  the  heat  when  it  is  desired  to  fuse  any  high-fusing 
substance. 

For  separating  iron,  copper,  tin,  lead,  or  zinc  from  gold,  the  follow- 
ing simple  method  may  be  adopted  :  After  passing  a  magnet  a  number 
of  times  through  the  filings  or  fragments,  to  remove  all  traces  of  iron 
or  steel,  put  the  gold  in  a  clean  crucible,  covered  with  another  cruci- 


ble, having  a  small  opening  or  hole  through  the  top ;  lute  the  two 
together  with  clay ;  place  them  in  a  bed  of  charcoal  in  the  furnace ; 
ignite  the  coal  gradually ;  afterward  increase  the  combustion  by 
means  of  a  current  of  air  from  a  pair  of  bellows,  or  by  turning  on  the 
draft ;  after  the  gold  has  melted  throw  in,  at  intervals  of  about  ten 
minutes,  several  small  lumps  of  nitrate  of  potash  (saltpeter)  and  sub- 
borate  of  soda  (borax),  and  keep  in  a  fused  state  for  thirty  or  forty 
minutes;  then  remove  the  crucible  and  plunge  in  water  to  cool  it; 
break  it  and  separate  the  lump  of  gold  from  the  dross ;  then  put  into 


8l6  MECHANICS — DENTAL    PROSTHESIS. 

another  crucible;  melt  with  a  little  borax,  and  pour  into  an  ingot- 
mold  of  the  proper  size,  previously  warmed  and  oiled.  Bichlorid 
of  mercury  (corrosive  sublimate)  is  sometimes  used  instead  of  or 
after  nitre,  for  the  purpose  of  dissipating  the  base  metals,  and  often 
with  more  certain  and  better  results,  especially  where  the  presence  of 
any  tin  is  suspected.  If  the  gold  cracks  on  being  hammered  or 
rolled,  it  should  be  melted  again,  and  more  nitre  and  borax  thrown 
in ;  the  inside  of  the  crucible  should  also  be  well  rubbed  with  borax 
before  the  metal  is  put  in.  It  is  sometimes  necessary  to  repeat  this 
process  several  times,  and  if  the  gold  still  continues  brittle,  a  little 
muriate  of  ammonia  (sal  ammoniac)  may  be  thrown  into  the  crucible 
when  the  gold  is  in  a  fused  state ;  after  the  vapor  ceases  to  escape, 
the  metal  should  be  poured  into  an  ingot-mold,  warmed,  and  oiled  as 
before  directed.  This  last  method  of  treatment  will  make  the  gold 
tough,  and  prevent  it  from  cracking  under  the  hammer  or  while 
being  rolled,  provided  it  is  from  time  to  time  properly  annealed  dur- 
ing the  process. 

To  separate  tin  and  lead  from  gold,  add  corrosive  sublimate 
(HgClj),  and  chlorid  of  zinc  (ZnCl^)  or  chlorid  of  lead  (PbClz)  are 
formed  and  with  the  mercury  are  volatilized.  To  separate  silver  from 
gold,  from  two  to  four  times  the  weight  of  the  gold  of  sulphid  of 
antimony  (SbjSg)  must  be  added  in  small  quantities,  the  sulphid  being 
decomposed  by  heat.  The  sulphids  are  formed  by  the  sulphur  unit- 
ing with  the  silver  and  other  base  metals,  and  the  antimony  unites 
with  the  gold,  forming  a  leaden-colored  alloy  in  the  bottom  of  the 
crucible,  while  the  sulphids  remain  on  the  surface.  The  antimony  is 
separated  from  the  gold  by  remelting  the  alloy  and  throwing  upon 
the  fused  mass  a  current  of  air  from  a  blowpipe.  The  oxid  of 
antimony  (SbjOj)  is  thus  formed,  which  is  volatilized,  and  the  process 
continued  until  fumes  can  no  longer  be  driven  off. 

To  remove  iridium  from  gold,  the  latter  is  alloyed  with  three  times 
its  weight  in  silver,  and  the  mass  melted  in  a  crucible,  by  which 
means  the  specific  gravity  is  so  greatly  lowered  that  the  infusible 
iridium  subsides  to  the  bottom  of  the  crucible,  when  the  gold  and 
silver  alloy  can  be  poured  off.  As  some  of  the  gold  still  remains 
with  the  iridium,  more  silver  must  be  melted  with  it  and  the  process 
repeated  as  often  as  is  necessary  to  remove  all  of  the  gold.  The 
silver  is  then  separated  from  the  gold  by  the  process  already  described. 
Platinum  can  only  be  removed  from  the  gold  by  the  humid  or  wet 
process. 

By  this  method  of  refining  gold,  known  as  the  dry  process,  or 
"refining  by  fire,"  sufficiently  accurate  results  will  be  obtained  for 
many  of  the   practical    jmrposes   of  prosthetic   dentistry,  since    the 


REFINING   AND   ALLOYING    GOLD.  817 

variation  of  an  eighth  or  a  quarter  of  a  carat  in  the  fineness  of  gold 
plate  is  not  often  a  matter  of  much  consequence.  Comparing  the 
two  classes  of  refining  processes — the  humid,  by  acids,  and  the  dry, 
by  fire — the  first  is  the  most  accurate,  and  the  only  way  to  remove 
platina  or  silver ;  but  it  is  the  most  troublesome,  and  requires  a 
familiarity  with  chemical  details,  which,  unfortunately,  many  dentists 
are  totally  ignorant  of.  The  second  may  remove  the  lead,  tin,  zinc, 
antimony,  and  bismuth,  if  in  small  quantity;  and  if  continued  for 
a  sufficient  length  of  time,  with  a  free  use  of  nitre,  may  remove  a 
large  proportion  of  copper.  It  can  scarcely  be  depended  upon  if 
the  object  is  to  make  an  ingot  of  pure  gold,  but  will  answer  admir- 
ably if  the  purpose  is  merely  to  lessen  the  alloy  or  remove  certain 
impurities. 

A  very  excellent  method  pursued  by  Dr.  Elliott,  of  Montreal,  is  as 
follows  :  * — 

"  The  following  implements  are  necessary  for  this  purpose  :  a  small 
draft  furnace ;  a  quantity  of  fine  hard-wood  coal ;  a  clean  crucible, 
with  a  sheet-iron  cover  (a  lump  of  charcoal  is  better)  ;  a  light  pair  of 
crucible  tongs;  an  ingot  mold,  made  of  soapstone  ;  a  little  nitrate  of 
potash,  carbonate  of  potash,  borax,  and  oil.  The  fireplace  of  the  fur- 
nace should  be  about  ten  inches  in  diameter  and  eight  or  ten  deep ; 
this  should  be  connected  by  means  of  a  pipe  with  the  chimney,  so 
that  a  powerful  draft  may  be  made  to  pass  through  the  coal.  A 
blast-furnace  is  objectionable,  for  the  reason  that  the  bellows  burns 
out  the  coal  immediately  under  the  crucible,  and  it  is,  therefore, 
constantly  dropping  down,  which  is  not  the  case  with  the  draft 
furnace ;  besides,  the  draft  furnace  produces  a  more  even  fire,  a 
quality  equally  indispensable. 

"In  preparing  for  a  heat,  the  furnace  should  be  filled  about  half 
full  of  coal,  and  after  it  is  well  ignited  it  should  be  consolidated  as 
much  as  practicable  without  choking  the  draft.  The  crucible  con- 
taining the  metal  and  a  little  borax  may  then  be  set  on,  and  more 
coal  placed  around  and  over  it,  the  door  of  the  furnace  closed,  and 
the  damper  opened.  It  should  remain  in  this  way  until  the  gold  is 
perfectly  fused.  The  coal  may  then  be  removed  from  over  the 
crucible,  and  a  bit  of  nitrate  of  potash  dropped  in,  in  quantity  equal 
to  the  size  of  a  pea  to  every  ounce  of  gold,  and  the  crucible  immedi- 
ately covered  with  a  plate  of  iron.  More  coal  may  then  be  placed 
over  and  around  the  crucible,  and  the  gold  kept  in  a  fused  state  at  a 
high  temperature,  until  the  scoria  ceases  to  pass  off,  which  it  will  do 
in  the  course  of  five  or  six  minutes.      The  ingot-mold,  having  been 

*  Atnerican  Jourttal  of  Dental  Science, 
52 


8l8  MECHANICS — DENTAL   PROSTHESIS. 

previously  warmed,  should  be  placed  in  a  convenient  position  for 
pouring,  and  filled  about  half  full  of  lamp  oil.  The  cover  should 
now  be  thrown  off  quickly,  the  crucible  seized  with  the  tongs,  and  at 
the  same  instant  another  small  bit  of  nitrate  of  potash  should  be  thrown 
into  it,  and  the  gold  rapidly,  but  carefully,  poured  into  the  mold. 

"  The  ingot  always  cools  first  at  the  edges,  and  shrinks  away  from 
the  middle.  On  that  account,  the  mold  should  be  a  little  concave 
on  the  sides,  so  that  the  shrinking  will  not  reduce  the  ingot  thinner 
in  the  center  than  at  the  edges. 

"Molds  of  the  best  form  will  sometimes  produce  ingots  of  irregu- 
lar thickness.  Such  ingots  should  be  brought  to  a  uniform  thickness 
under  the  hammer,  using  the  common  callipers  as  a  gauge.  If  this  be 
neglected,  the  plate  will  be  found  imperfect  at  those  points  where  the 
ingot  was  thinnest.  The  plate  should  be  annealed  occasionally 
during  the  process  of  hammering  and  rolling,  and  should  be  reduced 
about  one  number  in  thickness  each  time  it  passes  between  the  rolls. 
If  any  lead,  tin,  or  zinc  be  mixed  with  the  gold,  the  nitrate  of  potash 
must  be  used  in  much  larger  quantities,  and,  in  that  case,  it  is  better 
to  let  the  button  cool  in  the  bottom  of  the  crucible.  Then  break  the 
crucible  and  melt  it  in  a  clean  one  for  pouring,  using  borax  and 
nitrate  of  potash  in  very  small  quantities  for  the  last  melting. 

"In  case  the  subject  of  assay  be  in  the  form  of  filings  or  dust,  a 
magnet  should  be  passed  through  it,  so  as  to  remove  every  particle  of 
iron,  and  then,  instead  of  melting  it  with  borax,  it  should  be  melted 
first  with  carbonate  of  potash,  and  afterward  with  nitrate  of  potash,  in 
quantities  proportioned  to  the  necessities  of  the  case,  as  before 
directed.  Carbonate  of  potash  is  the  only  flux  that  will  bring  all  the 
small  particles  of  metal  into  one  mass.  Without  it,  a  great  portion 
of  the  gold  will  be  found  among  the  scoria,  adhering  to  the  sides  of 
the  crucible,  in  the  form  of  small  globules.  This  process  of  refin- 
ing answers  equally  as  well  for  silver  as  for  gold." 

ALLOYING    GOLD. 

Gold,  when  in  an  unalloyed  or  pure  state,  as  before  stated,  is  too 
soft  to  be  used  as  a  support  for  artificial  teeth  ;  consequently,  it  has 
been  found  necessary  to  combine  with  it  some  other  metal,  in  order 
to  harden  it.  Silver  and  copper  are  the  alloys  most  frequently  em- 
ployed. Many  dentists  prefer  the  former,  erroneously  supposing  that 
it  does  not  increase  the  liability  of  gold  to  tarnish  as  much  as  the 
latter.  But  this  opinion  is  sustained  neither  by  facts  nor  experience. 
Gold,  when  alloyed  with  copper,  unless  reduced  altogether  too  much 
for  dental  purposes,  will  resist  the  action  of  acids  as  effectually  as 
when  alloyed  with  silver,  and  the  former  renders  it  much  harder  than 


REFINING   AND   ALLOYING    GOLD.  819 

the  latter.  Besides,  it  renders  the  gold  susceptible  of  a  higher  and 
more  beautiful  finish.  If,  therefore,  but  one  of  these  metals  is  used, 
copper  may  be  regarded  as  preferable  to  silver. 

The  gold  employed  in  prosthetic  dentistry  by  most  practitioners 
is  altogether  too  impure  for  the  purpose,  it  being  not  more  than  eigh- 
teen carats  fine,  and  sometimes  it  is  reduced  even  to  fourteen.  When 
not  above  these  standards  of  fineness  it  is  discolored  by  the  buccal 
secretions,  imparts  a  disagreeable  taste  to  the  mouth,  and  becomes 
brittle  after  it  has  been  worn  for  a  few  years.  The  plate  which  is  to 
serve  as  a  basis  for  artificial  teeth  should  never  be  reduced  below 
twenty  carats ;  and  as  that  for  the  upper  jaw  does  not  require  to  be 
more  than  one-third  or  one-half  as  thick  as  that  of  the  lower,  the 
gold  for  the  latter  may  be  a  little  finer  than  that  employed  for  the 
former,  as  it  is  necessary  that  it  should  be  more  malleable.  The 
following  standards  of  fineness  may  be  regarded  as  the  best  that  can 
be  adopted  for  gold  used  in  connection  with  artificial  teeth :  plate  for 
the  upper  jaw,  twenty  carats ;  for  the  lower,  twenty-one ;  and  for 
clasps  and  wire  for  spiral  springs,  eighteen. 

In  reducing  perfectly  pure  or  twenty-four  carat  gold  to  these 
standards,  first  make  an  alloy  of  copper  and  silver,  which  may  be 
either  in  the  proportion  of  copper  4,  silver  i,  or  copper  9,  silver  i, 
according  to  the  qualities  required  in  the  plate.  The  effects  of  the 
two  metals  are  in  strong  contrast — copper  giving  hardness  and  elas- 
ticity, and  deepening  the  color  into  a  red ;  silver  preserving  the 
softness,  and  giving  a  greenish-white  shade  to  the  original  yellow 
of  the  pure  gold.  Of  these  alloys  take — to  twenty-one  grains  of  pure 
gold,  three  grains ;  to  twenty  grains  of  pure  gold,  four  grains ;  and 
to  eighteen  grains  of  pure  gold,  six  grains  ;  to  make,  respectively, 
twenty-one,  twenty,  and  eighteen-carat  gold.  In  the  latter  case,  the 
alloy  should  be  used  containing  most  silver,  as  so  large  a  percentage 
of  copper  makes  the  gold  too  hard  and  elastic,  and  gives  it  rather  too 
red  a  color. 

The  gold  should  be  first  melted  in  a  clean  crucible,  and  as  soon  as 
it  has  become  thoroughly  fused,  the  silver  and  copper  alloy  may  be 
thrown  in,  with  two  or  three  small  lumps  of  borax.  After  keeping 
the  whole  in  a  melted  state  for  some  five  or  ten  minutes,  it  should  be 
quickly  poured  into  an  ingot-mold  of  the  proper  size,  previously 
warmed  and  oiled.  If  the  gold  cracks  during  the  process  of  hammer- 
ing or  rolling,  it  must  be  melted  again  and  a  few  small  pieces  of 
borax  with  a  little  muriate  of  ammonia  thrown  in,  and  in  five  or  ten 
minutes  recast  into  an  ingot. 

When  scraps  and  filings  are  to  be  converted  into  plate  they  should 
first  be  refined,  afterward  properly  alloyed.     This  may  also  be  neces- 


820 


MECHANICS — DENTAL    PROSTHESIS. 


sary  with  all  gold  the  quality  or  fineness  of  which  is  not  known  ;  but 
with  national  coins  having  a  known  fixed  standard  this  will  not  be 
necessary.  When  they  are  above  these  standards  of  fineness,  the 
amount  of  alloy  necessary  to  reduce  them  to  the  required  fineness 
may  be  readily  found  by  calculation.  .It  is  often  unnecessary  to  change 
the  fineness  of  either  American  (21.6  carat)  or  English  (22  carat) 
coin  ;  especially  when  the  depth  of  the  plate  in  upper  cases,  or  the 
prominence  of  the  ridge  in  lower,  gives  additional  stiffness  to  the  plate. 

There  are  two  principles  upon  which  plates  are  alloyed.  The  first, 
and  common  one,  is  to  add  as  much  alloy  as  the  gold  will  stand ;  the 
second  is  to  add  the  least  possible  quantity.  The  first  results  in  eigh- 
teen-carat  gold,  and  uses  mainly  silver,  lest  the  six  grains  of  alloy 
should  make  it  too  brittle.  The  last  results  in  twenty  or  twenty-two- 
carat  gold,  and  uses  chiefly  or  exclusively  copper,  since  the  least 
quantity  of  this  gives  the  greatest  stiffness. 

The  simple  rule  is  to  have  the  purest  plate  which  the  form  of  the 
mouth  will  permit.  For  shallow  mouths,  requiring  increased  stiffness, 
a  twenty-carat  plate  may  be  used  ;  but  better  practice  still  is  to  increase 
the  rigidity  by  greater  thickness,  or  sometimes  by  doubling  some  part 
of  the  plate. 

In  connection  with  the  alloying  of  gold,  it  is  proper  to  make  some 
remarks  upon  the  terms  in  which  the  fineness  of  alloys  is  expressed^ 
and  the  means  of  ascertaining  it. 

Pure  gold  being  taken  as  the  starting-point,  it  may  be  expressed  by 
unity  (i),  or  by  24,  or  by  1000.  In  the  first  case,  fineness  is  given 
in  fractions.  In  the  second  case  by  parts  called  carats,  which,  for 
convenience,  may  be  considered  as  equivalent  to  a  grain ;  thus  repre- 
senting pure  gold  by  24  grains,  or  i  dwt.  In  the  third  case,  value  is 
expressed  in  decimals,  and  is  the  most  convenient  system,  although 
the  second  is  the  most  customary  with  jewelers  and  dentists. 

The  following  table,  prepared  by  the  late  Prof.  Austen,  will  show 
the  relative  value  of  these  three  systems  in  a  few  of  the  most  usual 
forms  of  gold  alloy: — 


Fractions. 

Carats. 

Decimals. 

I. 

\\ 
9 

1 

3 

1 
i 

24. 

22. 

21.6 

20. 

19.2 

18. 

15- 
12. 

8. 

1000. 
916.6 
900. 

833-3 
800. 

750- 
625. 
500. 
333-3 

Dentists'  gold,  best, 

"            "      good,    

Jewelers'  gold,  best, 

"            "      good,    

"            "      common, 

Commonest  solder, 

REFINING   AND   ALLOYING   GOLD.  82 1 

The  table  gives  the  amount  of  pure  gold  ;  subtracting  which  from 
the  number  at  the  head  of  each  column  will  give  the  amount  of  alloy. 
For  example  :  best  jewelers'  gold  contains  i8  carats  of  pure  gold  and 
6  carats  of  alloy  ;  or  three-fourths  pure  gold  and  one-fourth  alloy  ;  or 
750  parts  pure  gold  and  250  parts  alloy. 

To  know  how  much  alloy  is  required  to  reduce  gold  from  one  fine- 
ness to  another,  Prof.  Austen  gives  the  following  rule  :  Divide  the  lower 
carat  (c)  by  the  difference  betiveen  the  lower  carat  (c)  and  the  higher 
(C)  ;  divide  the  weight  (W)  of  the  gold  by  this  quotient  (c  -r-  (C  —  c)), 
and  it  will  give  the  amount  of  alloy  (A)  to  be  added.  He  also  gives 
the  following  table  of  divisors,  which  will  be  found  convenient,  as 
saving  the  necessity  of  much  calculation  : — 


Carats. 

22. 

21. 

20. 

19- 

18. 

16. 

14. 

12. 

24. 

II. 

■7 

•5 

3-8 

3- 

2. 

1.4 

I. 

22. 

21. 

10. 

6.3 

4-5 

2.6 

1-7 

1.2 

21.6 

35- 

12.5 

7-3 

5- 

2.8 

1.8 

1-3 

20. 

19. 

9- 

4- 

2-3 

1-5 

18. 

8. 

3-5 

2. 

The  first  vertical  column  represents  the  fineness  before  alloying ; 
first  horizontal  column  the  fineness  after  alloying.  Example :  To 
reduce  a  double  eagle  (weighing  516  grains,  21.6  carats  fine)  to  20, 
18,  and  i2-carat  plate,  divide  the  weight  by  12^,  5,  and  i^;  this 
gives  the  amounts  of  alloy  to  be  added — for  the  first,  41.3  grains;  for 
the  second,  103.2  grains;  and  for  the  third,  387  grains. 

When  it  is  required  to  know  the  fineness  of  the  plate  or  solder  made 
from  known  quantities  of  gold  and  alloy,  multiply  the  weight  (W)  of 
gold,  before  alloying,  by  its  carat  valuation  (C) ;  divide  this  product 
(CW)  by  the  weight  of  the  gold  after  alloying  (W  -\-  A)  ;  the  quotient 
will  be  the  carat  value  (c)  of  the  alloyed  gold. 

This  and  the  preceding  rules  may  be  also  expressed  by  algebraic 
formula :  — 

c  CW 

(i)         A  =  W  ^ .  (2)         c  = . 

C  —  c  W  +  A 

The  fineness  of  any  mixture  of  alloys  of  known  value  may  be 
found  by  a  simple  arithmetical  rule.  Multiply  each  weight  by  its 
carat  (pure  gold  being  24),  divide  the  sum  of  the  products  by  the 
sum  of  the  weights,  and  the  quotient  will  be  the  carat  value  of  the 
mass. 

The  following  formulas  may  be  employed  for  manufacturing  gold 


MECHANICS DENTAL    PROSTHESIS. 


plate  from  pure  gold  for  dental  purposes 
base,  and  No.  4  for  clasps : — 


Nos.  I,  2,  and  3  for  the 


No.  I. 
Gold  Plate  18  Carats  Fine. 

iSdwts. , pure  gold, 

4  dwts., pure  copper, 

2  dwts., pure  silver. 

No.  3. 
Gold  Plate  21  Carats  Fine. 

21  dwts., pure  gold, 

2  dwts.,  ...     •   .    .    .    pure  copper, 
I  dwt., pure  silver. 


No.  2. 
Gold  Plate  20  Carats  Fine. 

2odwts., pure  gold, 

2  dwts. , pure  copper, 

2  dwts. , pure  silver. 

No.  4. 
Gold  Plate  20  Carats  Fine. 

20  dwts., pure  gold, 

2  dwts., pure  copper, 

I  dwt., pure  silver, 

I  dwt., platinum. 


The  following  formulas  may  be  employed  for  manufacturing  gold 
plate  from  coin  gold  :   No.  i  for  the  base  and  No  2  for  clasps : — 


No.  I. 
Gold  Plate  18  Ca9-ats  Fine. 

20  dwts., coin  gold, 

2  dwts. , pure  copper, 

2 dwts., pure  silver. 


No.  2. 
Gold  Plate  20  Carats  Fine. 

20  dwts. , coin  gold, 

8  grs., pure  copper, 

10  grs. , pure  silver, 

20  grs.,     .......    platinum. 


Gold  plate  20  carats  fine  according  to  formulas  No.  4  and  No.  2  is 
suitable  for  clasps,  backings,  and  irregular  appliances  where  great 
strength  and  elasticity  are  required. 

The  following  formula  of  Johnson  Bros,  gives  an  i8-carat  gold 
plate : — 

United  States  gold  coin, 641^  dwt  ($60) 

Pure  silver, 13  dwt. 


CHAPTER  VII. 
INGOT   MOLDS,   ROLLING    MILLS,   SOLDER. 

The  gold,  after  being  refined  or  alloyed,  should  be  re-melted  in  a 
clean  crucible,  well  rubbed  on  the  inside  with  borax,  and  poured  into 
an  ingot  mold  (Figs.  917  a,  917  b)  of  proper  length,  width,  and 
thickness. 

Ingot  molds  may  be  of  iron,  soapstone,  asbestos,  charcoal,  or  car- 


INGOT    MOLDS,    ROLLING   MILLS,    SOLDER. 


823 


bon.  The  first  is  perhaps  most  convenient.  The  second  gives,  with 
the  same  gold,  a  tougher  ingot;  the  asbestos  ingot  block,  which  may 
also  be  used  for  melting,  is  a  perfect  non-conductor,  and  is  repre- 
sented by  Fig.  918;  it  is  25^  inches  wide  and  )^  inch  thick. 
With  the  charcoal  ingot  mold  the  greatest  toughness  of  metal  is 
obtained,  so  far  as  the  nature  of  the  ingot-mold  can  modify  it.  Pig- 
iron,  from  the  same  furnace,  run  into  molds,  may  be  white  and  brit- 


FlG.   917  A. 


Fig.  917  B. 


tie;  or  into  sand  molds,  gray  and  less  brittle  ;  or  into  charcoal,  dark 
gray  and  soft.  Some  such  modification  of  the  molecular  arrangement 
of  gold,  due  to  its  manner  of  cooling,  is  probably  the  correct 
explanation  of  the  fact  that  a  charcoal  mold  yields,  other  things 
being  equal,  a  tougher  ingot  than  iron. 

An  apparatus  is  now  in  use  which  combines  the  crucible  and  ingot- 


FiG.  918. 

mold,  in  which  a  crucible,  or  molded  carbon,  communicates  with 
an  ingot-mold,  both  held  in  position  by  a  clamp  underneath  and 
swiveling  on  a  cast-iron  stand.  The  metal  to  be  melted  is  placed  in 
the  crucible,  and  the  flame  of  a  blowpipe  is  directed  on  it  until  it  is 
perfectly  fused.  The  waste  heat  serves  to  make  the  ingot-mold  hot, 
and  the  whole  is  tilted  over  by  means  of  an  upright  handle  at  the 


824  MECHANICS — DENTAL   PROSTHESIS. 

back  of  the  mold.  A  sound  ingot  may  be  obtained  at  any  time  in 
about  two  minutes. 

The  charcoal  ingot  mold  is  easily  made.  Select  a  fine-grained 
piece ;  saw  in  half  and  make  smooth  by  rubbing  the  surfaces  together. 
Then  make  the  matrix  in  one  of  three  ways :  either  cut  the  shape 
required  out  of  one-half,  with  the  proper  gate ;  or  bend  a  heavy  wire 
into  shape  of  the  ingot  and  gate,  and  bind  it  between  the  surfaces; 
or  saw  off  a  charcoal  slab,  and  after  cutting  out  the  shape  of  the  ingot 
and  gate,  bind  it  between  the  surfaces.  Those  who  have  once  used  a 
charcoal  ingot  will  seldom  use  any  other. 

After  the  ingot  has  become  sufficiently  cool,  it  may  be  placed  on  an 
anvil,  and  its  thickness  reduced  to  about  an  eighth  of  an  inch  with  a 
hammer  weighing  from  one  to  one  and  a  half  pounds.  It  should  then 
be  well  annealed  by  being  placed  in  the  furnace,  lightly  covered  with 
small  pieces  of  charcoal,  and  heated  until  it  assumes  a  uniform  cherry- 
red  color;  or  it  may  be  annealed  with  a  blowpipe.  It  may  be  neces- 
sary, during  the  operation  of  hammering,  to  subject  it  once  or  twice 
to  this  process  to  prevent  the  gold  from  cracking.  If,  notwithstand- 
ing this  precaution,  it  should  crack,  it  must  be  again  melted,  and 
refined  with  muriate  of  ammonia,  etc.  Sudden  cooling  does  not  make 
it  brittle.  On  the  contrary,  some  jewelers  maintain  that  if  plunged 
in  alcohol  and  water  it  is  softer  than  when  slowly  cooled.  A  little 
sulphuric  acid  in  the  water  will  give  a  bright  surface  to  the  plate  by 
cleansing  off  the  oxid  of  copper ;  but  this  acid  pickle  is  only  neces- 
sary for  removal  of  the  metal  of  the  dies  used  in  swaging,  or  of  the 
borax  used  in  soldering ;  in  all  other  cases  we  prefer  to  have  the  oxid 
coating. 

After  the  gold  has  been  reduced  to  the  thickness  just  mentioned 
and  well  annealed,  it  may  be  placed  between  the  rolls  of  the  mill, 
previously  so  adjusted  as  to  be  the  same  distance  apart  at  both  ends, 
and  not  so  near  to  each  other  as  to  require  a  great  effort  to  force  it 
between  them.  The  rollers,  however,  should  be  brought  a  little 
nearer  to  each  other  every  time  the  plate  is  passed  between  them ;  and 
during  this  process  they  should  be  kept  well  oiled,  so  that  there  may 
be  as  little  friction  as  possible.  Many  roll  the  ingot  without  any 
previous  hammering.  In  the  process  of  rolling  care  must  be  had  to 
anneal  often,  and  to  roll  in  one  direction  until  sufficient  width  of 
plate  is  obtained;  then,  before  cross-rolling,  be  sure  to  anneal,  else 
the  plate  will  be  very  apt  to  crack. 

Rolling  mills  for  gold  are  variously  constructed.  Some  are  very 
simple,  while  others  are  quite  complex,  having  a  great  deal  of  ma- 
chinery connected  with  them.  The  rollers  also  vary  in  length  from 
three  to  five  inches.     For  the  gold  plate  used  by  dentists,  they  need 


INGOT    MOLDS,    ROLLING    MILLS,    SOLDER. 


825 


not  be  more  than  three  or  three  and  a  half  inches  long.  Fig.  919 
represents  a  form  of  rolling  mill,  with  the  cog-gearing.  It  is  a 
strong  but  simple  mill,  and  is  very  well  suited  to  the  dental  labora- 
tory. The  set-screws  at  the  top  are  turned  with  a  rod,  and  must  be 
both  moved  alike,  else  the  plate  will  be  thicker  on  one  side,  and  will 
curve  laterally  in  rolling. 

Fig.  920  represents  a  more  complicated  mill.     With  such  a  mill, 
all  the  heavy  rolling  of  a  labora- 
tory could  be  done  without  the 
aid  of  an  assistant. 

The  thickness  of  the  plate  may 
be  determined  by  a  gauge  plate. 
That  which  is  to  serve  as  a  basis 
for  artificial  teeth  for  the  upper 
jaw  may  be  reduced  until  it  fits 
the  gauge  at  25,  26,  or  27,  ac- 
cording to  the  quality  of  the 
plate  and  the  depth  or  irregu- 
larity of  the  arch.  For  the  lower 


Fig.  919. 


Fig.  920. 


jaw,  and  for  backings  and  clasps,  it  may  range  from  21  to  24.  When 
the  whole  alveolar  border  and  a  portion  of  the  roof  of  the  mouth  is  to 
be  covered,  it  may  be  a  little  thinner  than  when  applied  only  to  a 
small  surface ;  also  thinner  when  the  arch  is  deep  or  irregular.  The 
purer  the  gold  is,  the  thicker  must  be  the  plate.  When  very  wide 
clasps,  too,  are  employed,  it  is  not  necessary  that  the  gold  should  be 
as  thick  as  is  required  for  narrow  ones ;  and  low  or  wide  backings 
need  not  be  so  thick  as  long  or  narrow  ones.  Lower  plates,  if  wired 
around  the  edge  or  doubled  over  the  middle  third,  may  be  made  of 
the  same  thickness  as  an  upper  plate.  But  these  are  matters  which  the 
judgment  of  the  dentist  alone  can  properly  determine,  and,  conse- 


826 


MECHANICS — DENTAL    PROSTHESIS. 


quently,  no  rules  can  be  laid  down  upon  this  subject  from  which  it 
will  not  sometimes  be  necessary  to  deviate. 

Gauge  plates  are,  unfortunately,  not  uniform.     For  many  years  the 
most  reliable  were  those  manufactured  by  Stubbs.     But  it  is  difficult 


Fig.  921. 

to  procure  them.  At  the  same  time  it  is  very  important  that  some 
standard  should  be  adopted  in  the  profession.  Under  these  circum- 
stances w^e  approve  the  suggestion  of  the  late  Dr.  S.  S.  White,  who 
recommended  the  gauge  plate  given  in  Fig.  921,  which  has  been 
adopted  by  the  principal  brass  manufacturers  of  this  country. 


Fig.  922. 


It  may  be  necessary  sometimes  to  make  gold  wire  for  spiral  springs 
or  other  purposes,  also  hollow-tube  wire.  A  draw  plate  (Fig.  922), 
strong  pliers,  and  a  bench  vise  (Fig.  923)  are  the  necessary  tools  for 


INGOT   MOLDS,    ROLLING   MILLS,    SOLDER. 


827 


this  purpose.  The  draw  plate  should  be  of  the  hardest  steel,  with 
the  holes  diminishing  very  gradually.  The  pliers  should  be  rough 
at  the  end,  for  grasping  the  wire,  which  must  be  often  annealed 
during  the  process. 

Tube  wire  may  be  obtained  from  the  jewelers,  by  whom  it  is 
known  as  joint  wire.  But  it  is  seldom  over  sixteen  carats  fine.  For 
use  in  the  mouth  it  should  be  not  less  than  twenty  carats ;  but  for 
many  purposes  pure  gold  or  platinum  tubing  is  better.  It  is  easily 
made  as  follows :  Take  a  small  strip  of  plate  one-fourth  of  an  inch 
wide,  one  or  two  inches  long  ;  slightly  taper  one  end ;  bend  it  around 
a  mandrel  or  common  knitting  needle,  and  pass  it  into  one  of  the 
larger  holes  of  the  draw  plate.  Then  with  the  pliers  draw  it  through 
and  repeat  until  the  edges  of  the  strip  meet.     Remove  the  mandrel 


Fig.  923. 

and  solder  the  seam  with  fine  gold  or  else  pure  gold.  Lastly,  select  a 
mandrel  or  needle,  the  size  of  the  required  tube,  and  draw  the  wire 
until  it  has  the  proper  thickness.  If  the  bore  is  to  be  smaller  than 
any  needle  at  hand,  the  last  drawing  may  be  done  without  the 
mandrel. 

The  simplest  method  of  winding  wire  into  a  spiral  spring  is  to 
secure  it  between  two  blocks  of  wood,  held  between  the  jaws  of  a 
small  bench  vise,  as  shown  in  Fig.  923.  The  upper  end  of  the  wire 
is  then  grasped  by  a  hand  vise  or  sliding  tongs,  in  connection  with  a 
spindle  or  steel  wire  the  size  of  a  small  knitting  needle,  six  or  eight 
inches  in  length.  The  spindle,  resting  on  the  blocks  of  wood,  is 
made  to  revolve,  and  by  this  movement  the  gold  wire  is  drawn 
through  the  blocks  and  wound  firmly  and  closely  round  the  steel  rod. 


828  MECHANICS — DENTAL    PROSTHESIS. 

GOLD    SOLDER. 

In  making  gold  solder,  the  materials  employed  for  the  purpose,  if 
not  pure,  should  be  refined  separately.  Unless  this  is  done,  it  will  be 
difificult,  and  often  impossible,  to  ascertain  their  relative  purity, 
which  should  be  known  to  insure  the  desired  result.  The  gold  is 
placed  in  a  clean  crucible  with  a  little  borax,  and  as  soon  as  it  has 
become  perfectly  melted  the  silver,  and  afterward  the  copper,  are 
added.  When  all  are  melted,  the  alloy  may  be  immediately  poured 
into  an  ingot  mold,  previously  warmed  and  oiled.  The  process  of 
hammering  and  rolling  the  solder  is  the  same  as  that  described  for 
gold  plate.  In  consequence  of  the  large  amount  of  alloy  in  solder, 
it  is  sometimes  so  stiff,  and  even  brittle,  as  to  be  with  great  difficulty 
rolled  ;  this  difficulty  is  increased  by  the  fact  that  its  low  fusibility 
makes  it  not  very  easy  to  anneal  without  melting.  This  is  especially 
the  case  with  solders  in  which  zinc  or  brass  is  used. 

In  making  solder  into  the  composition  of  which  zinc  enters,  the 
other  ingredients  must  be  thoroughly  melted,  then  the  zinc  (or  brass) 
introduced  at  the  last  moment,  rapidly  stirred,  and  the  metal  quickly 
poured.  A  piece  of  charcoal  will  be  found  better  for  making  small 
quantities  of  solder  than  a  crucible. 

The  solder  employed  for  uniting  the  various  parts  of  a  piece  of 
dental  mechanism  should  be  sufficiently  fine  to  prevent  it  from  being 
easily  acted  on  by  the  secretions  of  the  mouth. 

If  pure  gold  is  used,  the  solder  will  be  of  finer  quality  than  if 
twenty-two-carat  gold  is  used,  but  will  not  flow  quite  so  readily.  But 
twenty-two-carat  plate  may  be  used,  if  its  alloy  is  known,  by  making 
due  allowance  for  the  amount,  which  is  easily  calculated  by  use  of 
preceding  rules.  The  following  makes  a  solder  sixteen  carats  fine, 
and  may  be  used  for  eighteen-  or  twenty-carat  gold  plate  ;  it  flows 
very  freely :  — 

No.  I. — Pure  gold, 6  dwts. 

Fine  silver, I     " 

Roset  copper, 2     " 

By  adding  one  or  two  grains  of  zinc,  a  solder  may  be  made  that 
will  flow  at  a  lower  temperature  than  that  made  by  recipe  No.  i.  It 
will  also  have  a  finer  gold  color ;  but  it  is  apt  to  impart  to  the  piece 
a  brassy  taste,  and  for  this  reason  is  objectionable.  Zinc  solders  are 
apt  not  only  to  have  a  brassy  taste,  but  also  to  become  brittle  after 
long  use. 

The  following  formulas  will  give  solder  fourteen  carats  fine  ;  the 
first  from  Johnson  Bros.  :  — 


INGOT   MOLDS,    ROLLING   MILLS,    SOLDER.  829 


No.  I. 

Pure  silver, 2)A  dwts. 

"    copper, 20       grs. 

"    zinc, 35         " 


No.  2. 

American  gold  coin $10 

Pure  silver, 4  dwts. 

"    copper, ,    .  2     " 


The  following  formulas  from  the  American  System  of  Dentistry  are 
suitable  for  bridge-  and  crown-work,  and  are  twenty  carats  fine: — 

No.  I. 

American  gold  coin  (21. 6  carats  fine)  $10  piece, 258      grs. 

Spelter  solder  (composed  of  equal  parts  of  copper  and  zinc)    20.64  " 

No.  2. 
Pure  gold, 5  dwts. 

"     copper, 6  grs. 

"     silver, 12    " 

Spelter  solder, 6   " 

Dr.  D.  H.  Goodno's  formula,  which  is  said  to  give  a  gold  solder 
which  is  remarkably  tough,  flows  readily,  and  does  not  discolor  in  the 
mouth,  is  composed  of  the  following  alloy :  — 

Pure  gold, 40     grs. 

"     silver, 2^  " 

"     copper, 2^  " 

"     zinc, 2 

In  the  melting  process  the  zinc  is  rolled  in  gold  foil  and  placed  in 
the  crucible  and  covered  with  borax.  The  copper  and  silver  are  then 
added  and  also  covered  with  borax,  and  the  whole  melted.  To  use 
this  alloy  for  a  twenty-carat  plate,  5  dwts.  of  pure  gold  are  added  to 
I  dwt.  of  the  alloy;  for  eighteen-carat  plate,  5^^  dwts.  of  pure  gold 
to  i^  dwts.  of  the  alloy. 

The  following  formulas,  taken  from  Dr.  Richardson's  work  on 
"Mechanical  Dentistry,"  furnish  solders  (No.  4)  over  fifteen  carats 
fine,  and  (No.  5)  eighteen  carats  fine  : — 

No.  4.  I                                 No.  5. 

Gold  coin, 6  dwts.  Gold  coin, 30  parts. 

Silver, 30  grs.  Silver, 4     " 

Copper, 20    "  Copper, i     " 

Brass, 10    "  \      Brass, i     " 


Other  recipes  might  be  added,  but  the  foregoing  have  been  found 
with  us  to  answer  every  purpose.  More  difficulty  arises  in  the  use  of 
solders  from  a  wrong  method  of  soldering  than  from  defect  in  the 
solders  themselves.     Almost  every  dentist  will  be  found  to  have  his 


830 


MECHANICS — DENTAL    PROSTHESIS. 


favorite  recipe,  which  "  invariably  flows  smoothly."  The  very  fact 
that  so  many  hundred  different  solders  work  so  well  goes  far  to  prove 
what  we  have  said.  Some  will  boast  of  using  a  solder  as  fine  as  the 
plate.  This  may  be  true  if  by  "fineness"  we  mean  simply  carat 
valuation.  But  a  solder  containing  two  grains  of  zinc  to  the  dwt.  is 
in  no  true  sense  as  fine  as  a  plate  alloyed  with  that  amount  of  copper; 
yet  both  are  twenty-two  carat  metal.  Rules  for  the  management  of 
solder,  plate,  and  blowpipe,  in  the  act  of  soldering,  will  be  hereafter 
given. 


CHAPTER  VIII. 


CUPS   AND    MATERIALS   FOR   IMPRESSIONS   OF   THE    MOUTH- 
PLASTER   MODELS. 

In  the  construction  of  a  dental  substitute,  mounted  upon  a  plate  or 
base,  it  is  necessary  to  obtain  an  exact  model  of  the  parts  upon  which 
it  is  to  rest  and  to  which  it  is  to  be  attached.  For  this  purpose  a  per- 
fect impression  of  these  parts  must  be  obtained,  involving — first,  the 
choice  of  a  suitable  impression  cup  or  tray  ;  secondly,  the  selection 
of  an  impression  material. 

IMPRESSION    CUPS    OR    TRAYS 

must  be  of  such  size  and  shape  as  to  permit  their  easy  introduction 
into  the  mouth ;  also  they  must  follow,  as  nearly  as  possible,  the  out- 


FiG.  924. 


Fig.  925, 


line  of  the  surfaces  to  be  copied,  allowing  a  uniform  space  of  one- 
fourth  or  one-eighth  of  an   inch  for  the  material.     These  trays  are 


MATERIALS    FOR   IMPRESSIONS    OF   THE    MOUTH. 


831 


sometimes  called  mouth  cups ;  but  we  think  the  name  given,  and  now 
generally  used,  is  greatly  to  be  preferred.  They  are  of  two  kinds, 
metallic  and  gutta-percha. 

Metallic  trays  were  formerly  made  of  sheet  tin,  cut  into  shape  and 
soldered,  and  were  so  imperfect  that  it  was  very  often  necessary  to 
swage  metallic  trays  to  suit  special  cases.  The  depots  now  supply  an 
excellent  assortment  of  well-shaped  Britannia  impression  trays,  of  which 
sixteen  will  constitute  a  full  set ;  namely,  six  sizes  for  full  upper  cases, 
and  three  for  full  lower ;  three  sizes  for  partial  upper  cases  (in  these 


Fig.  926. 


Fig.  927. 


the  outer  rim  rises  at  a  right  angle),  and  four  for  partial  lower 
(these  trays  have  a  depression  or  a  place  cut  out  to  receive  the  front 
teeth). 

Figs.  924  and  925  illustrate  full  upper  and  lower  impression  trays. 

Figs.  926  and  927  illustrate  partial  upper  and  lower  impression  trays 
with  flat  bottom  and  square  sides. 

Figs.  928  and  929  illustrate  adjustable  impression  trays.  In  taking 
impressions  of  deep,  narrow  mouths,  or  where  a  masticating  tooth 
standing  alone  widens  the  jaw  at  a  particular  point,  it  is  sometimes 
desirable  to  be  able  to  readily  adjust  the  size  and  shape  of  the  tray 


8>2 


MECHANICS — DENTAL   PROSTHESIS. 


used.     Upper,  Fig.  928,  and  lower, 


Fig.  928. 

posterior  lingual  wings,  which  enable 
rate  impression  of  the  jaw 
on  either  side  of  the  tongue. 
These  wings  may  easily  be 
spread  apart,  or  brought  to- 
ward each  other,  or  twisted, 
or  cut  away  to  adapt  the  tray 
to  nearly  any  size  or  shape  of 
the  edentulous  lower  jaw. 

^^S-  933  represents  Dr. 
Franklin's  tray  for  full  lower 
impressions;  the  slot  and 
upper  groove  permit  second- 
ary pressure  of  the  wax  or 
plaster,  after  the  surplus  ma- 
terial is  forced  up,  as  it  is 
pressed  on  the  alveolus. 

"  This  tray,  or  rather  dou- 
ble tray,  has  a  groove  or  space 
in  its  center  all  the  way  round. 
The  advantages  of  this  groove 
are,  that,  when  the  lower  part 


Fig.  929,  impression  trays  have 
been  designed  to  meet  this 
want.  Either  of  these  can  be 
made  into  a  partial  tray  by 
cutting  off  one  side. 

Fig.  930  illustrates  South- 
wick's  upper  impression  tray 
with  raised  palatine  edges  to 
prevent  the  plaster  from  slip>- 
ping  off. 

Fig.  931  illustrates  a  partial 
lower  tray  with  an  opening  to 
allow  the  front  teeth  to  pass 
through  and  the  tray  to  pass 
down  to  the  ma.xillary  ridge. 
A  piece  of  wet  paper  is  placed 
over  the  opening  when  the 
tray  is  filled  with  the  plaster- 
batter. 

Fig.  932  illustrates  Dorr's 
lower  impression  tray  with 
the  operator  to  obtain  an  accu- 


FiG.  929. 


MATERIALS    FOR   IMPRESSIONS    OF   THE    MOUTH. 


833 


of  the  tray  is  filled,  and  the  upper  part  one-fourth  full  of  plaster,  and 
placed  in  position  over  the  ridge,  the  operator,  with  the  end  of  the 


Fig.  930. 


Fig.  931. 


finger  or  other  suitable  means,  can  gently  agitate  the  whole  mass  of 
plaster  in  the  tray,  and  thus  prevent  air-bubbles,  blanks,  or  other  im- 


FiG.  932. 


Fig.  933. 


perfections  on  the  surface  of  the  impressions.     The  peculiar  shape  of 
the  outer  flanges  of  this  tray  is  such  as  to  distend  the  cheeks,  while  the 
53 


SjJr  MECHANICS — DENTAL    PROSTHESIS. 

lower    inner  edges,  pressing  upon   the  submaxillary  and    sublingual 


Fig.  934. 

glands,  depress  them  sufficiently  to  prevent  any  fold  or  ligamentous 

attachments  from  being 
embraced  by  the  impres- 
sion. 

Fig.  934  represents  a 
tray  for  lower  molars  in 
partial  cases. 

Fig.  935  represents  the 
Wardle  tray,  which  is  sup- 
plied with  a  movable  pal- 
ate plate,  so  adjusted  that 
it  is  capable  of  forcing 
the  center  of  the  impres- 
sion material  against  the 
highest  part  of  the  arch, 
as  well  as  laterally  against 
the  palatal  sides  of  the 
necks  of  any  remaining 
teeth. 

Fig-  936  represents 
Fouke's  impression  tray, 
by  which  it  is  claimed  a 
correct  impression  in  all  variety  of  cases,  both  partial  and  full,  can  be 
obtained.     It  consists  of  a  metallic  portion  with  a  canvas  lining. 


Fig.  935- 


MATERIALS    FOR    IMPRESSIONS    OF    THE    MOUTH. 


83s 


The  design  of  the  tray  suggests  of  itself  the  manner  of  using  it; 
which  consists  of  the  ordinary  pressure  against  the  metallic  part  of 


Fig.  936. 


Fig.  937. 


836 


MECHANICS — DENTAL   PROSTHESIS. 


the  tray,  in  connection  with  a  proper  distribution  of  pressure  with  the 
fingers  and  compressing  instrument  A,  against  the  canvas  lining  of 
the  tray,  C  C  ;  the  latter  pressure  must  be  made  with  a  degree  of 
firmness  and  steadiness  sufficient  to  compress  thoroughly  all  parts  of 
the  mouth. 

Fig-  937  represents  Weirich's  flexible  rim  tray  to  retain  plaster 
that  may  break  away  from  outside  of  ridge,  and  enable  it  to  be 
replaced. 

Exceptional  cases,  which  no  form  of  purchased  tray  will  suit,  may 
require  a  swaged  brass,  zinc,  copper,  or  silver  tray;  or  a  tray  cast  out 
of  Britannia  metal,  or  other  tin  alloy.     The  process  of  swaging  will 
hereafter   be   described ;    also,    the   method   of 
molding  a  tray    from  a  pattern  of  wax.     Most 
of  these  cases,  however,  may  be  met  by  bending, 
hammering,   or   cutting   the  ordinary  Britannia 
tray ;  remembering  always  that  a  wise  economy 
never  hesitates  to  sacrifice  the  tray  to  secure  ex- 
cellence of  the  impression  or  the  saving  of  time. 
Without  this  adaptation  of  the  tray  to  the  form 
of  the  alveolar  ridge  and  palate  it  is  impossible, 
in  certain  mouths,  to  get  a  good  wax  or  gutta- 
percha impression.     Fig.  938  illustrates  a  partial  upper  tray  for  one 
or  two  teeth,  which  is  useful  in  pivoting  and  bridge-work. 
Figs.  939  and  940  illustrate  partial  upper  or  lower  trays. 
Trays  similar  in  shape  to  the  Britannia,  but  not  in  so  many  varieties 
of  size,  are  also  made  of  hard  rubber  and  porcelain.     The  first  cannot 
easily,  and  the  latter  cannot  at  all,  be  modified  in  shape  to  suit  special 


Fig.  938. 


Fig.  939. 


cases.  The  porcelain  trays  are  handsome  and  clean  looking,  but  they 
are  easily  broken ;  and  when  plaster  is  used,  it  will  sometimes  leave 
the  glazed  surface  and  cling  to  the  mouth.  We,  therefore,  prefer  the 
Britannia  tray,  unless  the  case  requires  Prof.  Austen's  gutta-percha 
tray. 

These  trays  were  originally  devised  to  meet  a  difficulty  incident  to 


MATERIALS    FOR    IMPRESSIONS    OF    THE    MOUTH. 


837 


Fig.  940. 


vulcanite  partial  pieces.  Perfect  impressions  of  dove-tailed  inter- 
dental spaces,  and  the  lingual  side  of  molars  and  bicuspids,  often 
undercut,  are  impossible  in  wax  or 
gutta-percha.  Yet  Prof.  A.  re- 
garded this  as  essential  to  the 
proper  construction  of  a  partial 
vulcanite  set  of  teeth. 

They  are  thus  made :  Take 
wax  impression  and  make 
model;  in  partial  cases,  brush  over 
the  teeth  of  the  model  one  or  two 
layers  of  thin  plaster,  to  fill  up  all 
undercuts,  and  to  make  the  plate 
fit  loosely ;  saturate  the  model  with  water,  and  mold  over  it  a  gutta- 
percha tray.  This  last  is  done,  not  by  using  the  gutta-percha  in  sheet, 
but  by  first  making  into  a  ball ;  then  working  it  from  the  palate  out- 
ward, leaving  a  thick  mass  in  the  center.  It  should  be,  on  the  inside, 
from  one-fourth  to  one-half  of  an  inch  thick,  so  as  to  be  stiff  and 
unyielding ;  but  on  the  outside  not  more  than  one-eighth  or  one- 
sixteenth  thick,  so  as  to  be  slightly  elastic  and  yielding.  The  whole 
inside  of  the  tray  must  be  roughened  up  with  a  scaler  or  excavator  in 
such  a  way  that  the  plaster  can  take  firm  hold.  In  most  partial  cases, 
the  impression  will  have  to  be  removed  in  sections;  the  inside 
remaining  entire,  but  the  outside  and  the  parts  between  the  teeth 
coming  away  separately.  In  certain  cases  it  is  necessary  to  partially 
cut  through  the  tray  before  putting  in  the  plaster,  and  usually  upon 
the  thick  masses  of  gum  which  fill  the  interdental  spaces.  A  cut  on 
the  inside,  in  line  with  the  ridge,  gives  pliancy  to  an  otherwise  rigid 
tray,  and  permits  its  easy  removal.  When  it  is  desirable  to  extend 
the  tray  around  the  entire  arch,  so  as  to  get  an  exact  plaster  impres- 
sion, not  only  of  the  gum  but  of  all  the  remaining  teeth,  this  rim  of 
gutta-percha  must  be  slit  at  two  or  three  points,  to  give  that  pliancy 
which  is  a  chief  merit  in  this  form  of  tray.  These  trays  have  no 
handle,  but  are  removed  by  inserting  a  plugging  instrument  into  a 
small  hole  previously  made  in  the  back  part  of  the  tray,  where  it  is 
thickest. 

IMPRESSION    MATERIALS 

Must  possess  the  following  properties :  (i)  Plasticity  in  sufficient 
degree  to  copy  mucous  tissues,  avoiding  the  extremes  of  softness, 
which  permits  them  to  flow  from  the  tray,  and  of  hardness,  which 
requires  excessive  pressure.  (2)  The  property  of  hardening  within 
a  short  time,  and  under  conditions  not  incompatible  with  the  mouth. 
(3)  Absence  of  expansion  or  contraction,  except  in   very  moderate 


«3o  MECHANICS — DENTAL    PROSTHESIS. 

degree.  It  may  also  be  added  that  the  materials  should  not  be  such  as, 
in  taste,  smell,  or  appearance,  are  calculated  to  disgust  the  patient. 

There  are  four  materials  answering  to  these  requirements,  and  pos- 
sessing properties  as  distinctive  as  the  sources  whence  they  are  derived. 
From  the  Animal  kingdom.  Beeswax  ;  from  the  Vegetable  kingdom, 
Gutta-Percha  and  Modeling  Composition  ;  from  the  Mineral 
kingdom,  Plaster.  After  their  separate  description,  a  brief  review  of 
their  distinctive  properties  will  be  given.  No  one  of  the  four  can  be 
dispensed  with ;  no  one  should  be  exclusively  used. 

Beeswax. — Formerly  the  only  material  used,  and  is  yet  very  useful 
for  certain  cases,  and  is  absolutely  indispensable  for  other  dental  pur- 
poses. The  best  wax  is  from  virgin  combs,  and  has  a  rich  golden 
color.  Commercial  adulterations  with  tallow,  etc.,  injure  it,  and 
mixture  with  resin  makes  it  harsh  and  difficult  to  manage.  Gutta- 
percha is  sometimes  incorporated  with  it  to  give  hardness  in  warm 
weather;  bleached  or  white  wax  is  also  used  for  the  same  purpose. 

A  very  valuable  addition  is  paraffine.  Pure  paraffine  is  very  plastic, 
softening  at  a  low  temperature  (ioo°)  ;  but  the  folds  of  soft  paraffine 
have  no  tendency  to  reunite,  and  consequently  the  mass  is  full  of  easily 
separated  flakes  or  layers.  It  imparts  this  property  to  wax,  if  in  too 
large  proportion  ;  but  its  moderate  use  greatly  improves  the  wax.  It 
causes  it  to  soften  at  lower  heat,  makes  it  more  plastic  when  warm,  and 
harder  when  cool. 

The  depots  furnish  wax  and  its  compounds  in  very  pure,  neat,  and 
convenient  forms;  so  that  there  is  now  little  necessity  for  the  dentist 
to  spend  the  time  once  demanded  to  reduce  the  thick  cakes  into 
serviceable  shape.  It  may  be  well,  however,  to  state  briefly  how  to 
prepare  wax  for  impressions.  Melt  and  pour  into  cakes  one-quarter 
of  an  inch  thick ;  cut  into  pieces  about  two  inches  square ;  and  when 
nearly  cold  roll  on  a  wet  board,  with  a  wet  wooden  roller,  to  one-half 
or  one  fourth  this  thickness.  This  breaks  down  the  crystallization, 
and  reduces  it  to  a  form  very  convenient  for  softening  when  wanted 
for  use.  It  may  be  softened  over  a  broad  flame,  or  before  a  fire  or 
stove,  or  in  warm  water.  In  using  dry  heat  be  careful  not  to  melt  the 
surface,  or  give  the  peculiar  whitish  appearance  that  precedes  melting. 
In  using  water,  have  a  large  quantity,  to  secure  uniformity  of  tem- 
])erature,  and  keep  it  at  i2o°-i3o°  Fahrenheit.  Below  this  it  will 
not  yield  readily  to  the  gum  ;  above  this  it  becomes  adhesive. 

Some  ])ractice  is  necessary  in  knowing  the  proper  quantity  of  wax 
to  use  in  the  tray  ;  the  usual  mistake  is  to  take  too  much.  Select  a 
tray  of  proper  shape  and  size;  if  the  arch  is  a  deep  one,  put  some 
hard  wax  or  gutta-percha  in  the  center  to  force  up  the  wax  at  that 
point.     This  is  much  better  than  to  have  a  hole  in  the  tray  through 


MATERIALS    FOR    IMPRESSIONS    OF    THE    MOUTH.  839 

which  to  make  pressure  with  the  finger.  Such  trays  are  worse  than 
useless,  for  it  is  impossible  to  make  secondary  pressure  without  injury 
to  other  parts  of  the  impression,  except  in  case  of  wax  projecting 
above  the  tray,  outside  the  ridge.  Put  the  wax  in  the  tray ;  smooth 
the  surface,  which  should  be  a  little  softer  than  the  body  of  the  wax ; 
then  introduce  and  press  against  the  gums  or  teeth  with  a  steady, 
uniform,  and  moderately  strong  pressure ;  also,  as  nearly  as  possible, 
in  a  direction  at  right  angles  to  the  plane  of  the  alveolar  ridge. 

The  wax  above  the  tray  is  pressed  against  the  gums  on  each  side,  so 
that  an  exact  impression  may  be  obtained  of  all  the  depressions  and 
prominences  on  the  outside  of  the  arch.  But  this  must  be  done  with 
great  care,  holding  the  tray  firmly  and  pressing  the  finger  against  the 
cheek  or  lip,  rather  than  directly  upon  the  wax.  It  is  much  better  in 
all  cases  to  have  the  sides  of  the  tray  high  enough  to  give  the  wax 
support  at  all  points.  For  this  purpose,  it  becomes  necessary  some- 
times to  swage  or  cast  a  special  tray.  Very  perfect  wax  impressions 
can  be  taken  in  such  trays.  On  the  removal  of  the  trays  and  wax  from 
the  mouth,  the  greatest  precaution  is  necessary  to  prevent  injuring  or 
altering  the  shape  of  the  impression.  Holding  the  handle  firmly,  it 
must  be  drawn  directly  downward,  in  case  there  are  front  teeth,  in 
the  direction  of  the  axes  of  these  teeth.  Impressions  of  a  full  upper 
arch  sometimes  adhere  very  tightly.  They  can  generally  be  loosened 
by  drawing  up  the  cheek  and  lip  on  one  side  or  both  sides  alter- 
nately ;  or  by  a  slight  cough,  which,  acting  upon  the  palate,  admits 
air  behind  and  above  the  impression.  Any  violence  or  twisting 
motion  injures  the  impression ;  in  wax  or  gutta-percha  such  defects 
cannot  be  detected  until,  on  completion  of  the  plate,  maladjustment 
creates  suspicion  of  its  cause.  The  wax  must  be  kept  in  the  mouth 
long  enough  to  cool  and  harden.  A  small  piece  of  ice  in  a  napkin, 
held  against  the  under  side  of  the  tray,  will  rapidly  harden  it.  This 
simple  plan  is  preferable  to  the  use  of  double  trays,  into  which  a 
stream  of  cold  water  is  injected.  The  latter  are  not  only  expensive 
and  troublesome  to  use,  but  they  endanger  the  accuracy  of  the  im- 
pression. All  wax  impressions,  unless  for  models  on  which  other  trays 
are  to  be  made,  should  be  hardened  by  artificial  cold  ;  it  greatly  helps 
to  prevent  change  of  shape  on  withdrawal.  If  the  surplus  wax,  by 
contact  with  the  lips  or  teeth,  injures  the  impression,  then,  if  it  is  a  full 
case,  cut  off  the  surplus,  dip  into  warm  water,  and  introduce  the  same 
impression  a  second  time  ;  but  if  it  is  a  partial  case,  it  must  be  taken 
anew,  for  the  teeth  cannot,  with  any  accuracy,  enter  their  wax  im- 
pressions. 

Gutta-Percha. — This  very  valuable  material  will  be  found  useful  in 
taking  impressions  of  the  lower  jaw  and  in  some  partial  cases,  also 


840  MECHANICS — DENTAL   PROSTHESIS. 

frequently  in  full  upper  cases  where  the  teeth  are  set  on  a  vulcanite 
base.  The  manipulations  are  different,  accordingly  as  we  wish  to 
make  the  gutta-percha  adhere  to  the  tray,  or  wish  it  to  part  from  the 
sides  of  the  tray  as  it  shrinks  on  cooling.  In  the  first  case,  soften  in 
water  heated  to  i8o°-2oo°  Fahrenheit;  dry  off  the  water;  hold  for  a 
few  moments  over  a  flame,  and  press  into  a  warm  tray ;  keep  the  fin- 
gers wet,  to  prevent  the  gutta-percha  from  sticking,  but  do  not  let 
water  get  between  it  and  the  tray.  In  the  second  case,  keep  the 
surface  of  the  gum  wet,  and  introduce  it  into  a  cold  and  wet  tray. 
When  the  tray  is  filled,  place  again  in  water  at  180°;  then  press  it 
somewhat  into  shape,  and  introduce  into  the  mouth.  Pressure  must 
be  more  gentle  than  for  wax  ;  it  must  be  kept  longer  in  the  mouth, 
and  ice  should  be  used  to  cool  it.  Be  very  careful,  in  partial  cases 
where  there  is  much  undercut  or  a  dovetail  space  between  teeth,  not 
to  make  the  gutta-percha  too  hard,  else  it  will  be  almost  impossible  to 
get  it  out  of  the  mouth. 

Gutta-percha  copies  surfaces  with  all  the  accuracy  of  plaster,  but, 
although  harder  than  wax,  it  is  more  apt  than  plaster  to  change  its 
shape  upon  withdrawing  it  from  the  mouth.  Its  characteristic 
peculiarity  is  contraction  on  cooling ;  but  this  is  controlled,  when 
required,  by  the  directions  above  given  for  making  it  adhere  to  the 
tray.  It  is  less  easily  manipulated  than  wax,  and  not  so  generally  use- 
ful;  but  its  property  of  contraction  admirably  adapts  it  to  certain 
cases  in  which  plates,  otherwise  accurate,  fail,  because  too  large  and 
loose. 

Gutta-percha  for  impressions  is  supplied  in  convenient  form  by  the 
depots.  The  native  color  is  dark,  and  calculated  to  repel  fastidious 
patients.  For  this  reason,  also  to  give  it  body,  it  is  incorporated  with 
about  its  own  weight  of  white  oxid  of  zinc,  magnesia,  or  chalk,  and 
a  pinkish  color  given  by  vermilion.  Thus  prepared,  it  is  less  sticky 
when  softened,  and  becomes  harder,  when  cool,  than  the  crude 
article. 

Modeling  Composition  or  Compound  is  composed  of  gum  dammar, 
stearine,  French  chalk,  with  carmine  to  color  it,  and  a  perfume  to 
render  it  pleasant.  Four  varieties  are  manufactured — the  soft,  the 
medium,  the  hard,  and  the  extra  soft,  differing  as  to  the  quantity  of 
stearine  and  chalk  incorporated  with  the  gum.  Modeling  composi- 
tion is  an  excellent  material  for  impressions,  as  it  copies  very  accu- 
rately and  affords  a  smooth  model.  The  best  manner  of  using  it  is  to 
soften  this  material  in  boiling  water  contained  in  a  shallow  vessel. 
When  it  is  thoroughly  softened,  and  not  too  hot  to  handle,  the  tray 
for  its  reception  should  be  slightly  warmed,  into  which,  after  drying 
with  a  cloth,  it  is  introduced  in  the  same  manner  as  wax.     After  it  is 


MATERIALS    FOR    IMPRESSIONS   OF   THE   MOUTH.  84I 

applied  to  the  mouth,  it  is  allowed  to  cool  somewhat,  after  being  pressed 
around  the  outside  of  the  alveolar  ridge. 

The  same  care  is  necessary  in  removing  it  from  the  mouth  as  with 
wax,  and  it  should  be  immersed  in  cold  water  at  once,  to  harden  it. 
Before  pouring  the  plaster  the  impression  should  be  dipped  in  cold 
water.  To  remove  an  impression  of  this  material  from  the  plaster 
model,  both  are  immersed  in  boiling  water,  where  they  should  remain 
until  the  compound  becomes  soft,  but  not  adhesive,  when  it  is  easily 
separated  from  the  model. 

Plaster — Gypsum,  Sulphate  of  Lime,  or  Plaster-of-Paris — consists  qf 
28  parts  lime,  40  of  sulphuric  acid,  and  18  of  water;  the  first  its 
mineralogical  name,  the  second  its  chemical,  the  third  its  commercial. 
A  beautiful  translucent  variety  of  gypsum  is  known  as  alabaster ;  the 
transparent  crystalline  variety  is  called  selenite.  That,  however,  used 
in  agriculture  and  for  calcining  is  in  amorphous  masses  of  a  grayish  or 
bluish-white  color.  When  exposed  to  a  heat  between  300°  and  400° 
Fahrenheit,  most  of  the  water  of  the  gypsum  escapes.  It  is  then 
known  as  calcined  plaster,  plaster-of-Paris,  or  simply  plaster.  After 
being  properly  calcined  and  pulverized,  if  mixed  wdth  water  to  the 
consistence  of  thin  batter  or  cream,  it  hardens  in  a  few  minutes,  and 
acquires  great  solidity.  The  plaster  has  chemically  reunited  with  a 
portion  of  the  water,  while  another  portion  is  mechanically  held  in  the 
porous  mass,  and  may  be  driven  off  by  drying.  During  the  process  of 
consolidation  it  expands,  in  consequence  of  the  absorption  of  the 
water  by  the  particles  of  plaster.  If  the  plaster  is  very  fine-grained, 
this  absorption  takes  place  quickly,  and  the  expansion  occurs  while 
the  plaster  is  soft.  But  coarse-grained  plaster  sets  before  the  particles 
become  thoroughly  saturated  ;  hence  it  continues  to  expand,  more  or 
less,  for  some  time  after  solidification.  There  is  a  great  difference  in 
the  quality  of  plaster.  That  used  for  taking  impressions  of  the  mouth 
(and,  in  fact,  for  all  dental  purposes)  should  be  of  the  best  description, 
well  calcined,  finely  pulverized,  and  passed  through  a  sieve  of  bolting 
cloth  previous  to  being  used.  The  idea  of  taking  impressions  for 
full  sets  of  teeth  with  plaster  originated,  we  believe,  almost  simul- 
taneously with  Drs.  Westcott,  Dunning,  and  Bridges,  by  whom  and 
the  profession  generally  it  was  regarded  as  adapted  almost  exclusively  to 
full  impressions.  Prof.  Austen,  however,  introduced  a  method  of  using 
it  in  connection  with  gutta-percha  trays,  which  makes  it,  in  the  hands 
of  a  careful  manipulator,  universally  applicable  to  every  case  in  which 
a  dental  appliance  is  called  for.  He  would,  however,  by  no  means 
recommend  such  universal  application,  claiming  only  that  the  gutta- 
percha tray  will  give  with  plaster  a  correct  impression  of  partial  cases 
of  greatest  irregularity,  where  the  use  of  wax  or  gutta-percha  would  be 


842  MECHANICS DENTAL    PROSTHESIS. 

impossible.  A  composition  of  plaster-of- Paris,  white  sand,  sulphate  of 
potash,  and  Venetian  red,  a  formula  suggested  by  Dr.  Teague,  forms 
an  excellent  impression  material. 

For  plaster  impressions  in  ordinary  full  cases,  upper  and  lower,  select 
a  Britannia  tray,  about  one-eighth  of  an  inch  larger  than  the  alveolar 
ridge,  and,  in  case  of  a  deep  upper  arch,  build  up  with  wax,  so  as  to 
give  support  to  the  soft  plaster ;  also  supply  with  wax  any  deficiency 
in  the  size  of  the  tray  at  the  back  part  or  around  the  outside  edge.  In 
exceptional  cases  requiring  a  special  tray,  a  gutta-percha  one  will  be 
found  to  be  much  easier  made  than  a  swaged  or  cast  metallic  tray.  If 
properly  shaped,  it  will  fully  answer  the  purpose. 

The  late  Dr.  J.  B.  Bean's  practice  was  to  take  a  wax  impression, 
make  model  and  dies,  and  swage  a  plate  ;  then  solder  a  strip  from 
ridge  to  ridge,  to  hold  a  stick,  which  was  to  act  as  a  handle  in  remov- 
ing the  impression.  He  then  heated  the  plate,  and  coated  the  palatine 
surface  with  shellac,  pressing  a  lump  of  raw  cotton  against  the  adhesive 
resin.  The  cotton  fibers  caused  the  plaster  to  adhere  firmly  to  the 
plate,  thus  avoiding  the  great  annoyance  when  scales  of  plaster,  so  thin 
as  in  this  kind  of  tray,  break  off.  The  process  is  troublesome,  but  the 
results  are  very  satisfactory. 

To  take  a  plaster  impression,  place  a  patient  in  a  common  chair, 
and  after  the  tray  is  introduced,  incline  the  head  forward,  holding  it  in 
place  with  a  gentle  but  steady  pressure  upon  the  center  of  the  tray. 
The  plaster  should  be  very  fine-grained  and  mixed  rather  thin,  to  get 
rid  of  air  bubbles.  If  necessary,  a  little  salt  or  a  few  grains  of  sulphate 
of  potash  should  be  added,  to  quicken  slow-setting  plaster.  The  neces- 
sity for  salt  and  quantity  to  be  used  should  not  be  left  to  conjecture; 
hence  the  importance  of  setting  aside  in  a  well-closed  vessel  a  quantity 
of  "impression  plaster."  Also,  if  the  plaster  is  '"slow,"  set  aside  a 
large  bottle  of  salt  water  of  the  exact  strength  required  to  make  the 
plaster  set  properly.  There  will,  in  this  way,  be  no  danger  of  the 
plaster  setting  too  quickly  or  too  slowly.  If  made  to  set  too  rapidly, 
it  hurries  the  operator  and  increases  the  risk  of  failure  ;  if  it  sets  too 
slowly,  both  patient  and  operator  become  wearied  before  it  is  hard 
enough  to  remove.  Tepid  water  promotes  the  setting  of  plaster.  It 
should  require  about  three  minutes  to  harden  after  it  is  introduced  into 
the  mouth,  which  must  be  done  when  it  is  stiff  enough  to  allow  the 
plaster  to  be  molded  into  some  shape,  and  yet  soft  enough  to  permit 
no  sharp  points  or  angles  on  its  surface.  If  softer  than  this,  the  slightest 
pressure  forces  it  out  of  the  tray  to  run  sometimes  out  of  the  mouth, 
sometimes  on  the  tongue  and  fauces.  This  also  is  apt  to  occur  if  an 
excess  of  plaster  is  used.  These  unnecessary  accidents  are  well  calculated 
to  prejudice  patients  against  plaster,  and,  perhaps,  against  the  operator. 


MATERIALS    FOR    IMPRESSIONS    OF    THE    MOUTH.  843 

The  hardness  of  plaster  in  the  mouth  can  be  ascertained  by  the 
watch,  when  the  exact  time  required  for  setting  is  known,  or  by  testing 
some  of  the  plaster  remaining  in  the  bowl.  As  soon  as  it  breaks  with 
a  sharp  fracture,  it  should  be  removed.  To  keep  it  in  much  longer 
than  this  is  apt  to  give  unnecessary  pain  and  difficulty  in  removal, 
owing  to  the  absorbing  property  of  the  hardened  plaster,  which  causes 
it  to  cling  with  great  tenacity  to  the  mucous  membrane. 

Full  lower  impressions  are  generally  easy  to  withdraw  ;  but  some  full 
upper  ones  adhere  very  tenaciously.  Raising  the  cheek  on  one  side  or 
in  front,  and  depressing  the  tray,  will  detach  most  cases.  This  can  be 
done,  in  case  of  plaster,  without  risk  of  injuring  the  shape  of  the  im- 
pression. If  this  does  not  loosen  it  the  patient  may  be  requested  to 
give  a  slight  cough.  Where  there  is  much  undercut,  the  plaster  will 
break ;  but  it  can  readily  be  replaced.  Sometimes  the  action  of  the 
cheeks  and  lips,  or  of  the  soft  palate,  will  loosen  the  impression  ;  or 
an  instrument  may  be  used  to  press  up  the  palate,  and  thus  cause  air  to 
pass  in  at  the  back,  when  it  may  be  easily  removed.  Complicated 
modifications  of  the  tray  to  facilitate  removal  are  of  little  value,  and 
make  an  unnecessary  multiplicity  of  apparatus. 

In  partial  cases,  the  outer  rim  (which  for  this  purpose  is  made  elastic, 
or  else  in  sections)  is  first  detached,  and  the  central  portion  then 
loosened  by  an  instrument  inserted  into  the  back  part  of  the  gutta- 
percha cap.  If  there  should  be  many  broken,  detached  fragments, 
either  loose  or  caught  in  dovetail  spaces  between  the  teeth,  these  must 
be  very  carefully  removed ;  and  when  the  surface  moisture  has  dried 
off,  they  must,  with  the  utmost  nicety,  be  replaced  in  the  impression. 
This  is  sometimes  a  tedious  and  difficult  operation  ;  but  it  is  not  trouble 
misapplied,  since  it  is  the  only  way  in  which  perfect  impressions  of 
difficult  partial  cases  can  be  obtained.  Should  the  detached  plaster  be 
from  a  very  irregular  surface,  its  readjustment  is  made  much  easier  by 
touching  the  gutta-percha  at  that  point  with  a  camel's-hair  brush 
dipped  in  very  hot  water.  The  fragments  being  all  adjusted  and  the 
outside  ones  secured  by  a  little  resinous  cement,  should  there  be  much 
broken  surface  on  the  inside,  it  is  best  to  varnish  heavily  with  sand- 
arach  to  cement  the  pieces ;  otherwise,  let  the  surface  be  prepared,  as 
in  full  sets,  for  preventing  the  plaster  of  the  model  from  adhering. 

Wax  and  gutta-percha  require  nothing  for  this  purpose,  or,  at  most, 
a  very  thin  layer  of  oil.  Plaster  impressions  may  be  rendered  separ- 
able :  I,  by  an  alcoholic  varnish  of  sandarach  or  shellac,  or  a  diluted 
solution  of  soluble  glass,  with  a  little  oil  upon  the  varnished  surface 
when  dry;  2,  by  saturating  it  with  as  much  oil  as  it  will  take  up  with- 
out standing  upon  its  surface  ;  3,  by  coating  the  surface  with  a  dilute 
soap  mixture.     The  varnish  may  be  either  transparent  or  colored  ;  the 


844  MECHANICS — DENTAL   PROSTHESIS. 

transparent  varnish  consists  of  gum  sandarach,  5V ;  alcohol,  Oij ;  the 
colored  varnish  consists  of  the  same  proportions  of  gum  shellac  and 
alcohol.  The  gum  is  added  to  the  alcohol  and  digested  over  a  moder- 
ate heat  until  it  is  dissolved.  The  varnish  is  best  applied  with  a  small 
bristle  brush  ;  the  oil  and  soap  water  with  a  camel's-hair  brush  or  a 
stiff,  pointed  feather.  The  varnish  must  be  kept  well  stopped,  or  from 
time  to  time  diluted,  so  as  not  to  become  thick.  The  soap  mixture 
needs,  occasionally,  renewal,  as  the  plaster  gradually  neutralizes  its  oil 
and  renders  it  unfit  for  use. 

Some  dentists  take  plaster  impressions,  in  certain  cases,  thus :  First, 
a  wax  impression,  as  usual ;  then  enlarge,  by  pressure,  or  by  cutting 
out  the  depressions  formed  by  teeth  or  a  prominent  alveolar  ridge  ; 
lastly,  they  pour  in  a  thin  layer  of  plaster,  and  repeat  the  impression. 
Others  surround  certain  teeth  with  a  collar  of  wax,  preparatory  to  tak- 
ing a  plaster  impression. 

The  last  is  a  troublesome  method,  very  apt  to  fail,  from  the  slipping 
of  the  wax  collars ;  nor  has  it  any  superiority  over  a  wax  impression, 
to  compensate  the  trouble.  Dr.  C.  J.  Essig  suggests  the  following 
method  for  securing  a  plastic  impression  for  partial  cases:  "An  im- 
pression should  first  be  selected  of  the  proper  size  and  shape  ;  those 
with  the  flat  floor  are  best  for  partial  cases  ;  the  plaster  should  be  mixed 
thin,  almost  as  thin  as  water,  adding  chlorid  of  soda  to  facilitate 
setting.  Plaster  mixed  in  this  manner  does  not  become  hard  and  un- 
yielding as  that  mixed  merely  to  saturation.  Now  oil  the  tray  so  that 
it  will  readily  separate  from  the  impression  when  hard,  fill  the  tray  as 
soon  as  the  plaster  thickens  sufficiently,  then,  with  a  small  spatula, 
place  a  layer  of  the  soft  plaster  in  upon  the  palatine  surface ;  other- 
wise by  enclosing  the  air  in  the  deep  portion  of  the  arch  the  accuracy 
of  the  impression  may  be  impaired.  After  this  precaution  the  tray  is 
placed  in  the  mouth,  and  gently  pressed  up  until  its  floor  comes  in 
contact  with  the  teeth.  When  the  plaster  is  sufficiently  hardened, 
remove  the  tray,  which,  from  its  having  been  oiled,  is  done  without 
difficulty ;  with  the  thumb  and  index  finger  break  off  the  outside 
walls ;  the  portion  covering  the  palatine  surface  is  then  removed  by  the 
use  of  a  blunt  steel  spatula,  curved  at  the  end  in  the  form  of  a  hook. 
The  pieces  are  then  placed  back  into  the  tray,  where  they  will  be  found 
to  articulate  with  perfect  accuracy.  Should  the  first  attempt  be  ren- 
dered futile,  by  the  tendency  to  nausea  or  troublesome  gagging  on  the 
part  of  the  patient,  camphor  water,  as  recommended  by  Dr.  Louis 
Jack,  may  be  used  as  a  gargle,  which  will,  in  nearly  every  case,  prove 
an  effectual  remedy." 

The  comparative  value  of  the  four  impression  materials — wax,  gutta- 
percha, modeling  composition,  plaster — can  only  be  determined  by  a 


MATERIALS    FOR    IMPRESSIONS    OF    THE    MOUTH.  845 

careful  study  of  (i)  their  distinctive  peculiarities;  (2)  the  special  re- 
quirements of  different  mouths  ;  (3)  the  kind  of  base-plate  and  man- 
ner of  its  construction.  The  exclusive  use  of  one  is  as  reprehensible 
as  the  indiscriminate  use  of  all.  No  one  is  best,  nor  can  any  be  dis- 
pensed with.  Disregard  of  this  most  important  fact  is  a  fruitful  source 
of  failure  in  impressions ;  failures  arising  neither  from  defect  in  the 
material  nor  lack  of  skillful  manipulation  in  the  operator,  but  from 
want  of  philosophical  selection  of  resources. 

(i)  Wax  demands  strong  pressure  and  is  inelastic;  also,  it  neither 
expands  nor  contracts  on  cooling.  It  copies  a  hard  gum  accurately, 
although  it  never  gives  the  fine  tracery  of  gutta-percha,  modeling  com- 
position, or  plaster.  It  also  copies  a  soft  gum,  but  not  until  the  gum 
js  either  compressed  or  thrown  out  of  shape  by  the  strong  pressure  re- 
quired. Gutta-percha  requires  moderate  pressure  ;  is  slightly  elastic  ; 
also  has,  as  its  marked  peculiarity,  very  decided  contraction  on  cool- 
ing, which,  however,  is  under  control,  as  previously  explained.  Slight 
undercuts  it  will  take,  without  dragging,  as  wax  does;  but,  on  the 
other  hand,  it  will  occasionally  pass  into  very  narrow  interdental 
spaces  and  injure  the  impression  in  the  effort  to  withdraw  therefrom. 
Modeling  Compositioti  ranks  next  to  plaster  as  an  impression  material, 
and  when  thoroughly  softened  in  boiling  water,  and  when  not  too  hot 
to  handle,  will  give  an  accurate  impression  under  strong  pressure  and 
a  much  finer  tracery  than  wax.  Plaster  permits  only  gentle  pressure, 
taking  impressions  of  softest  tissues  in  natural  position.  It  slightly  ex- 
pands in  setting ;  but,  in  a  rigid  tray,  this  makes  no  appreciable  in- 
crease in  the  size  of  the  model.  It  sets  so  hard  that  it  will  break  before 
leaving  the  smallest  undercut ;  but,  by  virtue  of  the  same  quality,  it 
can  be  used  in  the  most  marked  cases  of  dovetail,  or  alveolar  undercut. 

(2)  Alveolar  and  palatine  surfaces,  and  their  investing  membranes, 
have  a  great  variety  of  conditions.  These  must  be  carefully  examined 
with  reference  to  the  properties,  just  named,  of  the  impression  mate- 
rials. We  have  large  or  small  arches  ;  deep  or  flat  ones  ;  irregular  or 
smooth  ridges.  The  mucous  surfaces  may  be  uniformly  hard  or  soft ; 
the  ridge  hard  and  palate  soft ;  or  the  more  difficult  combination  of 
soft  ridge  and  hard  palate ;  or  the  ridge  may  be  irregularly  hard  and 
soft.  No  one  material  can  possibly  be  equal  to  these  varying  condi- 
tions. 

(3)  The  mode  of  constructing  the  plate  will  often  determine  the 
choice  of  an  impression  material.  A  plate  swaged  upon  a  zinc  die  is 
smaller  by  the  shrinkage  of  the  die.  Here — apart  from  shape  or  hard- 
ness of  the  parts — plaster  would  be  best,  wax  next,  gutta-percha  the 
worst.  A  vulcanite  plate  is  larger  than  the  mouth,  by  the  expansion  of 
the  model.     Here,  the  contraction  of  gutta-percha  will  often  prove  a 


846  MECHANICS — DENTAL   PROSTHESIS. 

very  valuable  compensation  ;  also  the  compression  of  tissue  made  by 
the  pressure  of  wax ;  special  considerations  must  determine  which  of 
these  to  choose.  Plaster  is  the  most  reliable  impression  material  as  a 
general  rule,  and  is  the  only  material  in  difficult  cases  worthy  of  any 
reliance.  It  may  safely  be  asserted  that  the  operator  who  cannot  take 
an  accurate  plaster  impression  of  any  partial  case,  however  difficult, 
has  a  very  imperfect  idea  of  the  value  of  hard  rubber.  For  the  majority 
of  partial  cases,  where  swaged  work  is  used,  modeling  composition, 
or  wax,  if  properly  manipulated,  will  give  ample  accuracy.  Where, 
however,  the  undercut,  and  consequent  dragging  of  wax,  is  very  great, 
plaster  must  be  employed. 

Large,  or  hard,  or  irregular  mouths  are  best  copied  in  plaster,  great 
deviations  from  normal  size  or  shape  requiring  special  trays.  A  gum 
of  medium  softness,  but  uniform,  may  be  taken  equally  well  in  any 
material.  This  class  of  mouths  have  a  wonderful  adaptation  to  any- 
thing. Variations  in  size  or  form  must  determine  the  selection  of  the 
material.  A  gum  of  extreme  softness,  yet  uniform,  will  give  better 
results  sometimes  with  one  material,  sometimes  with  another.  It  is 
often  very  difficult  to  determine  beforehand  ;  but,  in  case  of  failure, 
let  the  second  impression  be  taken  always  with  a  different  material. 
This  is  especially  true  of  lower  sets,  where  the  gum  behind  is  soft  and 
flexible;  it  is  hard  to  say  whether  the  pressure  of  wax,  or  modeling 
composition,  or  the  softness  of  plaster  leaves  the  ridge  in  best  condi- 
tion ;  gutta-percha  is  often  very  useful  in  these  cases. 

Irregularity  of  texture  in  the  mucous  tissues  is  a  fruitful  source  of 
trouble.  A  hard  ridge,  with  a  soft  palatine  surface,  is  easily  fitted, 
and  any  impression  material  may  be  used.  But  the  reverse  condition 
will  often  require  the  firm  pressure  of  wax  or  modeling  composition 
upon  the  ridge  ;  also  in  all  cases  of  inequality  of  texture  in  the  ridge 
itself.  As  a  rule,  subject  to  exceptions,  a  harder  impression  material 
than  plaster  is  the  best  for  these  mouths,  and  occasionally  (especially 
for  vulcanite)  the  contraction  of  gutta-percha  is  useful ;  and  scraping 
the  model  for  a  vulcanite  plate,  and  building  on  a  thin  film  of  wax  for 
a  metal  plate  over  the  hard  portions,  is  often  serviceable  in  securing 
adaptation.  For  vulcanite  plates,  the  model  may  be  scraped  slightly 
on  either  side  of  the  hard  palatal  center. 

For  metal  plates,  a  thin  film  of  wax,  about  -^^  of  an  inch  in  thick- 
ness, is  built  along  the  entire  hard  palate,  terminating  in  thin  edges, 
the  space  to  be  thus  covered  varying  according  to  the  width  of  the 
mouth.  The  model  should  also  be  slightly  scraped  at  the  posterior 
edge  of  the  surface  to  be  thus  covered  by  the  plate  on  each  side  of  the 
hard  portion  of  the  palate,  so  that  the  plate  may  be  closely  adapted  at 
such  points. 


PLASTER    MODELS.  847 

It  is  evident  that  an  enumeration  of  all  the  complications  which 
call  for  exercise  of  judgment  in  the  selection  of  impression  materials 
is  impossible.  By  suggesting  a  few  varieties,  we  hope  to  direct  atten- 
tion to  a  much  neglected  point,  in  our  judgment  of  utmost  importance. 
Routine  practice,  which  inquires  into  the  reason  of  nothing,  and  the 
one-idea  system,  with  its  "  practice  makes  perfect  "  motto,  are  equally 
at  fault.  The  future  may  reveal  some  new  material ;  but  the  four  we 
now  have  are  alike  important  and  indispensable. 

PLASTER    MODELS. 

The  model  is  made  of  calcined  plaster,  mixed  vvith  water  so  as  to 
have  the  consistence  of  cream,  too  much  water  making  the  model 
fragile,  whilst  too  little  will  prevent  the  escape  of  the  air  contained  in 
the  plaster,  and  the  model  will  be  porous.  This  last  condition  also 
greatly  endangers  the  full  flowing  of  the  plaster  into  the  inequalities 
of  the  impression. 

The  model,  for  convenience  of  description,  is  said  to  have  a  face, 
back,  body,  and  sides — terms  scarcely  requiring  explanation.  The 
face,  corresponding  with  the  mouth  to  be  fitted,  requires  greatest  care; 
and  the  same  directions  answer  for  it  in  all  models.  The  body  of  the 
model  has  different  shape  and  size  according  to  the  use  to  be  made  of 
it.  The  back  should  be,  in  all  cases,  parallel  with  the  face.  The  sides 
are  to  be  either  vertical  or  slanting,  according  to  its  uses. 

In  making  models,  we  require  a  plaster  table,  with  a  rim  to  prevent 
scattering  of  waste  plaster,  having  at  least  two  drawers  in  front,  a 
shelf  at  the  back,  also  an  opening  for  escape  of  waste  plaster  into  a 
refuse  box;  a  tight  plaster-can  and  a  bucket  of  water  will  complete  the 
outfit  of  the  table.  The  implements  are  two  or  three  strong  bowls,  a 
plaster  scoop,  a  spatula,  an  iron  spoon,  a  plaster  knife,  a  scraper,  a 
sponge,  and  some  camel' s-hair  brushes  or  wing-feathers  of  poultry. 
Sometimes  a  marble  slab  or  slate  is  used  for  shaping  the  back  of  the 
model  upon  ;  but  if  the  table  is  kept  clean  and  smooth  with  the  scraper, 
this  is  not  essential ;  since,  in  any  case,  a  piece  of  wet  paper  should 
be  laid  down  to  permit  the  ready  removal  of  the  model,  for  the  pur- 
pose of  shaping,  whilst  yet  rather  soft. 

The  most  troublesome  models  are  the  thick  ones  for  sand  molding. 
The  surface  of  the  impression  being  prepared  as  above  directed,  the 
tray  is  surrounded  with  a  rim  of  wax,  waxed  cloth,  sheet  lead,  or  tin 
foil,  fitting  closely,  to  prevent  escape  of  plaster,  and  about  two  inches 
deep.  The  rims  should  be  slightly  curved,  to  give,  when  placed 
around  the  trays  the  requisite  flare.  Models  made  in  such  rims  need 
trimming  with  the  knife.  To  avoid  this,  and  also  to  give  greatest 
possible  smoothness  and  regularity  to  the  sides,  flaring  rings  of  sheet 


848 


MECHANICS — DENTAL    PROSTHESIS. 


tin  may  be  used  as  follows  :  Set  the  impression  level  on  the  table,  and 
surround  with  some  soft,  plastic  material,  such  as  potter's  clay  (wet 
newspaper  made  into  a  pulpy  mass  is  perhaps  the  most  convenient), 
and  into  this  set  a  ring  of  such  size  as  will  give  a  proper  shoulder  to 
the  model.  Fig.  941  shows  such  a  ring  arranged  for  making  such  a 
model  for  plastic  work,  such  as  vulcanizable  rubber,  the  models  for 
which  need  not  be  very  deep.  For  a  sand  model  the  ring  should  flare, 
should  conform  more  to  the  shape  of  the  tray,  and  be  smaller.  For  the 
dipping  process  of  making  counter-dies  and  dies,  the  model  needs  no 
specially  nice  trimming.  For  the  fusible-metal  process,  the  model 
should  be  cylindrical  and  not  flaring.  These  are  the  three  forms  of 
thick  or  deep  models. 

The  shallow  models  are  usually  made  without  rims.    The  impression 


Fig.  941. 

is  filled,  then  turned  down,  when  the  plaster  has  set  sufficiently  to  per- 
mit it,  on  the  remaining  plaster,  which  has  been  poured  on  a  strip  of 
wet  paper  placed  on  a  smooth,  flat  surface.  Whilst  plastic  it  is  shaped 
with  the  spatula.  If  for  vulcanite  or  other  plastic  work,  it  may  be 
taken  up  while  soft  enough  to  dress  with  a  sponge.  But  if  the  shallow 
model  is  to  be  used  in  sand  molding  or  in  Dr.  Gunning's  process,  it 
is  allowed  to  harden  and  is  then  trimmed  with  the  knife.  In  vulcan- 
ite models  it  will  save  time  and  insure  greater  accuracy  in  articulation 
to  extend  the  model  at  once  and  make  the  articulating  portion,  if  no 
metallic  articulating  frame  is  to  be  employed,  as  will  be  fully  explained 
when  describing  the  process  of  articulation.     The  sides  of  vulcanite 


PLASTER    MODELS.  849 

models  need  no  shaping  except  such  as  neatness  and  convenience  in 
handling  require,  since  they  are  subsequently  set  into  the  flask ;  but 
they  should  be  no  larger  or  thicker  than  strength  requires. 

When  rims  are  used,  the  impression  should  rest  upon  the  plaster 
table  ;  if  set  level,  the  back  will  necessarily  be  parallel  with  the  face, 
since  the  thin  plaster  poured  into  the  rim  finds  its  level.  In  making 
shallow  models  the  impression  is  held  in  the  hand,  thus  permitting 
the  flow  of  the  plaster  to  be  aided  by  moving  or  tapping  it.  As  before 
stated,  wax  or  gutta-percha  needs  no  oiling ;  plaster  may  be  oiled  or 
soaped,  or  else  varnished  and  oiled ;  it  must  also  be  saturated  with 
water  just  before  pouring  the  model. 

Calcined  plaster  for  models  should  not  set  too  rapidly,  as  this  will 
cause  haste  with  its  attendant  dangers.  Coarse  plaster  makes  a 
stronger  model,  but  it  has  greater  expansion.  Gum-water,  or  size, 
retards  the  setting,  but  makes  the  model  very  hard  ;  salt  quickens  the 
setting,  but  should  not  be  used  for  any  models  which  are  to  be  kept 


Fig.  942.  Fig.  943. 


as  permanent  records  of  the  case.  It  is  better  to  add  the  plaster  to 
the  water  than  the  reverse  ;  it  makes  smoother  work  by  permitting 
the  escape  of  the  air  ;  it  also,  by  the  amount  of  unsaturated  plaster, 
permits  the  operator  to  gauge  the  stiffness  of  the  batter. 

In  all  cases  the  face  of  the  model  is  the  part  first  made.  The  thin 
freshly-mixed  plaster  is  first  to  be  carefully  run  into  the  depressions 
of  the  teeth  or  their  ridges.  A  brush  or  feather  is  necessary  when  the 
tray  is  stationary;  when  in  the  hand,  motion  or  tapping  or  jarring 
•  will  cause  the  plaster  to  flow  as  desired.  Perhaps  the  surest  way  to 
prevent  defects  on  the  face,  from  confined  air,  is  to  have  a  little  sur- 
plus water  in  the  tray.  The  plaster  (which  in  this  case  must  not  be 
too  thin)  settles  at  once  into  the  smallest  crevice  under  the  water,  and 
if  not  stirred,  it  will  not  be  made  thin  and  rotten  by  it;  or  the 
plaster-batter  may  force  the  water  before  it  until  the  latter  escapes  at 
the  heel  of  the  impression. 

The  impression  once  filled,  the  formation  of  the  body  is  easy.     For 
54 


850  MECHANICS DENTAL    PROSTHESIS. 

deep  models,  the  remaining  plaster  should  be  poured  at  once,  that, 
while  thin,  it  may  form  a  smooth  and  level  back.  For  shallow  models 
the  plaster  must  slightly  stiffen,  lest  the  weight  of  the  impression 
should  make  it  settle  too  much  into  the  plaster  on  the  table.  The 
sponge  is  very  useful  in  dressing  up  a  model ;  it  cuts  more  or  less 
according  to  the  state  of  the  plaster.  It  may  be  used  to  trim  vulcan- 
ite models  directly  after  the  spatula,  or  to  give  finish  to  other  models 
after  the  use  of  the  knife.  But  when  plaster  is  fully  hardened  it  has 
no  effect. 

Figs.  942  and  943  represent  upper  and    lower  models  suitable  for 
sand  molding;    the  same  may  be  used  for  dipping.      Fig.  944  rep- 
resents  a  shallow  model  in    the  molding  flask, 
y  T      showing  how  the  body  of  the  die  is  formed  by 
^^^^  the  zinc  half  of  the  flask.     The  same  figure  may 

t^^^~^^^~^^^^\       be  taken  to  represent    the  position   of  the  thin 
{  '\  Ij      model  at  the  bottom  of  an  iron  tray,  in  the  pro- 

\\|       '    '       Ij         cess  of  making  the  counter-die  by  Dr.  Gunning's 
method. 

Fig.  944. 

Difficulties  arising  from  undercuts,  on  the  out- 
side of  the  upper  ridge  and  on  the  inside  of  the  lower,  may  be  over- 
come :  (i)  by  filling  up  the  undercut  with  wax  or  plaster  in  all  places 
where  it  is  unnecessary  or  impracticable  to  carry  the  metallic  plate  ; 
(2)  by  using  a  peculiarly-constructed  flask  for  molding,  such  as  the 
one  invented  by  Dr.  G.  E.  Hawes  (Figs.  950-952)  ;  (3)  by  filling  the 
undercut  with  movable  pieces  of  plaster,  technically  known  as  "  false 
cores."  They  should  be  so  shaped  as  to  admit  of  being  drawn  from 
the  sand ;  at  the  same  time  they  must  have  a  decided  angle,  so  as  to 
mark  distinctly  the  place  in  the  sand  for  their  replacement.  A  small 
nail  or  tack  in  the  sand,  above  the  core,  will  keep  it  in  place  while  the 
metal  is  being  poured.  (4)  By  making  a  sectional  model  (Fig.  945), 
as  suggested  by  Dr.  A.  Westcott.  It  may  be  made  by  filling  the  cen- 
tral third  of  the  wax  impression  with  the  plaster,  keeping  it  from  the 
lateral  thirds  by  a  temporary  use  of  clay  or  putty.  This  is  removed 
and  trimmed,  leaving  the  back  wider  than  the  face  (Fig.  945)  ;  then 
replaced  in  the  impression  and  filled  up  on  each  side  with  plaster;  the 
model  is  then  removed,  properly  trimmed,  and  varnished. 

Dr.  Bean's  method  of  making  a  model  in  two  parts  is  equally  appli- 
cable to  making  models  in  three  parts,  and  is  perhaps  better  than  the 
foregoing.  He  thus  described  it :  "  To  secure  a  division  in  the  model 
itself,  the  best  plan  is  to  set  up  in  the  impression  a  septum  of  thin 
sheet  lead,  forming  a  vertical  plane  in  the  median  line  of  the  palate, 
and  fitted  somewhat  to  the  inequalities  of  the  impression.  This  plate 
should  have  two  or  three  small  projections  struck  up  on  one  side,  by 


PLASTER   MODELS. 


851 


means  of  a  small  conical  punch,  and  the  opposite  side  has  some  cotton 
fiber  attached  with  shellac,  in  the  manner  described  for  preparing 
impression  trays.  Fig.  946  represents  the  shape  of  this  plate  (one-half 
the  size),  and  shows  the  side  on  which  are  the  projections.  Its  proper 
position  will  be  readily  understood  when  applied  to  an  impression  of 
one  of  those  deep  palates  now  under  consideration.  The  side  having 
the  projections  is  oiled,  the  cotton  on  the  other  side  wet  with  water, 
and  while  filling  up  the  impression,  this  plate  is  set  up  in  the  middle, 
along  the  median  line,  so  that  when  the  model  is  trimmed  to  proper 
size  and  shape,  it  may  be  carefully  broken  apart  and  placed  together 
again  in  the  same  position." 

Much  time  may  be  wasted  in  the  effort  to  overcome  difficulties  of 
undercut  in  sand  molding.  The  dexterous  removal  of  shallow  models 
will  suffice  for  most  cases  of  front  undercut ;  and  of  all  others,  it  may 


Fig.  945. 


Fig.  946. 


be  said  that  no  undercut  on  the  die  is  of  any  service  into  which  the 
plate  cannot  be  swaged,  or  in  removal  from  which  the  plate  is  apt  to 
be  bent. 

Removing  the  impression  is  a  fruitful  source  of  vexation,  because  of 
the  frequent  breaking  of  prominent  parts  of  the  model  and  other 
annoying  accidents.  But  these  are  in  every  case  the  result  of  haste, 
carelessness,  or  forgetfulness.  First,  the  model  must  have  time  to 
harden  ;  then  the  impression,  if  of  wax  or  gutta-percha,  must  be  thor- 
oughly softened.  The  common  practice  of  setting  the  model  on  the 
stove  is  bad ;  the  smell  of  burning  wax  is  often  the  first  warning  of  a 
softening  which  has  gone  too  far,  injuring  the  model  by  the  absorp- 
tion of  melted  wax.  It  is  far  better  to  place  it  in  water  at  140°  and 
150°  Fahrenheit,  leaving  it  long  enough  for  the  entire  mass  of  wax  to 


852  MECHANICS — DENTAL    PROSTHESIS. 

soften  ;  at  this  temperature  the  wax  does  not  melt,  yet  is  so  soft  that  it 
cannot  injure  the  most  delicate  point  of  the  model.  If  over  150°, 
some  portions  may  adhere  to  the  model  and  give  trouble  in  removing. 
Gutta-percha  impressions  must  be  thoroughly  softened  in  water  at 
200°;  if  over  this  temperature,  portions  of  gutta-percha  are  apt  to 
adhere  to  the  surface.  In  partial  cases  it  is  a  good  plan  to  first  remove 
the  tray,  then  turn  up  the  edges  of  softened  wax  or  gutta-percha,  till 
it  is  free  from  the  teeth,  and  then  remove  the  entire  mass. 

Plaster  impressions  require  a  different  treatment.  If  the  tray  is 
wholly  or  partly  of  wax  or  gutta-percha,  these  must  first  be  softened 
and  removed  ;  a  Britannia  tray  is  loosened  by  light  strokes  of  the 
plaster  knife  handle.  The  impression  is  then  broken  away  piecemeal. 
Dipping  it  in  hot  water  makes  it  rotten,  and  facilitates,  at  times,  its 
removal.  It  is  often  necessary  to  cut  nearly  through  the  impression 
in  places,  in  doing  which  the  knife  or  graver  must  be  held  so  as  to 
guard  against  injury  to  the  model  beneath.  Another  safeguard  is  to 
coat  the  impression,  before  pouring,  with  oil  colored  by  alkanet ;  or, 
better  still,  to  tinge  the  plaster  with  which  the  impression  is  taken 
with  vermilion  or  Brandon  red  ;  it  gives  the  dry  plaster  a  faint  pinkish 
tinge;  does  not,  in  this  small  proportion,  injure  its  setting  qualities; 
and  it  makes  a  very  distinct  contrast  with  the  pure  white  of  the 
model. 

Few  impressions  can  be  used  twice ;  those  taken  in  wax  or  gutta- 
percha trays,  never.  Partial  impressions  of  all  kinds  are  necessarily 
sacrificed  to  the  integrity  of  the  first  model.  But  plaster  impressions, 
in  a  smooth  Britannia  tray,  may,  with  proper  care,  be  replaced  in  the 
tray,  and  used  again  so  as  to  give  a  model  quite  equal  to  the  first. 
Some  of  these  will  come  from  the  model  entire ;  but  often  it  is  neces- 
sary to  cut  a  groove  over  the  alveolus,  and  break  off  the  outer  rim  in 
two  or  three  sections. 

Models  may  be  partly  trimmed  before  removing  the  impression,  but 
it  is  always  necessary  afterward  to  trim  the  shoulder.  Usually  this  is 
done  by  merely  taking  off  the  rough  edges,  following  the  outline  of  the 
edge  of  the  impression  ;  but  for  striking  up  a  plate  with  the  outer  edge 
turned  up,  a  flange,  or  shoulder,  about  the  fourth  of  an  inch  wide,  is 
formed  around  the  outside  of  the  plaster  model,  where  it  is  designed 
that  the  edge  of  the  base  plate  shall  terminate  on  the  alveolar  border. 
It  may  be  shaped  either  in  wax  or  plaster,  and  should  stand  off  from 
the  ridge  at  an  angle  of  about  90°  or  100°,  the  angle  of  the  rim  being 
completed  with  pliers  after  swaging.  A  plate  swaged  with  such  a  rim 
is  used  in  mounting  gum  or  block  teeth  and  in  continuous  gum  work  ; 
it  is  stronger  than  a  simple  plate,  and  is  susce])tible  of  a  more  beautiful 
finish.     For  a  lower  set  of  block  teeth  the  edge  of  the  plate  may  also 


PLASTER    MODELS.  853 

be  turned  up  all  the  way  round.  An  objection  to  a  swaged  rim  is  the 
occasional  diificulty  of  determining  just  how  far  over  the  ridge  the 
plate  should  extend  ;  for  any  change  is  impossible  without  destroying 
the  rim.  Hence  the  more  common  practice,  except  in  continuous  gum 
work,  is  to  solder  a  gold  band  or  wire,  after  adaptation  of  the  plate  to 
the  mouth,  as  hereafter  explained. 

The  model,  if  it  is  to  be  used  in  sand  molding,  should  have  several 
coats  of  shellac  or  sandarach  varnish  applied  with  a  small  bristle  brush, 
to  give  it  a  smooth,  hard,  and  polished  surface.  This  will  protect  it 
from  injury  by  use,  render  it  more  pleasant  to  handle,  and  cause  the 
sand  to  part  easily  from  it.  The  gum  shellac  varnish  may  be  prepared 
by  dissolving  five  ounces  of  shellac  in  one  quart  of  alcohol.  In  using 
this  varnish  on  a  damp  impression,  be  careful  not  to  apply  a  second 
coat  until  the  first  is  hard,  else  it  will  cause  the  first  to  peel  and  injure 
the  smoothness  of  the  surface.  Sandarach  varnish  is  preferable  to 
shellac,  as  it  is  harder;  it  is  also  more  transparent,  and,  consequently, 
does  not  color  the  plaster.  It  may  be  made  in  the  following  manner : 
Take  six  ounces  of  gum-sandarach,  one  ounce  of  elemi ;  digest  in  one 
quart  of  alcohol,  moderately  warm,  until  dissolved  ;  or  the  sandarach 
alone  may  be  used.  This  is,  perhaps,  as  good  a  varnish  as  can  be  used 
for  plaster  models.  It  is  easily  prepared,  but  the  alcohol  should  be 
warmed  in  a  sand  bath  or  hot  water,  t©  prevent  it  from  taking  fire. 
To  make  the  finest  varnish,  the  sandarach  should  be  of  best  quality, 
and  washed  in  water  before  being  put  into  the  alcohol.  Some,  how- 
ever, prefer  a  coating  of  charcoal  dust  or  plumbago  or  powdered  soap- 
stone  for  sand  models. 

Models  for  dipping  or  pouring,  or  the  fusible-metal  process,  should 
have  no  kind  of  varnish  upon  them.  Vulcanite  and  other  plastic  work 
models  may  have  a  protecting  coat  of  dilute  soluble  glass  (nine  parts 
water  to  one  part  of  the  glacial  syrup) ;  but  if  too  much  or  too  strong 
a  solution  is  used,  it  will  do  more  harm  than  good.  No  shellac  or 
sandarach  varnish  should  be  applied  to  plaster  models  for  either  vul- 
canite or  celluloid  work. 

For  the  preparation  of  the  surface  of  the  plaster  model  to  overcome 
the  difficulty  resulting  from  a  hard  ridge  or  prominence  in  the  center 
of  the  palatal  portion,  the  reader  is  referred  to  page  846. 


854  MECHANICS — DENTAL    PROSTHESIS. 

CHAPTER  IX. 

DIES  AND  COUNTER-DIES— SWAGING  PLATES. 

Various  methods  have  been  adopted  for  procuring  metallic  dies  and 
counter-dies.  The  three  following  are  all  which  the  author  deems  it 
necessary  to  describe.  The  first  of  these  consists  in  pouring  melted 
metal  into  a  mold  or  matrix,  made  in  sand  with  the  plaster  model.  By 
this  means  the  die  is  formed,  and  the  counter-die  is  obtained  by  pour- 
ing metal  upon  it.  The  second  consists  in  making  the  counter-die 
first,  either  by  immersing  the  plaster  model  in  metal  or  pouring  metal 
upon  it ;  the  die  is  formed  by  pouring  metal  into  this. 

The  third  consists  in  pouring  the  metal  for  the  metallic  die  directly 
into  the  impression.  A  very  ingenious  set  of  flasks  for  this  purpose, 
the  invention  of  Dr.  F.  Y.  Clark,  can  be  had  at  the  dental  depots. 
The  same  may  be  done,  less  conveniently,  perhaps,  with  the  usual 
Britannia  trays  and  molding  rings.  Take  a  piece  of  copper  or  brass 
gauze,  and  fit  into  the  tray  before  taking  the  impression.  Set  the  im- 
pression, thus  strengthened,  into  a  batter  (asbestos  or  sand  three  parts, 
plaster  one  part),  poured  into  a  narrow  iron  ring  (sheet  iron  will  an- 
swer) ;  carefully  work  the  batter  around  the  edges  of  the  impression ; 
then  place  upon  it  the  zinc-molding  half  of  a  Bailey  flask  (Fig.  947). 
If  the  impression  is  thoroughly  dried,  the  first  metal- 
lic die  will  be  perfect,  no  matter  how  much  under- 
cut there  may  be.  A  second  or  third  may  then  be 
taken,  more  or  less  defective,  but  very  useful  for  the 
first  stages  of  the  swaging  process.  Zinc  is  the 
metal  used  by  Dr.  Clark  for  the  die.     In  this  pro- 

FlG.  947.  ^  ^ 

cess  the  impression  may  be  plaster  or  plaster  and 
feldspar ;  but  the  investing  batter  should  have  only  enough  plaster  to 
bind  the  asbestos  or  sand  together.  Dr.  Clark  uses  a  copper  impres- 
sion tray,  which  Prof.  Austen's  process  dispenses  with.  The  flask  and 
impression  must  be  perfectly  dry,  and  heated  nearly  or  quite  up  to  the 
fusion  point  of  the  metal  used. 

The  second  method  admits  of  three  modifications:  i.  The ///j-/*^/^- 
/w^/^/ process ;  in  which  the  model  is  surrounded  with  thick  paper, 
and  fusible  metal  in  a  semi-fluid  state  is  dashed  over  it  with  a  spoon, 
the  model  being  cold,  so  as  to  rapidly  chill  the  metal.  While  still 
warm,  the  paper  is  removed  and  the  counter-die  trimmed  with  a  knife  ; 
for  at  this  temperature  it  can  be  cut  as  readily  as  cheese.  The  counter- 
die,  when  cold,  is  then  smoked  or  coated  with  whiting,  surrounded 
with  paper,  and  semifluid  fusible  metal  dashed  on  it,  to  make  the  die. 


DIES    AND    COUNTER-DIES.  855 

This  process  is  repeated  until  from  two  to  six  dies  are  made,  according 
to  the  irregularity  of  the  case.  The  model  should  be  in  a  ring  of 
nearly  circular  shape  and  cylindrical ;  it  should  also  be  at  least  half  an 
inch  larger  than  the  alveolar  ridge,  that  the  counter-die  may  have 
sufficient  metal  to  force  up  the  plate. 

2.  The  dipping  -^xoce?,?,  consists  in  pouring  melted  lead,  type-metal, 
or  pewter  into  a  sheet- or  cast-iron  cup  or  box,  three  and  a  half  or  four 
inches  in  diameter  and  three  or  four  inches  deep,  until  it  is  more  than 
half  full  ;  then,  stirring  the  fluid  mass  with  gradually  increasing  rapidity 
until  it  begins  to  granulate,  quickly  brush  off  the  surface  dross,  and  at 
once  immerse  the  plaster  model  more  or  less  deeply,  as  the  palate  is  a 
deep  or  shallow  one,  and  hold  it  there  until  the  metal  congeals.  To 
prevent  accident  from  air  confined  in  the  palatine  arch,  a  small  hole 
may  be  drilled  through  the  plaster  model.  It  is  then  removed,  and 
the  whole  upper  surface  of  the  counter-die  covered  with  a  thin  coating 
of  whiting  or  lamp  smoke,  as  before  directed.  After  this  has  become 
perfectly  dry,  melted  block  tin,  type  metal,  or  soft  solder,  at  a  temper- 
ature so  low  that  it  will  not  char,  or  even  discolor  white  paper,  is 
poured  in,  until  the  cup  is  filled.  If  the  counter-die  is  so  deep  that 
the  die  has  not  sufficient  thickness,  it  may  be  deepened  by  placing  on 
the  freshly  poured  metal  the  zinc  half  of  a  Bailey  flask,  and  continuing 
to  pour ;  the  metal  in  the  two  flasks  will  unite  and  form  one  die. 
When  cold,  the  castings  are  removed  from  the  iron  cup,  separated,  and 
are  then  ready  for  use. 

3.  Dr.  Gunning's  method,  called  also  the  "pouring  process,"  in 
which  a  very  thin  model  (made  of  plaster  two  parts  and  sand  or  feld- 
spar one  part)  is  placed  in  the  bottom  of  an  iron  box,  three  and  a 
half  to  four  inches  in  diameter  and  about  two  inches  deep.  It  is 
fastened  there  by  a  thin  layer  of  plaster  and  sand,  then  thoroughly 
dried  by  gradually  raising  box  and  all  to  the  temperature  of  the  melted 
metal,  which  is  next  poured  in,  and  the  box  set  in  a  shallow  vessel  of 
water  to  cool  it  rapidly  from  the  outside.  To  delay  the  cooling  in  the 
center  until  the  last  moment,  and  to  prevent  contraction  at  that  place, 
a  very  hot  pointed  iron,  somewhat  similar  in  shape  and  size  to  a 
tinner's  soldering  iron,  is  placed  upon  the  center  of  the  model  before 
the  metal  is  poured.  When  cold,  this  is  removed  and  the  conical 
space  filled  with  metal.  The  counter-die  is  thus  made  of  lead,  alloyed 
with  tin  or  type  metal.  The  die  is  made  by  placing  over  this  a  stout 
wrought  iron  ring  and  pouring  in  fusible  metal.  Dr.  Gunning  uses 
from  three  to  eight  dies,  according  to  the  sharpness  of  the  prominences 
of  the  model.  The  method  gives,  in  his  hands,  very  accurately  fitting 
plates. 

When  metallic  dies  are  to  be  obtained  by  the  first  method,  molding 


856  MECHANICS — DENTAL    PROSTHESIS. 

flasks  and  sand  are  required.  Flasks  may  be  of  wood  or  iron.  The 
molding  box  of  wood  should  be  about  six  inches  square.  This  is  to 
be  filled  with  fine  sand,  such  as  is  used  by  brass  founders,  in  the  follow- 
ing manner  :  The  deep  or  shallow  plaster  model  is  placed  on  the 
molding  table,  exactly  in  the  center  of  the  box,  with  its  face  upward. 
Sand  is  then  firmly  packed  around  the  sides  of  the  model.  Sand 
should  then  be  sifted,  covering  the  face  of  the  model  to  the  depth  of 
half  an  inch,  the  box  then  filled,  and  the  whole  rammed  with  a  firmness 
proportioned  to  the  coarseness  or  dryness  of  the  sand — damp  or  very 
fine  or  strong  (/.  <?.,  with  large  percentage  of  clay)  sand  not  permitting 
so  much  compression  as  sand  possessing  the  opposite  qualities,  because 
it  would  become  too  compact  to  permit  the  escape  of  the  vapors 
formed  during  the  process  of  pouring.  But  the  finest  sand,  rich  in 
clay  and  quite  moist,  may  be  used  if  it  is  dried  before  pouring.  Sand 
mixed  with  olive  or  sweet  oil  possesses  some  advantages  over  that 
mixed  with  water,  as  it  can  be  used  a  number  of  times  without  re- 
mixing, prevents  the  bubbling  common  to  sand  made  too  moist  with 
water.  .  The  sand  should  never  be  burned  by  pouring  on  it  very  hot 
metal ;  hence  it  is  better  to  stir  the  metal  until  it  has  cooled  somewhat 
before  pouring  it  into  the  mold.  The  metal  should  not  be  injured  by 
overheating.     Cooling  the  die  suddenly  in  water  renders  it  brittle. 

The  box  is  then  turned  over  and  gently  tapped  several  times 
with  some  light  instrument  or  hammer,  for  the  purpose  of  starting 
or  detaching  it  a  little  from  the  matrix,  and  then  carefully  removed. 
Great  care  is  necessary  that  this  tapping  does  not  depress  first  one 
side  and  then  the  other ;  this  would  make  the  die  too  deep  in  the 
center,  and  perhaps  cause  the  plate  to  rock.  The  model  may  be 
loosened  laterally,  by  holding  an  excavator  firmly  upon  the  center  of 
the  die  and  tapping  it  on  the  side.  If  the  model  be  composed  of 
three  pieces,  the  middle  section  is  first  removed,  and  afterward  the 
two  others.  There  are  two  ways  of  drawing  the  model :  first,  by 
screwing  into  it  an  excavator  or  gimlet,  and  carefully  drawing  it  out ; 
second,  by  throwing  it  out  with  a  dexterous  jerk  of  the  matrix.  The 
last  is  best ;  the  excavator  is  apt  to  break  through  the  center  of  the 
thin  model,  and  the  thick  one  falls  out  by  its  own  weight  better  than 
it  can  be  drawn.  Fig.  948  represents  the  two  ends  of  a  double  spatula, 
which  will  be  found  very  useful  in  sand  molding. 

If  the  deep  model  is  used,  the  matrix  is  now  ready  for  pouring ; 
but  first  remove  all  loose  sand,  and  make  a  groove  at  the  back  part  of 
the  matrix  to  receive  the  first  flow  of  the  metal.  If  the  thin  model 
is  used,  a  ring  must  be  set  upon  the  sand  after  the  model  is  drawn,  to 
give  the  additional  size  which  the  die  requires  to  prevent  cracking 
under  the  swaging-hammer. 


DIES    AND    COUNTER-DIES. 


857 


The  mold  being  prepared,  the  metal  to  be  employed  for  the  casting 
should  be  put  into  a  tolerably  thick  wrought  or  cast-iron  ladle  and 
melted  in  a  common  fire  or  furnace.  Mr.  Fletcher  has  invented  a  very 
useful  melting  apparatus,  which  is  also  suitable  for  drying  and  boiling 
purposes.  If  brass  is  used,  a  blast  furnace  will  be  required  to  melt  it ; 
but  if  zinc,  block-tin,  or  lead,  a  common  fire  will  afford  sufficient 
heat.     As  soon  as  the  metal  has  become  thoroughly  melted  it  is  poured 


Fig.  948. 

into  the  furrow  formed  in  the  sand,  whence  it  will  flow  into  the  back 
part  of  the  mold.  It  is  necessary  to  convey  the  melted  metal  into 
the  mold  in  this  way  to  prevent  the  injury  which  the  surface  of  the 
sand  might  sustain  by  pouring  directly  upon  it. 

There  have  been  quite  a  number  of  molding  flasks  devised  to  super- 
sede the  wooden  one  just  described  or  the  common  cart-wheel  box, 
which  was  once  much  used.  Some  of  these  are  worse  than  useless; 
others  are  very  convenient,  and  have  the  advantage  of  requiring  only 


Fig.  949. 

a  small  quantity  of  sand ;  also  of  permitting  the  sand  to  be  dried, 
which  cannot  well  be  done  in  the  wooden  box.  The  simplest  and 
perhaps  best  flask  is  that  invented  by  Dr.  E.  N.  Bailey.  Fig.  949 
represents  the  shape  and  working  of  this  flask. 

Half-flask  sis  placed,  joint-edge  downward,  over  a  thin  model,  and 
firmly  packed  with  sand.  It  is  then  turned ;  the  sand  compressed 
around  the  edge  of  the  model  ;  then  trimmed,  so  that  the  model  may 
be  easily  drawn  (a  properly  shaped  model  renders  much  sand  trim- 


858 


MECHANICS — DENTAL    PROSTHESIS. 


ming  unnecessary)  ;  the  model  is  then  lightly  tapped  and  thrown  out. 
All  operations  on  the  thin  model  must  be  conducted  with  great  care,  for 
it  is  easily  displaced  in  its  matrix,  so  as  to  destroy  the  accuracy  of  the 
latter.  Next,  pour  zinc  into  the  mold,  and  at  once  place  on  half 
flask  A,  and  complete  the  pouring.  When  cool,  remove  the  sand, 
invert  the  flask,  with  zinc  die  contained,  and  pour  the  lead  (c)  upon 
the  zinc  for  the  counter-die. 

In  cases  of  moderate  undercut  in  front,  the  thin  model  can  gen- 
erally be  drawn  by  a  dexterous  backward  movement.  But  for  a 
deeper  undercut  in  front,  also  for  those  at  the  side,  the  molding 
flask  of  Dr.  Hawes  (Figs.  950,  951,  952)  will  be  found  useful.  In 
Fig.  950  the  lower  section  of  the  flask  is  slightly  opened  to  show 
joints.  In  Fig.  952  the  upper  section.  In  Fig.  951  the  lower  sec- 
tion is  closed  and  confined  by  a  pin,  with  the  plaster  model  placed 
in  it. 


Fig.  950. 


Fig.  951. 


Fig.  952. 


The  manner  of  using  is  thus  described  by  Dr.  C.  C.  Allen  :  "If 
the  model  be  considerably  smaller  than  the  space  between  the  flanges 
projecting  inward,  small  slips  of  paper  may  be  placed  in  the  joint, 
extending  to  the  sides  of  the  model,  so  as  to  part  the  sand  when  open- 
ing the  flask  for  the  removal  of  the  pattern.  The  sand  may  now  be 
packed  around  the  model  up  to  the  most  prominent  part  of  the  ridge. 
It  should  be  finished  smoothly  around  it,  slightly  descending  toward 
the  model,  so  as  to  form  a  thick  edge  of  sand  for  the  more  perfect 
parting  of  the  flask.  The  sand  and  face  of  the  model  must  now  be 
covered  with  dry  pulverized  charcoal,  sifted  evenly  over  the  whole 
surface.  When  this  is  done,  the  upper  section  of  the  flask  is  placed 
over  the  lower  and  carefully  filled  with  sand.  It  is  then  raised  from 
the  lower  one,  which  may  now  be  parted  by  removing  the  long  pin, 
and  the  model  gently  taken  away.     When   closed,  and  the  two  put 


DIES   AND    COUNTER-DIES.  859 

together  again  and  inverted,  it  is  ready  to  receive  the  melted  metal." 
After  the  metal  has  cooled,  it  may  be  removed  and  turned  over,  so  that 
the  face  of  the  die  shall  be  upward,  while  the  remainder  is  buried  in 
the  sand.  Thus  placed,  it  is  encircled  with  the  ring  (Fig.  952)  and 
the  metal  for  the  counter-die  poured  upon  it. 

The  metals  most  commonly  used,  when  metallic  dies  are  made  by 
sand  molding,  are  zinc  and  lead.  For  many  reasons  these  are,  per- 
haps, the  best  metals  for  general  use  that  can  be  employed.  Zinc  is 
the  hardest  metal  that  the  dentist  can  conveniently  melt.  In  case  of 
deep  or  large  arches,  and  for  mouths  where  the  mucous  membrane  is 
very  hard,  should  its  shrinkage  prevent  the  close  adaptation  of  the 
plate,  a  finishing  die  may  be  made  of  block  tin,  type  metal,  soft  solder, 
or  Babbitt  metal  (a  patent  alloy  of  copper,  tin,  and  antimony,  the  best 
formula  for  which  is  Dr.  Haskell's  :  copper,  i  part ;  antimony,  2  parts; 
tin,  8  parts),  which  last  is  nearly  as  hard  as  zinc  and  has  decidedly  less 
shrinkage.  When  a  metal  softer  than  zinc  is  used,  several  dies  will  be 
necessary  to  complete  the  swaging.  As  this  Babbitt  metal  fuses  at  a 
lower  temperature  than  lead,  it  is  necessary  to  use  a  counter-die  in 
which  tin  forms  a  part ;  Dr.  Haskell  therefore  recommends  the  follow- 
ing formula:  lead,  5  parts;  tin,  i  part.  The  die  should  be  coated 
with  whiting  solution  before  pouring  the  counter-die. 

The  late  Prof.  Austen,  by  careful  experiment,  found  that  an  average- 
size  zinc  die,  measuring  two  inches  transversely,  contracts  j^^  of  an 
inch  from  outside  to  outside  of  the  alveolar  ridge,  being  equivalent  in 
thickness  to  three  ordinary  book  leaves.  He  remarks  :  "In  the  first 
case  (upper  jaw),  the  plate  would  'bind,'  and  if  the  ridge  were  cov- 
ered by  an  unyielding  mucous  membrane,  it  would  prevent  accuracy  of 
adaptation.  In  the  second  case  (upper  jaw),  the  plate  would  have  too 
much  '  play,'  and  consequently  lack  stability.  Again,  in  a  moderately 
deep  arch,  say  half  an  inch  in  depth,  the  shrinkage  between  the  level 
of  the  ridge  and  the  floor  of  the  palate  will  be  nearly  y^jVo — rather 
more  than  one  leaf.  In  the  deepest  arches  this  shrinkage  may  give 
trouble,  except  where  the  ridge  is  soft,  and  then  it  becomes  a  positive 
advantage.  In  the  shallower  cases,  it  is  not  of  much  moment,  as  there 
is  no  mouth  so  hard  as  not  to  yield  the  ywjts  ^^  Tinnr  ^^  ^^  inch." 

A  counter-die  should  be  soft.  When  but  one  metal  is  used,  lead  is 
decidedly  the  best  metal  for  this  purpose;  tin  may  also  be  used  if  the 
die  is  made  of  zinc,  but  tin  counter-dies  are  only  employed  for  the 
final  swaging,  and  after  the  use  of  lead  counter-dies.  It  is  desirable, 
if  practicable,  that  the  metal  last  poured  (in  sand  molding,  this  is  the 
counter-die)  should  melt  at  a  lower  temperature  than  the  other.  In 
this  respect  zinc  and  lead  are  admirably  suited — zinc  melting  at  770° 
and  lead  at  600°.     Tin  melting  at  440°  might  be  supposed,  in  this 


86o 


MECHANICS — DENTAL   PROSTHESIS. 


respect,  better  than  lead  ;  but  such  is  not  the  fact,  owing  to  the  tend- 
ency of  tin  and  zinc  to  form  alloys,  while  lead  and  zinc  have  no  such 
affinity. 

The  requisites  for  a  die  are  non- 
shrinkage,  hardness,  strength,  smooth- 
ness of  surface,  and  fusibility  at  a  low 
temperature.  The  Babbitt  metal  after 
the  formula  before  given  furnishes  such 
qualities. 


Fig.  953- 


Fig.  954. 


Fig.  953  represents  an  excellent  gas  furnace  for  melting  and  refining 
gold  and  other  precious  metals  and  for  melting  zinc,  lead,  etc.,  of  the 
baser  metals.  Fig.  954  represents  a  sectional  diagram  of  the  same  fur- 
nace. In  using  plumbago  crucibles,  etc., 
they  must  be  heated  slowly  when  first  em- 
ployed. Mr.  Fletcher's  small  gas  furnace, 
which  is  well  adapted  for  melting  the  metals 


Fig.  955- 


employed  for  dies  and  counter-dies,  is  represented  by  Fig.  955. 

In  a  paper  on  metallic  dies,  published  in  the  fourth  volume  of 
the  American  Journal  of  Dental  Science,  Prof.  Austen  gives,  as  the 


DIES   AND    COUNTER-DIES. 


86l 


result  of  careful  experiment,  the  following  tabular  view  of  the  fusible 
alloys — zinc  being  introduced  for  the  purpose  of  comparison  :  — 


1.  Zinc 

2.  Lead,  2;   tin,  i, 

3.  Lead,  I  ;   tin,  2, 

4.  Lead,  2;   tin,  3;  antimony,  I,     . 

5.  Lead,  5;   tin,  6;   antimony,  I, 

6.  Lead,  5  ;  tin,  6;  antimony,  I  ;  bis- 

muth, 3, 

7.  Lead,  I  ;   tin,  I  ;   bismuth,  i,  .    . 

8.  Lead,  5  ;   tin,  3  ;   bismuth,  8,    .    . 

9.  Lead,  2  ;   tin,  i  ;  bismuth,  3,    .    . 


Melting 
Point. 


770° 
440° 
340° 
420° 
320° 
300° 

250° 
200° 
200° 


Contrac- 

Hard- 

tility. 

ness. 

.01366 

.018 

.00633 

.050 

.00500 

.040 

•00433 

.026 

.00566 

•035 

.00266 

.030 

.00066 

.042 

.00200 

•045 

.00133 

.048 

Brittle- 

NESS. 


The  last  column  contains  an  approximate  estimate  of  the  relative 
brittleness  of  the  samples  given.  As  in  the  other  columns,  the  low 
numbers  represent  the  metals,  so  far  as  this  property  is  concerned, 
most  desirable.  Those  marked  below  5  are  malleable  metals ;  those 
above  5  are  brittle;  zinc,  marked  5,  separates  these  two  classes,  and 
belongs  to  one  or  the  other  according  to  the  way  in  which  it  is 
managed. 

In  all  cases  of  melting  it  is  a  safe  rule  to  pour  the  metals  at  the  low- 
est temperature  at  which  they  will  flow.  It  is  prudent,  also,  to  coat 
the  metal  on  which  other  metal  is  poured  with  a  mixture  of  alcohol 
and  whiting,  to  prevent  all  chance  of  adhesion.  One  more  very  im- 
portant caution  in  the  melting  of  zinc  and  lead  is  invariably  to  use 
separate  ladles ;  for  any  lead  left  from  a  previous  melting  flows  from 
the  ladle  with  the  last  portions  of  the  zinc,  and,  being  heavier  (in  the 
proportion  of  11  to  7)  and  more  fluid,  falls  at  once  to  the  bottom  of 
the  matrix,  making  the  alveolar  ridge  more  or  less  of  a  soft  metal, 
thus  totally  destroying  its  usefulness. 

The  elastic  vapor  generated  by  the  contact  of  the  water  in  the  sand 
with  the  hot  metal  sometimes  collects  under  or  rises  through  the 
metal,  and  renders  the  casting  more  or  less  imperfect.  This  may  be 
prevented:  i,  by  drying  the  sand;  2,  by  using  coarse  or  loosely- 
packed  sand  and  avoiding  too  much  moisture;  3,  by  mixing  the  sand 
with  oil  instead  of  water.  The  slightest  moisture  on  one  metal, 
previous  to  the  pouring  of  another  metal  upon  it,  will  make  the  latter 
imperfect.  The  following  method  has  been  suggested  to  overcome 
this  difficulty  :  "To  prevent  imperfections  or  bubbles  in  the  palatal 
portion  of  metallic  dies,  it  is  not  necessary  to  dry  the  mold  after  it  is 
formed,  or  to  use  more  than  ordinary  precaution  as  to  the  heat  of  the 


862 


MECHANICS  —  DENTAL    PROSTHESIS. 


metal.  The  best  result  is  obtained  when  the  plaster  model  is  quite 
thick  and  the  mold  consequently  deep.  This  is  then  tipped  forward, 
raising  the  back  part  or  condyles  to  the  highest  point  possible,  pour- 
ing the  metal  in  at  the  front  slowly,  and  lowering  the  mold  at  the  same 
time  until  the  palatal  portion  is  covered  and  the  mold  filled  to  the  top." 
The  use  of  oiled  sand,  however,  as  before  remarked,  will  prevent  im- 
perfections by  bubbling  on  the  palatal  portion  of  the  die. 

In  making  metallic  dies  for  partial  cases,  about  three-fourths  of  the 
crowns  of  the  teeth  should  be  cut  from  the  plaster  model  before  using 
it  for  molding.  The  plate  can  be  fitted  more  easily  and  perfectly  than 
can  be  done  when  the  teeth  remain  on  the  plaster  model  and  zinc  die ; 
for,  in  the  former  case,  the  plate  need  not  be  cut  to  fit  the  teeth  until 
it  has  been  swaged  ;  while  in  the  latter  this  must  be  done  first ;  conse- 
quently, in  striking  it  up,  it  will  be  drawn  to  a  greater  or  less  distance 
away  from  them.  There  is  also  danger  of  splitting  the  plate,  in  swag- 
ing it  into  the  spaces  between  the  teeth,  if  these  are  left  on  the  metallic 
die.  Half  or  partial  counter-dies  adapted  to  the  palatal  portion  of  the 
die  only,  and  not  extending  quite  to  the  ridge,  are  useful  in  the  case 
of  a  deep  arch,  and  prevent  the  plate  from  tearing  during  the  swaging 
process. 

We  shall  conclude  the  section  on  metallic  dies  by  giving  some 
practical  suggestions  by  Prof.  Austen  on  the  properties  and  uses  of  the 
metals  and  alloys  employed  for  this  purpose. 

Many  of  the  properties  of  these  metals,  though  most  interesting, 
are  not  practically  useful  to  the  dentist ;  but  there  are  some  points, 
for  which  he  usually  refers  to  his  memorandum  book,  that  should  be 
printed  on  the  page  of  his  memory.  The  following  tables  present  two 
properties  of  certain  metals  in  a  form  convenient  for  memorizing ; 
although  not  absolutely  accurate,  they  are  quite  enough  so  for  use  in 
the  dental  laboratory  : — 


Order  of  Fusibility. 

Copper, 2000° 

Antimony, 900° 

Zinc,      770° 

Lead, 600° 

Bismuth, 500° 

Tin  and  cadmium, 440° 


Order  of  Specific  Gravity. 

Lead, 1 1. 5 

Bismuth, 10. 

Cadmium, 8.5 

Tin, 7-5 

Zinc, 7. 

Antimony, 6.5 


In  the  fusibility  table,  copper  is  given  to  show  how  unsuited  it  is 
for  laboratory  use.  Remembering  that  900°  is  red  heat,  the  next  four 
numbers  may  be  easily  memorized.  In  the  specific  gravity  table, 
copper  9.  and  iron  8.  are  omitted,  so  as  to  present  the  table  in  a  form 
easily  remembered. 


DIES    AND    COUNTER-DIES.  863 

The  only  pure  metals  suitable  for  a  die  are  zinc  and  tin  ;  for  a 
coanterdie,  tin  and  lead.  When  one  metal  is  used  for  either  die  or 
counter-die,  zinc  makes  the  best  die  and  lead  the  best  counter-die. 
Copper  is  too  hard  to  fuse;  antimony  and  bismuth  are  too  brittle; 
cadmium  is  too  expensive.     All  other  metals  used  in  swaging  are  alloys. 

Zinc  and  lead  are  valuable  because :  They  are  so  unlike  that  they 
are  not  easily  mistaken  for  each  other — a  very  common  error  when 
alloys  are  used.  They  have  no  such  disposition  to  alloy  as  zinc  and 
tin  or  tin  and  lead  have.  Zinc  is  so  hard,  one  die  will  suffice  for 
many  cases ;  three  are  sufficient  for  the  most  difficult.  The  brittle- 
ness  may  be  corrected  by  the  size  of  the  die.  Its  shrinkage  is  often  a 
decided  advantage  ;  and  in  some  cases,  where  it  makes  the  plate  bind 
on  the  alveolus,  the  contraction  may  be  anticipated  by  coating  these 
parts  on  the  model  with  one  or  two  layers  of  very  thin  plaster.  Zinc, 
after  repeated  use,  becomes  defective,  hence,  a  supply  of  new  metal 
should  always  be  kept. 

No  metal  used  alone  equals  lead  as  a  counter-die.  Its  weight  and 
softness  are  in  its  favor  for  this  purpose.  A  counter-die  cannot  be  too 
large  or  heavy;  convenience,  of  course,  limits  its  size.  A  difficult 
plate  cannot  be  swaged  with  a  small  counter-die,  unless  the  work  is 
nearly  completed  by  partial  counters,  hammers,  etc.,  before  using  it. 
As  regards  softness,  the  greater  the  disparity  between  die  and  counter, 
the  less  will  be  the  change  in  the  die  by  the  act  of  swaging.  The  plate 
is  forced  by  the  counter  into  the  depressions  of  a  die,  not  so  much  by 
its  hardness,  as  by  its  vis  inertia  under  the  swaging  blows.  The  little 
disparity  in  the  hardness  of  the  two  dies  is  one  serious  objection  to 
the  use  of  the  second  class  of  operations.  It  is  a  common  practice  to 
use  several  counters,  and  perhaps  only  one  die.  One  die  may  in  a 
few  cases  suffice  ;  two  are  better,  and  often  three ;  but  good  swaging 
never  demands  more  than  one  counter-die,  where  that  is  properly 
made. 

With  zinc,  lead,  and  one  fusible  alloy  (tin  and  bismuth,  equal  parts, 
or  Babbitt's  metal)  all  swaging  operations  may  be  completed  when 
the  dies  are  made  by  sand  molding  or  by  pouring  zinc  into  the  im- 
pression. But  since  many  prefer  other  methods  of  making  dies,  it  is 
important  to  understand  the  subject  of  alloys.  Experiment  is  here  the 
only  basis  of  knowledge,  for  no  a  priori  reasoning  could  deduce  the 
singular  changes  caused,  and  new  properties  developed,  by  alloying. 

The  alloy  of  two  brittle  metals  is  always  brittle,  and  a  brittle  metal 
usually  imparts  this  property  to  a  tough  one  nearly  in  proportion  to  its 
percentage.  But  that  two  tough  metals  can  make  a  brittle  alloy  is 
remarkable.  Malleable  copper,  with  half  its  weight  of  brittle  zinc, 
gives  hard  brass,  which,  though  less  tough  than  copper,  is  not  brittle. 


864 


MECHANICS DENTAL    PROSTHESIS. 


But  malleable  copper,  with  malleable  tin  in  the  same  proportions, 
makes  speculum  metal — the  most  brittle  alloy  known.  A  similar  in- 
stance is  that  of  lead,  the  softest  of  metals,  which  will,  in  minute 
quantities,  make  gold,  the  most  malleable  of  all  metals,  very  brittle. 

Another  remarkable  property  of  all  alloys  is  fusibility.  Alloys  fuse 
below  the  average  melting  point  of  their  constituents.  Ternary  com- 
pounds exhibit  thismore strikingly  than  binary.  The  following  table, 
in  illustration  of  this  property,  will  be  found  practically  useful  to  the 
dentist  in  the  selection  of  alloys: — 

Alloys  of  Bismuth,  Lead  and  Tin. 


Bismuth,  500°. 

Lead,  600°. 

Tin,  440°. 

Fahrenhkit. 

I 

10 

I 

540° 

2 

5 

I 

510° 

3 

2 

I 

440° 

4 

I 

I 

370° 

5 

2 

3 

335° 

6 

I 

2 

340° 

7 

I 

5 

380- 

8 

I 

4 

4 

320° 

9 

I 

2 

2 

290° 

lO 

I 

I 

I 

260° 

II 

2 

I 

I 

220° 

It  will  be  noticed  that  two  pounds  of  lead  do  not  make  one  pound 
of  tin  harder  to  melt,  whilst  a  half  pound  reduces  its  fusion  point 
100°.  Also,  Nos.  6  and  7,  though  containing  more  tin  than  No.  5, 
are  harder  to  melt.  Again,  a  pound  of  bismuth  added  to  alloy  No.  4 
reduces  its  melting  point  110°.  No.  1 1  and  all  alloys  containing  much 
bismuth  are  brittle.  The  alloys  of  this  table  vary  somewhat  in  hard- 
ness, but  all  are  harder  than  tin. 

The  "  alloying  metals  "  of  the  dental  laboratory  are  copper,  anti- 
mony, and  bismuth.  Copper  gives  hardness  to  zinc  and  tin,  and  is 
sometimes  combined  with  alloys  of  the  two.  But  the  high  fusion  point 
of  copper  renders  it  less  useful  to  the  dentist  than  the  other  two  metals. 
The  alloy  of  copper,  antimony,  and  tin  (Babbitt  metal)  is  perhaps  the 
only  one  of  practical  interest.  Its  advantage  over  zinc,  in  being  less 
liable  to  contract,  is  perhaps  set  off  by  the  tendency  of  most  alloys  to 
change  their  composition  by  frequent  melting ;  and  the  danger  of 
mixing  different  alloys,  from  the  absence  of  such  distinctive  marks  as 
separate  zinc  and  lead. 

Antimony  is  a  more  valuable  alloying  metal.  It  hardens  tin,  but 
its  chief  use  in  the  laboratory  is  to  harden  lead,  making  type  metal. 
Small  types  composed  of  lead  4,  antimony  i,  are  too  brittle;  and  large 


DIES   AND    COUNTER-DIES.  86 5 

types,  lead  6,  antimony  i,  are  scarcely  fit  for  laboratory  use.  In  the 
proportion  of  9  to  i,  antimony  corrects  the  excessive  contraction  of 
lead  and  hardens  it,  yet  leaves  it  tough,  so  as  to  resist  the  blows  of 
swaging.     It  is  suitable  only  for  counter-dies. 

The  very  common  opinion  that  antimony  causes  lead  to  expand  on 
cooling  is  erroneous.  The  alloy  has  a  slight  expansion  at  the  moment 
of  solidification  ;  but  after  that  it  obeys  the  universal  law  of  all  metals, 
and  contracts  as  it  cools.  Actual  contraction  depends  upon  the  ratio 
of  contraction  and  the  fusion  point ;  thus,  lead  contracts  more  than 
zinc  because  its  high  ratio  of  contraction  more  than  compensates  its 
lower  fusion  point. 

Another  common  error  is  that  a  zinc  die  poured  very  hot  is  smaller 
than  if  poured  at  its  fusion  point.  Of  course,  contraction  begins  the 
moment  cooling  begins ;  but  so  long  as  the  metal  is  fluid  it  necessarily 
fills  the  matrix,  and  contraction  causes  simply  subsidence  of  the  metal. 
No  die  begins  to  leave  the  walls  of  the  matrix  until  it  solidifies;  hence, 
the  amount  of  contraction  is  the  same  in  all  cases.  Very  hot  zinc 
copies  minutely  the  sand  surface,  and  thus  has  not  that  bright,  smooth 
appearance  of  cooler  zinc,  which  sets  before  penetrating  the  sand  in- 
terstices ;  but  both  are  equally  good.  Another  difference  is  in  the 
greater  depth  in  the  cavity  on  the  back  of  the  hot-poured  die.  But 
this  is  not  as  objectionable  as  many  think  ;  no  good  mechanic  strikes 
directly  upon  the  die,  but  upon  some  ovoid  or  conical  piece  of  metal 
covering  the  cavity  in  the  back. 

Bismuth  is  perhaps  the  most  valuable,  to  the  dentist,  of  the  three  al- 
loying metals.  Antimony  gives  hardness,  but  not  much  fusibility; 
bismuth  gives  fusibility,  but  no  great  hardness.  The  table  above  given 
shows  the  marked  effect  of  this  metal.  It  is  seldom  used  as  a  binary 
alloy,  because  its  fluxing  qualities  are  more  fully  brought  out  in  ternary 
combination ;  also  because  of  its  expensiveness,  and  its  tendency  to 
impart  brittleness.  Type  metal  is  rendered  more  fusible  by  the  addi- 
tion of  .05  per  cent,  of  bismuth. 

Bismuth,  antimony,  and  zinc  are  readily  distinguished — bismuth  by 
its  great  weight  and  characteristic  pinkish  color;  antimony  by  its  pe- 
culiar crystallization  and  its  excessive  brittleness.  But  the  alloys  of 
these  metals  with  tin  and  lead  have  such  a  general  resemblance,  that 
they  must,  with  much  care  and  system,  be  kept  apart  in  properly  labeled 
boxes  ;  otherwise,  if  more  than  one  alloy  is  used,  the  annoyance  caused 
by  using  one  for  another  will  more  than  offset  their  utility  ;  in  fact, 
such  negligence  defeats  their  usefulness. 

But  the  formula  of  Dr.  L.  P.  Haskell  for  preparing  the  Babbitt 
metal  is  superior  to  all  others  for  use  as  a  die :  tin,  8  parts  ;  copper, 
I  part  ;  antimony,  2  parts.  For  a  counter-die  for  such  a  die  :  lead, 
55 


866  MECHANICS — DENTAL    PROSTHESIS. 

5  parts;  tin,  i  part.     He  claims  that  such  a  Babbitt  alloy  for  the  die 
cannot  be  excelled. 

Dr.  C.  J.  Essig  recommends  zinc  for  a  counter-die  for  swaging  a 
plate  of  platinum-gold  or  iridium-platinum ;  and  also  that  such  a 
counter  die  is  of  especial  service  in  partial  cases  where  a  number  of 
teeth  remain.  For  difficult  swaging  he  recommends  three  sets  of  dies 
and  counter-dies,  the  most  imperfect  of  the  dies  being  furnished  with 
a  lead  counter-die,  to  be  first  used,  and  the  next  in  quality  to  be  used 
with  a  zinc  counter-die,  and  the  nearest  perfect  of  all  with  a  lead 
counter-die  as  a  finishing  die. 

SWAGING. 

A  die  and  counter-die  having  been  obtained,  a  piece  of  tin  foil  or 
sheet  lead  is  adapted  to  the  former,  and  the  dimensions  of  the  plate 
marked  upon  it.  Paper  is  sometimes  used  for  this  purpose,  but  is 
not  so  good  as  thin  sheet  lead  or  heavy  tin  foil.  The  pattern  thus 
made  is  cut  out,  flattened,  and  laid  upon  the  gold  plate,  and  its  out- 
line marked  upon  it.  The  outline  of  the  plate  may  be  marked  on 
the  plaster  model  and  the  pattern  cut  in  conformity  therewith.  The 
margins  of  the  plate  for  the  upper  jaw  should  extend  as  high  as  pos- 
sible, and  especially  over  the  position  of  the  canine  teeth,  in  order  to 
restore  the  expression,  which  is  greatly  changed  by  the  loss  of  the 
natural  teeth  at  such  points ;  back  of  the  canine  teeth  the  margin  of 
the  plate  should  be  lowered  so  as  to  avoid  the  attachment  of  the  muscles 
and  to  allow  the  latter  free  motion  or  action.  The  plate  should  also 
embrace  the  maxillary  tuberosities  in  order  to  obtain  stability,  and 
the  margins  at  such  points  may  extend  higher  than  over  the  bicuspids 
and  first  molars.  The  plate  should  be  cut  a  little  too  large,  to  allow 
for  trimming  and  any  accidental  slipping  upon  the  die.  In  partial 
cases  the  pattern  should  be  carried  partly,  or  fully,  over  the  excised 
teeth,  and  no  attempt  made  to  fit  it  accurately  around  the  necks  of 

the  teeth  until  the  swaging  is  nearly 
or  quite  completed.  With  a  pair  of 
strong  shears  the  portion  of  plate 
thus  marked  is  cut  out.  Fig.  956 
represents  a  pair  of  shears,  with  long 
J,        ,  and     conveniently-shaped     handles. 

The  blades  of  some  shears  are  curved 
laterally;  but  this  form  is  not  desirable.  A  fine  watch  spring  saw, 
Fig.  613  (p.  679),  should  be  used  for  curves  which  the  straight  shears 
will  not  cut ;  curved  shears  may  also  be  used  for  such  a  purpose  ;  for 
very  short  curves — around  teeth,  for  instance — a  pair  of  cutting  for- 
ceps will  be  found  useful. 


SWAGING    PLATES. 


867 


Figs.  957,  958,  959  represent  nippers  or  cutting  forceps  for  cutting 
out  plate. 

Cutting  plates  to  shape  before  swaging  is,  however,  not  only  un- 
necessary, but  is  in  many  cases  a  positive  disadvantage.     Swaging  the 


Fig.  957. 

square  plate  is  greatly  preferable  in  the  lower  jaw,  since  it  permits 
working  from  the  center  outward.  And  in  both  upper  and  lower 
plates,  the  two  triangular  pieces  outside  the  ridge  help  to  prevent 
plaiting,  or  doubling  of  the  plate.     Purchased  plates  are  ordered  to 


Fig.  958. 


pattern  on  the  score  of  economy  ;  but  the  difference  is  trifling,  since 
good  plate  scrap  has  nearly  the  same  value  as  the  original  plate,  and 
every  careful  operator  separates  his   plate  scrap  from  his  solder  scrap 


Fig.  959. 


and  filings.  After  swaging  is  nearly  completed,  with  partial  counters 
and  hammers,  the  square  plate  may  be  quickly  trimmed  to  shape  by 
means  of  a  jeweler's  saw. 


868 


MECHANICS — DENTAL    PROSTHESIS. 


The  plate  must  be  well  annealed,  and  partially  fitted  by  wooden, 
horn,  or  leaden  hammers,  to  that  part  of  the  die  inside  the  ridge. 
There  is  no  better  hammer  for  this  purpose  than  lead ;  but,  of  course, 
the  plate  must  be  thoroughly  cleansed  of  all  trace  of  the  lead  before 
annealing.  The  swaging  is  continued  by  the  use  of  partial  counter- 
dies  ;  these  are  made  by  placing  a  rim  of  clay  or  putty  around  the 
ridge  and  back  part  of  the  metallic  die,  and  pouring  on  it  fusible 
metal.  In  this  way,  the  plate  should  be  perfectly  fitted  so  far  as  the 
ridge.  Then,  clamping  the  plate  between  the  die  and  the  partial 
counter,  the  edge  is  to  be  gradually  carried  over  the  top  and  outside 
of  the  ridge  with  hammers  and  small  wooden  or  ivory  stakes.     The 


No.  I. 


Fig.  960. 


plate  may  be  clamped  in  a  vise,  or  by  means  of  a  string  passing  over 
the  die  and  under  the  foot ;  but  a  much  more  convenient  method  is 
found  in  the  use  of  Dr.  T.  H.  Burras's  clamps,  Fig.  960.  Of  the  two 
forms  here  given,  the  sliding  arm  (No.  2)  is  preferable  to  the  long 
screw  (No.  i).  The  application  of  the  clamp  is  so  plainly  shown  in 
No.  I  that  any  description  is  unnecessary. 

It  is  the  practice  of  some  to  cut  out  V-shaped  pieces  from  the  front 
or  back  part  of  the  plate,  to  prevent  the  plaiting  of  the  metal.  This 
is  very  bad  practice  and  is  never  called  for,  if  due  care  is  used  in 
swaging  and  the  metal  is  of  proper  fineness.  To  avoid  plaits  or  folds, 
anneal  often,  and  in  deep  arches  carry  the  plate  down  very  gradually; 


SWAGING   PLATES.  869 

also  take  care  in  such  cases  that  the  plate  be  thick,  to  allow  for  stretch- 
ing or  drawing.  In  swaging  over  the  ridge,  it  is  a  very  common  mis- 
take to  hammer  down  the  outside  before  fully  striking  up  (with 
hammer  and  stakes)  the  parts  nearest  the  partial  counter-die.  Always 
make  it  a  rule,  in  carrying  the  plate  over  the  ridge,  to  swage  from  the 
center  outward,  and  carry  the  plate  "  home  "  as  you  proceed.  In  deep 
arches,  irregular  alveolar  ridges,  and  in  prominent  lower  ridges 
swaging  must  be  done  slowly  and  with  great  care. 

In  the  use  of  forceps  for  bending  lower  plates  (Fig.  961),  care  must 
be  taken  not  to  bruise  the  metal,  as  will  any  steel  or  hard  metal  instru- 
ments. There  is  no  shape  of  arch  or  of  plate  which,  by  the  above 
simple  process,  cannot  be  perfectly  fitted  with  a  20-carat  plate.  The 
elaborate  forms  of  a  window  cornice  or  a  jelly  mold  should  teach  any 
dentist  how  poor  a  mechanic  he  is  when  he  complains  of  the  difficulty 
of  swaging  so   highly  malleable  a  metal  as  gold  into  and  over  the 


Fig.  961. 

irregularities  of  the  mouth.     And  when,  to  save  his  skill,  he  pleads 
want  of  time,  he  exposes  a  graver  deficiency — dishonesty. 

The  fitting  of  the  plate  being  thus  almost  completed  by  hammers 
and  partial  counters,  it  should  be  trimmed  to  its  exact  shape,  and 
then  placed  between  a  fresh  die  and  the  full  counter-die,  and  carried 
"home"  by  several  firm  blows  of  the  hammer,  given  directly  over 
the  center  of  the  die.  The  hammer  should  not  weigh  more  than 
three  pounds,  with  a  handle  about  a  foot  long.  It  is  a  great  mistake 
to  use  a  very  heavy  or  a  very  long-handled  hammer.  The  striking- 
block  may  be  an  anvil,  or  a  large  wooden  block  set  in  sand  or  on  a 
cushion,  and  the  base  of  the  counter-die  must  rest  steadily  upon  it. 
Dr.  Haskell  describes  a  movable  swaging-block  to  be  kept  under  the 
bench  as  follows:  "  Eight  inches  wide  at  the  top,  and  eleven  inches 
at  the  bottom,  just  high  enough  to  pass  under  the  bench.  Make  it  of 
pine  with  a  plank  bottom,  to  which  attach  heavy  casters,  a  handle  on 


870  MECHANICS — DENTAL   PROSTHESIS. 

one  side,  and  a  pocket  for  the  hammer.  Have  an  iron  6-inch  cube 
cast,  and,  filling  the  box  nearly  full  of  sawdust,  place  the  iron  cube  in 
it  so  it  will  extend  two  inches  above  the  box."  It  greatly  facilitates 
swaging,  and  makes  one  independent  of  any  striking  block,  to  have  a 
very  thick  and  heavy  lead  counter.  As  there  is  always  a  hollow  in 
the  back  of  a  zinc  die,  a  conical  piece  of  iron,  steel,  or  other  hard 
metal  should  be  placed  upon  it  to  centralize  the  blow  of  the  hammer. 
An  eggshell  filled  with  plaster  is  useful  as  a  model  for  making,  at  the 
time  of  molding  the  die,  several  zinc  blocks  for  this  purpose.  To  a 
disregard  of  these  precautions  is  due  much  of  the  difficulty  so  often 
complained  of  in  the  tilting  or  rocking  of  plates  and  dies. 

Throughout  the  entire  process  of  swaging  the  plate  must  be  fre- 
quently annealed.  It  may  be  suddenly  cooled  after  all  except  the 
final  annealing,  vhen  the  cooling  must  be  very  gradual,  so  as  to  avoid 
warping  or  springing.  The  malleability  of  gold  plate  will  permit  a 
great  deal  of  swaging  without  annealing  ;  yet  the  neglect  of  this  simple 
operation  is  unsafe.  One  broken  or  cracked  plate  gives  more  trouble 
than  the  annealing  of  a  dozen.  The  plate,  after  final  swaging,  must 
be  taken  from  the  counter  very  carefully,  to  avoid  change  of  shape. 
Thin  paper  in  the  counter-die  makes  removal  easier;  it  is  also  easier 
when  only  one  counter  is  used.  Too  much  swaging  gives  the  plate  a 
loose  fit. 

When  block-tin,  lead,  or  fusible  metal  dies  or  counter-dies  are  used 
in  swaging  the  plate,  any  portion  of  these  metals  which  may  adhere 
to  it  should  be  removed  before  annealing,  as  their  fusion  upon  its 
surface  alloys  them  with  the  gold,  and  will  render  it  brittle  and  impair 
its  ductility,  or  else  eat  holes  in  the  plate  at  the  spot  where  the  parti- 
cles of  baser  metal  form  an  alloy,  fusible  at  the  annealing  heat.  This 
is  done  either  by  mechanical  or  chemical  means.  If  acfd  is  used,  it 
should  be  dilute  nitric,  since  sulphuric  will  not  dissolve  lead;  but  be 
very  careful  that  the  nitric  acid  contains  no  hydrochloric,  else  the 
plate  will  be  acted  upon.  A  copper  or  lead  acid-dish  may  be  employed, 
many  preferring  one  made  of  thick  sheet  lead.  Oiling  the  dies  will 
also  prevent  the  base  metal  from  adhering  to  the  plate,  as  any  particles 
of  the  former  can  be  readily  wiped  off. 

The  plate,  in  the  case  of  a  full  upper  denture,  should  be  so  outlined 
as  to  have  the  highest  portion  of  the  rim  over  the  cuspids,  curving 
downward  back  of  such  points  to  the  maxillary  tuberosities,  where 
it  again  should  ascend  so  as  to  extend  over  these  prominences.  (Fig. 
962.)  Space  should  also  be  made  for  the  frenum  of  the  lip  by  cutting 
away  the  edge  or  rim  for  its  reception.  In  the  case  of  a  full  lower 
denture,  the  bending  pliers  may  be  used  first,  and  its  outline  should  be 
such  that  it  does  not  interfere  with  the  muscles  and  loose  integruments. 


SWAGING    PLATES.  871 

For  a  very  flat  ridge,  the  lower  plate  should  be  double  to  give  strength, 
and  for  partial  lower  dentures  it  is  better  to  double  the  plate  where 
strength  is  required  ;  strength  is  also  secured  by  the  plate,  in  such 
cases,  extending  above  the  necks  of  the  teeth,  in  some  instances  half 
way,  where  the  attachment  of  the  muscles  would  otherwise  necessitate 
a  very  narrow  plate.  Each  piece  of  a  double  plate  should  be  swaged 
separately,  and  the  two  parts  then  soldered  together,  wire  clasps  being 


Fig.  962. 


used  to  hold  them  in  position  during  the  soldering  process.  If  the 
denture  is  to  be  retained  by  clasps,  the  plate,  either  upper  or  lower, 
should  extend  at  least  one-fourth  of  an  inch  beyond  the  clasped  tooth 
in  order  to  secure  stability.  In  soldering  the  two  parts  of  a  double 
plate,  the  edges  of  one  should  slightly  overlap  the  other  so  as  to  facil- 
itate the  process. 

Figs.  963  and  964  represent  the  general  forms  of  upper  and  lower 


Fig.  963. 

plates  after  the  swaging  process  is  completed.  In  the  upper  plate  is 
represented  the  proper  sjze  and  position  of  a  vacuum  cavity,  according 
to  area  of  mouth,  whenever  it  may  be  thought  proper  to  use  one.  The 
question  of  the  cavity  will  be  elsewhere  discussed. 

If  on  trial  of  the  plate  in  the  mouth  it  does  not  fit  properly,  the 
operator  must  proceed  to  ascertain  the  cause  of  failure.  And,  first, 
whether  it  is  temporary  or  permanent.     A  plate  which  falls  because  it 


872  MECHANICS — DENTAL    PROSTHESIS. 

rocks  over  a  hard  palate  will  never  improve  ;  if  because  it  fails  to  go 
fully  into  the  palate  it  may  daily  improve,  and  ultimately  adhere  with 
great  firmness.  Most  plates  made  soon  after  extraction  fit  badly  until 
the  alveolar  prominences  are  pressed  down  by  wear.  Some  very  hard 
mouths  will  not  retain  the  plate  until  it  has  been  worn  for  a  time,  es- 
pecially if  the  mouth  is  very  flat.  Deep  arches,  or  uniformly  soft 
mouths,  should  retain  the  plate  firmly  from  the  first. 

The  use  of  pliers,  except  for  bending  the  edge  into  some  alveolar 
undercut,  is  an  evidence  of  bad  work.  The  back  margin  of  upper 
plates,  so  often  adjusted  in  this  way,  is  much  better  fitted  by  scraping 
the  model  at  the  place  where  the  plate  should  bind  ;  this  should  be 
done  to  a  depth  proportioned  to  the  softness  of  the  membrane. 

Much  judgment  is  demanded  in  deciding  upon  the  necessity  for  a 
new  plate.  The  impressioh  may  have  been  badly  taken,  or  with  a 
material  not  adapted  to  the  mouth.  The  dies  may  have  been  carelessly 
made,  or  the  swaging  imperfectly  done.  Trial  of  the  plate  is  essential 
to  ascertain  all  these  points,  that  the  articulation,  soldering,  etc.,  may 
not  be  so  much  additional  labor  in  vain. 

In  fitting  a  plate,  the  operator  should  see  that  its  posterior  margin, 
especially  at  the  center,  is  so  closely  adapted  as  to  exclude  air.  Dr. 
Haskell  recommends  wetting  the  plate  before  placing  it  in  the  mouth, 
and  then  by  a  "pumping  process"  watching  for  the  escape  of  air 
bubbles.  At  the  same  time  the  plate  should  not  press  so  hard  at  the 
center  of  its  posterior  margin  as  to  irritate  the  mucous  membrane.  To 
determine  whether  a  lower  plate  infringes  upon  the  muscles  and  lower 
integuments,  the  patient  may  be  directed  to  raise  the  tongue,  which 
will  dislodge  the  plate  if  it  so  interferes  by  its  depth.  The  lip  can  also 
be  raised  in  front  to  determine  if  the  plate  extends  too  deep  at  that 
point. 

The  difiFerent  forms  of  plates,  full  and  partial,  will  hereafter  be  con- 
sidered. They  are  retained  in  the  mouth  by  clasps  or  stays ;  by  the 
adhesion  of  contact  or  by  the  vacuum  cavity,  the  retaining  force  being 
atmospheric  pressure;  by  the  elastic  spring  of  the  wings  of  the  plate; 
by  spiral  springs.  These  will  be  taken  up  in  a  subsequent  chapter  and 
their  relative  merits  discussed.  We  pass  now  to  the  step  which,  in 
swaged  work,  comes  next  in  order  to  the  fitting  of  the  plate — the  means 
for  securing  its  exact  relation  to  the  natural  teeth,  or,  in  double  sets, 
its  relation  to  the  opposing  plate.  These  processes  come  under  the 
technical  head  of  Articulation. 


ARTICULATION.  873 

CHAPTER  X. 

ARTICULATION. 

The  term  Articulation,  as  used  in  Dental  Mechanics,  comprehends 
several  distinct  operations,  implied  in  the  use  of  the  terms  (i)  Articu- 
lating impressions  ;  (2)  Articulating  plates  ;  (3)  Articulating  models. 

In  many  partial  tests  it  is  best,  after  fitting  the  swaged  plate  to  the 
mouth,  to  take  a  wax  impression  with  the  plate  in  situ.  This  gives  the 
precise  relation  of  the  plate  to  the  adjacent  teeth ;  and  upon  application 
of  a  model  of  the  lower  jaw,  it  gives  the  relation  of  the  plate  to  the  an- 
tagonist teeth.  This  and  all  other  impressions  of  the  relation  of  plates  to 
the  teeth  or  to  each  other  in  the  mouth  we  call  articulating  impressions. 

A  base  plate  becomes  an  articulating  plate  when  the  articulating 
rim  is  attached  which  has  the  impress  of  its  opposite  rim  or  teeth. 
In  swaged  work  it  is  the  gold  plate  itself;  in  plastic  work  it  is  some 
temporary  plate  of  tin,  lead,  or  gutta  percha. 

The  articulating  models  make  up  what  is  technically  called  an 
^'Articulator,"  of  which  there  are  many  forms  ;  all,  however,  compre- 
hended under  three  varieties  :  {a)  Those  wholly  of  plaster  poured 
into  the  articulating  plates.  (Ji)  Those  in  which  the  model  portion 
is  poured  into  the  articulating  plates,  but  the  back  or  hinged  portion 
is  metallic.  {/)  Those  in  which  the  original  models  are  set  into  the 
articulating  plates,  and  some  complicated  metallic  articulator  adjusted 
to  them.  Each  of  these  classes  have  special  advantages  adapting  them 
to  various  exigencies  of  practice. 

Whenever,  in  partial  cases,  there  are  three  points  of  contact  suffi- 
ciently apart  to  give  firm  antagonism,  Prof.  Austen's  plan  was  to  take 
an  impression  of  the  lower  teeth ;  this  gives  a  model  which  antago- 
nizes perfectly  with  the  upper  model,  and  makes  the  articulator  with- 
out further  trouble.  This  plan,  specially  applicable  to  vulcanite  work^ 
is  adapted  to  swaged  work  by  taking  the  articulating  impression  de- 
scribed in  the  second  paragraph  of  this  chapter.  Such  articulators 
require  no  backward  extension  or  hinge,  because  the  articulation  is 
determined  by  the  articulating  cusps  of  the  teeth. 

In  partial  cases,  where  there  are  only  one  or  two  points  of  antago- 
nism, and  where,  consequently,  the  opposition  of  the  corresponding 
teeth  would  be  uncertain,  the  necessity  exists  for  some  third  point 
of  support.  This  is  best  given  by  a  backward  extension  of  the  model, 
so  as  to  permit  motion  of  the  two  halves  of  the  articulator,  some- 
what resembling  that  of  the  natural  jaws,  though  many  partial  cases 
do  not  require  such  an   extension.     In  putting  this  wax  rim  on  the 


874 


MECHANICS DENTAL    PROSTHESIS. 


plate  it  is  better  in  all  cases  to  trim  it,  as  is  done  for  full  upper  sets; 
but  where  there  are  remaining  teeth  the  antagonism  of  these  deter- 
mines the  proper  closure  of  the  mouth,  and  this  is  not  essential.  The 
plate  and  adherent  wax  are  placed  in  the  mouth  ;  the  patient  is  then 
requested  to  close  the  mouth  naturally,  imbedding  the  teeth  of  the 
lower  jaw  in  the  wax.  While  the  mouth  is  thus  closed,  the  wax  on  the 
outside  of  the  teeth  and  alveolar  ridge  is  pressed  closely  against  them. 
This  done,  the  plate  and  wax  impression  are  carefully  removed, 
filled  with  plaster,  and  placed  on  a  piece  of  wet  paper,  with  the  wax 
downward.  The  upper  side  of  the  plate  is  then  oiled.  As  the  plaster 
stiffens  it  may  be  applied  until  it  is  raised  half  an  inch  above  the  plate, 
and  extended  back  of  it  on  the  paper  an  inch  and  a  half  or  two 
inches.  As  soon  as  the  plaster  has  set,  its  edges  may  be  neatly 
trimmed ;  and  at  the  back  of  the  surface  next  the  paper  a  deep  trans- 
verse or  T-shaped  groove  should  be  cut  to  serve  as  a  model  for  the 

formation  of  a  corre- 
sponding ridge  on  the 
half  model  with  which 
this  is  to  antagonize. 
This  grooved  surface 
must  be  coated  with  oil 
or  soap  water  or  varnish, 
or  covered  with  a  layer 
of  tin  foil  or  thin  paper. 
Then  partly  fill  the  space 
inclosed  by  the  wax  rim 
with  clay,  putty,  or  wet 
paper,  and  pour  on  plas- 
ter to  form  the  other  half  model.  In  running  plaster  into  the  wax 
impressions  of  the  teeth,  be  very  careful  to  avoid  air  bubbles  and  flaws, 
and  do  not  oil  the  wax.  After  the  plaster  has  set  it  may  be  trimmed 
as  before  directed. 

Another  and  often  more  convenient  method  is  to  take  a  strip  of 
sheet  lead  one  and  a-half  inches  wide,  and  bend  it  to  the  required 
outline  of  the  articulator.  Pour  this  partly  full  of  plaster,  and  set  the 
plate,  previously  filled  with  plaster,  upon  it.  Cut  the  grooves  as  be- 
fore described,  and  pour  the  other  half  of  the  articulator.  The  lead 
rim  saves  much  manipulation  and  trimming,  which,  in  the  other  case, 
the  plaster  requires.  When  the  half  last  made  has  become  sufficiently 
hardened,  the  two  pieces  may  be  separated,  after  softening  the  wax  in 
warm  water,  and  the  wax  carefully  removed.  The  model  is  then  var- 
nished, for  greater  comfort  in  handling,  and  when  put  together  may 
present  an  appearance  exhibited  in  Fig.  965. 


ARTICULATION.  875 

The  artist  has  failed  in  this,  and  in  other  designs  of  the  plaster  ar- 
ticulator, to  represent  the  tapering  shape  which  it  is  best  to  give  to 
the  back  half  of  the  models,  for  greater  convenience  of  holding  them 
while  adapting  the  teeth.  The  fault  of  many  plaster  articulators  is 
that  they  are  too  large  and  clumsily  shaped.  In  any  given  case  the 
proper  distance  of  the  groove  or  hinge  is  the  distance  from  the  patient's 
external  auditory  meatus  to  the  line  of  the  front  teeth  or  alveolar 
ridge.  The  width  and  thickness  of  the  articulator  must  vary  with  the 
size  or  depth  of  the  mouth,  avoiding  any  excess  of  plaster  not  neces- 
sary to  give  requisite  strength. 

For  a  full  upper  set,  or  where  two  or  more  remaining  molars  have 
no  antagonism,  it  is  a  very  common  practice  to  place  on  the  plate  a 
roll  of  wax  sufficiently  large  to  receive  the  imprint  of  the  lower  teeth, 
and  to  prevent  these  from  closing  too  far  by  the  insertion  of  a  piece  of 
wood  buried  in  the  wax  and  projecting  at  the  median  line.  The 
closure  is  better  arrested  by  two  lumps  of  sealing  wax  attached  oppo- 
site the  bicuspids,  and  trimmed  to  the  required  length  before  putting 
on  the  wax.  But  the  articulation  ought  to  determine  other  points 
besides  the  single  one  of  space.  Hence  the  antagonizing  plate  should 
be  made  by  adjusting  a  rim  of  wax  corresponding  in  width  to  the 
length  proposed  for  the  artificial  teeth,  and  trimming  it  until  all  the 
teeth  in  the  lower  jaw  touch  it  at  the  same  instant.  Instead  of  wax,  a 
rim  of  gutta-percha  may  be  used  to  represent  the  required  length  and 
external  fullness  of  the  teeth.  When  this  is  satisfactorily  adjusted,  a 
small  rim  of  soft  wax  is  placed  upon  the  wax  or  gutta-percha,  and  the 
mouth  closed  as  naturally  as  possible  until  the  teeth  touch  the  latter. 
The  gutta-percha  can  be  readily  trimmed  with  a  sharp  knife.  Rims 
thus  shaped  give  opportunity  to  ascertain,  by  the  effect  on  the  expres- 
sion of  the  lips,  etc.,  exactly  what  length  and  fullness  of  tooth  suits  the 
particular  case.  Gutta-percha  is  better  than  wax  in  arresting  the 
closure  of  the  teeth,  and  is  decidedly  best  for  the  temporary  articulating 
plates  of  plastic  work ;  but  the  latter  is  more  easily  attached  to  a  gold 
plate  and  is  more  easily  trimmed.  By  making  the  wax  cold,  or  by 
imbedding  a  small  block  of  wood  opposite  the  bicuspids  on  each  side, 
with  the  grain  of  the  wood  running  transversely,  for  easy  trimming, 
the  wax  rim  offers  a  firm  resistance. 

There  is  a  tendency  on  the  part  of  the  patient  to  close  the  mouth  to 
one  side,  and  nearly  always  to  project  the  jaw  too  far  forward  ;  it  is 
impossible  to  close  it  behind  the  natural  articulation.  The  simplest 
method  for  regulating  this  is  to  keep  the  body  erect  and  throw  the 
head  backward,  so  as  to  make  as  tense  as  possible  the  throat  muscles, 
which  thus  act  as  a  bridle,  and  almost  compel  a  correct  closure  of  the 
mouth.     It   may  also   be   done   by  careful   observation    of  repeated 


876  MECHANICS DENTAL    PROSTHESIS. 

closures  made  by  the  patient  while  sitting  in  an  erect  natural  position. 
The  operator  must  avoid  impressing  upon  his  patient  the  necessity  for 
an  easy  natural  closure  ;  such  directions  invariably  defeat  their  object. 
Of  course,  these  trials  are  to  be  made  before  attaching  the  soft  wax 
which  receives  the  impress  upon  the  final  closure.  A  vertical  median 
line,  traced  on  the  wax,  is  of  service  in  observing  the  articulation  and 
in  the  subsequent  adjustment  of  the  artificial  teeth.  Fig.  966  repre- 
sents such  a  rim  with  its  original  fullness  cut  away. 

For  a  double  set  of  artificial  teeth  the  following  method  of  articula- 
tion is  often  adopted.  After  having  accurately  fitted  both  plates,  a  rim 
of  soft  beeswax  is  placed  between  them,  about  an  inch  and  a  quarter  in 

width.  A  piece  of  wood,  exactly  cor- 
responding in  width  to  the  proposed 
length  of  the  upper  and  lower  central 
incisors,  is  passed  through  the  wax 
between  the  plates  at  the  median  line ; 
or,  still  better,  one  piece  on  each  side 
between  the  bicuspid  part  of  the  plates. 
The  whole  is  now  placed  in  the  mouth, 
and  each  plate  accurately  adjusted  to 
"^  ^g  the  alveolar  border.     The  patient  is 

then  directed  to  close  the  mouth  until 
the  plates  are  brought  in  contact  with  the  edges  of  the  interposed  piece 
of  wood.  This  done,  the  plate,  wax,  and  wood  are  together  removed 
from  the  mouth. 

But  a  far  better  method  consists  in  placing  a  rim  of  wax  or  gutta- 
percha on  each  plate,  giving  the  length,  outline,  and  fullness  respectively 
designed  for  the  teeth  of  each  jaw.  The  two  plates  are  put  in  the  mouth, 
and  the  jaws  are  carefully  closed  ;  if  the  rims  of  wax  touch  at  any  one 
point  sooner  than  another,  the  plates  are  removed  and  the  wax  trimmed  ; 
this  operation  is  repeated  until  the  two  rims  of  wax  meet  all  the  way 
round  at  the  same  instant,  and  give  the  proper  contour  .to  the  cheeks 
and  lips.  The  median  line  is  then  marked,  and  the  final  closure  of 
the  mouth  made  with  the  utmost  care,  so  that  there  shall  be  no  lateral 
or  forward  deviation.  The  exact  position  being  secured,  the  lower 
jaw  is  to  be  held  with  the  left  hand,  while  with  the  right  some  six  or 
eight  oblique  indentations  are  made  with  a  wax-knife  across  the  line  of 
contact  between  the  two  rims.  Some  fasten  them  together  by  a  warm 
wax-knife  or  by  pins  or  by  small  slips  of  brass  plate  warmed  and  forced 
into  the  wax.  The  pieces  are  removed  jointly  or  separately  from  the 
mouth  ;  if  separately,  they  can,  by  the  aid  of  these  marks,  be  accurately 
readjusted. 

From  these   articulating  plates  a  plaster  articulator    (Fig.  967)  is 


ARTICULATION. 


S77 


made  substantially  in  the  manner  described  for  a  partial  case.  If  the 
precaution  is  taken  to  fill  the  space  within  the  wax  rims  and  between 
the  plates  with  paper  pulp,  it  is  not  material  which  half  is  filled  first. 
Usually  the  lower-jaw  model  will  be  thickest,  and  in  this,  made  first, 
it  is  best  to  cut  the  grooves.  Fig.  967  represents  a  plaster  articulator 
with  the  plates  removed,  in  which  figure,  from  neglect  of  this  point, 
the  thin  upper  half  is  much  weakened  by  the  V-shaped  cut. 

Dr.  J.  G.  Templeton  suggests  the  following  method  of  properly 
articulating  a  set  of  teeth:  "Having  to  make  a  full  upper  set  of 
teeth,  we  will  suppose  the  impression  and  model  to  have  been  made 
in  the  usual  way.  Take  modeling  composition,  and  make  of  it  a  trial 
plate  (a  gutta-percha  plate  will  answer  also).  It  should  accurately  fit 
the  model.  Melt  a  little  wax  around  on  the  ridge,  then  press  a  roll 
of  softened  wax  on  that,  and  trim  to  what  is  supposed  to  be  a  sufficient 


„^,rr'.,rrr^ 


Fig.  967. 


length,  then  try  in  the  mouth  and  carefully  trim  the  lower  edge  to  the 
proper  length  for  the  teeth ;  if  it  is  not,  either  add  or  cut  away  until 
the  wax  represents  the  proper  length  of  the  teeth.  This  wax  should 
be  so  cut  on  its  articulating  surface  that  all  the  lower  natural  teeth  will 
strike  it  at  the  same  time  when  tried  in  the  mouth.  Now  remove  and 
soften  the  articulating  wax  surface  just  a  little  over  the  flame,  then 
replace  in  the  mouth,  and  do  not  let  patient  bite  into  it  until  you  have 
the  head  drawn  well  back  so  as  to  put  the  anterior  muscles  of  the  neck 
on  a  stretch ;  then  have  the  patient  bite  a  little  on  the  wax  just  to  get 
an  impression  of  the  cusps  and  cutting-edges  of  all  the  lower  teeth. 
Next  take  an  accurate  impression  of  the  lower  teeth,  from  which  make 
a  plaster  model,  which  will  fit  into  the  slight  impressions  of  the  teeth 
made  in  the  bite  taken,  and  then  place  the  whole  on  any  good  articu- 
lator which  can  be  set  to  maintain  the  relative  positions.     Remove  the 


878  MECHANICS — DENTAL    PROSTHESIS. 

bite,,  and  you  are  ready  to  set  the  teeth  to  a  correct  articulation,  and 
if  all  has  been  carefully  done  the  teeth  will  come  together  properly 
without  any  subsequent  grinding. 

"  For  a  double  set  (upper  and  lower)  make  trial  plates  of  modeling 
composition  to  take  the  bite  on,  putting  a  piece  of  rather  stiff  wire  in 
the  lower  one  to  stiffen  it.  Wax  the  ridges  as  previously  prescribed. 
Place  a  roll  of  softened  wax  on  the  upper  trial  plate,  place  the  lower 
trial  plate  in  the  mouth,  being  careful  to  see  that  it  is  in  its  proper 
place,  and  hold  it  there  while  putting  in  the  upper  plate  with  the  wax 
on  it.  Do  not  allow  the  patient  to  bite  until  the  head  is  drawn  back 
as  far  as  you  can  get  it ;  then  tell  the  patient  to  bite,  and  keep  the 
jaws  closed  until  with  one  finger  the  wax  has  been  well  pressed  on  to 
the  trial  plates.  Mark  the  center  or  median  line  on  the  wax.  Have 
patient  close  the  lips,  and  then  take  a  small;  straight  instrument  and 
mark  on  the  wax  the  height  of  the  lower  lip.  This  mark  should  extend 
from  one  angle  of  the  mouth  to  the  other  ;  you  then  have  the  line  of 
fissure  or  line  of  lip-closure,  in  other  words,  the  height  of  the  lower 
lip  and  length  of  the  upper,  to  serve  as  a  guide  in  making  the  wax 
models.  After  thus  taking  the  bite,  place  each  of  the  models  in  the 
bite  so  obtained,  and  fasten  in  any  good  articulator;  then  prepare 
corresponding  wax  models,  which  should  be  tried  in  the  mouth  to 
verify  their  correctness.  They  should  come  together  in  the  mouth 
the  same  as  on  the  articulator,  and  if  they  do  not  they  should  be  made 
to  do  so  before  proceeding  further.  Take  pains  to  be  satisfied  that 
the  wax  models  are  correctly  adjusted  and  give  a  natural  expression  to 
all  the  facial  features,  observing  that  the  lower  third  of  the  wax  model 
is  in  proper  proportion  or  length  with  the  upper  two- thirds,  and  be 
sure  to  produce  the  proper  fullness  over  the  region  of  the  upper  cuspids 
to  give  as  near  as  possible  the  natural  contour.  Then  take  the  upper 
and  lower  plaster  models  off  the  metal  articulator,  and  make  a  plaster 
extension  to  the  back  part  of  upper  model,  on  which  place  the  wax 
models,  which  have  been  marked  while  in  the  mouth  so  that  they  can 
be  put  in  the  same  position  out  of  the  mouth.  The  lower  plaster 
model  is  placed  in  position,  and  a  plaster  extension  added  to  fit  to  that 
of  the  upper  plaster  model.  After  separating  these,  the  lower  wax 
model  is  placed  on  the  lower  plaster  model,  and  the  inside  space  filled 
with  wet  paper,  and  plaster  is  poured  over  all  to  make  the  lower  articu- 
lating plate,  to  which  the  lower  teeth  are  to  be  set.  Next  place  the 
upper  model  in  position,  and  set  the  upper  teeth  to  the  lower  ones 
which  have  just  been  set  to  the  lower  articulating  plate,  and  when 
ready  for  flasking,  if  for  vulcanite  plates,  saw  off  articulating  ends. 
Always  set  the  lower  teeth  first." 

Partly  to  save  plaster,  but  chiefly  to  permit  modification   of  the 


ARTICULATION.  S79 

articulation  where  inaccuracy  is  suspected,  quite  a  number  of  metallic 
articulators  have  been  recommended.  One  of  the  first  contrived  for 
this  purpose  was  by  Dr.  Thomas  Evans,  of  Paris,  and  made  of  heavy 
brass  wire. 


Fig,  968. 


Fig.  968  represents  a  very  convenient  form  of  metallic  articulator. 
But  in  using  this  and  every  similar  contrivance  the  operator  should 
remember  that  facility  of  changing  the  articulation,  after  the  guiding 


Fig.  969. 

wax  rims  are  removed,  is  a  very  questionable  advantage.  It  tempts  to 
carelessness  in  articulating.  Moreover,  if  the  width  of  space  or  other 
relation  of  the  parts  is  such  as  leads  to  suspicion  of  inaccuracy,  any 
change  of  articulation  is,  at  best,  a  sort  of  random  guess-work.     The 


88o 


MECHANICS — DENTAL    PROSTHESIS. 


most  certain  correction  of  surmised  error  is,  undoubtedly,  to  take  the 
articulation  anew.  Hence  some  prefer  the  old-fashioned  plaster  articu- 
lator, with  its  unaccommodating  fixedness,  that  neither  offers  a  pre- 
mium on  carelessness,  nor  puts  the  careful  workman  at  the  mercy  of 
some  loose  joint  or  screw. 

There  is  another  class  of  articulators  more  complicated  than  the 
above,  which  are  very  useful  in  those  cases  where  the  original  models 
are  used,  instead  of  special  models  cast  in  the  articulating  plates. 
Fig.  969  represents  an  articulator  devised  by  Dr.  J.  B.  McPherson,  the 
valuable  feature  of  which  is  the  clamping  fixture  for  holding  the  plaster 
model.  The  danger  of  breaking  frail  models  in  removing  them  from 
the  articulator  is  overcome,  as  they  can  be  removed  by  simply  loosening 
the  clamp.  It  has  also  a  lateral  movement  resembling  that  of  the  jaw. 
Dr.  W.  Storer  How  suggests  the  use  of  soft  yet  sufficiently  stiff  and 
thin  metal  plates  for  securing  an  exact  tooth-length  and  a  correct 
articulation,  which  he  terms  "  true  bite-plates."  His  description  of 
these  plates  and  method  of  using  is  as  follows  :* — 

"  In  Fig.  970  is  seen  an 
upper  bite-plate  of  suitable 
thin  metal,  having  a  palatal 
portion  A,  a  plane  portion 
B,  and  a  contoured  edge  or 
border  C.  When  a  full  up- 
per denture  is  contemplated, 
the  bite  is  at  once  taken  by 
placing  on  the  bite-plate, 
Fig. 970,  a  sufficient  quantity 
of  warmed  beeeswax  to  secure  a  completely  good  impression,  and  at  the 
same  time  afford  material  for  modeling  the  labial  and  buccal  surfaces 
in  a  suitable  manner  to  produce  the  proper  facial  expression. 

"The  bite-plate  here  exhibits  its  novel  and  useful  functions  in  en- 
abling the  dentist  to  readily 
lengthen  or  shorten  the  bite, 
and  also  adapt  the  bite- 
plane  B  to  the  lip-line,  as 
well  as  to  the  occluding 
lower  teeth.  When  this  has 
been  carefully  done  and  the 
mass  removed  from  the 
mouth,  the  appearance  will 
approximate  that  of  Fig. 
971.     If  the  bite  then  requires  an  increase  of  length,  the  bite-plate  is 


Fig.  970. 


Fig.  971. 


*  Dental  Cosmos. 


ARTICULATION.  88 1 

held  a  moment  over  the  Bunsen  flame,  when  it  will  fall  on  a  paper 
napkin  held  in  the  hand.  It  is  then  covered  with  a  thin  sheet  of  wax, 
replaced  on  the  modeled  wax,  trimmed  with  the  wax-knife  along  the 
contour  border  C,  again  put  in  the  mouth,  and  conformably  remodeled 
and  readjusted.  The  quickly  transmitted  heat  of  the  metal  bite-plate 
permits  facile  changes  in  occlusive  adaptation  and  contour,  without 
disturbance  of  the  fit  of  the  impression  portion  of  the  wax,  an  advan- 
tage of  real  consequence  and  value. 

"  If  upon  further  study  it  is  desired  to  shorten  the  bite,  the  mass  is 
removed  from  the  mouth,  the  plate  quickly  warmed  over  the  Bunsen 
flame,  all  replaced  in  the  mouth,  and  the  patient  instructed  to  close 
the  teeth  firmly  on  the  bite-plane,  which,  while  accurately  maintaining 
the  plane  of  the  occluding  teeth  to  which  it  has  been  conformed,  will 
at  the  same  time  cause  the  softer  wax  immediately  in  contact  with  the 
plate  to  gradually  yield  until  the  bite  becomes  suitably  shortened. 


Fig.  972. 


Fig.  973- 


"  In  this  connection  it  is  important  to  note  the  functional  difference 
of  this  metal  bite -plane  from  the  common  wax  plane,  which  yields 
and  is  indented  by  any  considerable  pressure  of  the  occluding  teeth ; 
whereas,  in  the  present  instance,  so  soon  as  the  wax  has  cooled  to  a 
slight  stiffness,  the  patient  is  directed  to  press  the  teeth  hard  on  the 
bite-plate  (see  Fig.  972),  and  the  result  is  a  bite-gauge  identical  in 
length  with  that  which  the  finished  denture  will  have  under  the  ordi- 
nary pressure  of  the  closed  jaws.  Many  of  the  usual  disappointing 
discrepancies  between  the  common  soft  wax  bite-gauges  and  the  result- 
ing defectively  articulating  dentures  rtiay  now  be  avoided. 

"  The  smooth  and  hard  surface  of  the  bite-plane  B  fixes  a  constant 
and  firm  limit  to  the  bite-length  while  allowing  the  utmost  freedom  of 
lower-jaw  movement  in  occlusion  during  the  adjusting  and  modeling 
processes  to  secure  a  natural  oral  and  facial  expression,  with  a  proper 
lip  line  as  indicated  in  Fig.  973.  This  having  been  accomplished,  a 
56 


882 


MECHANICS— DENTAL    PROSTHESIS. 


roll  of  warmed  wax  is  placed  on  the  under  side  of  the  bite-plate,  which 
is  replaced  in  the  mouth,  and  the  patient,  while  the  previous  process 
was  going  on,  having  been  instructed  and  practiced  in  the  correct 
manner  of  closing  the  jaw,  the  head  being  thrown  back  to  bring  the 


Fig.  974. 


Fig.  975. 


face  horizontal  and  the  jaw  held  as  far  back  as  possible,  the  teeth  are 
pressed  through  the  wax  on  to  the  bite-plate,  and  kept  there  while  with 
the  finger  the  labial  and  buccal  portions  of  the  soft  wax  are  pressed  in 
upon  the  natural  teeth.     The  mass  is  then  carefully  removed  from  the 


ARTICULATION. 


Fig.  976. 


mouth  and  kept  in  safe  readiness  for  transfer  to  the  plaster  model  when 
obtained  from  the  plaster  impression,  and  it  is  unnecessary  to  dwell 
upon  the  advantages  of  securing  a  certainly  correct  bite  at  the  time  of 
the  sitting  secured  for  taking  the  plaster  impression.  Fig.  974  shows 
a  bite  thus  taken  and  transferred  to  the  model  set  in  an  articulator, 
and  Fig.  975  represents  the  correct  bite  so  obtained.  This  novel 
bite-plate   provides    for   the 

taking  of  a  very  short  bite,  as  .  ^',',JM;^;m:.^./M.^i^-ii^-^-^y- 
shown  in  Fig.  975.  In  fact, 
the  bite-plane  B  may  rest 
directly  upon  the  gums,  and 
the  under  teeth  strike  the 
plate,  yet  the  rigidity  of  the 
metal  plate  is  such  that  the 
wax  impression  and  model- 
ing will  not  warp  in  the  ad- 
justing, shaping,  and  remov- 
ing manipulations  ;  whereas, 

by  the  old  mere  wax  methods,  a  trustworthy  very  short  bite  is  imprac- 
ticable. 

"  Fig.  976  exhibits  a  median  line  section  exemplifying  the  relations 
between  the  bite-plate  A,  B,  C,  the  wax  W,  the  modeling  M,  the 
upper  jaw  J,  the  lower  jaw  J\  and  the  occluding  lower  teeth.  Obvi- 
ously, by  simply  first  warming  the  bite-plate  and  then  while  in  the 
mouth  sliding  it  suitably  forward,  the  contour  modeling  may  be  done 

to  produce  a  result  like 
that  of  the  median  line 
section,  Fig.  977.  In  any 
given  case  the  bite-plate 
border  C  can  be  easily  cut 
or  filed  to  suitably  modify 
its  contour  to  the  desired 
configuration  of  the  model- 
ing, although  it  is  best  to 
have  at  hand  several  sizes  of 
the  bite-plate  to  use  with- 
out delay  for  adaptation. 
"  By  cutting  away  the  wax  W  to  expose  the  upper  anterior  gum  G  and 
ridge-crest  from  cuspid-place  to  cuspid-place,  as  shown  in  Fig.  978, 
the  space  between  the  bite-plane  border  C  and  the  ridge-crest  may  be 
accurately  gauged  to  determine  the  availability  of  artificial  teeth 
having  cross-pin,  or  up-and-down-pin  bite  length  ;  it  being  a  matter  of 
importance  at  the  outset  to  decide  the  question  of  permissible  bite- 


FiG.  977. 


884 


MECHANICS DENTAL    PROSTHESIS. 


space  between  the  gum  crest  and  the  down-pin  border  of  the  teeth- 
backs.  The  overbite  or  lap  of  the  upper  oral  teeth  over  the  incisive 
edges  of  the  lower  teeth  may  then  be  provided  for  by  means  of  some 
softened  wax  on  the  under  side  of  the  bite-plane,  modeling  some  wax 
overtheanterior  gum  and  edges  of  the  lower  teeth,  as  shown  in  Fig.  979. 
"  Bite  impressions  for  partial  dentures,  however  irregular  the  jaw 
surfaces  or  occlusive  dispositions,  can  be  most  conveniently  and  cor- 
rectly produced  by  means  of  the  modified  bite-plates  herein  shown  and 


Fig.  978. 


Fig.  979. 


described.  In  some  instances  modeling  compound,  plaster,  or  moldine 
may  be  advantageousl}'  employed  instead  of  wax. 

"For  partial  upper  dentures,  sections  of  the  bite-plate  are  with 
plate-nippers  cut  out,  as  at  EE,  Fig.  980,  and  the  bite  taken  in  the  way 
previously  described. 

"  The  lower  bite-plate,  Fig,  981,  is  of  like  character  with  that  of 
Fig.  970,  the  lingual  portion  D  being  designed  to  approximate  the 


i  E 


Fig.  980. 


Fig.  981. 


lingual  conformation  of  the  lower  jaw,  while  the  bite-plane  Band  con- 
tour border  C  have  the  bite-taking  functions  of  the  upper  bite-plate. 
For  partial  lower  dentures,  sections  may  be  cut  out,  as  at  EEF,  Fig.  982, 
to  permit  the  passage  of  the  remaining  natural  teeth  through  the  bite- 
plate,  the  intermediate  planes  of  which  can  be  shaped  to  conform  to 
any  plane  of  the  occluding  upper  tooth  or  teeth. 

"When  either  jaw  is  a  very  flat  one,  it  is  best  to  take  first  on  the  bite- 


ARTICULATION. 


885 


plate  a  good  impression  in  wax,  and  then  with  a  spoon  spatula  scoop 
out  about  an  eighth  of  an  inch  deep  over  the  surface  of  the  impres- 
sion, smear  over  it  some  rather  thick  mixed  plaster,  and  take  another 
complete  impression.  This,  when  allowed  to  get  quite  hard  and 
suitably  trimmed  at  its  borders,  may  be  often  replaced,  and  readily 
retained  in  the  mouth  during  the  modeling  and  adjusting  process 
requisite  in  obtaining  the  bite  by  the  methods  already  described.  In 
fact,  this  is  the  preferable  procedure  for  bite-taking  in  the  greater 
number  of  full-denture  cases,  since  the  plaster  contact  with  the  jaw  is 
unvarying  and  retentive,  while  the  bite-plate  is  adjustably  movable 
on  the  intermediate  modelable  wax.  There  is,  furthermore,  the  cer- 
tainty that  the  plaster  bite  impression  will  fit  the  plaster  model ;  in 
fact,  it  may  sometimes  supersede  the  plaster  impression  if  found  in 
some  particulars  the  better.     Thick-mixed  plaster  may  be  piled  on  the 


i  E 


fJl 


Fig.  983. 


under  surface  of  the  bite-plane,  and  the  occluding  surfaces  of  the  under 
teeth  be  perfectly  copied  for  reproduction  in  fusible  metal  if  desired. 

"  If  the  maxillary  vault  is  a  very  low  one,  an  upper  bite-plate  with 
its  plane  B  resting  on  a  flat  block  may  be  struck  with  a  hammer  on  its 
arch  A,  Fig.  970,  to  suitably  depress  it  to  conform  to  the  low  vault. 
To  suit  a  narrow  high  vault,  set  the  buccal  edge  on  a  block  or  anvil 
and  strike  it  with  a  hammer  on  the  opposite  edge  to  contract  the  wings 
and  raise  the  arch  A. 

"In  taking  the  bite  for  a  full  denture,  theupper  and  lower  bite-plates 
are  used  as  already  described,  and  the  facility  with  which  the  model- 
ing, contouring,  lip-line,  and  relative  upper  and  lower  teeth  lengths 
may  be  determined  will  agreeably  surprise  experienced  prosthetists 
accustomed  to  the  old  wax-model  methods.  The  upper  and  lower 
metal  bite-planes,  during  the  process  of  adjustment,  perfectly  main- 
tain the  bite- length,  yet  slide  freely  upon  each  other  during  the  mas 


886 


MECHANICS DENTAL    PROSTHESIS. 


ticatory  movements  of  the  jaw  requisite  in  repeated  trials  to  determine 
the  correctness  of  the  modeling  and  the  bite-lengths.  When  that  has 
been  satisfactorily  accomplished,  the  patient  is  instructed  to  properly 
close  the  jaws  and  hold  them  firmly  closed  while  the  median  line 
mark  is  made,  and  the  lips  on  either  side  held  apart  while  the  usual 
cross-lines  are  scratched  over  the  modeling  and  the  two  bite-plate 
edges  somewhere  near  the  molar  regions  on  both  sides. 

"Both  models  are  then  removed,  the  bite-planes  dried,  slightly 
warmed,  placed  upon  each  other  so  that  the  median  line  and  scratched 
marks  shall  exactly  coincide  and  be  held  so,  while  with  a  stick  of 
melted  hard  wax  the  inside  edges  of  the  bite-planes  are  stuck  fast  to 
each  other.  The  correctness  of  the  bite  may  be  verified  by  replacing 
the  united  bite-plates  in  the  mouth,  distending  the  lips  and  cheeks 
with  the  forefinger  to  free  them  from  entanglement  with  the  plates, 
and  making  careful  renewed  observations  to  be  sure  that  the  bite  is 
correct.     The  median  line  section,  Fig.  983,  shows  such  a  bite. 

"^  In  the  duplex  bite-plate.  Fig.  984,  the  two  plates,  Figs.  970  and 
980,  are  made  as  one  ;  and  with  a  full  understanding  of  the  processes 
previously  described,  it  may  be  in  like  manner  used  to  take  the  bite  for 
a  full  upper,  or  full  upper  and  lower  denture,  as  the  case  may  be,  Fig. 
974  serving  as  an  example  of  the  taken  bite  in  either  case. 

"  The  duplex  bite-plate  has  an  occasional  supplemental  use  for 
taking  simultaneous  impressions  of  the  teeth  in  both  jaws  for  regulating 
purposes ;  when  it  is  desired,  for  instance,  to  make  a  vulcanite  or  cast- 
metal  plate,  a  portion  of  which 
is  to  cap  the  molars  or  other 
teeth.  In  such  a  case  the 
bite-plane  is  to  be  cut  away  to 
allow  the  passage  of  the  an- 
terior teeth,  leaving  such  parts 
of  the  bite-plane  as  may  be 
required  to  rest  upon  the  teeth 
which  are  to  be  capped.  The 
wax  on  the  upper  and  under 
side  of  the  remaining  portions 
of  the  bite-plane  will  insure 
in  the  articulator  models  a  representation  of  the  occluding  surfaces  in 
their  exact  relations  to  each  other,  and  separated  by  the  desired  thick- 
ness of  the  vulcanite  caps  of  the  regulating  fixture. 

"  In  some  instances,  as  when  the  vault  is  very  high,  the  central  part 
^f  the  palatal  portion  A  is  slit  and  bent  wide  open,  or  with  plate  nip- 
pers suitably  cut  to  allow  the  pressing  up  of  the  wax  by  the  forefinger, 
to  get  a  good  impression  of  the  deep  vault. 


Fig.  984. 


ARTICULATION.  SS7 

"These  bite-plates  provide  for,  and  emphasis  is  laid  upon  the  im- 
portance of  procuring,  a  complete  and  perfect  impression,  which  will 
fit  the  plaster  cast  taken  from  the  plaster  impression  and  thus  insure 
the  correctness  of  the  bite  as  reproduced  on  the  articulator.  (See 
Fig.  975.)  In  some  instances  modeling  composition  is  used  instead  of 
wax.  In  every  case  the  tendency  to  redundancy  of  labial  and  buccal 
material  in  the  modeling  is  to  be  thoughtfully  avoided,  as  may  well  be 
done  since  the  good  palatal  fit  will  serve  to  retain  the  plate  even  when 
the  labial  part  of  the  maxillary  ridge  is  not  covered  by  the  modeled 
wax. 

"It  is  best  to  first  take  the  bite,  and  follow  with  the  impression, 
which  is  usually  taken  in  plaster  and  attended  with  more  or  less  dis- 
comfort to  the  patient. 

"  Not  the  least  of  the  notable  excellences  of  the  new  bite-plate  is  the 


Fig.  985. 


certainty  that  after  the  modeling  has  been  done  (see  Figs.  972  and  973), 
the  patient  will  bite  through  the  soft  under  wax  until  the  teeth  strike 
and  are  stopped  by  the  bite-plane,  thus  invariably  and  accurately 
gauging  the  teeth-length.  Indeed,  both  the  means  and  the  methods 
are  submitted  in  the  confidence  that  time  and  practice  will  insure 
their  general  approval  and  adoption  by  the  profession." 

A  further  series  of  bite-plate  exemplifications  following  the  above, 
and  relating  to  the  adaptation  of  the  bite-plate  to  partial  dentures,  are 
as  follows :  — 

"Take,  for  instance,  a  case  like  that  of  Fig.  985,  the  superior  cus- 
pids only  remaining.  A  sheet  of  thick  tin  foil,  or  of  pattern  tin,  is  to 
be  cut  to  the  outline  of  an  upper  bite-plate  (Fig.  970),  placed  in  the 
mouth,  and  with  the  forefinger  rubbed  on  to  the  gum  ridge  and  around 
the  cuspids  to  show  their  relative  positions.     This  rude  pattern  laid 


888 


MECHANICS — DENTAL   PROSTHESIS. 


on  an  upper  bite-plate  will  indicate  the  points  to  be  cut  out  with  plate 
nippers,  as  at  EE,  Fig.  980.  The  bite-plane  B  may  be  sheared  to 
shape,  and  the  bite-plate  by  repeated  trials  in  the  mouth  be  quickly 
prepared  to  receive  the  wax  for  obtaining  the  preliminary  bite-gauge 
as  shown  in  Fig.   986.     This,  when  removed  from  the  mouth,  will 


Fig.  986. 


appear  as  seen  in  Fig.  987.  When  the  additional  wax  for  modeling 
and  contour  has  been  supplied,  the  case  will  jjresent  the  appearance 
illustrated  in  Fig.  988,  the  median-line  mark  shown  being  a  trans- 
ference from  that  of  the  plaster  models  after  the  bite  had  been  taken 
(as   described  on   page   886)  and    placed    on    the   articulator   as   in 


Fig.  987. 


Fig.  974.  Another  instance  is  given  in  Fig.  989.  Here  the  pattern- 
plate  procedure  is  the  same  as  above  described,  the  bite-plate  being 
readily  fitted  so  that  a  piece  of  the  bite-plane  B,  Fig.  980,  shall  enter 
every  space  that  is  to  be  occupied  by  an  artificial  tooth  or  teeth. 
There  is  no  risk  of  overestimating  the  value  of  this  adjunct  of  the 


ARTICULATION. 


889 


partial-denture  process  which  results  in  an  accurate  bite  ready  for 
transfer  to  the  model  when  obtained  from  the  succeeding  plaster  im- 
pression. 


Fig.  990. 


''Fig.  990  shows  the  taken  bite  with  the  labial  and  buccal  portions 
of  the  under  wax  cut  away  to  illustrate  a  defect  in  the  common  pro- 
cess of  bite  taking,  not  in  fact  manifest  in  the  present  instance,  because 
the  cuspids  and  other  teeth  compel  a  correct  closure  that  is  evidenced 


8qo 


MECHANICS — DENTAL    PROSTHESIS. 


by  the  thin  fihns  of  wax  at  the  points  of  occlusion  contact  seen  on 
removing  the  bite,  which  is  proven  to  be  accurate  when  completed  by 
the  addition  of  wax  over  the  labial  and  buccal  surfaces  of  the  lower 
teeth  and  a  transference  to  the  impression  model  on  the  articulator, 
the  result  being  such  as  shown  in  Fig.  991. 

"  The  common  defect  just  referred  to  is  the  massing  of  too  much 

wax  on  the  under  side  of 
the  trial  plate,  or  bite- 
plate,  and  the  consequent, 
sliding  forward  of  the 
lower  front  teeth  as  the 
inclined  planes  of  their 
lingual  surfaces  are  forced 
into  the  deep  mass  of  wax, 
somewhat  as  is  observable 
in  the  case  illustrated  by 
Fig.  990,  and  is  made 
further  obvious  by  Fig.  992.  There  is  no  practical  need  for  a  bite 
impression  of  the  lingual  surfaces  of  the  lower  teeth  below  the  point 
P,  Fig.  992,  while  on  the  other  hand  there  is  a  serious  reinforcement 
of  the  natural  tendency  to  lower  jaw  protrusion  in  the  act  of  desired 
bite-closure  when  the  wax  is  massed  as  above  mentioned.  The  new 
bite-plate  permits  the  use  of  merely  sufficient  wax,  as  in  Fig.  993,  to 
reproduce  the  cutting-edges  and  cusps  of  the  teeth  without  any  aid  to 


Fig  991 


„,„i'""'"" 


Fig.  992. 


the  protrusive  tendency  whatever.  While  the  teeth  remain  closed  for 
coronal  bite  reproduction,  additional  wax  may  be  pressed  on  to  the 
labial  and  buccal  surfaces  of  the  lower  teeth  to  produce  as  perfect  a 
representation  as  is  shown  in  Fig.  991. 

"It  is  hoped  that  the  foregoing  illustrations  and  descriptions  will 
suffice  as  intimations  of  the  manifold  adaptation  of  the  several  bite- 
plate  modifications  to  meet  any  and  every  case  arising  in  practice,  and 


ARTICULATION.  89 1 

as  affording  ready  means  for  the  obtaining  a  correct  bite  prior  to  the 
taking  of  the  usual  plaster  or  modeling-composition  impression,  yet  at 
the  same  sitting. 

"The  bite-plate  method,  while  at  the  outset  reasonably  requiring 
the  expenditure  of  some  time  and  study,  is  still  an  economizer  of  both 
time  and  labor,  inasmuch  as  it  enables  the  dentist  to  meet  the  patient 
at  the  second  sitting  with  a  complete  denture.  In  any  case  he  may  be 
ready  with  a  trial-plate  on  which  the  teeth  shall  have  been  arranged 
and  articulated  so  naturally  that  but  slight  alterations  will  probably  be 
necessary.  Especially  will  this  be  the  case  if  instead  of  wax,  as  at  w, 
Fig.  993,  moldine  shall  have  been  used,  and  fusible  metal  poured  in 
the  coronal  impressions  to  insure  sharply-defined  and  non-abrasive 
cusps  for  accurate  articulation." 

Dr.  W.  G.  A.  Bonwill,  who  has  devoted  much  time  to  the  study 
of  the  geometric  and  mechanical  laws  of  articulation,  and  devised  an 
anatomical  articulator  (Fig.  994)  in  accordance  therewith,  treats  this 
subject  as  follows  : — 

"  We  find  from  28  to  32 
teeth  in  each  jaw,  arranged 
in  such  a  manner  that  no 
two  strike  directly  against 
each  other,  but  antagoniz- 
ing in  such  a  manner  as  to 
prevent  the  whole  denture 
from  becoming  very  irregu- 
lar,    which    would    be  the 

.,         .,  .  .      ^  Fig.  994- 

case  if  striking  one  against 

another.  By  this  arrangement,  when  one  tooth  is  lost,  the  regularity 
of  the  arch  is  not  interfered  with.  As  necessary  as  this  is  in  nature, 
it  is  not  positively  necessary  to  follow  it  in  artificial  work,  although 
for  the  sake  of  harmony  it  should  be  done. 

"  It  will  be  found  in  95  per  cent,  of  cases  that  the  upper  teeth  pro- 
ject over  the  lower,  and  the  depth  of  overbite  varies  as  the  depth  of 
the  cusps  of  the  bicuspids  are  deep  or  shallow  ;  and  the  ramus  will  be 
found  to  come  upward  and  backward  in  relative  proportion  to  the 
length  of  the  cusps  and  the  overbite. 

"  One  point  of  very  great  importance  has  not  been  laid  down  in 
general  or  special  anatomy — the  peculiar  tripod  arrangement  of  the 
lower  jaw,  forming  an  equilateral  triangle. 

"From  the  center  of  one  condyloid  process  to  the  other,  four  (4) 
inches  is  about  the  average ;  and  it  will  be  found  that  from  this  same 
center  of  the  condyloid  process  to  the  median  line  at  the  point  where 
the    inferior    centrals   touch   at   the    cutting    edge   is    also  four   (4) 


S92  MECHANICS — DENTAL    PROSTHESIS. 

inches.  It  is  strange  it  should  have  been  overlooked  ;  but  it  only 
shows,  when  studied  in  a  geometrical  and  mechanical  sense,  the  great 
wisdom  in  our  formation.  It  varies  slightly,  but  never  more  than 
one-fourth  of  an  inch,  which  would  make  but  a  trifling  difference  in 
describing  the  arc  of  a  circle.  You  will  perceive  that  in  setting  your 
artificial  teeth  a  one-fourth  inch,  the  radius  of  the  circle  would  not 
materially  alter  the  articulation.  Without  such  an  arrangement  the 
teeth  would  have  to  be  flat  on  their  grinding  surfaces  to  admit  of  lat- 
eral movement.  Besides,  you  would  not  have  the  beautiful  and  wise 
curvature  at  the  ramus  for  equalizing  the  force  applied  to  the  teeth 
in  all  directions. 

"Imagine  the  human  jaw  jointed  at  the  pharynx,  or  as  you  see  in 
the  ordinary  brass  articulators.  Do  you  suppose  that  there  would  be 
any  greater  wisdom  displayed  in  such  hinging  or  articulating  a  part 
destined  to  such  varying  motions  and  powerful  wrenching  force? 
No  !  We  must  see  the  true  use  or  function  of  the  jaw  and  the  teeth, 
and  the  food  destined  for  us,  and  how  it  should  be  comminuted ; 
there  is  no  chance  work  about  it !  There  is  law  and  order  pervading 
every  part ;  the  jaw  forms  a  perfect  triangle  for  the  purpose  of  bring- 
ing into  contact  the  largest  amount  of  grinding  surface  of  the 
bicuspids  and  molars,  and  at  the  same  time  to  have  the  incisors  all 
come  into  action  during  these  lateral  movements. 

"  You  will  also  find  that  from  the  cuspids  the  bicuspids  and  molars 
run  in  nearly  a  straight  line  instead  of  a  curved  one  back  toward  the 
condyloid  process,  enabling  them  to  keep  the  largest  amount  of  sur- 
face always  presented  for  mastication.  Another  thing  which  has 
never  been  explained  by  anatomists  or  naturalists  is  the  law  of  the 
normal  relation  of  the  upper  to  the  lower  incisors.  The  normal  jaw 
should  overjet  and  also  have  a  corresponding  underbite.  With- 
out such  a  law  the  incisors  would  lose  largely  their  functions,  that  of 
incising  on  the  principle  of  a  pair  of  scissors.  Where  the  incisors 
strike  directly  upon  each  other  the  power  to  cut  off  food  is  very  much 
lessened.     The  length  of  bicuspids  and  molars  proves  the  law. 

''Another  unobserved  fact  where  law  is  expressed,  where  there  is 
an  overbite  and  underbite,  just  in  proportion  to  their  depth  will  be 
the  length  of  the  cusps  of  the  cuspids,  bicuspids,  and  molars.  By 
drawing  two  lines  from  T  to  F,  Fig.  looi,  or  T  to  a  and  e,  Fig.  995, 
we  have  the  lengths  of  the  cusps  of  the  bicuspids,  ^,  in  the  upper 
and'  c  in  the  lower,  and  also  d,  the  second  upper  molar.  The  depth 
of  the  underbite  is  one-eighth  of  an  inch  from  the  cutting  edge  of 
the  inferior  central  incisor  e  to  that  of  the  superior  central  incisor  a. 
Did  the  teeth  extend  as  far  back  as  A,  A,  there  would  be  flat  surfaces 
at  those  points.     But  in  articulating  artificial  teeth,  when  the  superior 


ARTICULATION.  893 

second  molar  is  reached,  its  distal  cusp  has  to  be  raised  from  line  T  e 
to  T  a,  Fig.  995,  to  allow  the  molar  teeth  on  the  opposite  side,  not 
in  mastication,  to  touch,  for  merely  balancing  the  plate,  as  Fig.  998, 
M,  N,  otherwise  the  second  molars  would  be  of  no  use  in  lateral 
movement,  nor  would  the  first  molars.  This  curvature  at  the  ramus 
(see  Figs.  999  and  1000)  commences  at  the  first  molar,  although  it 
shows  itself  slightly  in  the  bicuspids.  Practically  it  need  commence 
at  the  first  upper  molar.  This  curve,  then,  will  always  be  propor- 
tioned by  the  underbite  at  a,  e.  The  length  of  the  cusps  on  bicuspids 
will  never  be  more  than  an  eighth  of  an  inch  normally  ;  the  groove 
deeper  than  that  would  cut  the  palatal  cusp  off  and  make  of  it  a 
cuspid.  It  would  in  reality  be  cut  in  twain.  This  is  another  tin- 
obset^>ed  fact.  It  ahvays  has  been  and  will  be  found  in  the  archtype 
of  human  jaws.  So  that  when  you  see  a  first  superior  bicuspid,  it  can 
very  well  be  told  from  the  length  of  the  cusps  whether  the  jaw  from 


^ 


Fig.  995. 

which  it  came  had  a  depth  of  underbite  of  one-sixteenth  of  an  inch 
or  more.  Where  the  teeth  all  strike  fairly  one  upon  the  other  and  no 
overbite,  then  you  have  no  occasion  for  cusps.  If  originally  there 
they  would  soon  be  worn  off  from  the  abnormal  articulation. 

"  This  provision  of  articulation  is  most  wise,  carrying  out  still  more 
fully  the  exact  law  by  which  the  anatomical  movements  of  the  lower 
jaw  for  perfect  mastication  are  governed.  This  movement  we  will 
find,  in  the  artificial  sets  arranged  upon  this  law,  will  prevent  the 
plate  from  tilting.  In  the  natural  denture  the  incisors  are  really  the 
first  teeth  to  be  arranged  ;  though  the  first  molars  emerge  first,  to 
assist  in  the  more  perfect  mastication  of  food  and  to  keep  the  jaws  at 
the  proper  distance.  The  incisors  show  a  definite  fixedness  of  purpose 
to  arrange  themselves  after  their  typal  shape,  and  to  form  the  overjet 
and  overbite  at  a  given  depth  for  the  accommodation  of  the  bicuspids 
and  molars  which  are  soon   to  appear,  having  cuspids  of  a  definite 


894  MECHANICS — DENTAL    PROSTHESIS. 

length,  so  that  the  law  of  articulation,  which  has  been  premeditated  to 
a  certain  typal  shape  and  construction,  be  carried  out. 

"  It  will  also  be  found  that  the  grinding  surfaces  of  the  bicuspids 
and  molars  have  a  typal  shape — allowing  them  to  meet  with  all  their 
surfaces  touching — for  an  express  purpose,  after  a  preordained  and  estab- 
lished law,  from  which  the  greatest  area  is  gained  for  mastication  ;  and 
that  the  inner  cusps  of  the  lower  teeth  are  as  necessary  as  the  outer  of 
the  superior,  when  laterally  moved.  The  law  is  still  further  carried 
out  in  the  curvature  at  the  ramus,  from  the  second  bicuspids  to  the 
third  molar,  to  permit  all  the  surfaces  on  one  side  to  be  in  contact  (Fig. 
1000),  while  the  other  unused  side  is  only  partially  so  (Fig.  999).  The 
nearly  straight  line  of  arrangement  from  the  cuspids  to  the  last  molar  is 
also  in  keeping  with  the  underbite  (Fig.  995). 

"  This  triangle  can  only  be  found  within  a  perfect  circle  in  which 
you  have  the  greatest  breadth  and  area  of  surface.  No  other  geo- 
metrical angle  would  have  given  such  perfect  beauty  and  symmetry 
to  the  face.  The  compactness  brings  the  largest  number  of  teeth 
nearest  the  center  of  motion.  The  double  joint  permits  the  greatest 
strength  and  the  easiest  lateral  movement  with  the  greatest  range  of 
this  at  the  least  expense  of  power  and  compass.  It  permits  the 
largest  number  of  teeth  to  antagonize  at  every  movement,  and  not 
least  of  all,  this  very  triangle  is  the  means  by  which  nature  develops  the 
typal  shape  of  the  ramus,  and  of  the  fonnation  of  the  Jaws,  the  under- 
bite, etc. 

''It  will  be  observed  that  in  making  the  lateral  movement  of  the 
lower  jaw  to  the  left  the  condyle  of  the  left  side  stands  still  or  does  not 
move  backward,  it  merely  revolves  or  rotates  in  the  socket,  which  is 
but  a  trifle.  The  right  condyle  moves  forward  in  the  glenoid  cavity 
fully  half  an  inch,  when  at  its  farthest  limit,  causing  the  outer  cusps  of 
the  upper,  from  the  centrals  to  the  last  molar,  to  touch  the  outer  and 
inner  or  buccal  and  lingual  cusps  of  the  lower  on  same  side — the  left 
(Fig.  1000,  and  J  K,  Fig.  998)  ;  and  on  the  opposite  side  (Fig.  999, 
and  M,  N,  Fig.  998) — the  right — we  find  only  the  inner  cusps  of  the 
bicuspids  and  molars  of  the  upper  to  come  in  contact  with  the  outer 
of  the  lower,  and  the  centrals  to  the  cuspids  do  not  touch.  And  why 
so  little  surface  touching  on  right  side  when  the  lower  jaw  is  thrown 
to  the  left  ?  You  cannot  masticate  on  more  than  one  side  at  once, 
and  when  you  throw  the  jaw  to  the  left  in  the  act  of  masticating,  the 
food  is  upon  that  side,  hence  there  is  no  necessity  for  the  right  side 
to  have  so  much  surface  in  contact.  But  why  should  it  touch  at  all 
on  the  right  ?  In  order  that  the  muscles  on  both  sides  should  act 
equally,  which  could  not  be  done  if  the  teeth  were  not  allowed  to 
strike  there,  giving  support  to  that  side  of  the  jaw,  and  equalizing  the 


ARTICULATION.  895 

force  brought  to  bear  upon  that  side,  although  no  food  be  there.  If 
tnere  were  no  touching  of  the  teeth  on  that  side  while  mastication  is 
going  on  upon  the  left  side,  there  would  result,  as  a  sequence,  that 
peculiar  movement  of  the  lower  jaw  at  the  condyloid  process,  which 
makes  it  difficult  to  place  in  teeth  for  the  aged,  or  those  even  in  early 
life  who  have  lost  all  the  grinders  on  one  side. 

''The  form  of  triangle  is  necessary  again  for  the  purpose  of  giving 
the  largest  number  of  muscles  a  chance  to  act  on  both  sides  simul- 
taneously and  concentratedly,  and  thereby  keeping  the  circle  or  arch 
of  grinders  down  to  their  work,  and  equalizing  the  pressure  on  all 
sides.  It  enables  the  teeth  on  the  side  where  the  chewing  is  being  done 
to  arrange  themselves  when  erupting,  so  that  they  will  be  very  nearly 
in  a  line  with  the  left  condyle,  which  is  now  passive  on  this  side, 
and  forms  one  point  of  the  dividers  in  forming  the  arc  of  a  circle  ;  and 
by  this  condyle  being  where  it  is — four  inches  from  the  other — the 
molars  and  bicuspids,  as  well  as  the  central  of  that  side,  all  come 
into  the  most  perfect  contact  for  chewing  and  incising,  thereby  carry- 
ing out  this  absolute  natural  law  of  the  perfect  adaptation  of  geometry 
and  mechanics  to  her  uses,  and  having  no  lost  motion  or  function  in 
any  part. 

"Again,  the  triangle  gives  us  an  extra  motion  forward,  which 
brings  the  lower  teeth  in  contact  with  the  upper  to  incise  or  cut  off 
food  presented  there.  This  could  not  have  been  with  any  other  arrange- 
ment than  the  triangle.  One  central  point  at  the  pharynx  or  on  the 
median  line  would  have  been  a  single  swivel  joint,  and  have  brought 
the  teeth  across  each  other  in  such  a  way  that  as  soon  as  any  lateral 
movement  commenced  they  would  be  drawn  away  from  each  other 
very  rapidly,  and  but  little  surface  be  in  contact.  This  triangle  will 
enable  you  to  get  just  the  exact  depth  of  underbite  from  the  incisors 
to  the  last  molar  and  the  exact  shape  of  arches;  and  particularly  that 
of  the  ramus,  which  is  not  a  matter  of  chance — neither  is  the  length 
of  cusps  on  the  bicuspids  and  molars  mere  chance.  The  type  has  been 
preordained,  just  as  the  nose  on  your  face,  or  the  peculiar  shape  of  the 
eye,  or  any  other  one  part  of  the  body.  And  you  will  find  that  where 
a  superior  bicuspid  has  a  cusp  of  a  given  length,  the  overbite  will  be 
governed  and  ruled  by  it.  It  cannot  be  otherwise.  If  in  the  ar- 
rangement of  the  teeth  in  the  human  jaw  no  type  or  design  were 
laid  down  in  conception  or  embryonic  life,  what  malformed  crea- 
tures we  should  be,  mentally  and  physically  !  And  it  will  be  found 
that  just  in  proportion  as  there  is  congenital  insanity,  or  want  of  will 
or  directing  power,  there  will  be  a  malformation  of  the  teeth  afid  their 
arrangement. 

"  The  next  step  is,  now  that  we  know  the  exact  shape  of  the  jaw 


896  MECHANICS — DENTAL    PROSTHESIS. 

and  its  philosophy  of  form  and  functions,  we  must  have  at  our  com- 
mand something  so  nearly  approaching  it  that  we  can  place  our  models 
upon  it,  and  thus  again  restore  nature's  '  lost  art.'  I  believe  I  have  it 
here  so  nearly  that  it  will  be  found  to  answer  our  most  fastidious 
notions  of  setting  by  a  system  teeth  on  plate.  The  instrument  is 
made  of  brass  wire  one-eighth  of  an  inch  in  diameter  (Fig.  994),  and 
of  such  shape  and  movements  as  to  correspond  exactly  with  the 
mechanism  of  the  human  jaws.  The  base  with  its  movements  forms 
one  part,  and  the  two  bows  another.  But  one  base  is  necessary  for 
any  number  of  cases.  The  bows  which  here  are  separated  from  the 
base  can  be  duplicated  to  any  extent.  They  are  held  firmly  by  thumb- 
screws, and  after  a  case  is  once  articulated  to  the  bows  they  can  be 
laid  aside  for  future  use.  The  lateral  motion  forbids  the  use  of  a  prop 
to  keep  the  bows  apart.  At  first  sight  it  would  seem  that  the  lower 
bow  is  moving  in  the  wrong  direction.  Its  motions  are  precise  and 
correct.  This  has  never  been  changed  in  design  since  first  invented, 
in  1858.  It  permits  of  seeing  whether  the  palatal  and  lingual  cusps 
properly  touch.  In  using  it  to  get  the  lateral  movement,  one  condyle 
must  be  kept  close  to  the  point  where  it  is  held  by  the  spiral  spring, 
while  the  opposite  one  moves  forward.  Never  use  both  springs  at  once, 
except  in  bringing  the  lower  jaw  forward  for  incising.  This  method 
demonstrates  that  there  is  but  oneway  to  make  a  set  of  teeth  articulate. 
"Before  placing  the  wax  models  in  the  articulator,  it  will  not  be 
out  of  place  to  say  a  word  about  this  arrangement  of  the  wax  on  the 
base  plate  and  the  selection  of  teeth  in  full  sets.  Always  model  the 
upper  wax  first,  judging  of  the  length  of  incisors  by  the  trial  of  an 
artificial  tooth  in  the  mouth,  such  as,  in  shape,  length,  and  width, 
would  look  natural  and  appropriate  when  held  under  the  lip.  This 
will  enable  you  to  get  the  height  of  wax  and  the  contour  after  success- 
ful trial.  The  modeling  of  the  wax  on  the  upper  plate  is  not  arbitrary 
or  fixed,  so  far  as  a  definite  law  is  concerned,  in  being  able  to  work 
after  a  set  pattern  ;  here  the  true  dental  artist  comes  in.  You  get  the 
length  by  trial  of  several  blocks,  or  single  gum,  or  plain  teeth,  as  may 
be,  as  well  as  shade  of  same.  As  to  the  arch  of  upper,  you  must  add  to 
and  take  from,  making  depressions,  etc.,  until  your  judgment  tells 
you  it  is  correct.  To  aid  amazingly  in  this  work  of  art,  draw  out  the 
patient  in  a  smile  or  broad  convulsive  laugh ;  compel  him  to  do  so ; 
nothing  tends  so  to  relax  most  universally  every  muscle  and  give  true 
expression  to  the  countenance.  If  the  wax  is  not  in  keeping  with 
symmetry  you  will  see  where  the  trouble  lies.  Look  at  them  in  front 
and  on  either  side  when  they  are  laughing,  as  a  sculptor  would  upon 
his  model.  Be  sure  that  the  arch  at  the  cuspids  that  form  a  double 
keystone  to  the  arch  stand  out  more  prominently  than  any  others.    The 


ARTICULATION.  897 

superior  first  bicuspid  should  nearly  always  fall  back  somewhat  behind 
the  cuspids. 

"Now  that  the  upper  wax  is  correct,  the  same  rule  applies  to  the 
lower.  It  is  easy  to  make  this  conform  to  the  upper  ;  you  may  have 
to  change  the  upper  in  some  respects  when  tried  with  the  lower,  but 
not  much.  The  length  of  wax  at  the  molars  may  have  to  be  trimmed 
to  allow  of  equalizing  the  length  of  the  teeth  on  upper  and  lower 
plates.  Laughing  and  smiling  will  here  again  tell.  Be  sure  to  mark 
the  center  at  the  median  line,  making  marks  or  grooves  through  on 
either  side,  running  from  upper  to  lower  for  guide ;  they  can  be  re- 
moved and  are  now  ready  for  the  articulator,  with  their  bows  pushed 
into  their  sockets  in  the  base,  which  are  retained  by  mere  friction. 
The  plaster  models  or  casts  with  the  wax  articulation  or  bite  thereon — 
and  all  fastened  together  by  wax  or  cement  to  prevent  being  displaced 
from  the  cast — are  now  placed  on  this  lower  bow  of  the  articulator, 
and  the  upper  bow  brought  over  upon  the  upper  cast.  Your  eye  soon 
detects  whether  the  median  line  or  wax  is  in  the  center.  To  get  the 
cast  in  proper  place  have  a  pair  of  calipers  four  inches  between  points, 
and  by  it  place  the  cast  in  position,  with  center  of  lower  teeth  just  four 
inches  from  the  condyles  on  either  side.  Hold  in  position  while 
with  plaster  you  secure  the  upper  to  the  bow,  and  when  hard,  the  lower 
bow  to  the  plaster  cast  in  the  same  way. 

"  It  may  be  asked,  Where  is  the  set  screw  to  hold  open  the  jaws  of 
articulation  after  wax  is  taken  off?  I  have  never  found  it  necessary  in 
this  kind  of  frame.  Before  taking  off  the  wax,  I  take  a  pair  of  dividers, 
or  a  piece  of  wire  bent  with  the  points  about  one  inch  and  a  half  apart, 
and  mark,  with  one  foot  on  plaster  cast  and  the  other  at  cutting  edge 
of  wax,  the  bite  at  the  median  line.  Do  this  for  both  jaws.  To 
secure  this  height  for  future  repairs  mark  on  each  cast  with  the  divid- 
ers the  distance  apart  or  width  of  dividers,  and  this  will  always  be  your 
guide  for  height.  Take  off  all  the  upper  wax — except  a  section  at  the 
molars — first,  and  let  the  lower  remain  as  a  guide  for  the  arch  of  the 
upper.  The  first  block  or  tooth  fitted  on  the  upper  when  backed  with 
wax  answers  perfectly  to  keep  the  jaws  of  the  articulator  apart.  The 
set  screw  would  be  in  the  way  with  the  lateral  movements.  I  stated 
that  the  length  or  depth  of  underbite  in  full  sets  is  restricted  to  the 
width  of  the  jaws  and  length  of  the  centrals,  which  it  is  presumed  have 
been  selected  to  suit  the  individual  case.  Knowing  how  much  the 
underbite  is  to  be,  you  can  very  nearly  guess  how  much  to  cut  out  the 
bicuspids  and  molars  on  all  the  grinding  surfaces  before  any  of  them 
are  fastened  to  the  base  plate,  and  how  much  arch  upward  at  the  ramus, 
from  the  second  bicuspid  backward  and  upward.  If  the  underbite  at 
the  centrals  is  to  be  an  eighth  of  an  inch,  then  the  bicuspids  in  the 
57 


898  MECHANICS — DENTAL   PROSTHESIS. 

upper  will  have  grooves  between  the  cusps  not  quite  so  deep,  and  the 
molars  still  less.  From  the  cuspids,  then,  the  cusps  are  less  to  the 
second  molar ;  were  the  incisors  to  strike  equally  and  directly  upon 
each  other  there  could  be  no  cusps  or  they  would  be  of  no  use.  The 
inner  cusps  of  the  upper  should,  as  a  general  rule,  be  longer  or  higher 
than  the  outer.  (See  Figs.  996  and  998.)  The  outer  cusp  is  more 
acute,  the  inner  rounded.  The  lower  the  reverse — inner  sharper  and 
outer  rounded,  where  the  upper  closes  over  the  lower.  For  full  sets 
you  need  but  slight  underbite,  only  enough  to  permit  the  lower  to 
come  forward  and  act  as  shears  for  cutting ;  at  the  same  time  it  per- 
mits of  cusps  to  both  bicuspids  and  molars,  and  gives  all  double  amount 
of  grinding  surface,  there  being  cusps  that  touch  on  palatal  and  lingual 
sides,  at  same  time  as  the  buccal.  Always  bear  in  mind  that  the  cur- 
vature upward  at  the  ramus,  of  the  upper  set,  is  always  in  proportion 
to  the  underbite. 

"  If  for  an  upper  set  alone  you  can  tell  how  much  the  upper  in- 
cisors should  overbite  by  looking  at  the  curvature  of  lower  molar  teeth 
remaining.  If  an  eighth  of  an  inch  out  of  line  the  overbite  should 
be  fully  so.  This,  when  once  understood,  can  give  no  trouble.  The 
grooves  in  bicuspids  and  molars  will  form  with  the  cusps,  buccal 
and  lingual,  an  ogee,  as  seen  in  Figs.  996  and  998,  to  give  double  the 
grinding  surface  when  worked  laterally,  besides  giving  double  cut- 
ting edges.  All  these  grooves  can  be  cut  out  before  any  are  fastened 
with  wax,  so  nearly  that  but  little  touching  will  be  needed  when  the 
lower  is  articulated  to  upper.  The  first  bicuspid  in  the  lower  jaw 
should  have  but  one  cusp.  This  perfect  design  will  be  seen  in  the 
articulator  why  it  should  have  but  one.  Two  would  not  only  be  in 
the  way  of  the  tongue,  but  be  of  no  use.  Be  sure  that  the  groove  in 
the  upper  is  made  nearer  the  buccal  side,  and  for  the  lower  or  lingual 
side,  for  a  reason  which  you  will  presently  have  explained,  as  seen  in 
Fig.  996.  Now  that  the  grooves  are  completed  in  the  upper  and  all 
the  teeth  in  place  in  the  arch,  we  will  articulate  the  teeth  on  the  lower 
base.  The  height  is  soon  ascertained  by  the  dividers,  and  the  central 
incisors  tried  on  to  see  what  changes  will  be  needed.  Fasten  it 
temporarily  with  wax,  and  try  it  with  the  lateral  motion  and  the 
points  adjusted  to  meet  all  the  surface  on  palatal  side  of  upper  teeth, 
when  the  lower  is  thrown  to  the  side  of  the  tooth  being  fitted.  Cut 
from  the  cutting  surfaces  of  each,  whichever  will  make  the  most  nat- 
ural and  strongest  case.  If  for  a  very  young  subject,  be  careful ;  but 
for  a  middle-aged  or  elderly  person  do  not  scruple  about  the  cutting 
edge  and  grinding  surfaces,  but  sacrifice  even  the  labial  or  palatal 
surface  for  the  sake  of  effect  and  usefulness. 

"  I  sometimes  turn  the  buccal  side  of  a  molar  inward  to  save  sub- 


ARTICULATION.  899 

Stance  and  get  effect  and  for  better  adjustment ;  frequently  for  want 
of  room  at  ramus  I  do  this ;  and,  occasionally,  turn  buccal  side  up- 
ward for  the  grinding  surface.  If  using  blocks,  before  the  front  ones 
are  fastened  securely  to  the  base  plate,  and  while  they  are  temporarily 
in  their  right  place,  try  the  bicuspid  blocks  to  find  out  how  much  of 
the  joint  should  come  off  of  the  incisors  or  the  bicuspid  block,  or 
divide  it.  This  will  secure  a  better  and  more  continuous  joint  and 
give  the  lower  better  chance  to  be  arranged  to  the  upper.     Before 


Fig.  996. 


Fig.  997. 


taking  off  too  much  of  the  joint  of  either  of  these  blocks  try  the 
lower  incisor  and  bicuspid  block  temporarily  on  wax,  to  know  where 
the  cusps  are  going  to  come.  Regulate  the  joints  by  this.  You  can 
make  the  groove  in  the  lower  blocks  the  reverse  of  the  upper,  and  cut 
them  all  out  before  much  jointing  is  done,  taking  care  that  the 
groove  is  now  on  the  lingual  side  and  that  the  buccal  cusps  are 
rounded  and  the  inner  more  acute,  as  in  the  buccal  of  the  upper. 
Never  cut  off  any  of  the  lingual  cusps  of  the  lower  bicuspid  and  molar 
teeth,  such  as  are  now  made,  as  they  are  universally  too  short,  and  to 


— R 


Fig.  998. 


get  them  long  enough  for  service  a  large  portion  of  the  buccal  cusps 
have  to  be  cut  down  and  rounded. 

"The  palatal  cusps  of  the  upper  strike  between  the  outer  and 
inner  of  the  lower  (see  Fig.  996)  and,  at  the  same  time,  these  cusps 
should  be  long  enough  to  allow  in  the  lateral  movement  the  incisors 
and  cuspid  on  that  same  side  to  touch  simultaneously  all  the  surface 
from  the  central  to  the  last  molar.  If  they  do  not,  then  your  remedy 
is  to  make  the  groove  deeper  in  both  upper  and  lower,  or  perhaps  the 
lower  only,  or  the  upper  only  (see  J  K,  Fig.   998);  experience  here 


poo  MECHANICS DENTAL    PROSTHESIS. 

will  soon  teach  you  which.  When  all  the  cusps  are  touching,  inner  and 
outer  and  the  front  one,  take  the  opposite  bicuspid  and  do  likewise  ; 
and  with  the  additional  precaution,  when  the  lower  jaw  of.  the 
articulator  is  turned  to  the  left,  to  make  the  inner  cusps  of  the 
upper  strike  the  outer  cusps  of  the  lower  (M  N,  Fig.  998) 
and  vice  versa,  when  thrown  to  the  lateral  right  or  left  (J  K,  Fig.  998). 
The  molars  must  have  the  same  rule  applied,  with  yet  another  ad- 
ditional point  of  great  im- 
portance. 

"The  curvature  of  the 
ramus  must  be  made  to  con- 
form to  the  depth  of  over- 
bite (see  Figs.  999  and 
1000),  so  that  when  the 
lower  jaw  is  thrown  to  the 
Fig.  999.  ^    ~-       right,  the   outer   and  inner 

cusps  of  both  upper  and 
lower  sets  on  that  side  come  together  at  the  same  time  that  the 
bicuspids  and  incisors  do  (see  Fig.  1000) ;  but  the  curvature  should 
be  great  enough  to  permit  on  the  opposite  side  of  the  second  molai 
tooth  in  the  lower,  which  slides  forward  to  meet  the  first  molar  in  the 
upper,  apparently  moving  backward  (Fig.  999) — if  they  were  on  a 
plane  they  would  never  touch,  on  account  of  the  jaws  opening  as  they 
move  laterally  to  the  right  or  left — to  mount  up  on  the  cusps  of  the 
incisors  an  eighth  of  an  inch,  which  would  not  allow  the  molars  to 
touch,  if  on  a  straight  line  backward.  But,  inasmuch  as  on  the  plane 
of  grinding  surface  the  first  upper  molar  stands  higher  in  the  upper 
plane,  the  sliding  forward 
of  the  lower  jaw  in  the 
glenoid  cavity  brings  the 
higher  second  molar  in  the 
lower  in  continuous  con- 
tact with  the  first  superior 
molar,  as  well  as  both  outer 

.  KIG.   1000. 

and  inner  cusps  of  bicus- 
pids and  molars  of  the  upper  and  lower  jaw  (Fig.  999).  This  is 
specially  done  to  equalize  the  pressure  and  force  on  both  sides  or 
parts  of  the  dental  arches.  This  permits  of  the  most  compensating 
arrangement  of  the  teeth  for  equalizing  the  action  of  muscles  on  both 
sides  simultaneously,  and  getting  the  greatest  amount  of  grinding 
surface  at  each  movement.  This  arrangement  of  bicuspids  and  molars 
is  found  in  nearly  all  the  lower  animals  ;  the  incisors,  however,  never 
touch  when  the  jaws  are  in  lateral  movement.     Turn  the  lower  jaw  to 


ARTICULATION.  90I 

either  side  and  the  effect  is  the  same.  As  I  before  said,  but  one  side 
of  the  mouth  can  be  used  at  the  same  instant,  leaving  the  other  free  to 
balance  the  other  side  at  work. 

"  If  the  upper  arch  of  incisors  of  the  natural  teeth  should  be  broad 
or  deep  on  account  of  the  thickness  of  the  base  or  body  of  the  in- 
cisors, or  where  they  are  much  inclined  to  protrude,  then  the  arch  at 
the  ramus  is  not  so  great.  In  artificial  sets  this  need  never  occur, 
carrying  out  the  same  rule  in  nearly  every  case,  of  controlling  the 
curvature  at  the  ramus  by  the  depth  of  overbite  and  length  of  cusps 
of  bicuspids.     This  system  holds  good  in  partial  sets  as  well. 

"  This  is  all  that  is  necessary  to  be  said  on  articulation  proper ;  it 
remains  only  to  give  a  few  points  having  a  bearing  on  the  perfection 
of  the  same.  Select  the  broadest  grinding  surfaces  to  bicuspids  and 
molars,  that  the  bolus  of  food  may  be  held  securely  on  their  faces, 
taxing  less  the  muscles  of  the  face  engaged  in  mastication.  Narrow 
surface  would  rather  tend  to  cut  the  food  than  grind  it.  This  is  of 
no  mean  importance  in  rendering  artificial  teeth  of  greatest  use. 

"To  produce  the  most  natural  effect  the  centrals  should  be  the 
lightest  in  color,  and  the  cuspids  a  shade  or  so  darker,  with  a  differ- 
ence in  color  of  all  the  back  teeth.  I  prefer  on  this  account  to  set 
plain  teeth  wherever  admissible — and  nearly  all  lower  cases  are  so — 
and  use  different  shades  and  arrange  irregularly.  The  lower  incisor 
teeth  are  mostly  crowded,  and  I  find  to  lap  them  over  and  distort 
them,  even  to  a  great  extent,  adds  very  greatly  to  their  natural 
appearance.  Don't  be  afraid  of  getting  any  case  too  irregular;  very 
few  natural  sets  can  boast  of  perfect  symmetry. 

"After  the  teeth  are  fixed  temporarily  on  the  plate  they  should 
always  be  tried  in  the  mouth  to  see  if  they  are  perfectly  correct.  A? 
the  mouth  is  more  yielding  in  one  part  than  another,  the  closing  of 
the  jaws  rather  firmly  will  allow  of  slight  readjusting  of  themselves 
on  the  wax.  If,  when  finished,  they  are  found  not  to  articulate  prop- 
erly— which  is  sometimes  the  case  from  the  soldering  or  vulcanizing — 
have  the  patient  bite  on  a  strip  of  wax  placed  between  the  grinding 
surfaces  to  show  the  relation  of  each.  Tnen  put  this  back  into  the 
articulator  and  rearrange  the  grinding  surface.  It  will  be  found  to 
need  but  a  trifling  alteration. 

"  The  false  movement  of  the  lower  jaw  at  the  condyles  is  found  in 
nearly  all  persons  who  have  had  but  one  or  two  teeth  remaining  in 
the  front  arch,  to  reach  which  the  jaw  must  be  thrust  forward  and 
laterally ;  and  when  artificial  ones  are  placed  in,  the  same  old  move- 
ments are  continued  until  their  attention  is  called  to  it.  It  can  be 
corrected  without  any  special  arrangement  other  than  following  the 
law  herein  laid  down. 


902 


MECHANICS DENTAL    PROSTHESIS. 


"  TTie  Equilateral  Triangle  within  the  Main  Triangle. — The  outline 
drawings  in  Fig.  looi  may  be  thought  ideal.  But  any  one  at  all 
acquainted  with  geometry,  who  has  followed  me  in  my  argument  and 
description,  must  be  struck  with  wonder  at  the  marvelous  ingenuity 
of  the  contrivance  based  alone  on  the  equilateral  triangle.  It  will 
be  seen  that  perfection  must  be  the  result,  since  each  part  is  complete 
within  itself  and  the  whole  supporting  each  individual  part. 

"  How  have  I  arrived  at  this  divination?  The  law  is  based  upon 
the  measurement  of  over  two  thousand  human  skulls.  First,  make  an 
equilateral  triangle,  4  inches  each  angle,  A,  A,  F ;  draw  a  line  from 
T  to  F.  What  is  the  guide  to  form  the  arch?  Know  the  actual 
width  of  the  superior  central,  lateral,  and  cuspid  at  their  greatest 
diameter  from  the  mesial  to  distal  surfaces,  say  if,  as  in  Fig.  996. 

Measure  this  off  with 
the  dividers,  and  place 
one  arm  at  F  and  de- 
scribe an  arc  from  D  to 
D  through  I.  Then 
place  dividers  at  I,  and 
intersect  the  line  just 
made  from  F,  and  it 
will  be  found  that  at  D 
will  be  found  the  ex- 
tremest  point  of  the 
arch  D,  F,  D,  and  will 
be  the  distal  surface 
of  the  superior  cuspid. 
Place  the  dividers  at  I, 
and  describe  the  arc 
from  D  to  D  through 
F,  which  will  constitute  the  normal  and  positive  arch  of  the  superior 
jaw.  There  will  be  an  equilateral  triangle  from  D,  F,  I  on  either  side 
of  the  mesial  line  at  F.  The  same  will  be  found  the  base  of  each 
superior  incisor. 

"  Next  draw  a  line  from  A  to  D  on  either  side,  which  will  be  the 
guide  for  the  bicuspids  and  molars  as  to  width  and  depth.  Then,  by 
jjlacing  the  dividers  at  A  and  B,  describe  another  arc  to  C,  which  will 
give  the  width  of  first  superior  bicuspid.  The  line  from  A  to  D 
passes  through  its  palatal  base,  and  will  pass  through  center  of  base 
of  triangle  of  this  tooth.  Form  another  triangle  by  drawing  a  line 
from  H  to  H,  through  B,  which  will  pass  through  the  center  of  the 
first  molar,  and  will  give  the  width  between  the  palatal  surfaces,  or  their 
depth  or  thickness.     Placing  the  dividers  at  I  and  F,  we  intersect  the 


( 

^% 

E/(/"      /^ 

\    "Vx 

vf^'/     ^ 

\'^r 

f 

°"\ 

"1 

' 

ARTICULATION.  903 

line  from  F  to  T  at  Y.  Draw  a  line  through  Y  to  E,  E,  forming 
another  equilateral  triangle.  From  B  to  F  is  now  the  radius  of  another 
arc,  which  intersects  the  line  from  D  to  A  at  V,  and  the  line  A  to  D  at 
O.  A  line  now  drawn  E  to  E  through  Y  intersects  the  center  of  the 
second  molar  at  E,  E. 

"  Get  half  the  distance  between  the  points  at  E  on  the  line  from  D 
to  A,  and  the  width  of  the  first  molar  is  made,  and  also  the  second, 
which  is  the  angle  of  the  equilateral  of  each.  This  leaves  room  be-, 
tween  the  first  bicuspid  and  first  molar,  and  is  the  width  of  second 
bicuspid  ;  or  it  is  shown  by  placing  the  dividers  at  A  and  Y,  and 
intersecting  line  from  D  to  A  at  W,  same  as  from  B  to  C,  for  the 
first  bicuspid's  width.  The  distance  from  D  to  D  is  the  same  as  from 
D  to  the  distal  surface  of  the  second  molar.  P  to  P  through  Z  forms 
another  equilateral  triangle,  giving  the  wisdom  tooth's  place  in  the 
arch. 

"The  arrangement  of  J  and  K  (Fig.  looo)  on  the  left  shows  the 
teeth  in  the  act  of  mastication,  while  on  the  right  M  and  N  (Fig.  999) 
the  inner  cusp  of  molars  of  the  upper  and  outer  of  the  lower  molars 
come  in  contact  when  not  in  use.  There  is  double  the  surface  touch- 
ing at  every  lateral  movement.  Fig.  999  shows  right  side,  as  at  M  and 
N,  and  Fig.  1000  that  of  left  side  (J,  K)  in  action  from  the  mesial  to 
the  last  molar.  Fig.  996  shows  both  bicuspids  and  molars  in  normal 
relation." 

Dr.  W.  Storer  How*  has  described  a  method  of  utilizing  plaster 
impressions  for  obtaining  accurate  antagonizing  models  as  follows:  — 

"In  the  process  of  procuring  counterparts  of  the  jaws  for  which 
dental  substitutes  are  to  be  constructed,  every  step  should  be  taken 
with  the  greatest  degree  of  exactness  attainable,  and  accurate  impres- 
sions are  therefore  essential  as  matrices  in  which  the  working  models 
are  to  be  cast.  Impressions  of  edentulous  jaws  are  commonly  taken  in 
mixed  plaster,  which  is  held  in  the  bare  tray,  or  in  the  wax  impression 
previously  taken  in  the  tray.  An  elucidation  of  this  part  of  the  subject 
is  not  now  entered  upon,  but  it  is  assumed  that  in  any  case,  whether 
the  jaw  be  completely  or  partially  toothless,  an  impression  will  be 
taken  in  plaster,  and  that,  when  practicable,  the  thinnest  part  of  the 
body  of  the  impression  will  be  not  less  than  the  sixteenth  of  an  inch 
thick.  Fig.  1002  exemplifies  such  an  impression  of  a  toothless  upper 
jaw,  and  Fig.  1003  in  like  manner  illustrates  the  plaster  impression  of 
an  edentulous  lower  jaw.  In  both  instances  the  trays  are  omitted  from 
the  cuts  as  not  necessary  to  be  shown. 

"  Plaster    impressions  are  commonly  varnished  with   an   alcoholic 

*  Dental  Cosmos,  September  No.,  1888. 


904 


MECHANICS — DENTAL   PROSTHESIS. 


solution  of  shellac  or  sandarach,  and  then  oiled  to  insure  the  separation 
of  the  casts.  The  preferable  way  in  most  cases  is  to  thoroughly  brush 
the  surface  with  a  soft  brush  and  strong  soap-suds,  and,  after  an  inter- 
val of  a  few  minutes  to  allow  for  absorption  of  the  water  of  the  suds,  to 
fill  the  impression  with  a  properly  mixed  batter  of  plaster. 

"  Several  hours  should  preferably  elapse  before  attempting  to  separate 
the  cast  from  the  impression,  which  should  be  preserved  as  nearly 
^entire  as  possible,  and  when  there  is  not  much  overhang  the  separation 
may  be  safely  effected  by  progressive  smart  tappings  with  alight  mallet 
over  the  whole  surface  of  the  impression.  If,  however,  the  labial 
portion  must  needs  be  first  cracked  off,  this  may  be  done,  after  cutting 
a  groove  in  the  impression  as  near  along  the  crest  line  of  the  cast  as 
may  be  guessed,  using  quick,  light  mallet-blows  to  knock  off  the  sec- 
tions. These  are  to  be  carefully  kept,  and  after  the  separation  has 
been  accomplished  are  to  be  replaced  with  the  palatal  portion  on  the 
cast  and  with  a  thin-mixed  plaster  built  up  to  the  approximate  shape 


Fig.  1002. 


Fig.  1003 


of  an  articulating  model.  When  this  has  become  quite  hard  it  is 
removed  from  the  cast,  which,  of  course,  it  perfectly  fits.  It  will  also, 
if  as  an  impression  it  was  correctly  taken,  perfectly  fit  the  jaw,  and 
may  therefore  be  placed  in  the  mouth  and  judiciously  trimmed  until 
the  proper  expression  has  been  produced,  and  the  exact  dimensions 
and  contour  of  the  desired  denture  embodied  in  this  plaster  articulat- 
ing model.  Such  a  model  isshown  in  Fig.  1004.  In  like  manner  one 
may  prepare  a  similar  model  of  the  inferior  jaw.  Such  rigid  and  exact- 
fitting  models  can  obviously  be  replaced,  trimmed,  and  readjusted  in 
the  mouth  until  the  best  skill  of  the  dentist  shall  have  been  expended 
in  obtaining  models  at  once  artistic  and  correct.  The  median-line 
mark  is  then  made  with  a  pencil  or  knife,  and  cross-lines  are  made  on 
the  sides  of  both  models  while  they  are  pressed  together  in  the  mouth, 
after  many  openings  and  shuttings  of  the  jaws,  to  be  sure  that  at  last 
the  proper  relations  of  the  models  have  been  obtained.     The  occluding 


ARTICULATION.  905 

surfaces  are  then  dried,  warmed,  some  hot  wax  is  dropped  on  them, 
the  models  are  instantly  replaced  in  the  mouth,  and  the  side-marks 
and  median-line  marks  made  to  exactly  coincide,  while  the  models  are 
pressed  together  by  a  firm  closure  of  the  jaws  until  the  wax  has  quite 
stiffened.  The  joined  models  can  then  be  taken  from  the  mouth  and 
replaced  upon  the  casts.  These  are  to  be  fixed  with  care  in  a  suitable 
articulator,  and  the  result  will  be  a  precise  reproduction  of  the  relative 
positions  previously  occupied  by  the  models  when  placed  on  the  natural 
jaws  (see  Fig.  1005).  Attention  is  here  called  to  the  fact  that,  nor- 
mally, the  horizontal  line  of  occlusion  is  not  straight,  but  curved  so 
that  the  superior  cuspids  are  at  the  bottom  of  the  depression,  as  illus- 
trated in  the  lines  of  the  models,  Fig.  1005.  In  the  construction  of 
models  for  full  dentures  it  is  important  to  maintain  this  curved  line  of 
occlusion  for  two  reasons :  First,  the  process  of  mastication  is  facili- 
tated by  the  impingement  of  the  lower  bicuspids  and  molars,  as  these 


Fig.  1004.  Fig.  1005. 

are  occluded  with  their  downward-graded  antagonists  by  the  antero- 
lateral movements  of  the  lower  jaw  in  the  act  of  grinding  the  food; 
second,  the  facial  expression  is  improved  by  the  rising  of  the  respective 
planes  of  occlusion  at  those  points,  thus  in  some  degree  producing  the 
effect  that  the  limner  accomplishes  by  upwardly-curved  lines  at  the 
corners  of  the  mouth. 

"Fig.  1006  also  shows  (though  imperfectly)  the  correctness  with 
which  the  plaster  models  may  be  made  to  anticipate  the  outlines  of 
forms  which  the  completed  dentures  are  subsequently  to  assume  in 
becoming  both  useful  and  beautifying  works  of  art.  The  thin, 
sharp,  inflexible  borders  of  contact  with  the  gum  along  lines  which 
provide  for  a  firm  bearing  of  the  model,  and  yet  permit  the  free  play 
of  all  the  muscles  concerned  in  acts  of  mastication  and  facial  expres- 
sion, are  noticeable  in  Figs.  1004  and  1005  as  being  producible  in 
plaster  models.  It  is  likewise  observable  in  Fig.  1005  that  the  normal 
overlap  of  the  upper  incisors  upon  the  lower  may  be  reproduced  in 


9o6  MECHANICS — DENTAL    PROSTHESIS. 

plaster  models  and  prove  an  important  factor  in  sustaining  the  lips  in 
proper  profile  relations, — a  circumstance  too  often  ignored  or  over- 
looked in  the  preparation  of  the  ordinary  wax  models.  These  are,  in 
fact,  commonly  so  crudely  and  clumsily  formed,  and  are  withal  so 
lacking  in  resistance  to  adverse  impressions,  that  not  only  can  no 
dependence  be  placed  upon  them  as  correct  representatives  of  the 
relative  parts  previously  studied  and  produced  in  the  mouth,  but  from 
the  very  fact  that  wax  forms  are  so  easy  of  displacement  and  dis- 
figurement, the  steps  in  the  process  of  obtaining  such  articulating 
models  are  hesitatingly  and  hastily  taken,  and  of  course  result  in 
faulty  dentures,  which,  more  than  any  other  class  of  dental  operations, 
proclaim  the  frequent  failure  of  the  dentist  to  so  closely  imitate 
nature  as  to  conceal  the  fact  that  such  an  endeavor  has  been  made. 
The  practical  permanence  of  the  plaster  model  obviates  all  these  de- 
fects, and,  furthermore,  admits  of  such  a  firm  final  closure  of  the  jaws 


Fig.  1006.  Fig.  1007. 


that,  when  at  last  the  corresponding  denture  is  placed  in  the  mouth, 
both  the  occlusion  and  the  articulation  are  found  to  be  correct,  as 
could  never  be  the  case  after  a  timid  trial  closure  upon  a  soft,  slippery 
wax  model. 

"In  Fig.  1005,  as  in  the  succeeding  figures,  the  models  and  casts 
are  to  be  viewed  as  mounted  on  articulating  frames,  which  do  not 
appear  because  not  necessary  for  the  purpose  of  illustration. 

"  Upon  the  removal  of  the  models  from  the  casts,  after  these  have 
been  mounted  on  the  articulator,  both  representatives  of  the  eden- 
tulous jaws  will  appear  as  seen  in  Fig.  1006,  and  in  these  cases  the 
border  outlines  of  the  models  are  indicated  to  emphasize  the  need  of 
making  them  conform  to  the  muscle  insertion  lines  whenever  this  is 
practicable  ;  and  that  not  only  because  of  the  increased  stability  of 
the  dentures  when  they  are  free  from  liability  to  displacement  b)'' 
the  lifting  action  of  muscles  improperly  so  covered,  but  also  because 


ARTICULATION. 


907 


the  mobility  of  the  adjacent  features  in  the  consequent  naturahiess 
of  the  facial  expression  will  depend  in  great  degree  upon  the  judicious 
definition  of  the  boundaries  of  the  dentures. 

"Fig.  1007  shows  the  cast  of  the  upper  jaw  in  its  relation  to  the 
articulating  model  in  place  on  the  cast  of  the  lower  jaw,  and  Fig. 
1008  likewise  illustrates  the  cast  of  the  lower  jaw  as  related  to  the 
articulating  model  in  position  on  the  cast  of  the  upper  jaw. 

"A  close  observation  and  study  of  these  illustrations  will  make 
clear  the  many  points  of  advantage  to  be  obtained  by  the  employ- 
ment of  plaster  in  the  construction,  fashioning,  and  adjustment  of 
prosthetic  models  for  full  dentures. 

"  Complete  upper  artificial  dentures  for  use  with  more  or  less  com- 
plete lower  natural  dentures  constitute  a  large  class  of  the  cases  coming 
within  the  province  of  the  dentist,  and  for  these  the  plaster  articulating 
models  are  especially  adapted. 

"Such  a  model  as  that  shown  in   Fig.  1004  may  be  suitably  shaped 


Fig.  I 


Fig.  1009. 


to  articulate  with  the  natural  teeth  of  a  lower  jaw,  as  illustrated  in 
Fig.  1009,  and  in  the  process  of  shaping  the  plaster  model  great 
satisfaction  will  be  derived  from  the  security  of  the  model's  reten- 
tion in  the  mouth,  the  firmness  with  which  the  lower  teeth  may  be 
closed  upon  it,  and  the  certainty  with  which,  by  frequent  repetitions, 
a  natural  occlusion  may  be  obtained.  When  this  has  been  done,  and 
all  the  artistic  conditions  are  complied  with  in  perfecting  the  shape  of 
the  model,  it  is  to  be  removed,  warmed,  and  thus  dried  on  its  occlud- 
ing surface,  so  that  a  roll  of  very  soft  impression-wax  may  be  placed 
upon  it  and  all  be  quickly  replaced  in  the  mouth. 

"Repeated  normal  closures  of  the  jaws  are  to  be  made,  and  the 
jaws  are  then  held  tightly  closed  while  the  fingers  of  the  operator  are 
rapidly  pressed  upon  the  wax  which  covers  the  face  of  the  teeth,  so 
that  on  opening  the  jaws  and  carefully  removing  the  model  and 
wax  there  will  be  found  an  accurate  impression  of  the  teeth,  which 


908  MECHANICS — DENTAL    PROSTHESIS. 

will  have  to  pass  through  the  wax  to  the  model,  pressing  it  firmly 
into  its  seat.  The  result  is  shown  in  the  articulated  model  and  cast. 
Fig.  loio  shows  the  articulated  casts  when  the  model  has  been  re- 
moved. 

"If  proper   care   has   been  taken    in  pursuing  this  process  up  to 
this  point,  the  succeeding  steps  in  the  construction  of  a  continuous 

gum,  gold,  celluloid,  or  vulcanite 
denture  may  be  taken  with  com- 
plete confidence  that  the  substi- 
tute, if  made  in  strict  conform- 
ity to  the  models,  will  exactly 
fit  the  maxilla,  articulate  with 
the  natural  teeth,  and  impart  an 
appropriate  expression  to  the 
related  features  of  the  patient. 
"The  foregoing  method  may 
Fig.  1010.  in  some  cases  be  practiced  when 

modeling  composition  has  been 
used  in  taking  the  impression  ;  or  the  composition  may  be  employed 
in  building  the  model  upon  the  cast  which  has  been  made  from  a 
plaster  impression.  But  for  general  use — and  all  the  more  so  as  the 
practice  shall  become  familiar — plaster  will  be  found  most  reliable  and 
satisfactory  as  a  material  for  both  the  impressions  and  the  models." 


CHAPTER  XI. 


SELECTION    AND   ADJUSTMENT   OF   PORCELAIN   TEETH   TO   THE 
PLATE— FINISHING   TOUCHES. 

In  selecting  porcelain  teeth  for  dentures  a  number  of  points  must  be 
considered,  such  as  Size, — width  and  length,  especially  of  the  front 
teeth  ;  Shape, — straight  or  wedge-shaped  ;  Shade, — to  conform  to 
age  and  temperament,  and  for  partial  dentures  to  match  natural  teeth 
in  the  mouth  ;  Character, — flat,  or  curved  on  the  labial  surfaces, 
transversely  or  from  the  gum  to  the  cutting  edge,  thin,  translucent, 
and  delicate,  or  thick,  dense,  and  massive ;  Peculiarities, — the  pres- 
ence or  absence  of  grooves,  ridges,  or  lines,  straight  or  rounded  cutting 
edges. 

Where  vacancies  between  natural  teeth  are  to  be  filled  it  is  highly 
important  that  the  artificial   teeth  should   correspond  in  shade  and 


SELECTION    AND    ADJUSTMENT    OF    PORCELAIN    TEETH.  OO9 

color  with  the  natural  organs  ;  for  in  proportion  as  they  are  whiter  or 
darker,  will  the  contrast  be  striking  and  their  artificial  character 
apparent.  Of  the  two  faults  it  is  better  that  they  should  be  a  little 
darker  than  any  whiter.  They  should  also  resemble  in  shape  those 
which  have  been  lost,  so  far  as  it  is  possible  to  ascertain  this.  Minute 
accuracy  as  to  shades  of  color  involves  the  necessity  of  a  large  assort- 
ment, unless  one  is  located  near  a  depot  or  agency.  But  the  facilities 
of  mail  and  express  greatly  lessen  this  necessity,  provided  there  is  time 
to  send  for  the  tooth  or  teeth  required.  It  is  desirable,  in  view  of  this 
method  of  matching  shades  of  color,  to  keep  all  refuse  or  broken  teeth 
to  be  used  as  samples  in  sending  orders. 

The  manufacturer  supplies  three  varieties  of  plate  teeth — plain, 
gum,  and  sections.  The  latter  have  the  advantage  of  showing  few 
joints,  but  are  less  easily  repaired  and  are  not  applicable  to  so  wide 
a  range  of  cases.  Gum  teeth  or  sections  are  applicable  only  where 
there  has  been  sufficient  absorption  to  permit  the  extra  fullness  of 
the  artificial  gum.  Many  mouths  are  deformed  by  a  foolish  craving  on 
the  part  of  the  patient,  which  the  dentist  is  equally  foolish  in  yielding 
to  whenever  plain  teeth  are  more  appropriate.  In  point  of  strength, 
durability,  and  facility  of  repair,  plain  teeth  are  superior  to  the  others; 
they  are  also  more  readily  adapted  to  the  plate. 

The  manufacture  of  gum  teeth  in  sections  of  two,  three,  or  four 
teeth  has  been  brought  to  such  perfection  that  comparatively  few 
single  gum  teeth  are  now  used;  especially  since  new  methods  of 
attaching  these  sections  to  the  plate  have  rendered  unnecessary  that 
exact  fitting  of  blocks  which  was  one  objection  to  their  use.  This 
perfection  of  manufacture  has  also  done  away  with  the  necessity,  on 
the  part  of  the  dentist,  of  devoting  to  the  making  of  block  teeth  the 
very  large  proportion  of  his  time  formerly  demanded  by  this  difficult 
process.  Whenever  special  cases  demand  blocks  or  sections  made 
to  order,  it  will  be  found  more  satisfactory  to  send  proper  models 
and  descriptions,  and  have  such  teeth  made  by  those  who  are  thus 
constantly  occupied,  than  to  incur  the  disappointments  and  delays 
inevitably  attendant  upon  infrequent  and  irregular  attempts  at  block- 
work. 

For  the  proper  shaping  of  models  and  articulators  to  accompany 
such  orders  directions  will  hereafter  be  given.  These  blocks,  when 
received,  do  not  need  much,  if  any,  grinding.  But  all  plain  teeth, 
single  gum  teeth,  and  ordinary  sections  or  block  teeth  require,  after 
selection,  to  be  more  or  less  accurately  fitted  to  the  base  plate.  For 
this  purpose  they  must  be  ground  on  emery  or  corundum  wheels  until 
accurately  fitted,  and  must  be  so  arranged,  in  full  cases,  as  to  meet 
the  teeth  with  which  they  are  intended   to  antagonize  at   the  same 


9IO  MECHANICS DENTAL    PROSTHESIS. 

instant  around  the  entire  arch  ;  in  partial  cases  the  natural  teeth  should 
touch  their  antagonists  more  decidedly  than  the  artificial  ones.  A 
correct  articulation  will  enable  the  dentist  to  antagonize  the  teeth  with 
perfect  accuracy. 

The  movements  of  the  tongue,  lips,  and  cheeks  must  be  considered 
in  the  adjustment  of  artificial  teeth,  and  the  expression  must  be  care- 
fully studied  ;  hence  some  general  rules  may  prove  serviceable.  The 
median  line  of  the  face  should  exactly  come  between  the  upper  and 
lower  central  incisors;  the  centrals  and  laterals  on  each  side  should 
lean  slightly  toward  the  median  line,  the  laterals  a  little  more  so  in 
most  cases  than  the  centrals,  the  cuspids  very  slightly,  and  the 
bicuspids  and  molars  almost  perpendicular.  In  a  full  denture  the 
anterior  teeth  should  lap  but  slightly,  only  enough  to  permit  the 
cutting  edges  of  the  upper  front  teeth  to  pass  over  those  of  the  lower 
teeth ;  the  six  anterior  teeth,  therefore,  should  not  meet,  but  the 
pressure  should  be  upon  the  bicuspids  and  molars,  and  be  equal  on 
both  sides.  Lisping  is  prevented  by  having  the  front  teeth  lap  but 
slightly,  and  the  stability  of  the  denture  is  increased.  The  articulat- 
ing model  will  govern  the  length  of  the  teeth,  especially  the  anterior 
ones.  The  arrangement  of  the  posterior  teeth  should  correspond  to 
that  of  nature,  the  articulating  surfaces  of  the  inferior  second 
bicuspids  and  first  molars  curving  downward,  so  that  the  second 
bicuspids  and  first  molars  are  somewhat  shorter  than  the  first  bicuspids 
and  second  molars  ;  by  such  an  arrangement  the  denture  is  less  liable 
to  be  forced  forward  in  mastication. 

For  proper  expression  the  anterior  lower  teeth  should  occupy  a 
perpendicular  position,  as  it  is  seldom  necessary  to  incline  them  out- 
ward or  inward.  Even  when  the  lower  jaw  projects  somevvhat  the 
lower  teeth  should  be  perpendicular  and  the  upper  teeth  incline  or 
project  out  to  meet  them.  Fullness  of  the  gum  under  the  nose  should 
be  avoided,  as  the  lip  is  given  an  unnatural  fullness  by  such  a  thick- 
ness of  material.  It  is  frequently  necessary  to  make  considerable 
fullness  of  the  gums  of  the  cuspid  teeth. 

There  should  be  an  outward  curve  of  both  upper  and  lower  teeth 
when  the  face  is  observed  in  profile. 

In  arranging  an  entire  set  for  the  upper  or  for  both  jaws  the  molars 
should  be  so  adjusted  that  the  inner  or  palatine  tubercles  come 
together  as  well  as  the  outer  ones.  This  precaution  is  necessary  in 
antagonizing  single  as  well  as  block  teeth.  If  the  outer  tubercles 
strike  first  the  pressure  there  will  spring  and  loosen  the  plate.  For 
the  same  reason  upper  molars  and  bicuspids  should  not  be  set  so  that 
the  force  of  mastication  falls  outside  of  the  ridge.  The  inferior 
teeth  should  be  placed  well  on  the  alveolar  ridge,  and  not  inclined 


SELECTION    AND    ADJUSTMENT    OF    PORCELAIN    TEETH.  9II 

inward  or  too  much  outward,  and  sufficient  space  be  allowed  for  the 
movements  of  the  tongue. 

The  lower  teeth  of  an  entire  denture  may  with  advantage  be  longer 
than  the  upper  teeth,  and  thus  insure  greater  stability ;  hence  the 
lower  front  teeth  (incisors)  should  be  arranged  first,  then  the  upper 
teeth  of  the  same  class,  and  the  same  rule  followed  in  regard  to  the 
remaining  teeth.  An  unnatural  regularity  in  the  arrangement  of 
artificial  teeth  should  be  avoided,  as  a  slight  irregularity  will  often 
harmonize  with  the  features.  The  first  bicuspids  of  the  upper  jaw 
should  articulate  between  the  first  and  second  bicuspids  of  the  lower 
jaw,  so  that  each  tooth  meets  two  opposing  teeth.  The  upper  first 
bicuspids  should  be  partially  hidden  by  the  cuspids  when  the  denture 
is  in  the  mouth,  and  the  upper  bicuspids  and  molars  should  project 
slightly  over  the  corresponding  teeth  in  the  lower  jaw. 

Placing  artificial  teeth  outside  the  ridge  is  often  a  cause  of  failure 
in  securing  serviceable  dentures.  The  curve  of  the  arch  in  both  jaws 
should  be  made  by  the  six  anterior  teeth,  and  by  these  alone.  The 
prominence  of  the  cusps  of  the  posterior  teeth  should  be  preserved ; 
hence  the  necessity  for  careful  articulation,  that  it  may  not  be  neces- 
sary, after  the  denture  is  completed,  to  grind  off  the  masticating  sur- 
faces of  such  teeth.  The  greatest  pressure  of  mastication  should  be 
upon  the  second  bicuspids  and  first  molars ;  hence  the  second  molars 
may  be  arranged  so  that  they  are  somewhat  shorter  than  the  teeth  re- 
ferred to. 

In  partial  upper  dentures  supplying  the  first  and  second  molars,  and 
in  some  cases  also  the  bicuspids,  on  both  sides,  should  a  natural  infe- 
rior molar  remaining  in  the  mouth  have  an  inclination  forward,  as  is 
generally  the  case  when  the  teeth  in  front  of  it  are  wanting,  such  a 
tooth  should  be  avoided  in  the  articulation  ;  otherwise,  the  denture  is 
liable  to  be  forced  forward  by  the  pressure  of  such  a  natural  tooth 
against  the  teeth  on  the  denture,  as  such  pressure  increases  as  the  jaws 
are  closed  together. 

A  small  space  should  be  left  between  the  last  tooth  of  the  upper 
and  of  the  lower  jaw  in  those  cases  where  the  crown  of  the  lower 
molar  looks  forward,  its  posterior  edge  being  a  little  higher  than  the 
anterior. 

It  is  often  necessary  to  cut  away  a  considerable  portion  of  a  tooth 
in  order  to  make  it  fit  accurately  to  the  plate.  This  makes  the  pro- 
cess of  grinding  very  tedious,  unless  the  operator  has  a  number  of 
sharp-cutting  wheels  varying  from  half  an  inch  to  three  or  four  inches 
in  diameter.  Corundum  wheels  of  various  shapes  and  sizes  are  em- 
ployed for  grinding  teeth ;  also  wheels  of  carborundum,  a  new  mate- 
rial composed  of  carbon  and  silicon,  the  combination  being  effected  by 


912 


MECHANICS DENTAL    PROSTHESIS. 


electrical  action  ;  it  is  claimed  that  carborundum  wheels  and  points 
cut  faster  than  corundum,  and  may  be  used  wet  or  dry. 

Fig.  ion  represents  an  excellent  form  of  corundum  wheel  (the  sug- 
gestion of  Dr.  S.  I^ee)  for  jointing  porcelain  gum  teeth,  and  is  made 
of  various  grits. 

These  wheels  may  be  attached  to  a  hand  lathe,  such  as  represented 
by  Fig.  IOI2  (Coy's  noiseless  hand  lathe).  The  foot  lathe  is,  how- 
ever, far  more  convenient  for  laboratory  use,  where  much  grinding  is 
to  be  done.  Of  these  the  depots  furnish  some  excellent  varieties. 
Fig.  1013  and  1014  represent  the  Snowden  &  Cowman  and  the  S.  S. 


Fig.  ion. 


White,  which  are  admirable  lathes  for  dental  purposes,  while  in  Fig. 
10 1 5  we  have  the  Amateur  lathe,  which  is  a  larger,  stronger,  and  more 
powerful  lathe,  capable  of  very  rapid  motion  ;  also  adapted  to  the 
making  of  small  instruments,  handles,  etc. 

The  lathe  of  Dr.  Lawrence,  with  detached  driving  wheel  and  head 
that  can  be  attached  to  any  convenient  board,  shelf,  or  table  (Fig. 
1016),  has  advantages  that  will  make  it  very  desirable  to  many. 

Wheels  may  either  be  set  at  intervals  on  a  long  spindle,  or  screwed 
singly  on  the  end  of  the  mandrel  (Fig.  1016).  In  the  latter  case  they 
should  be  fixed  with  a  screw  chuck  in  the  center,  so  as  to  be  quickly 
changed  from  coarse  to  fine  or  from  large  to  small.     In  grinding  the 


SELECTION    AND    ADJUSTMENT   OF   PORCELAIN   TEETH.  913 

wheel  should  revolve  toward  the  operator  and  be  kept  constantly  wet 
with  a  sponge  held  either  in  a  sponge-holder  or  between  the  ring  finger 
and  little  finger  of  the  left  hand. 

The  thumb  and  forefinger  of  each  hand  must  be  free  tc  hold  the 


Fig.  1013. 


Fig.  1014. 


tooth,  the  right  wrist  being  steadily  supported  on  the  hand  rest  (Fig. 
1017).  Two  faults  are  very  common  in  grinding;  one  is  revolving 
the  wheel  too  rapidly  ;  the  other,  bearing  the  tooth  too  heavily  against 
the  wheel.  The  first  hinders  rather  than  helps  grinding ;  the  second 
58 


914 


MECHANICS — DENTAL    PROSTHESIS. 


is  very  apt  to  throw  the  tooth  from  the  fingers  and  destroy  the  delicacy 
of  touch  necessary  for  accurate  grinding. 

Fig.  1018  represents  the  Coolidge  grinding  lathe  head,  which  is 
also  operated  by  a  driving  wheel,  and  can  be  attached  to  a  table,  and 
is  an  admirable  appliance. 


Fig.  1015. 


In  grinding  blocks  and  gum  teeth,  and  often  in  plain  teeth,  very 
small  wheels  are  required  to  make  them  fit  the  curves  of  the  plate. 
Thin  edges  of  gum  teeth  and  blocks  must  be  ground  with  very  fine- 
grained wheels ;  in  jointing  them  a  three-inch  wheel  should  be  used, 


Fig.  1016. 


perfectly  flat  on  its  outer  side,  and  running  very  true  (Fig.  101 1). 
Wheels  when  worn  down  to  small  size  increase  in  value,  because  they 
grind  out  curves  inaccessible  to  larger  ones.  In  warm  weather  large 
and  thin  wheels,  when  not  in  use,  should  rest  on  a  flat  surface;  such 


SELECTION    AND    ADJUSTMENT    OF    PORCELAIN    TEETH. 


915 


wheels  are  often  warped  by  the  softening  of  the  shellac  as  they  lie 
carelessly  among  other  wheels.  Wheels  running  on  the  end  of  a  man- 
drel and  attached  by  a  screw  chuck  can  be  made  to  run  true  by  warm- 


FiG.  1017. 


ing  the  mandrel  with  a  spirit  lamp,  and  at  the  same  time  revolving 
the  wheel  rapidly. 

The  accuracy  of  the  fit  necessarily  depends  upon  the  kind  of  work 


Fig    1018. 


and  mode  of  attachment  to  the  base  plate.     In  general  terms  it  may 
be  stated  that  whenever  any  permanent  plastic  material  is  in  contact 


91 6  MECHANICS — DENTAL    PROSTHESIS. 

with  the  base  of  the  teeth,  or  forms  the  bond  of  union  between  the 
teeth  and  plate,  grinding  is  much  simplified.  It  is  sometimes  better 
in  such  cases  to  have  a  moderate  space  between  the  base  of  the  tooth 
and  the  plate  or  fhe  model,  than  to  have  actual  contact.  But  in  all 
cases  the  lateral  jointing  of  block  or  single  gum  teeth  requires  care. 

The  order  of  grinding  a  set  of  teeth  is  usually  to  fit  the  central  in- 
cisors, then  the  laterals,  next  the  bicuspids,  and  so  on  ;  in  case  of  sec- 
tions, in  the  same  order.  This  order  will  be  found  most  conducive  to 
uniformity  of  arrangement ;  of  course,  it  may  be  modified  to  any 
desired  extent.  In  case  of  a  double  set  there  is  much  diversity  of 
practice.  Some  adapt,  first,  the  entire  upper  set,  others  the  entire 
lower ;  some,  again,  adjust  the  two  sets  of  incisors,  then  the  bicuspid 
blocks  of  both  pieces,  lastly,  the  molars.  Whichever  method  is 
adopted,  when  all  or  part  of  one  of  the  articulating  rims  is  removed, 
the  antagonizing  rim  must  be  retained  to  guide  in  the  adjustment  of 
the  teeth. 

Fig.  1019  represents  a  holder  for  teeth  while  grinding;  a  slot  admits 
the  pins,  and  the  side  clamp  holds  the  tooth  securely. 

During  the  process  of  grinding  the  teeth  are  temporarily  attached 
to  the  plate  in  several  ways.  Either  the  articulating  rim  is  cut  away 
sufficiently  to  receive  the  tooth  (Fig.  1020),  or  the  rim  is  entirely  re- 
moved and  its  place  supplied  with  a  mass  of  wax  covering  the  plate 
to  the  top  of  the  ridge,  and  to  which  the  teeth  are  severally  attached 
as  they  are  ground ;  others  fasten  the  teeth  to  the  plate  with  cement. 
Dr.  Richardson  gives  the  following  formula  for  a  tenacious  wax  for 
temporarily  securing  the  teeth  :  Beeswax,  fb.  j ;  gum  mastich,  5ij  ', 
Spanish  whiting,  §j. 

For  melting  wax  and  its  compounds  in  temporarily  attaching  teeth 
to  metal  plates  and  for  "  waxing  up  "  the  plastic  work,  the  small  Bun- 
sen  burners  represented  in  Figs.  102 1  and  1022  will  be  found  very 
useful. 

Fig.  1023  represents  what  is  known  as  the  "  Duplex  burner,"  which 
is  well  adapted  for  laboratory  use.  To  the  usual  Bunsen  burner  is 
added  a  large  flame  for  the  blowpipe,  which  is  applied  by  rotating  the 
upper  portion  upon  the  base.  By  means  of  a  small  jet  either  flame 
can  be  ignited,  rendering  it  always  ready  for  use. 

An  excellent  "  waxing  burner  "  is  shown  by  Fig.  1024.  The  tube 
cannot  be  clogged  with  wax,  as  the  heat  will  melt  it  and  it  will  escape 
at  the  opening  for  the  air-supply. 

Definite  rules  of  arrangement,  or  wood-cuts  illustrating  various 
forms  of  teeth  and  manner  of  setting  them  in  the  arch,  are  not  all 
that  is  necessary.  This  branch  of  dental  esthetics  must,  of  necessity, 
be  worked  out  by  every  one  for  himself.     He  will  succeed  or  fail  just  in 


SELECTION    AND    ADJUSTMENT   OF   PORCELAIN    TEETH. 


917 


proportion  as  he  has  the  ability  to  observe  the  hundreds  of  models  which 

are  perpetually  before  him,  and  as  he  has  the  further  and  rarer  ability 

to  apply  his  observations  to  the  special  cases  that  are  in  his  laboratory. 

Imitation   of  nature  is  the  rule.     Imitations  of  art  and  individual 


Fig.  1019. 


Fig.  1022. 


incapacity  make  exact  observance  of  this  rule  comparatively  rare.  We 
replace  the  sixteen  teeth  with  only  fourteen,  and  often  make  them 
shorter  and  every  way  smaller  than  the  natural  organs.  We  do  not 
make  the  grinding  surfaces  interlock  with  such  deep  cusps  as  in  nature. 


gi8 


MECHANICS — DENTAL    PROSTHESIS. 


At  one  time  we  cannot  avoid  an  unnatural  fullness  of  artificial  gum; 
at  other  times  the  contraction  of  the  absorbed  arch  compels  the  set- 
ting of  molar  teeth  nearer  the  median  line  than  the  original  teeth. 


Fig.  1024. 


Notwithstanding  these  and  many  other  disadvantages  the  perfection 
of  the  dento-ceramic  art  is  such  that  a  skilled  artist  who  is  quick  to 
observe  what  nature  requires  can  in  the  majority  of  cases  falling  under 


SELECTION    AND    ADJUSTMENT    OF    PORCELAIN    TEETH.  919 

his  care  supply  the  lost  dental  organs  with  great  accuracy,  and  preserve 
that  higher  order  of  beauty  which  grows  out  of  the  harmony  of  his 
work  with  the  expression  of  the  face  and  entire  person.  But  no  den- 
tist can  give  to  his  work  this  kind  of  beauty  who  does  not  systemati- 
cally study  the  natural  organs  as  they  daily  present  themselves  in  the 
operating  chair.  Few  patients  would  object  to  the  pressure  of  a  roll 
of  wax  (two  inches  long  and  about  half  an  inch  thick)  against  the 
closed  teeth.  A  model  from  this  impression  would  give  the  size,  form, 
arrangement,  and  articulation  of  all  except  the  molar  teeth.  A  well- 
matched  porcelain  tooth  (more  than  one  might  be  required)  would 
add  to  these  data  the  color  of  teeth  and  gum.  To  this  add  also  the 
age,  sex,  physical  characteristics  of  the  face,  and  the  physical  tempera- 
ment. If  the  dentist  would  have  a  case-book  for  the  registration  of 
one  such  carefully  made  observation  every  week  he  would,  at  the  end 
of  two  years,  have  a  collection  which  as  a  practical  guide  in  the  selec- 
tion and  arrangement  of  artificial  teeth  would  prove  of  incalculable 
value.  These  fixed  records  of  minute  details  are  made  still  more  use- 
ful by  a  habit  of  close  observation  in  society.  In  this  way  a  set  style, 
or  mannerism,  maybe  avoided,  which  so  often  stamps  work  with  mean- 
ingless uniformity  of  expression. 

Artificial  teeth  should  imitate  the  natural  organs;  yet  there  is  a 
perfection  of  form  and  arrangement  which  it  is  not  advisable  to  imi- 
tate. To  disarm  suspicion  as  to  their  artificial  character,  it  is  often 
desirable  to  impart  a  measure  of  irregularity.  An  overlapping  lateral, 
a  missing  bicuspid,  a  worn  canine,  an  incisor,  bicuspid,  or  molar 
apparently  decayed  and  filled  with  gold,  an  exposed  neck  from  absorp- 
tion of  the  alveolus,  are  among  the  legitimate  devices  of  the  skillful 
mechanician  who  has  the  "art  to  conceal  his  art."  If  there  are  any 
defective  natural  teeth  remaining  to  be  matched,  still  higher  art  is 
required.  A  perfect  porcelain  incisor  is  no  fit  companion  for  one  that 
is  partly  broken,  decayed,  and  discolored  ;  and  since  no  art  can  make 
the  defective  tooth  perfect,  and  yet  the  patient  retains  it,  there  is  no 
alternative  but  to  give  so  much  imperfection  to  the  artificial  one  as 
shall  take  away  that  striking  contrast  which  so  painfully  offends  our 
esthetic  sense  of  fitness. 

In  this  class  of  operations  a  "  diamond  drill  "  is  of  great  value  ;  in 
fact,  so  very  useful  is  it  in  many  ways  that  we  regard  it  as  an  abso- 
lutely indispensable  instrument  in  the  laboratory.  Cutting  away  parts 
of  teeth  or  blocks  inaccessible  to  wheels ;  changing  the  shape  of  teeth 
near  the  gum  ;  drilling  cavities  to  be  filled  with  gold,  or  holes  for  the 
repair  of  broken  blocks,  these  are  some  of  the  operations  which  the 
diamond  drill  will  accomplish  as  no  other  instrument  can. 

The  selection  and  grinding  of  artificial  teeth  require,  first,  a  high 


920 


MECHANICS DENTAL    PROSTHESIS. 


order  of  esthetic  culture;  secondly,  great  patience  and  skillful  manipu- 
lation. The  latter  are  often  taxed  to  the  utmost  to  make  a  set  of 
blocks  answer  the  requirements  of  a  given  case ;  especially  when  the 
blocks  must  be  closely  fitted  to  a  gold  plate  preparatory  to  attachment 
by  soldering.  Single  gum  teeth  are  more  easily  fitted  to  the  plate ; 
but  there  are  some  joints  ;  hence  it  is  doubtful  if  much  time  is  saved. 
The  principal  advantage  of  single  gum  teeth  is  that  a  single  tooth,  if 
broken,  may  be  replaced  without  interfering  with  the  adjoining  ones. 
Another  reason  why  many  prefer  them  is  that  a  small  stock  of  teeth 
in  this  form  is  adapted  to  a  larger  variety  of  cases  than  blocks  would  be. 

We  think,  however,  that  dentists  living  at  a  distance  from  the  manu- 
facturer should  depend  upon  a  great  variety  of  samples  rather  than 
upon  duplicates  of  certain  forms,  however  desirable. 

In  joining  a  set  of  blocks  or  single  gum  teeth  one  point  must  be 
remembered  which  has  already  been  alluded  to.  In  soldering  the 
metal  expands,  while  the  teeth  held  in  the  investment  are  brought 
closer  together  by  its  contraction,  and  in  this  slightly  altered  position 
they  are  soldered   to  the  plate.     The  contraction   of  the   plate  on 


Fig.  1025. 


Fig.  1026. 


cooling  is  irresistible  and  may  result  in  one  or  both  of  two  accidents 
— chipping  off  the  brittle  edges  of  the  teeth  thus  brought  too  closely 
together,  or  warping  the  plate  because  of  the  resistance  which  the 
teeth  or  blocks  offer  to  the  contraction  of  the  plate.  Thin  letter  paper 
slipped  between  the  side  joints  will  suffice  to  prevent  these  accidents. 

Fig.  1025  gives  an  external  view  of  a  full  upper  set  of  single  gum- 
teeth,  arranged  on  a  gold  plate,  preparatory  to  the  operations  which 
precede  soldering,  or  other  modes  of  fastening  them  to  the  base.  Fig. 
1026  is  a  similar  view  of  a  set  of  blocks,  with  a  soldered  rim  covering 
the  upper  edge. 

Usually,  in  first  or  temporary  pieces,  and  sometimes  after  the  alveo- 
lar absorption  is  completed,  the  fullness  of  the  gum  is  such  as  to  forbid 
the  addition  of  an  artificial  gum  to  the  ten  incisors,  canines,  and  bi- 
cuspids. In  such  cases  the  plate  must  be  cut  away  from  the  front  of 
the  ridge  as  far  as  the  first  or  second  bicuspid,  and  the  teeth  ground 
with  great  accuracy  to  fit  the  gum  itself.  Single  plain  teeth  will 
usually  be  best  adapted  to  such  cases ;    but  an  excellent  effect   can 


SELECTION    AND    ADJUSTMENT    OF    PORCELAIN    TEETH. 


921 


sometimes  be  produced  by  grinding  a  block,  when  the  shade  of  gum  is 
well  matched,  to  fit  directly  upon  the  natural  gum.  In  partial  cases 
the  tooth  or  block  must  invariably  be  fitted  to  the  gum ;  no  plate 
should  be  seen  above  or  at  the  side.  In  fitting  directly  to  the  plaster 
model  this  should  be  scraped  (after  the  tooth  is  ground),  so  that  it 
may  press  firmly  on  the  corresponding  gum. 

The  teeth  or  blocks  being  now  arranged  and  fitted  to  the  plate,  the 
next  step,  preparatory  to  soldering,  is  to  get  access  to  the  pins  on  the 
inside  for  the  purpose  of  backing  them.  Set  the  articulating  model 
on  the  table  with  the  teeth  upward  ;  bend  a  strip  of  lead  (an  inch 
wide)  outside  the  arch  and  about  half  an  inch  from  the  teeth ;  then 
fill  the  space  with  plaster,  inserting  a  strip  of  tin  foil  opposite  the 
median  line,  so  that  the  plaster  rim  will  readily  break  at  that  point 
when  removed.  In  a  double  set  do  the  same  with  each  half  of  the 
articulator.  When  the  plaster  has  set  remove  all  wax  or  cement  from 
the  teeth  and  plate,  and  proceed  to  examine  the  pins,  also  the  relations 


Fig.  1027. 


of  the  teeth  or  blocks  to  the  plate  and  to  each  other.  This  tempor- 
ary plaster  band  we  regard  as  essential  in  every  case,  except  a  few 
varieties  of  partial  sets.  It  is  equally  essential  in  vulcanite  and  other 
forms  of  plastic  work,  as  will  be  hereafter  explained.  It  is  a  common 
but  not  good  practice,  where  the  teeth  are  soldered,  to  substitute  for 
this  temporary  band  the  soldering  investment. 

Fig.  1027  will  give  an  idea  of  the  shape  of  this  rim,  except  that, 
being  here  designed  for  a  different  purpose,  it  does  not  show  the  im- 
press of  the  teeth.  Fig.  1028  represents  the  inner  surface  of  a  set  of 
blocks  with  the  wax  removed,  which  we  may  suppose  just  withdrawn 
from  the  plate  in  the  preceding  figure.  Blocks  or  sections  are  readily 
replaced  in  their  proper  positions;  but  single  teeth  are  sometimes  so 
similar,  especially  bicuspids,  that  they  are  apt  to  be  misplaced.  To 
prevent  such  accidents  have  a  circular  wooden  block  four  inches  in 
diameter,  with  twenty-eight  cups  or  depressions,  so  marked  that  each 
tooth  can  be  instantly  put  into  and  taken  from  its  proper  cup. 


922 


MECHANICS — DENTAL    PROSTHESIS. 


The  teeth  being  thus  arranged,  a  gold  plate  or  backing  large  enough 
to  cover  the  entire  width,  and  from  eight-  to  nine-tenths  of  the  height 
of  the  posterior  surface  of  each,  is  fitted  to  them  in  the  following 
manner.  Each  tooth  has  securely  fixed  in  the  back  part  of  it  two 
platina  rivets  for  the  purpose  of  connecting  it  to  the  backing.  Each 
backing,  therefore,  should  have  two  holes  punched  through  it  by- 
means  of  a  pair  of  punch  forceps,  as  represented  in  Fig.  1029,  large 
enough  to  admit  the  rivets  of  the  teeth.  After  having  punched  one 
hole  a  rivet  is  inserted ;  then  by  moving  the  strip  of  gold  plate  two 
or  three  times  to  the  right  and  left  a  mark  will  be  left  upon  it,  indi- 
cating the  distance  the  rivets  are  apart.  But  previously  to  this  the 
rivets  should  be  made  parallel  (being  very  careful  not  to  strain  them 
in  the  tooth)  and  the  ends  filed  off  level.     Otherwise  the  pins  will  not 


Fig.  1029. 


go  into  the  holes  punched,  and  there  will  be  an  uncertainty  as  to  which 
side  of  the  pin  the  mark  on  the  plate  corresponds. 

Dr.  Samuel  Mallet  has  very  ingeniously  invented  a  punch  which  will 
save  much  trouble  in  finding  the  proper  position  of  the  second  hole 
(Fig.  1030).  After  straightening  the  pins,  one  is  placed  in  the  hole, 
/,  at  the  head  of  the  punch,  the  other  pin  pressing  out  the  movable 
punch,  e  (which  works  by  the  spring,  g'),  until  it  slips  into  the  slot, 
h  ;  the  two  punches,  f  e,  then  make  the  holes  at  the  exact  distances 
apart  to  receive  the  pins. 

A  simple  form  of  punch,  and  one  not  liable  to  accident,  is  a  piece 
of  steel  half  an  inch  square  and  three  or  four  inches  long.  It  con- 
sists of  two  halves  riveted  together  at   the  top,  each  tapering  nearly 


SELECTION    AND    ADJUSTMENT    OF    PORCELAIN    TEETH. 


923 


to  a  point.  By  turning  a  small  screw,  inserted  midway  in  one  leg, 
the  points  held  opposite  the  pijjs  are  separated  to  their  exact  distance. 
A  slight  tap  of  the  hammer  marks  this  upon  the  backing,  and  then 
the  holes  are  made  with  an  ordinary  punch.  Pins  often  set  very  irregu- 
larly in  a  tooth ;  they  should  be  parallel,  but  not  necessarily  perpen- 
dicular. Too  much  bending  of  a  pin  close  to  the  tooth  makes  it 
more  liable  to  fracture  in  soldering  or  by  use  in  the  mouth.     Pins  also 


Fig.  1030. 


vary  much  in  thickness ;  it  is  better  to  have  the  pin  of  the  punch 
forceps  of  medium  size,  and  to  ream  with  a  broach  for  large  platina 
pins.  A  set  of  broaches  are  indispensable  in  backing  teeth  and  in 
many  other  operations. 

The  holes  should  be  slightly  countersunk  on  both  sides,  and  after 
placing  the  backing  on  the  tooth  it  is  made  fast  by  splitting  with 
a  strong  knife  or  a  wedge-shaped  excavator  the  ends  of  the  platina 
rivets  or  pinching  them   together  with  pliers.     If  the  ends  of  the 


Fig.  1031. 


platina  rivets  are  hammered  so  as  completely  to  fill  the  holes  in  the 
backings,  it  will  prevent  the  solder  from  flowing  in  and  uniting  the 
two  as  firmly  as  it  should  do.  The  backings  should  be  slightly  hol- 
lowed before  they  are  put  on ;  by  so  doing  they  will  fit  up  closely  to 
every  part  of  the  back  of  the  tooth.  Fig.  1031  represents  a  pair  of 
forceps  designed  to  give  a  general  form  to  the  backing  by  punching  it 
from  a  piece  of  gold  plate  of  the  required  thickness. 


924  MECHANICS — DENTAL    PROSTHESIS. 

After  the  backings  have  been  made  fast  to  the  teeth  they  are  to  be 
accurately  fitted  to  the  plate,  standing  off  from  the  plate  enough  for  a 
very  thin  piece  of  watch  spring  to  be  passed  under  it.  This  shows 
that  the  tooth  is  not  raised  by  the  backing  from  its  place  in  the  invest- 
ment. A  much  wider  space  makes  the  flow  of  solder  uncertain  ;  the 
practice  of  placing  scraps  of  gold  under  badly-fitting  backings  is  a 
very  slovenly  one;  and  where  such  imperfections  occur  it  is  much 
better  to  fill  such  spaces  with  gold  foil. 

Some  dentists  back  the  teeth  as  they  grind  and  fit  them  and  before 
investing;  others  invest  with  the  plaster  and  sand,  and  back  without 
taking  them  from  the  investment;  others,  again,  partially  invest  with, 
the  soldering  mixture,  remove,  and  back  the  teeth,  then  replace,  and 
add  more  plaster  and  asbestos  or  sand  over  the  edges  of  the  teeth. 
The  last  method  is  unsafe,  because  the  two  layers  of  batter  are  apt  to 
separate  in  heating  and  may  displace  the  teeth. 

Backings  (called  also  stays  or  standards)  vary  much  in  size,  shape, 
and  thickness.  Some  variations  are  matters  of  taste  :  as,  Avhether  they 
shall  be  rounded,  square,  or  beveled  at  the  top  corners ;  whether 
chamfered  to  a  thin  edge,  or  left  thick,  and  then  beveled  or  rounded. 
But  other  points  often  considered  optional  are  not  so,  inasmuch  as 
they  affect  the  appearance  or  stability  of  the  work.  Backings  which 
cover  the  translucent  edge  of  the  tooth  darken  it  by  the  refraction  of 
the  oxidized  surface  next  the  tooth,  and  which  cannot  be  kept  bright ; 
even  if  it  could,  the  gold  would  impart  a  yellowish  tinge.  They 
should  cover  enough  of  the  tooth,  and  fit  so  accurately  as  to  prevent 
motion  of  the  tooth ;  for  this  will  inevitably  cause  the  pins,  sooner  or 
later,  to  break  off.  Backings,  in  relation  to  each  other,  must  either 
be  so  far  apart  at  their  base  that  the  solder  will  not  flow  from  one  to 
the  other,  forming  a  continuous  band,  or  they  must  be  in  contact 
throughout  whatever  distance  the  solder  will  unite  them.  This  rule  is 
particularly  applicable  to  backings  of  single  gum  teeth,  which  are 
often  (perhaps  usually)  made  the  full  width  of  the  tooth  up  to  the 
shoulder.  This  continuous  band  gives  great  stiffness  to  the  plate. 
But  the  contraction  of  the  solder  will  certainly  warp  it,  unless  pre- 
vented by  actual  contact  of  the  edges  soldered.  In  case  of  plain  teeth 
a  heavy,  continuous  line  of  solder  will  almost  certainly  warp  the  plate. 
A  block  may  be  backed  for  soldering  in  one  piece,  or  in  parts  closely 
fitted,  or  in  distinct  backings  opposite  each  tooth.  A  block  much 
curved  is  with  difficulty  backed  in  one  piece ;  long  or  thin  blocks  are 
liable  to  be  cracked  by  the  contraction  of  a  backing,  either  in  one 
piece  or  made  continuous  by  soldering.  Backings  should  be  of  the 
same  gold  as  the  plate,  but  heavier,  especially  if  long  or  large. 

Sometimes  the  shape  of  a    gum    or  block  tooth  may  require  the 


SELECTION    AND    ADJUSTMENT    OF    PORCELAIN    TEETH.  925 

removal  of  the  plaster  rim,  which  can  readily  be  done ;  then  replaced 
after  the  backing  is  completed  for  the  final  adjustment  of  the  teeth. 
The  teeth  are  next  to  be  fastened  to  the  plate  with  a  small  quantity  of 
cement  (resin  mixed  with  wax,  or,  still  better,  the  wax,  gum  mastich, 
and  whiting  compound),  and  a  small  roll  of  softened  wax  (not  melted 
or  made  adhesive)  placed  over  the  entire  surface  to  be  soldered.  In 
Fig.  1032  the  inner  band  may  be  taken  to  represent  the  width  of  this 
wax  roll,  which  is  of  great  service  in  preventing  any  plaster  of  the 
investment  from  getting  accidentally  upon  the  parts  to  be  soldered. 
If  the  teeth  have  been  previously  soldered  to  the  backings  this  wax 
strip  should  be  narrower ;  but  if  rivets  and  backings  are  to  be  soldered 
at  the  same  time,  the  rim  must  be  made  carefully  to  cover  every  point 
where  solder  is  to  flow.  The  plaster  band  is  then  very  carefully  re- 
moved and  the  piece  surrounded  with  the  soldering  investment,  which 
must  be  no  thicker  than  is  sufficient  to 
protect  the  teeth  and  hold  them  in  place. 
The  wax  and  cement  are  easily  removed, 
leaving  the  surfaces  perfectly  clean  and 
ready  for  the  borax  and  solder.  The 
investment  should  not  project  so  far  over 
the  inner  edge  of  the  teeth  as  to  obstruct 
the  blowpipe  flame ;  it  should  not  cover 
the  lingual  surface  of  the  plate,  nor  should 
it  be  thick  on  the  palatine  surface.     On  fig.  1032. 

the  palatine  side  it  might  be  well  also  to 

cut  along  the  median  line  nearly  or  quite  through  the  investment ;  th«e 
object  of  this  is  to  give  play  to  the  lateral  expansion'of  the  plate,  the 
antero-posterior  expansion  being  usually,  from  the  shaj^e  of  the  plate, 
sufficiently  free.  This  we  regard  the  simplest  and  best  method  to 
prevent  warping  of  the  plate,  so  often  caused  by  the  very  means  taken 
to  prevent  it. 

We  have  said  nothing  of  fastening  the  teeth  with  a  firm  body  of 
cement  instead  of  wax,  so  as  to  try  them  in  the  mouth  before  solder- 
ing, because  a  correctly  taken  articulation  makes  this  unnecessary. 
As  remarked  in  the  chapter  on  articulation,  this  process  admits  of  per- 
fect accuracy.  Its  very  object  is  to  prevent  the  necessity  of  any  change 
in  arrangement  after  teeth  are  adjusted.  An  error  of  articulation  will 
often  involve  a  change  in  the  jointing  of  blocks  more  troublesome  than 
the  original  grinding;  in  fact,  neatly  ground  blocks  (or  gum  teeth) 
will  not  permit  the  slightest  change  of  position  without  fresh  grinding 
somewhere.  Trial  of  teeth,  merely  to  test  the  correctness  of  articu- 
lation, may  in  some  cases  be  especially  necessary  when  used  to  test 
correctness  in  the  selection  of  teeth  ;  for  it  requires  experience  to  en- 


926  MECHANICS — DENTAL    PROSTHESIS. 

able  us  to  determine,  a  priori,  just  what  style  of  work  is  best  adapted 
to  the  case.  But  the  awkward  and  momentary  retention  of  a  plate  to 
which  the  teeth  are  so  slightly  attached  is  no  test  of  its  esthetic  cor- 
rectness, unless  the  selection  has  been  grossly  misjudged.  It  is  only 
after  the  patient  has  become  habituated  to  the  piece,  giving  time  for 
the  natural  form  of  the  lips  and  motions  of  the  mouth,  that  we  can 
best  decide  whether  or  not  our  work  has  beauty  of  expression  as  well 
as  artistic  finish. 

Mr.  Andrew  Wilson,  of  Scotland,  adopts  the  following  method  of 
backing  teeth  :  After  having  partially  fitted  the  tooth  to  the  plate, 
take  a  piece  of  platina  foil,  as  thick  as  can  be  used  conveniently,  and, 
pressing  it  against  the  tooth,  perforate  it  where  it  is  marked  by  the 
pins ;  then  cut  it  into  the  required  shape  of  the  backing  and  press  it 
as  closely  as  possible  to  the  back  of  the  tooth.  Apply  a  little  borax 
to  the  platina  pins  which  come  through  the  back ;  then  place  the 
tooth,  with  its  face  downward,  upon  a  thin  piece  of  pumice,  covered 
with  dry  plaster,  putting  upon  the  platina  sufficient  gold  for  the  thick- 
ness required  ;  slowly  heat  it,  gradually  raising  the  heat  until  the  gold 
melts,  when  it  will  rapidly  flow  over  the  whole  platina  surface,  uniting 
so  firmly  with  the  pins  in  the  tooth  that  Mr.  W.  has  never,  during 
eight  years'  use,  seen  a  case  in  which  they  have  loosened,  even  where 
there  has  been  sufficient  violence  to  break  the  tooth.  After  the  back- 
ing has  been  run  and  the  tooth  allowed  to  cool  slowly,  it  is  filled  to 
the  requisite  thickness  and  shape;  tooth  and  backing  are  then  closely 
fitted  and  finally  soldered  to  the  plate.  In  arranging  the  teeth  on  the 
plate  for  soldering,  Mr.  Wilson  uses  an  investment  of  white  sand  and 
plaster,  equal  pa'rts,  placing  a  thin  strip  of  platina  on  the  outside  of 
the  teeth,  with  a  layer  of  the  investment  on  both  sides  of  it,  so  that, 
should  the  plaster  crack  in  soldering,  the  platina  may  keep  the  teeth 
from  shifting  their  places.  The  whole  time  occupied  in  heating  and 
backing  a  tooth  is  about  half  an  hour  ;  when  several  are  done  at  once 
a  little  longer  time  is  required.  Of  course,  all  the  backings  of  the  set 
should  be  flowed  at  the  same  heating. 

Instead  of  using  the  strip  of  platina  plate  to  prevent  the  teeth  from 
becoming  displaced,  in  case  the  plaster  cracks,  thin  sheet-iron  rings 
one  inch  deep  or  iron  wire  may  be  used  ;  but  platina  is  undoubtedly  the 
neatest,  and  has  the  advantage  of  being  indestructible  ;  it  may  be 
narrow  and  thin,  so  that  its  cost  would  form  no  objection  to  its  use. 
But  if  the  plaster  is  not  in  excess  the  investment  will  not  crack.  A 
batter  made  of  three  or  four  parts  of  asbestos  to  one  of  plaster  will 
stand  the  hottest  fire  of  the  laboratory.  Many  prefer  equal  parts  of 
plaster  and  sand,  as  forming  a  more  solid  investment  in  which  to  back 
up  the  teeth.     Mr.  Wilson's    method   might  be   improved,  first,  by 


SELECTION    AND    ADJUSTMENT    OF    PORCELAIN    TEETH. 


927 


completely  fitting  the  tooth  before  backing ;  secondly,  by  running  the 
thin  platina  backing  one-sixteenth  of  an  inch  on  the  plate,  to  any  ir- 
regularities of  which  it  can  be  quickly  burnished  down.  This  flange 
secures  a  very  perfect  and  strong  attachment  to  the  plate,  and  is  the 
method  of  backing  (with  heavier  platina)  sometimes  practiced  in  the 
continuous-gum  work. 

Ordinary  backings,  after  they  have  been  fitted  to  the  plate  and  held 
to  the  teeth  by  bending  or  splitting  the  pins,  may  be  removed  from 
the  plate,  set  in  a  batter  of  plaster  and  asbestos,  and  soldered  ;  the 
piaster  should  be  so  stiff  as  not  to  flow  over  the  backings.     The  solder 


should  be  rather  harder  to  fuse  than  that  used  to  fasten  the  teeth  to 
the  plate.  The  backings,  after  slowly  cooling,  should  be  filed,  and 
may  even  be  Scotch-stoned.  Backings  can  be  better  and  more  quickly 
finished  singly  than  when  attached  to  the  plate.  This  method,  or  Mr. 
Wilson's,  is  much  to  be  preferred  to  the  common  practice  of  soldering 
the  backings  to  both  teeth  and  plate  at  the  same  heating. 

A  piece  invested  preparatory  for  soldering  and  placed  upon  a  lump 
of  solid  charcoal  is  seen  in  Fig.  1033. 

Directions  for  applying  borax  and  solder  are  given  in  the  chapter  on 


928  MECHANICS — DENTAL    PROSTHESIS. 

soldering.  Some  cut  the  solder  into  very  small  pieces  ;  others  use  one 
piece  to  each  tooth  at  its  base,  and  a  second  for  the  pins  unless  pre- 
viously soldered  ;  in  the  figure  the  pieces  are  unnecessarily  small.  If 
the  backings  are  soldered  to  the  teeth  beforehand  a  more  fusible  grade 
of  solder  should  be  used  at  the  second  soldering.  The  work  must  be 
very  gradually  and  thoroughly  heated  up  before  directing  the  flame 
upon  the  plate  or  backings.  The  last  point  to  be  touched  with  the 
flame  is  the  solder,  and  this  not  before  a  slight  melting  of  the  edge 
shows  that  it  is  just  on  the  point  of  flowing.  If  every  preparation  for 
soldering  has  been  properly  made  the  actual  flowing  of  the  solder  on 
a  full  piece  will  take  less  than  a  minute,  and  will  be  so  smooth  as  to 
require  no  other  finish  than  the  Scotch  stone  and  the  polishing  wheels. 
After  soldering,  the  cover  should  be  placed  upon  the  soldering  pan 
(Fig.  1054)  and  the  work  allowed  to  become  quite  cold  before  removal ; 
when  a  charcoal  kmip  (Fig.  1033)  or  pumice  stone  is  used  the  work 
must  also  be  covered  while  cooling. 


CHAPTER   XII. 

PRINCIPLES   AND    APPLIANCES   OF   SOLDERING. 

Soldering  is  the  union  of  two  metallic  surfaces,  either  by  slightly 
fusing  the  surfaces  themselves  (technically  termed  sweating,  or  auto- 
genous soldering),  as  in  the  union  of  a  plate  of  silver  to  a  block  of 
copper  preparatory  to  rolling  into  Sheffield  plate,  or  by  the  fusion  of 
an  alloy  which  melts  more  readily  than  the  metals  to  be  soldered. 
The  conditions  of  successful  soldering  are  as  follows :' — 
I.  Careful  and  proper  investment.  2.  Careful  cleansing  of  surface 
on  which  the  solder  is  to  flow;  which  implies  absence  of  oxid.  3. 
Careful  application  of  the  flux  and  of  the  solder.  4.  Careful  heating 
up.  5.  Proper  amount  and  direction  of  heat  in  flowing  the  solder. 
One  condition  requires  good  solder;  of  this  we  have  elsewhere  spoken. 
To  limit  the  flow  of  the  solder  and  protect  all  places  which  it  should 
not  encroach  upon,  a  thin  layer  of  plaster  batter  or  a  solution  of  whit- 
ing may  be  applied  with  a  camel's-hair  brush.  Another  calls  for  the 
use  of  borax,  the  specific  action  of  which,  as  a  flux,  is — first,  the 
removal  of  existing  oxid  by  virtue  of  its  powerful  affinity  for  it ; 
secondly,  the  prevention  of  further  oxidation  by  the  exclusion  of  the 
oxygen  of  the  air.  Another  condition  demands  a  skillful  management 
of  the  blowpipe  flame ;  this  is  the  principal  difficulty  with  most  begin- 
ners and,  indeed,  with  not  a  few  old  practitioners. 


PRINCIPLES   AND    APPLIANCES    OF   SOLDERING.  929 

The  borax  (flux)  should  be  used  in  the  lump  and  rubbed  with  pure 
(distilled  or  rain)  water  upon  a  coarsely-ground  glass  slab  until  a 
creamy  paste  is  formed.  Into  this  the  pieces  of  solder  may  be  placed, 
and  also  some  of  it  applied  with  a  small  brush  or  feather  to  the  sur- 
faces over  which  the  solder  is  required  to  flow.  Hard  water  and  the 
common  practice  of  rubbing  borax  on  a  slate  make  it  impure  and  to 
some  extent  interfere  with  soldering.  Too  much  borax  is  objection- 
able, and  gold  requires  less  than  silver.  The  solder  is  placed  along 
the  base  of  the  backing,  and  if  this  is  short  the  solder  can  be  directed 
in  its  flow  by  the  flame  of  the  blowpipe  to  the  holes  of  the  pins ;  if  the 
backings  are  long,  it  may  be  best  to  place  a  small  piece  of  solder  over 
the  holes  of  the  pins  in  addition  to  the  piece  along  the  base  of  the 
backing.  The  solder  should  be  tested  before  using  by  melting  it  on  a 
piece  of  silver  plate. 

In  fulfilling  another  condition — the  management  of  the  heat — the 
following  points  demand  attention  :  (a)  To  raise  the  heat  very  grad- 
ually, until  the  water  of  crystallization  of  the  borax  is  slowly  driven 
off;  for  if  this  is  done  rapidly  the  borax  puffs  up  and  throws  off  the 
solder ;  rapid  heating  at  the  outset  is  apt  also  to  crack  the  teeth.  ((^) 
To  diffuse  the  heat  when  using  the  blowpipe,  so  that  the  solder  shall 
not  become  melted  before  the  metallic  surfaces  are  hot  enough  to 
unite  with  it,  else  it  will  roll  into  a  ball  or  flow  with  an  abruptly- 
defined  edge;  whereas  it  should  unite  so  smoothly  with  the  plate  that, 
except  for  the  difference  in  color,  its  line  of  termination  cannot  be 
detected,  (c)  To  manage  the  fine  point  of  the  blowpipe  flame  so  as 
to  be  able  to  direct  the  flow  of  the  solder  to  any  given  point ;  the 
rule  being  that,  unless  prevented,  solder  will  flow  toward  the  hottest 
point.  There  are  two  kinds  of  flame  given  by  the  blast  of  the  blow- 
pipe: I.  The  broad,  heating-up,  or  oxidizing  flame;  this  is  produced 
by  holding  the  tip  a  little  behind  or  at  the  edge  of  the  flame.  2.  The 
pointed,  soldering,  or  deoxidizing  flame ;  this  is  produced  by  passing 
the  tip  more  or  less  into  the  flame.  A  very  general  mistake  is  to  use 
too  strong  a  blast. 

The  apparatus  required  for  soldering  includes  a  lamp  to  give  a  suf- 
ficiently hot  flame;  a  blowpipe  to  give  intensity  and  direction  to  the 
flame;  borax,  brush,  glass,  slate,  solder,  and  solder-tongs;  investing 
materials  and  clamps  to  protect  the  teeth,  also  to  hold  the  parts  in 
relation  to  each  other  until  soldered  ;  a  receptacle  to  retain  or  give 
additional  heat  during  the  process  of  soldering ;  an  acid  (sulphuric) 
bath  to  remove  the  glass  of  borax. 

As  accidents  sometimes  occur  from  the  flame  communicating  with 
the  explosive  mixture  of  air  and  alcoholic  vapor  in  the  body  of  the 
lamp,  it  IS  prudent  to  make  a  safety  lamp  by  connecting  the  wick  tube 
59 


93° 


MECHANICS — DENTAL   PROSTHESIS. 


with  the  body  of  the  lamp  by  a  small  tube  which  shall  be,  under  all 
circumstances,  full  of  alcohol.  Figs.  1034  and  1035  represent  such 
lamps.     If  the  wick  is  not  permitted  to  run  below  the  shoulder  above 

the   horizontal  tube   this 
tube  will  remain  always 
jgm  i|jr  filled  with  alcohol.     The 

top  of  the  wick  tube 
should  be  beveled  off  in 
a  direction  just  the  re- 
verse of  that  shown  in  the 
drawing,  so  as  to  permit 
the  downward  projection 
of  the  flame.  Fig.  1036 
Pjj,  is  a  very  ingenious  modi- 

fication of  the  safety 
lamp,  made  by  Dr.  B.  W.  Franklin,  so  constructed  as  to  retain  the 
alcohol  uniformly  at  the  same  level. 

The  fluid  used  in  these  lamps  is   usually  alcohol.     For  all  purposes 
of  dental  soldering  alcohol  gives  a  suffi- 
cient degree  of  heat,  and  is  much  more 

cleanly  than   the  carboniferous  flame  of  /^^=1LJ  ^^^ -. 'A^~^ 

ethereal  oil,  sperm  oil,  coal  oil,  or  gas. 


Fig.  1035. 


Fig.  1036. 


To  give  intensity  and  proper  direction  to  the  heat  of  the  lamp,  a 
blowpipe  is  necessary.  The  simplest  is  a  tapering  tube,  fifteen  to 
eighteen  inches  long,  and  curved  at  the  smaller  end  (Fig.  1037).     At 


Fig.  1037. 


this  end  the   bore   for  the   last  half-inch  should  be  perfectly  cylin- 
drical and  about  as  large  as  a  medium-sized  knitting  needle.     This 


PRINCIPLES   AND    APPLIANCES    OF   SOLDERING. 


93^ 


may  be  modified  in  several  ways  and  made  more  useful:  First,  by 
cuttuig  it  within  three  inches  of  the  flame  end  and  inserting  a  small, 
hollow  ball  or  cylinder,  to  receive  the  condensed  moisture,  which, 
in  the  plain  blowpipe,  often  interrupts  the  blast.  Secondly,  by 
attaching  a  flattened  mouth-piece,  which  is  much  less  fatiguing  to 
the  lips  to  grasp.     Thirdly,  by  connecting  the  flame  end  to  the  mouth- 


FiG.  1039. 


Fig.  1038. 

piece  by  from  six  to  twelve  inches  of  flexible  tubing.  The  flame  end 
ought  to  be  straight,  and  from  four  to  six  inches  long;  a  cigar  holder 
makes  an  excellent  mouth-piece.  A  bulb  or  enlargement  in  the  tube 
might  be  serviceable  in  retaining  condensed  moisture  ;  but  it  is  less 
liable  to  accumulate  in  rubber  tubing  than  in  the  metal  pipes.  There 
are  m.any  forms  of  mouth  blowpipes,  and  some  quite  expensive  ones  ; 
but  the  pipe  with  flexible 
tube,  as  here  described, 
will  be  found  very  conve- 
nient for  the  laboratory. 

Figs.  1038,  1039,  and 
1040  represent  different 
forms  of  blowpipes  devised 
for  the  purpose  of  prevent- 
ing the  moisture  which 
accumulates  within  the 
tube  from  being  blown 
from  the  orifice  and  in- 
terrupting the  blast. 

Figs.  1039  and  1040  are 
modifications     introduced 

by  Mr.  Thomas  Fletcher,  and  for  the  latter  it  is  claimed  that  the 
month-piece  is  the  easiest  to  use,  and  the  heaviest  continued  blowing 
causes  no  strain  on  the  lips,  while  the  tongue  has  the  necessary  con- 
trol over  the  opening.  Being  held  as  a  pencil,  the  chamber  on  the 
stem  stops  all  condensed  moisture  and  prevents  the  heat  ascending  to 
the  end. 

The  mouth  blowpipe  requires  in  its  use  a  peculiar  management  of 
the  muscles  of  the  chest,  cheeks,  and  palate,  by  virtue  of  which  an 


Fig.  1040. 


932  MECHANICS — DENTAL    PROSTHESIS, 

uninterrupted  and  regular  current  of  air  is  thrown  from  the  lungs 
through  the  pipe.  The  simplest  way  to  learn  how  to  do  this  is  to  first 
practice  blowing  exclusively  during  /aspiration  ;  this  calls  into  action 
the  cheek  muscles  and  involuntarily  closes  the  opening  between  mouth 
and  fauces.  Then  use  the  pipe  solely  during  ^^vpiration  ;  this  teaches 
control  of  the  chest  muscles  in  the  emission  of  a  steady,  gentle  blast. 
The  art  of  using  the  blowpipe  without  fatigue  consists  in  alternating 
the  action  of  these  two  sets  of  muscles ;  the  art  of  giving  a  perfectly 
steady,  uninterrupted  blast  implies  control  over  these  muscles  and  the 
ability  to  pass  from  one  set  to  the  other  at  the  moment  of  opening  or 
closing  the  entrance  to  the  fauces.  After  persevering  practice  of  the 
two  methods  of  blowing,  the  art  of  connecting  them  will  come  almost 
unconsciously;  when  once  learned  it  is  never  forgotten.  Those  who 
are  too  indolent  to  master  the  first  difficulty  of  learning  it  become 
the  slaves  to  mechanical  appliances,  which,  however  useful  for  many 
purposes,  can  never  supply  the  place  of  this  simplest  and  best  of  all 
blowpipes. 

Blowpipes  working  by  artificial  blast  may  be  divided  into  four 
classes:  i.  Alcoholic  or  self-acting  blowpipes;  2.  Mechanical  or  bel- 
lows blowpipes;  3.  Hydrostatic  blowpipes;  4.  Oxy-hydrogen  or 
aero-hydrogen  blowpipes.  Of  each  of  these  we  shall  give  an  example. 
To  enumerate  all  the  forms  that  inventive  talent  has  devised  would  fill 
too  much  of  our  space. 

The  SELF-ACTING  blowpipes  derive  the  force  of  their  blast  from  the 
vapor  of  hot  alcohol,  which,  igniting  as  it  passes  through  the  flame, 
adds  to  the  intensity  of  the  heat. 

Small,  portable  lamps  are  made,  of  which  quite  a  number  of 
different  patterns  are  to  be  found  in  the  depots.  The  principle  and 
general  plan  of  construction  are  very  clearly  shown  in  Fig.  1041,  de- 
signed by  Dr.  S.  S.  White.  All  alcoholic  blowpipes  give  intensity  of 
heat,  but  are  greatly  inferior  to  the  mouth  blowpipe  in  the  control 
which  the  operator  has  over  the  force  and  direction  of  the  jet. 

The  different  forms  of  the  mechanical  blowpipe  are  almost  infinite. 
The  principle  of  construction  is  either  that  of  the  bellows  or  the  force 
pump,  combined  with  a  reservoir  of  air  to  give  uniformity  to  the  blast, 
which  would  otherwise  issue  in  jets. 

A  common  house  bellows  secured  to  the  floor  will  form  a  simple 
and  good  arrangement.  A  spring  should  separate  the  handles,  the 
upper  one  of  which  forms  a  treadle.  An  india-rubber  pipe  should 
pass  from  the  nozzle  to  an  air-tight  box,  from  which  a  second  tube 
comes  out  and  is  attached  to  the  blowpipe.  If  the  bellows  is  made 
double,  like  a  blacksmith's,  the  upper  half  forms  the  air-chamber  in 
place  of  the  air-tight  box. 


PRINCIPLES    AND    APPLIANCES    OF    SOLDERING. 


933 


Fig.  1042   represents  the  Burgess  blowpipe,  which  is  a  convenient 
and  efficient  form,     a  is  the  cylinder  of  the  pump,  which  is  2^4  inches 


in  diameter,  allowing  a  3-inch  stroke 
toe  treadle  for  driving  the  pump. 
D,  the  receiver,  12  inches  high  by 
3  inches  in  diameter,  into  which 
the  air  is  forced.  The  whole  height 
of  the  machine  is  24  inches;  the 
base  is  12  inches  by  5. 


B,  piston  rod.     c  is  a  heel-and- 


FiG.  1041. 


Fig.  1042. 


Figs.  1043  and  1044  represent  Fletcher's  bellows  blowpipes,  capable 
of  being  adjusted  in  any  desired  position. 

Figs.  1045  and  1046  represent  two  forms  of  the  Fletcher  automatic 
blowpipe,  one  of  which  is  mounted  on  a  ball-joint.     These  forms  ■»*€ 


Fig.  1043. 


Fig.  1044. 


very  convenient  for  soldering,  especially  in  the  manufacture  of  gold 
crowns  and  bridge-work. 

Fig.  1047  represents  a  style  of  foot  bellows  by  which  the  bellows 
and  automatic  blowpipes  are  operated.     Fig.  1048  represents  a  carbon 


934 


MECHANICS — DENTAL   PROSTHESIS. 


block  for  use  as  a  support  in  soldering.  It  is  a  perfect  non-conductoi 
and  much  cleaner  than  charcoal.  Fig.  1049  represents  a  carbon 
cylinder,  the  cupped  end  of  which  answers  as  a  good  support  for  small 
cases,  such  as  crowns,  while  soldering. 


Fig.  1045. 


Fig.  1046. 


Fig.  1050  represents  Macomber's  gas  blowpipe.  The  direction  of 
the  point,  i,  is  regulated  by  the  joint,  3,  and  the  supply  of  gas 
controlled  by  the  stopcock,   2.     The  air  is  supplied  from  the  lungs, 


Fig.  1047. 


Fig.  1048. 


Fig.  1049. 


or  from  some  form  of  mechanical  or  hydrostatic  blowpipe,  through 
the  flexible  tube. 

Fig.  105 1  represents  an  automatic  blowpipe  to  be  worked  by  a  foot- 
blower  or  bellows. 

Fig.  1052  represents  a  hand  blowpipe,  into  which  the  air  is 
admitted  at  a  and  conducted  through  a  small  tube  to  the  upper  end 


PRINCIPLES    AND    APPLIANCES    OF    SOLDERING. 


935 


of  the  gas-pipe,  b.     The  supply  of  both  gas  and  air  is  regulated  by 
pressure  of  the  thumb  or  fingers  on  the  rubber  tubes,  c.  c. 

The  THIRD  class  of  blowpipes  is  sometimes  combined  with  the 
second  to  regulate  the  blast,  or  with 
the  first  to  intensify  it.  In  its  uncom- 
bined  form  it  consists  essentially  of 
a  blowpipe  point  attached  by  a  flexi- 
ble tube  to  an  air-chamber,  from 
which  the  air  is  forced  by  the  steady 
pressure  of  water.  When  once  set  in 
operation,  it  is  self-acting,  and  in  this 
respect  has  great  advantage  over  the 
second  class.  This,  with  the  perfect 
regularity  of  the  blast,  makes  a  prop- 
erly constructed  hydrostatic  blowpipe 
much  the  best  of  all  substitutes  for 
the  lungs  and  mouth  blowpipe. 

The  gasometer  of  the  nitrous  oxid 
gas  apparatus  makes  a  very  excellent  hydrostatic  blowpipe.     Its  form, 
and  the  manner  of  using  it,  are  so  familiar  to  dentists  as  to  render 
any  illustration  or  description  unnecessary.     Any  required  force  of 


Fig.  1050. 


Fig.  1051. 


Fig.  1052. 


blast  may  be  given  by  detaching  the  counterpoise,  or  by  adding  weights 
to  the  descending  cylinder. 

The  fourth  class  of  blowpipes  is   analogous  in  its  operation  to  the 


936 


MECHANICS — DENTAL    PROSTHESIS. 


oxy-hydrogen  blowpipe.  The  point  is  double,  consisting  of  a  tube, 
through  which  comes  the  supporter  of  combustion  (oxygen  or  common 
air),  surrounded  by  a  cylinder,  through  which  comes  the  combustible 
(alcoholic  vapor,  illuminating  gas,  or  hydrogen).  In  Count  Rich- 
mont's  aero-hydrogen  blowpipe  the  hydrogen  is  generated  in  a  vessel 
by  the  action  of  dilute  sulphuric  acid  upon  zinc,  and  the  air  forced 
through  the  center  tube,  either  with  a  bellows  or  from  the  lungs.  The 
heat  is  less  intense  than  that  of  the  oxy-hydrogen  blowpipe,  but  is  too 
great  for  most  laboratory  purposes.  The  gas  blowpipe  is  a  very  con- 
venient instrument ;  the  principle  is  similar  and  the  heat  very  great. 
Fig.  1053  represents  an  ingenious  oxy-hydrogen  blowpipe  invented 


Fig.  1053. 

by  Dr.  J.  Rollo  Knapp,  which  consists  of  an  iron  stand  in  which  is 
secured,  by  a  thumb-screw,  a  loo-gallon  cylinder  of  nitrous  oxid  gas. 
By  means  of  a  yoke  and  set-screw  the  valve  of  the  cylinder  is 
connected  with  the  tubes  and  valves  of  the  blowpipe  in  such  manner 
that  the  proportions  of  the  mixture  of  nitrous  oxid  and  illuminating 
gases  are  under  perfect  regulation  and  control. 

There  are  two  pipe-nozzles,  which  may  be  used  at  the  same  time, 
or  one  at  a  time,  according  as  a  large  or  small  flame  may  be  desired. 
One  pipe-nozzle  is  shown  as  hung  upon  its  hook,  and  the  other  as 
if  directed  upon  work  held  on  the  pivoted  bracket-iable.     It  can  be 


PRINCIPLES    AND    APPLIANCES    OF    SOLDERING.  937 

used  wherever  illuminating  gas  is  available.  Any  of  the  soldering 
operations  of  the  laboratory,  from  the  largest  piece  of  crown-work  to 
the  most  delicate  joining  of  the  narrowest  bands  or  finest  wires,  are 
accomplished  with  equal  facility.  With  illuminating  gas  of  good  qual- 
ity and  sufificient  pressure  a  pennyweight  of  20-carat  gold  can  be 
melted  in  thirty  seconds.  A  large  investment  must  be  heated  first  by 
other  means. 

The  apparatus  consists  of  the  blowpipe  attachments,  connected  to 
the  yoke  of  a  nitrous  oxid  gas-cylinder,  the  cylinder  being  set  upright, 
and  secured  by  a  thumb-screw  on  one  end  of  an  iron  base  or  stand, 
at  the  other  end  of  which  is  pivoted  a  table  upon  which  to  rest  the 
work.  The  blowpipe  proper  is  a  continuation  of  the  outlet-tube  of 
the  gas-cylinder.  A  lever-valve,  g,  regulates  the  supply  of  nitrous 
oxid.  Just  beyond  this  valve  is  the  mixing-chamber,  k,  to  which 
the  illuminating  gas  is  conducted  from  the  gas-bracket  by  means  of 
rubber  tubing,  entering  the  bottom  of  the  chamber  through  the  valved 
tube,  c.  The  lever,  d,  controls  the  supply.  The  mixing-chamber  is 
provided  with  a  gauze  screen  to  prevent  the  flame  from  being  drawn 
into  the  supply-tubes.  Immediately  beyond  the  mixing-chamber  the 
pipe  is  branched  to  afford  two  flames  of  different  sizes,  e  and  f,  which 
can  be  used  independently  of  each  other  or  both  together.  The 
valve-lever,  l,  regulates  the  flame  in  both.  For  greater  convenience 
in  manipulation  the  pipe-nozzles  are  connected  with  the  branched  pipe 
by  rubber  tubing.  From  the  body  of  the  valves,  l,  an  arm  extends, 
at  the  end  of  which  is  a  small  scalloped  disk  as  a  holder  for  the  flame- 
nozzles  when  not  in  use.  In  the  illustration  one  of  the  nozzles  is 
shown  in  the  holder,  the  other  being  directed  to  the  revolving  table. 

In  the  operation  of  soldering  the  parts  to  be  united  must  be  held 
together  in  their  exact  relative  positions.  This  can  sometimes  be  done 
by  simply  laying  them  together  ;  but  usually  they  must  be  held  in  place, 
either  by  iron  wire  bound  around  them,  or  by  small  clamps  of  iron 
wire,  or  by  rivets;  or  else  by  some  investing  material,  which,  in 
dentistry,  is  always  plaster  mixed  with  some  substances  that  will 
counteract  its  tendency  to  shrink  and  crack  under  soldering  heat. 
This  substance  maybe  coal  ashes,  soapstone  dust,  feldspar,  clean  sand, 
or  asbestos.  The  two  latter  are  the  best,  and  may  be  mixed  in  pro- 
portions varying  from  2  to  6  parts  sand  or  asbestos  to  4  of  plaster. 
As  a  rule,  the  less  plaster,  the  less  shrinkage  ;  but  a  very  small  quan- 
tity makes  the  investment  too  friable. 

A  common  mistake  is  to  use  too  large  a  quantity  of  investing 
material.  This  almost  invariably  results  in  the  warping  of  the  plate  ; 
for,  as  all  investments  have  some  degree  of  permanent  contraction, 
and  all  metals  must  expand,  if  the  latter  is  bound  by  a  rigid,  unyield- 


938 


MECHANICS — DENTAL    PROSTHESIS. 


ing  mass  it  will  inevitably  warp.  Hence,  as  a  rule,  use  no  more 
investing  material  than  is  necessary  to  keep  the  parts  to  be  soldered 
in  their  position  and  to  protect  the  porcelain  surfaces  from  direct  con- 
tact with  the  flame.  This  subject  will  be  further  considered  when 
speaking  of  the  soldering  of  teeth  to  the  plate. 

In  selecting  a  suitable  receptacle  for  the  work  to  be  soldered,  it  is 
important  to  retain  the  heat,  especially  when  using  the  mouth  blow- 
pipe. A  funnel-shaped  mat  made  with  scraps  of  woven  iron  wire,  or 
a  large  lump  of  pumice  stone,  or  one  of  close-grained  charcoal,  with 
the  outside  coated  over  with  a  thin  layer  of  plaster,  form  very  simple 
and  convenient  receptacles  for  smaller  pieces  of  work.  For  larger 
work,  or  for  very  high  temperatures,  it  is  important  to  receive  addi- 


FiG.  1054. 


tional  heat  from  ignited  charcoal,  for  which  purpose  the  soldering  pan 
(Fig.  1054)  is  a  very  admirable  contrivance.  The  movable  lid  re- 
mains during  the  heating  up  and  the  cooling  off",  but  is,  of  course, 
removed  during  the  act  of  soldering. 

Fig.  1055  represents  the  form  of  soldering  blocks  which  are  made 
of  either  plumbago  or  asbestos. 

After  soldering  the  work  should  cool  gradually,  unless  it  is  to  be 
re -swaged.  If  there  is  any  porcelain  attached  the  cooling  must  be 
very  gradual.  When  cold,  it  may  be  placed  in  dilute  sulphuric  acid 
and  slowly  raised  to  the  boiling  point,  kept  there  for  a  few  moments, 
and  then  slowly  cooled.  This  dissolves  the  glass  of  borax,  which  is  so 
hard  that  it  injures  the  edge  of  files  and  scrapers. 


PRINCIPLES   AND    APPLIANCES   OF   SOLDERING. 


939 


A  few  general  considerations  may  be  of  service  in  the  use  of  the 
above-described  appliances  for  soldering.  It  is  an  operation  regarded 
by  many  as  attended  with  much  risk;  and  by  students  generally  it  is 
considered  the  pons  asinorum  of  dentistry.  Whereas,  there  is  no  pro- 
cess in  dental  prosthesis  in  which  the  desired  result  can  be  with  more 
certainty  obtained,  provided  such  care  and  skill  are  exercised  as  alone 
can  give  success  in  any  department  of  the  art. 

Plates  warp  from  want  of  support  when  heated  or  from  excess  of 
investing  batter;  they  are  burnt,  blistered,  or  melted  from  careless  or 
ignorant  use  of  the  blowpipe.  Teeth  are  broken  from  rapid  heating 
or  cooling  ;  they  are  displaced  by  the  shrinking  of  an  ill-judged  invest- 
ment. Solder  is  condemned  because  it  will  not  bridge  a  chasm  one- 
eighth  of  an  inch  wide,  will  not  run  over  plaster,  will  not  attach  itself 
to  an  oxidized  surface,  or  will  obstinately  roll  up  into  a  ball  rather 
than  flow  over  a  surface  too  cold  to  receive  it.  These  and  all  other 
vexations  of  soldering  are  the 
result  of  haste,  ignorance,  or 
want  of  skill.  If  there  should 
be  spaces  under  the  teeth  or 
backings,  which,  however,  ^ 
should  always  be  avoided  if  | 
possible  by  adapting  the  teeth  | 
in  grinding  to  the  surface  of  jr 
the  plate  and  having  the  back-  e 
ings  of  a  proper  length,  such 
spaces  should  be  filled  with 
gold  foil.  As  much  of  the  sur- 
face of  the  plate  should  be  ex- 
posed as  can  be  done  by  trimming  away  the  plaster  without  affecting 
the  stability  and  safety  of  the  teeth,  so  that  no  obstruction  is  present 
to  the  flame  of  the  blowpipe ;  this  direction  is  especially  applicable  to 
a  lower  denture  either  full  or  partial.  Good  soldering  depends  upon 
the  perfect  heating  up  of  the  investment  and  plate,  so  that  the  solder 
can  be  brought  by  the  heat  of  the  blowpipe  flame  as  near  the  melting 
point  of  the  plate  as  possible  without  injury  to  the  latter. 

In  soldering  two  surfaces,  as  in  the  doubling  of  lower  or  shallow 
upper  plates,  the  borax  must  contain  no  particles  preventing  contact 
of  the  plates ;  also  the  heat  must  be  directed  on  the  side  opposite  the 
pieces  of  solder,  so  that  when  melted  it  may  flow  between  the  plates 
from  one  side  to  the  other.  Clamps  are  preferable  to  plaster  batter  for 
holding  parts  together,  whenever  practicable,  as  in  soldering  a  wire  or 
band  around  plates ;  but  when  the  relation  must  be  preserved  with 
utmost  accuracy,  as  in  clasps,  the  plaster  investment  is  essential.     It  is 


94°  MECHANICS — DENTAL    PROSTHESIS. 

also  necessary  for  the  protection  of  porcelain  from  the  direct  action  of 
flame. 

In  soldering  teeth  to  a  plate  the  batter  must  have  such  proportion 
of  plaster  with  asbestos  or  sand  as  to  admit  of  being  used  in  small 
quantity,  and  yet  be  so  strong  when  heated  that  it  will  not  crack  and 
endanger  the  position  of  the  teeth.  Backings  and  clasps  must  fit 
accurately  wherever  they  are  to  be  fastened.  There  should  be  no 
trace  of  plaster  on  a  surface  where  solder  is  to  flow;  or,  in  fact,  sub- 
stances of  any  kind  except  borax,  and  not  too  much  of  that.  Borax 
must  be  pure  and  clean,  and  used  with  soft  water,  and  the  heating 
must  be  gradual,  in  view  of  its  liability  to  throw  off  the  solder. 
Solder  must  be  of  good  quality  and  carefully  placed,  never  putting 
two  pieces  where  the  position  will  allow  the  proper  quantity  to  lie  in 
one  piece.  It  is  a  very  common  practice  to  cut  solder  into  very  small 
pieces  under  the  idea  that  it  will  flow  more  evenly  ;  but  if  a  plate  is 
properly  heated  and  the  blowpipe  flame  skillfully  managed  the  large 
pieces  melt  instantly  and  flow  into  their  proper  position. 

It  is  quite  possible,  by  careful  observance  of  these  directions  and 
by  expertness  in  the  management  of  the  blowpipe,  to  solder  any  set 
of  teeth,  bridge-  or  crown-piece,  so  that  there  shall  be  no  roughness 
or  abrupt  edges  requiring  the  use  of  files  and  scrapers.  In  fact,  these 
tools  are  never  needed  to  give  finish  to  a  perfectly  soldered  joint ;  the 
natural  flow  of  the  solder  takes  a  shape  which  cannot  be  improved. 

Finishing  Process. — When  the  piece  is  cold  it  may  be  placed  in 
water  to  soften  the  plastic  investment,  which  should  be  carefully 
removed  from  the  teeth ;  the  set  is  then  placed  in  a  glass  or  porcelain 
vessel  containing  a  mixture  of  equal  parts  of  sulphuric  acid  and  water, 
and  heat  applied.  As  soon  as  the  borax  (which,  by  the  process  of 
soldering,  has  lost  its  water  of  crystallization  and  assumed  a  glassy 
hardness)  is  decomposed,  the  vessel  is  removed  and  allowed  slowly  to 
cool.  This  process  is  termed  by  jewelers  "pickling,"  and  requires 
from  ten  minutes  to  half  an  hour  for  its  completion,  according  to  the 
strength  of  the  acid  and  the  quantity  of  vitrified  borax  on  the  plate. 
After  this  the  acid  is  washed  from  the  piece  ;  or  it  is  still  more  effect- 
ually deprived  of  acid  by  boiling  in  water  containing  a  little  caustic 
soda. 

In  removing  the  roughness  which  may  have  been  occasioned  by 
imperfect  soldering,  care  must  be  taken  not  to  cut  away  too  much  of 
the  plate.  For  this  purpose  scrapers,  files,  and  lathe  burs  are  used, 
according  to  the  position  and  quantity  of  surplus  solder.  Fig.  1056 
represents  a  set  of  solder  burs  for  trimming  off  superfluous  solder. 
After  the  work  has  been  made  as  smooth  as  possible  with  scrapers, 
etc.,  it  should  be  rubbed  wjth  pieces  of  Scotch  stone  and  water  until 


PRINCIPLES    AND    APPLIANCES    OF    SOLDERING. 


941 


every  scratch  is  removed  ;  some  use  a  fine,  smooth  coi  k  attached  to 
the  lathe,  and  charged  with  water  and  powdered  pumice  or  silex. 
The  piece  is  then  polished  with  Tripoli,  applied  by  means  of  oil  or 
tallow  to  a  brush  wheel  (Fig.  1060),  which  is  made  to  revolve  rapidly 


Fig.  1056. 

against  the  work.  Felt,  rubber,  walrus  leather,  and  cotton  wheels  and 
cones  are  also  employed  in  polishing.  Fig.  1057  represents  a  felt 
wheel  and  cone.  Fig.  1058  shows  one  of  the  various  forms  of  vulcan- 
ite burs  for  carrying  polishing  powders.  As  to  the  rapidity  with 
which  a  lathe  should  be  worke'd  :   drills  and  burs  require  a  slow  move- 


FiG.  1057. 


ment ;  corundum  wheels  a  quicker  one ;  rotten  stone  a  rapid  motion  ; 
and  whiting,  zinc-white,  or  rouge  the  most  rapid  of  all. 

The  piece  may  now  be  placed  in  a  porcelain  vessel  containing  the 
following  mixture:    niter,  2  ounces;    salt  and  alum,  each   i  ounce — 


942 


MECHANICS — DENTAL    PROSTHESIS. 


dissolved  in  4  ounces  of  water.  After  boiling  for  half  an  hour  in  this 
to  decompose  the  copper  from  the  surface-layer  of  the  solder  and  plate, 
it  is  boiled  a  few  minutes  in  a  solution  of  i  ounce  of  caustic  soda  in  4 


Fig.  105S. 


Fig.  1060. 


Fjg.  1059, 


ounces  of  water  to  neutralize  the  acid,  then  washed  with  a  brush  in 
pure  water. 

The  removal  of  the  copper  from  the  surface  of  the  plate  gives  to  the 
gold  the  beautiful  orange  hue,  which  is  its  natural  color,  and  which  it 


PRINCIPLES    AND    APPLIANCES    OF    SOLDERING.  943 

will  retain  until  the  friction  of  mastication  wears  off  this  surface. 
The  secretions  of  the  mouth  will  fail  to  tarnish  it ;  and  it  will  be  free 
from  the  disagreeable  taste  of  which  so  many  complain  who  wear  arti- 
ficial teeth  set  on  metallic  plate.  But  when  plate  is  made  from  coin 
without  alloy,  or  is  20-carats  fineness,  and  the  solder  has  a  correspond- 
ing quality,  the  pickling  process  may  be  omitted. 

The  process  of  finishing  is  completed  by  polishing  every  part  of  the 
lingual  surface  of  the  plate,  backings,  and  clasps  with  highly  tempered 
and  finely  polished  steel  burnishers.  Fig.  1059  represents  various 
forms  of  plate  burnishers.  They  should  be  frequently  rubbed  on  a 
piece  of  wet  Castile  soap,  and  carried  backward  and  forward  in  the 
same  direction  over  the  plate  until  every  part  of  the  gold  exhibits  a 
high  polish.  Burnishers  of  different  shapes  are  required  for  different 
parts  of  the  work  ;  bloodstone  burnishers  are  also  used. 

A  piece,  however,  can  be  polished  in  less  time,  if  not  more  per- 
fectly, with  brush  wheels  (Fig.  1060).  Brush  wheels  vary  in  diameter, 
thickness,  and  material.  Bristle  wheels  vary  in  stiffness  and  length 
of  bristle ;  the  stiffer  being  used  for  Tripoli  or  rotten  stone,  the  softer 
for  whiting  and  rouge.  Cotton  is  often  substituted  for  bristles  ;  buck- 
skin or  felt  are  also  much  used  for  wheels  or  circular  "  laps,"  and  are 
especially  useful  in  dressing  up  the  recesses  of  a  plate.  It  is  of  the 
utmost  importance  that  wheels  or  laps  used  for  different  polishing  sub- 
stances should  be  kept  entirely  separate  ;  a  little  Tripoli  or  pumice 
powder  on  a  rouge  wheel  may  render  useless  the  work  of  an  hour. 
The  brush  should  be  set  on  the  spindle  of  the  lathe,  then  lightly 
smeared  with  suet  by  holding  a  small  piece  against  it  while  it  is 
revolving.  The  rotten  stone  is  applied  in  the  same  manner,  and  with 
the  brush  thus  charged,  the  polishing  may  commence  ;  but  the  plate 
must  not  be  exposed  too  long  to  the  friction,  as  it  will  rapidly  wear 
away  the  pure  gold  surface  brought  out  by  the  pickle ;  hence  some  use 
only  the  burnisher  or  rouge  after  pickling.  Tripoli  has  a  sharper  grit 
and  cuts  more  rapidly  than  the  ordinary  rotten  stone ;  but  the  latter 
gives  a  very  smooth  surface,  and  will  in  most  cases  give  a  sufficiently 
brilliant  finish  without  rouge.  A  very  high  watch-case  finish  can  only 
be  given  by  very  rapid  revolution  of  wheels  or  buffers,  charged  with 
the  finest  quality  of  rouge,  wet  with  alcohol.  The  piece  must  be  pre- 
viously washed  with  soap  and  water,  so  as  to  remove  every  trace  of  oil. 
Sometimes  rouge  is  applied  on  a  piece  of  soft  buckskin,  wrapped  or 
sewed  around  small,  blunt-pointed  pieces  of  cork  or  wood.  The 
lingual  surface  of  the  plate  is  the  only  one  that  should  be  polished. 
The  dead  color  of  the  palatine  surface  throws  out  the  polish  of  the 
other  side  and  greatly  improves  the  appearance  of  the  piece.  The 
adhesion  of  a  plate  is  frequently  improved  by  roughening  the  plate 


944 


MECHANICS — DENTAL    PROSTHESIS. 


with  a  file  or  by  engraving  lines  upon  it.  The  process  of  finishing  on 
a  gold  piece,  properly  soldered,  is  a  very  simple  matter,  and  one  of 
secondary  importance.  A  set  with  Scotch-stone  finish  is  in  every 
respect  as  useful  and  esthetically  as  beautiful  as  the  most  highly 
polished  plate.  There  is,  however,  no  objection  to  this  sort  of  appeal 
to  the  eye,  provided  it  is  not  the  chief  merit  of  the  work. 

There  are  three  methods  adopted  for  the  retention  of  dental  plates, 
and  many  modifications  of  form  required  by  the  various  circumstances 
of  different  mouths.  An  enumeration  of  all  the  required  forms  would 
be  impossible  in  this  work  ;  but  we  hope  to  represent  a  sufficient 
variety  to  enable  the  operator  to  decide  which  is  best  for  any  given 
case.  We  think  it  far  more  important,  however,  to  endeavor  to  ex- 
plain, as  far  as  can  be  done,  the  principles  which  determine  these 
different  forms  and  modes  of  retention,  than  to  lay  down  any  set  of 
didactic  formulas  for  unreasoning  adoption. 


CHAPTER  XIII. 


RETENTION  OF  BASE  PLATES— THEIR  SIZE  AND  FORM  OF 

OUTLINE. 

The  utility  of  a  piece  depends  largely  upon  the  firmness  with  which 
it  keeps  its  place  during  mastication  or  in  conversation.  The  means 
adopted  to  secure  this  are  fourfold  :  The  first  two  retain  the  plate  by 
extrinsic  support ;  the  last  two  depend  upon  an  intrinsic  quality  of 

the  plate  itself,  i.  Spiral  springs, 
by  constant  pressure,  keep  the  plates 
of  a  double  set  in  position.  2. 
Clasps,  by  grasping  some  natural 
tooth,  hold  a  partial  piece  firmly  in 
place.  3.  Spring  plates,  which  are 
constructed  of  vulcanized  rubber, 
and  are  available  only  in  partial 
cases.  4.  The  close  adaptation  of 
the  plate,  whether  of  a  t'uU  or  partial 
set,  causes  it  to  adhere  with  a  force 
which  is  lessened,  first,  by  the  amount 
of  air  between  the  surfaces;  secondly,  by  the  liability  to  displacement. 
These  modes  of  retention  will  be  considered  in  the  order  named. 

Spiral  springs,  formerly  very  much  used,  are  now  seldom  employed  ; 
they  are  applied  only  to  double  dentures.     Fig.  io6i   gives  a  correct 


Fig.  1061. 


RETENTION    OF    BASE    PLATES. 


945 


idea  of  the  position  of  the  springs,  their  points  of  attachment,  length, 
and  direction  of  curvature.  Fig.  1062  represents  the  detached  por- 
tions of  the  spring,  consisting  of  standards,  screws,  tangs,  and  spiral 
coil.  The  tendency  of  the  curved  spring  to  straighten  presses  each 
plate  upon  the  alveolus,  acting  at  the  points  of  attachment  of  the 
standards.  These  points  are  chosen,  first,  in  the  uppper  jaw,  as  nearly 
as  possible  on  the  line  of  equipoise,  which  will  be  somewhere  between 
the  centers  of  the  second  bicuspid  and  of  the  first  molar;  secondly,  in 
the  lower  jaw,  where  a  vertical  line  from  the  upper  standard  meets  it. 
Perforated  bicuspids  and  molars  are  sold,  adapted  to  such  cases;  and 
the  usual  plan  is  to  attach  the  standards  before  soldering  the  teeth. 
A  more  accurate  method  is  to  determine  the  position  of  th£  standards 
after  the  pieces  are  finished.  The  presence  of  the  teeth  makes  solder- 
ing of  the  standards  more  troublesome,  but  not  impossible  ;  they  may 
also  be  riveted  to  the  outer  rim  of  the  plate.  With  the  diamond 
drill  holes  can  be  made  through  the  teeth  or  blocks  opposite  each 
standard. 

Directions  for  making  the  coil   have  already  been  given  ;  they  are 


■'"rr'''r7mam 


usually  purchased  ready  made.  Their  length  must  be  such  that  the 
curve  will  not  irritate  the  ascending  ramus  of  the  lower  jaw.  If  too 
stiff  their  forcible  pressure  will  irritate  the  gum  ;  if  too  slight  they 
will  fail  to  keep  up  the  piece.  The  tangs  are  held  in  the  coil  by 
closeness  of  fit;  when  loose  they  may  be  tightened  by  floss  silk.  The 
screws  represented  in  the  figure  are  troublesome  to  make,  and  are  very 
apt  to  loosen.  A  better  plan  is,  to  pass  a  headed  pin  through  stand- 
ard, tang,  and  tooth,  and  rivet  or  solder  it  in  the  backing.  This  plan 
makes  the  tang  jjermanent ;  the  pieces  are  separated  by  detaching  the 
upper  or  lower  tangs  from  the  coils.  It  adds  greatly  to  the  strength 
of  the  pin  to  pass  it  through  the  tooth  or  block.  There  should  also 
be  a  shoulder  on  the  standards  to  limit  the  movement  of  the  tang  ; 
else  the  springs,  by  too  great  upward  or  downward  motion,  may  irri- 
tate the  mouth.  It  is  unnecessary,  in  view  of  the  present  limited  use 
of  springs,  to  describe  other  and  very  ingenious  methods  of  attaching 
them. 

60 


946 


MECHANICS DENTAL    PROSTHESIS. 


Fig.  1063. 


Dr.  I.  I.  Stedman  has  devised  a  new  form  oi'"  springs  for  dental 
plates.     Fig.  1063  represents  the  Stedman  springs. 

The  use  of  springs  is  now  confined, 
first,  to  very  flatly-arched  upper  jaws, 
usually  small,  covered  with  hard  mem- 
brane, and  having  the  attachment  of  the 
facial  muscles  close  to,  or  quite  upon, 
the  ridge ;  also  to  lower  cases  where  all 
trace  of  the  ridge  is  gone.  Secondly, 
to  pieces  inserted  so  soon  after  extrac- 
tion that  the  rapid  absorption  will 
quickly  destroy  the  adaptation.  We  shall  speak  elsewhere  of  other 
means  adapted  to  meet  these  exigencies,  in  failure  of  which  spiral 
springs  are  to  be  used.  But  they  are  troublesome  to  make,  annoying 
to  wear,  diffcult  to  keep  clean,  and  liable  to  accident ;  hence  we  only 
use  them  as  a  last  resort.  In  conclusion,  it  should  be  noticed  that  the 
upper  plate  of  spiral-spring  pieces  does  not  cover  the  palate,  but  is 
shaped  more  like  the  lower  piece.  This  is  one  of  its  compensating 
advantages;  for  it  is  an  objection  to  the  otherwise  valuable  principle 
of  atmospheric  pressure  that  it  covers  so  large  a  portion  of  the  mucous 
surface. 

CLASPS. 

This  method  of  retention,  necessarily  applicable  only  to  partial 
pieces,  has  fallen  into  much  disfavor,  and  given  place  to  methods  in 
lieu  thereof  which  are  really  more  objectionable.  But,  like  many 
other  time-honored  practices  which  modern  dentistry  has  thrown  in 
its  waste-basket,  there  are  very  decided  advantages  in  this  mode  of  re- 
tention, which  make  it  in  certain  cases  the  best  possible  one.  The 
disuse  of  clasps  has  grown  out  of,  first,  their  injurious  effects,  due  to 
improper  construction  and  injudicious  application  ;  secondly,  the 
difficulties  of  making  a  clasp  piece.  We  venture  the  assertion  that 
one-half  the  dentists  do  not  really  know  how  to  make  a  perfectly 
adapted  clasp  piece  :  and  that  of  the  remaining  half  two-thirds  will 
not  take  the  trouble.  The  tediousness  of  clasp  adjustment  is  out  of 
place  in  that  rapidity  of  manipulation  demanded  by  the  cheapness  of 
modern  dentistry.  Nor  can  we  expect  to  see  the  easily  made  but  in- 
effectual vacuum  cavity  give  place  in  turn  to  the  clasp  attachment, 
which  it  has  to  such  an  extent  superseded,  until  the  profession  becomes 
awakened  to  the  necessity  of  substituting  good  work  for  fast  work — 
economical  high-priced  work  for  expensive  low-priced  work  ;  until 
the  mechanician  so  far  respects  himself  as  to  value  his  labor  more  than 
the  cost  of  his  materials,  and  ceases  to  use  certain  substances  because 
they  are  cheap,  rather  than  others  because  they  are  better. 


RETENTION    OF    BASE    PLATES.  947 

Next  to  pivoting,  the  clasp  is  the  most  secure  of  all  methods  of 
attaching  artificial  teeth  in  partial  cases.  But  it  is  not  universally 
applicable  for  reasons  hereafter  stated.  In  deciding  upon  the  pro- 
priety of  using  clasps,  the  remaining  teeth  must  be  carefully  examined 
to  determine  whether,  in  shape,  position,  texture,  and  relation  to  other 
teeth  and  to  the  proposed  plates,  there  are  many  which  admit  of  being 
clasped.  If  there  are  such  teeth,  a  perfect  impression  of  them  is 
necessary  ;  then  greatest  accuracy  in  fitting  the  clasp  ;  lastly,  a  most 
exact  adjustment  of  this  to  the  plate,  to  which  it  is  to  be  fastened  with 
great  care.  Scrupulous  observance  of  these  points,  in  connection  with 
a  properly  fitted  and  shaped  plate,  will  take  from  clasp  work  the  force 
of  the  objections  urged  against  it. 

In  the  selection  of  teeth  to  be  clasped  the  points  for  consideration 
are  :  i .  Their  condition  :  never  clasp  loose  teeth  or  those  where  there 
is  much  alveolar  absorption  ;  or,  if  possible  to  avoid  it,  those  which 
have  filed  surfaces.  2.  Their  shape:  avoid  all  conical  teeth,  such  as 
third  molars  and  canines  ;  also  teeth  considerably  larger  at  the  grind- 
ing surface  than  at  the  gum.  The  proper  shape  for  clasping  is  the 
cylinder,  or  rounded  prism  ;  and  only  so  much  or  such  part  of  any 
tooth  should  be  clasped  as  has  this  shape.  Hence  it  is  that  thick, 
narrow  clasps  are  best,  because  few  teeth  have  much  breadth  of  cylin- 
drical shape.  3.  Their  position  :  incisors,  canines,  and  third  molars 
must  be  rejected  for  this  reason  ;  and  second  molars  are  unfit,  if  the 
plate  holds  incisor  teeth.  The  incisors  and  cuspids  are  of  all  the  teeth 
less  suited  for  the  attachment  of  a  clasp.  It  is  exceedingly  difficult 
to  apply  clasps  to  these  teeth  in  such  a  manner  as  to  retain  even  a  sin- 
gle tooth  with  sufficient  stability  to  be  worn  with  any  degree  of  com- 
fort. We  remember  once  to  have  seen  a  case  in  which  a  central 
incisor  (natural  tooth)  was  inserted  and  kept  in  place  by  a  gold  wire 
projecting  from  each  side  of  the  tooth  into  holes  drilled  into  the 
adjoining  teeth.  A  stage  of  dental  progress  that  permitted  such  a 
process  might  also  have  allowed  the  clasping  of  incisors ;  but  we  know 
of  no  possible  circumstances  that  will  justify,  in  the  present  state  of 
dental  art,  the  clasping  of  any  of  the  six  front  teeth.  No  lower  teeth 
should  be  clasped ;  but  in  some  cases  a  stay  (half-clasp)  may  be  used. 
The  best  teeth,  in  respect  of  position,  are  the  second  bicuspids;  next, 
the  first  molars;  thirdly,  the  first  bicuspids;  and  lastly,  the  second 
molars.  These  eight  teeth  are  the  only  ones  that  should  ever  be 
clasped ;  and  if  possible  the  choice  should  be  confined  to  the  first 
four.  4.  Their  relation  to  the  plate  and  to  the  other  teeth.  Let  the 
clasped  tooth  be  as  near  the  line  of  equipoise  as  is  consistent  with 
other  considerations.  For  incisors  alone  we  should,  for  this  reason, 
give  preference  to  the  first  over  the  second  bicuspids ;  and  in  case  of 


948  MECHANICS DENTAL    PROSTHESIS. 

the  loss  of  the  ten  or  twelve  anterior  teeth  we  should  use  no  clasp  on 
the  remaining  molars.  Teeth  not  decayed  should  never  be  separated 
from  others  with  which  they  are  in  contact  for  the  purpose  of  passing 
a  clasp.  If  no  other  tooth  can  be  found  a  stay  (half-clasp)  must 
suffice. 

Observance  of  the  conditions  above  enumerated  restrict  very  much 
the  range  of  cases  that  admit  of  clasps.  In  the  matter  of  position  and 
relation  to  the  plate,  circumstances  may  compel  a  choice  not  the  most 
favorable  to  success;  but  in  other  respects  it  is  far  better  to  dispense 
with  clasps  than  to  apply  them  so  as  to  incur  risk  of  failure  or  injury 
to  good  teeth. 

The  liability  to  decay  of  the  tooth  around  which  a  clasp  is  applied 
is  always  greatly  increased  by  the  removal  of  any  portion  of  its  enamel. 
The  application  of  clasps  to  diseased  or  loose  teeth  always  aggravates 
the  morbid  condition  of  the  parts,  and  causes  the  substitute,  which 
they  keep  in  place,  to  become  a  sort  of  annoyance  to  the  patient. 
Besides,  such  teeth  can  be  retained  in  the  mouth  only  for  a  short 
time,  and  when  they  give  way  the  artificial  appliance  becomes  com- 
paratively or  entirely  useless;  and  even  before  their  loss  it  is  not  held 
firmly  in  its  place.  Its  instability  exposes  its  presence  to  the  observa- 
tion of  the  most  careless  observer,  and  this  motion  is  injurious  to  all 
the  teeth  near  or  against  which  the  piece  comes.  In  the  lower  jaw 
jiarts  of  sets  are  much  less  frequently  called  for  than  in  the  upper,  and 
when  they  are,  the  use  of  clasps  may  be  dispensed  with  altogether.  A 
clasp  can  seldom  be  applied  advantageously  to  a  lower  molar.  The 
lower  front  teeth  are  least  liable  to  decay  of  any  in  the  mouth,  and 
therefore  do  not  require  replacement,  except  in  full  sets,  unless  lost  by 
a  blow  or  by  the  destructive  action  of  salivary  calculus.  A  partial 
lower  front  piece  calls  for  half-clasps  or  stays ;  but  other  partial  lower 
pieces  (replacing  bicuspids  and  molars)  should  not  depend  for  their 
stability  upon  any  remaining  bicuspid  or  cuspid. 

If  the  injurious  effects  liable  to  result  from  the  application  of  clasps 
to  teeth  selected  according  to  the  rules  given  could  not  in  any  way  be 
counteracted,  dental  substitutes  retained  in  the  mouth  by  this  means 
would,  in  the  majority  of  cases,  be  productive  of  more  injury  than 
benefit;  but  they  may  be  in  great  measure  prevented.  They  are  not 
caused,  as  many  have  erroneously  supposed,  solely  by  the  mechanical 
action  of  the  clasps  upon  the  teeth,  but  also  by  the  chemical  action  of 
the  secretions  of  the  mouth  and  decomposing  particles  of  food.  The 
method  of  measurably  preventing  these  deleterious  effects  is  twofold  : 
First,  to  prevent  the  chemical  action,  the  removal  of  the  artificial 
teeth  and  thorough  cleansing  of  them  and  the  natural  organs  ;  this 
should  be  done  every  night  and  morning,  and  the  teeth  rubbed  with  a 


RETENTION    OF    BASE    PLATES.  949 

brush  and  waxed  floss  silk  until  every  particle  of  clammy,  vitiated 
mucus  and  foreign  matter  is  removed.  The  inner  surface  of  the  clasps 
should  be  freed  from  all  impurities,  and  the  whole  piece  cleansed  with 
a  brush  and  water.  Secondly,  to  prevent  or  lessen  the  mechanical 
action  the  clasp  should,  as  before  remarked,  fit  with  great  accuracy 
the  parts  of  the  tooth  protected  with  hard  enamel ;  the  whole  piece 
should  have  such  closeness  of  adaptation  as  to  prevent  motion  of  the 
clasp  upon  the  tooth.  We  have  elsewhere  spoken  of  other  injurious 
consequences  of  clasps  placed  too  near  the  gums  or  exposed  necks. 
Rapid  decay  and  breaking  off  of  the  teeth,  inflammation  of  the  gums, 
of  the  peridental  membrane,  destruction  of  the  alveoli  and  loosening 
of  the  teeth,  are  among  the  common  results  of  the  clasping  of  teeth  as 
it  is  too  often  practiced.  Consequences  such  as  these  have  led  many 
to  an  unqualified  condemnation  of  this  method ;  yet,  as  we  have  said, 
when  suitable  teeth  are  selected  for  clasping,  and  the  work  is  properly 
executed,  it  is  the  best  and  most  durable  way  in  which  a  partial  piece 
can  be  secured. 

Shaping  and  Adjusting  Clasps. — The  gold  employed  for  clasps  should 


Fig.  1064. 


be  about  one-third  or  one-half  thicker  than  the  plate,  and  as  wide  as 
the  cylindrical  portion  of  the  crowns  of  the  teeth  to  be  fitted.  Some 
clasps  are  best  made  of  half-round  wire,  and  narrow;  others  may  be 
broader  and  thinner ;  thick,  narrow  clasps  are  more  universally  appli- 
cable. In  quality  it  is  better  that  clasp  and  plate  be  the  same,  except 
when  the  plate  is  of  pure  coin.  In  this  case  add  copper  (but  no  silver) 
to  give  elasticity.  Platina,  often  used  for  this  purpose,  imparts  too 
much  brittleness,  after  the  piece  has  been  worn  for  some  time.  Some 
may  fit  the  tooth  close  to  the  gum ;  but  in  other  cases  the  shape  of  the 
tooth,  absorption  of  the  alveolus,  or  morbid  sensitiveness  of  the  neck, 
forbid  this.  Enamel  surfaces  best  resist  the  wearing  action  of  clasps ; 
dentine,  exposed  by  the  file  or  chisel,  is  more  liable  to  abrasion  or 
decay;  cementum  should  in  no  case  be  brought  in  contact  with  clasp 
or  plate.  If  the  clasps  chafe  against  sensitive  parts,  inflammation  of 
the  peridental  membrane  may  be  set  up,  followed  by  wasting  of  their 
sockets  and  ultimate  loss  of  the  teeth.  Fig.  1064  represents  a  clasp 
bender. 


95° 


MECHANICS — DENTAL    PROSTHESIS. 


With  the  plate  in  position  in  the  mouth,  a  wax  impression  may  be 
talcen  ;  the  plate,  adhering  to  it,  on  being  withdrawn,  will  have  a 
correct  relation  to  the  teeth  which  are  to  be  clasped.  Others  adopt 
the  less  accurate  method  of  adjusting  the  plate  to  the  original  plaster 
model.  But  as,  for  reasons  before  given,  it  is  advisable  to  cut  off  the 
teeth  from  the  model  used  in  molding,  a  second  model  is  necessary, 
and  usually  for  this  purpose  a  second  impression.  Moreover,  if  the 
mouth  has  marked  irregularities  or  rugae,  and  the  plate  covers  much 
surface,  it  cannot  be  fitted  upon  a  plaster  model  so  as  to  hold  the 
same  precise  relation  to  the  teeth  as  when  in  the  mouth. 

When  accurately  fitted,  clasps  may  be  at  once  soldered  on  the 
model,  or  may  be  attached  to  the  plate  by  means  of  a  small  piece  of 
wax  or  cement  composed  of  one  part  wax  and  two  of  resin,  or  gum- 
shellac,  or  sealing-wax,  or  softened  modeling  composition  ;  these  should 
be  softened  or  melted  and  applied  to  the  plate  and  to  the  inner  side 
of  each  clasj).  The  plate  and  clasps  thus  united  are  carefully  removed 
from  the  plaster  model  and  laid  with  the  convex  side  downward  on  a 
piece  of  paper.  Plaster  is  then  poured  on  the  upper  side  of  the  plate, 
covering  it  and  the  clasps  to  the  thickness  of  half  an  inch.  After 
this  has  set  the  piece  may  be  taken  from  the  paper,  placed  on  char- 
coal, the  wax  being  softened  and  removed,  and  prepared  for  soldering. 
This  is  the  simplest  way  of  fitting  clasps  to  the  plate  and  preparing  the 
piece  for  soldering.  Fig.  1065  shows  the  usual  form  of  clasp  ;  but  when 
the  clasp  teeth  deviate  from  a  vertical  position,  or  when  the  teeth  are  of 

such  a  shape  that  the  wax  impression 
does  not  copy  them  accurately,  this 
method  is  in  such  cases  not  reliable. 
The  clasps  must  be  fitted  to  the  teeth 
in  the  mouth,  instead  of  on  the 
plaster  model,  and  may  then  be  at- 
tached to  the  plate  as  just  directed. 
Often  only  one  can  be  attached  at  a 
time,  and  after  this  has  been  soldered  the  piece  is  replaced  in  the 
mouth,  and  the  other  made  fast  to  the  plate.  The  greatest  care  is 
necessary  to  prevent  altering  the  position  of  the  clasp  in  taking  the 
piece  from  the  mouth. 

The  following  is  Dr.  Fogle's  method  for  securing  accurate  adapta- 
tion of  the  clasps.  They  are  first  fitted  to  the  plaster  model,  leaving 
the  ends  straight.  A  narrow  strip  of  plate  about  five-eighths  of  an 
inch  in  length  is  used  as  a  temporary  fastening,  one  end  of  which 
is  soldered  to  the  lingual  surface  of  the  clasp ;  the  plate  and  clasp  are 
now  both  placed  on  the  model  (made  from  impression  taken  while  the 
plate  is  in  the  mouth),  and  the  other  end  fitted  and  soldered  to  the 


Fig.  1065. 


RETENTION    OF    BASE    PLATES. 


951 


plate,  forming  a  sort  of  semicircle  or  bow.  Fig.  1066  represents  the 
plate,  clasps,  and  temporary  fastenings  on  the  plaster  model. 

The  clasps  are  now  adjusted  to  the  model ;  however  accurately  this 
is  done,  it  will  be  found,  on  applying  the  plate  to  the  mouth,  that 
they  will  not  fit  the  teeth  there.  After  properly  adjusting  them  the 
temporary  fastenings  will  be  found  sufficient  to  hold  the  clasps  in 
their  exact  position  while  the  piece  is  being  removed.  This  done,  it 
may  be  invested,  placed  on  charcoal,  and  the  other  steps  connected 
with  the  process  of  permanent  soldering  gone  through  with,  detaching 
the  temporary  fastenings  when  the  investment  has  fixed  the  clasps  in 
position. 

Dr.  Cushman  advises,  in  very  difficult  cases  of  adjustment,  as  where 
the  clasp  teeth  are  much  inclined,  and  where  you  have  to  fasten  to 
second  molars,  a  slight  modification  of  this  plan.     After  soldering  one 


end  of  the  strip  to  the  clasp,  and  having  bent  the  other  to  touch  the 
plate  when  on  the  model,  put  both  in  their  proper  place  in  the  mouth; 
then,  with  a  sharp-pointed  instrument,  indicate  the  point  where  the 
bow  touches  the  plate ;  place  them  on  the  model  again  ;  adjust  the 
end  of  the  bow  to  the  point  marked  ;  confine  it  there  and  solder  fast. 
Dr.  Cushman  considers  Dr.  Fogle's  method  of  adjusting  clasps  so 
valuable  that  he  never  ventures  to  set  clasps  permanently,  even  in  the 
simplest  case,  upon  the  original  model  with  the  plaster  teeth  as  the 
only  guide  for  position. 

Dr.  Lester  Noble's  method  is  as  follows :  Place  the  plate  in  the 
mouth,  and  let  the  clasp  bind  upon  the  tooth  with  only  sufficient  firm- 
ness to  keep  it  in  its  proper  place.  Then  mix  a  small  quantity  of 
plaster  from  a  lot  which,  by  previous  trial,  you  find  requires  four  or 
five  minutes  to  set;  put  it  upon  a  piece  of  paper  or  sheet  lead  about 


952  MECHANICS — DENTAL   PROSTHESIS. 

an  inch  square,  and  just  before  it  begins  to  harden  introduce  it  into 
the  mouth  upon  the  forefinger,  pressing  it  into  gentle  contact  with  a 
portion  of  the  plate  and  about  one-half  of  the  clasp.  It  must  be  held 
there  for  three  or  four  minutes,  until  it  is  sufficiently  hard  to  break 
with  a  sharp  fracture;  this  point  you  can  determine  by  examining  the 
plaster  left  in  your  bowl.  The  plaster  must  then  be  withdrawn.  Some- 
times plate,  clasp,  and  plaster  will  be  brought  away  together;  or  the 
]jlaster  and  clasp  together,  leaving  the  plate  ;  or  the  plaster  will  sepa- 
rate, leaving  both  clasp  and  plate  in  the  mouth.  Should  the  plaster 
by  any  accident  break,  it  can  readily  be  united  at  the  point  of  the 
fracture,  without  in  the  least  altering  its  shape — one  great  advantage 
over  wax.  If  the  plaster  adheres  to  the  plate  on  withdrawal  from  the 
mouth,  it  must  then  be  carefully  detached,  the  plate  replaced,  and  the 
same  process  repeated  for  the  second  clasp  ;  or  possibly  the  impressions 
for  both  clasps  can  be  taken  at  once. 

Several  precautions  are  necessary.  If  the  clasp  bind  too  tightly 
around  the  tooth  its  ends  Avill  when  removed  spring  together ;  and 
thus  it  will  not  exactly  fill  the  original  impression  made  in  the  plaster. 
If  the  part  of  the  clasp  which  you  design  to  cover  with  plaster  be  so 
regular  in  shape  as  to  make  its  adjustment  when  out  of  the  mouth 
uncertain,  mark  it  with  a  file  or  a  small  point  of  solder;  this  will  be 
copied  in  the  plaster,  and  remove  all  doubt  as  to  its  definite  position. 
If  the  plaster  be  extended  over  some  part  of  the  edge  of  the  plate,  it 
will,  in  the  absence  of  any  marked  irregularities  of  surface,  give  a 
better  guide  for  its  readaptation.  Lastly,  if  the  plaster  cover  too  much 
of  the  clasp  tooth,  it  will  be  more  liable  to  break  on  being  withdrawn. 

Take  now  the  clasps,  place  them  each  in  their  separate  impressions 
in  the  pieces  of  plaster,  securing  them  if  necessary  by  a  small  piece  of 
softened  wax.  Place  one  end  of  your  plate  in  its  corresponding  bed 
in  one  of  the  plaster  pieces.  If  proper  care  has  been  used,  both  clasp 
and  plate  will  fit  into  the  plaster  with  unerring  accuracy,  and,  of 
course,  hold  the  precise  relation  as  when  in  the  mouth.  While  in  this 
position  cover  the  clasp  and  the  under  surface  of  the  plate  with  fresh 
plaster,  or  plaster  and  sand  or  asbestos ;  when  this  has  hardened  re- 
move the  first  plaster,  just  as  in  other  cases  you  would  remove  the  wax, 
preparatory  to  soldering. 

The  methods  of  Drs.  Fogle  and  Noble  may  be  thought  too  tedious 
for  cases  where  the  shape  and  position  of  the  teeth  are  such  that  a  wax 
impression  will  accurately  copy  them  ;  but  in  the  great  majority  of 
cases  it  will  be  found  essential  to  accurate  adjustment  to  resort  to  one 
or  other  of  them.  Sealing-wax  or  shellac  may  also  be  used  to  retain 
the  clasps  in  position  until  tliey  are  soldered  to  the  plate. 

If  the  clasp  stands  off  from  the  tooth  on  its  coronal  edge,  the  food 


RETENTION    OF    BASE    PLATES.  953 

is  apt  to  pack  into  the  wedge-shaped  space  and  loosen  it,  or  even 
change  its  shape ;  if  on  the  edge  near  the  gum,  it  gives  lodgment  to 
the  food  and  mucous  secretions,  to  the  injury  of  the  tooth.  Dr. 
Spalding  recommends,  as  a  preventive  against  such  lodgment,  to  use 
in  all  cases  thick,  narrow  clasps ;  to  attach  them  by  two  or  more 
standards  (Fig.  1067),  if  the  clasp  is  long;  to  put  them  well  up  on 
long  teeth,  and  on  short  teeth  to  cut  away  the  plate.  In  this  way 
most  of  the  neck  is  exposed  to  the  cleansing  action  of  the  tongue. 

The  close  adaptation  of  the  clasp  to  the  surface  of  the  tooth  is  too 
often  neglected.  It  is  commonly  done  with  round  pliers,  making  trial 
from  time  to  time  upon  the  tooth  of  the  model.  This  is  an  uncertain 
method  in  any  case,  and  in  many  utterly  worthless.  Prof.  Austen 
advised  always  to  take  a  separate  plaster  impression  of  the  teeth  to  be 
clasped ;  for  which  purpose  a  small  partial  impression  tray  is  used  (Figs. 
939  and  940).  Let  the  pilaster  get  quite  hard  ;  then  slightly  open  the 
impression  ;  withdraw  it  and  close  up  the  fissure.  Make  from  this 
either  a  plaster  or  a  fusible-metal 
tooth ;  if  the  former,  harden  it  with 
soluble  glass.  With  round  pliers  and 
a  hammer  clasps  can  be  fitted  with 
great  exactness  to  such  a  metallic 
tooth.  Extreme  accuracy  of  fit  may 
most  easily  be  obtained  when  the 
contour  of  the  tooth  is  irregular  by  fig.  1067. 

the  following  method  :   burnish  down 

to  the  tooth  a  strip  of  very  thin  platina;  then  on  the  outside  of  this 
strip  lay  pieces  of  gold  (of  the  fineness  suitable  for  clasps),  with  borax, 
and  flow  them  with  the  blowpipe. 

A  common  error  in  soldering  clasps  is  to  make  their  union  to  the 
plates  too  wide.  Clasps  are  often  called  springs,  but  if  soldered 
through  nearly  their  whole  length  they  become  rigid  stays,  devoid  of 
elasticity.  Fig.  1068  shows  the  proper  extent  of  clasps  embracing 
the  posterior  natural  teeth.  There  should  always  be  a  proportion  be- 
tween the  size  of  the  clasp  and  the  width  of  its  attachment ;  in  no 
case  should  it  exceed  three-sixteenths  of  an  inch,  and  one-eighth  of 
an  inch  is  ample  for  most  cases.  When  practicable  the  two  arms  of 
a  clasp  should  be  of  equal  length  ;  but  in  short  clasps  it  is  sometimes 
preferable  to  throw  all  the  elasticity  into  a  single  arm.  A  single  at- 
tachment is  better  than  two,  as  it  gives  more  play  to  the  arms  of  the 
clasp  in  the  slight  unavoidable  motions  of  the  plate.  Again,  in  shap- 
ing the  plate,  cut  it  well  off  from  the  tooth,  allowing  a  tapering  tongue 
to  extend  up  the  clasp  for  its  attachment.  In  clasp  pieces  and  in  all 
partial  pieces  remember  that  the  plate  should  come  in  contact  with  the 


954 


MECHANICS DENTAL    PROSTHESIS. 


teeth  it  approaches,  or  else  stand  as  far  off  as  the  case  will  permit ; 
the  narrow  band  of  gum  so  often  left  between  plate  and  teeth  is  liable 
to  irritation  by  compression  between  the  two;  this  is  productive  of 
more  annoyance  and  injury  than  the  direct  contact  of  the  plate  against 
the  tooth. 

Partial  Clasps  or  Stays. — These  differ  from  clasps  in  the  absence 
of  elastic  arms  grasping  the  tooth.  Taking  a  short,  rounded  prism 
(triangular  in  case  of  bicuspids,  in  molars  quadrangular)  as  the  "  type  " 
of  a  clasp  tooth,  the  clasp  proper  must  grasp  a  side  and  two  angles  or 
two  sides  and  three  angles.  If  it  lies  against  two  sides  and  one  angle, 
or  if  two  opposite  sides  are  so  inclined  (in  the  line  of  the  clasp)  that 
it  will  not  take  hold,  then  it  becomes  merely  a  stay  (Fig.  1069). 

Stays  demand  for  serviceable  action  a /c"/;?/  (fappui;  hence  they 
must   be   in  pairs — lying   either  against  the  two   teeth  bounding  an 


Fig.  1068. 


interdental  space,  or  against  teeth  on  opposite  sides  of  the  mouth. 
They  have  great  value  in  all  partial  cases  where  there  are  no  isolated 
teeth  suitable  for  clasps.  Their  function  is  to  give  stability  to  the 
plate  by  preventing  lateral  motion.  When  the  bicuspids  or  molars 
have  inclined  or  bulging  inner  surfaces  the  stays  hold  the  piece  after 
the  manner  of  a  clasp,  the  elastic  force  being  given  by  the  plate. 
This  result  can  only  be  obtained,  however,  by  a  very  carefully  taken 
plaster  impression  when  a  vulcanite  plate  is  made,  or  in  case  of  gold 
plate  by  getting  the  exact  relation  of  the  parts  by  Dr.  Noble's 
method.  It  is  a  mistake  to  attempt  forcible  retention  of  a  plate  by 
the  lateral  thrust  of  stays ;  any  such  pressure  causes  the  teeth  to  yield, 
and  then  the  stays  can  only  act  as  in  the  cases  first  given. 

It  will  be  observed  that  when  the  stay  on  each  side  is  double,  as  in 


RETENTION  OF  BASE  PLATE>.  955 

Fig.  1070,  it  not  only  prevents  lateral  motion,  but  the  points  between 
the  teeth  prevent  backward  motion.  The  stability  given  in  this  man- 
ner by  stays,  taken  with  an  exact  adaptation  of  the  plate,  is  far  more 
trustworthy  than  that  given  by  any  form  of  vacuum  cavity. 

In  connection  with  clasps  we  shall  briefly  notice  two  methods  occa- 
sionally practiced  for  the  retention  of  plates.  First,  by  the  pressure 
of  wood  against  the  tooth.  This  method  was  formerly  much  used 
when  human  or  ivory  teeth  were  set  on  bone.  Stays  were  carved  in 
bone  (see  Fig.  1070)  ;  or  metallic  stays  or  clasps  were  riveted,  or 
grooves  and  cavities  were  cut,  holding  slips  of  some  hard  wood  which 
pressed  against  the  teeth.  This  method  was  applied  by  Dr.  Stokes 
to  metallic  plates — soldering  gold  tubes  to  the  plate  near  the  teeth  so 
that  the  end  of  the  inserted  wooden  pivot,  slightly  projecting,  pressed 
on  each  side  of  the  tooth  selected. 

Secondly,  by  drilling  into  one  or  two  sound  roots  of  incisors, 
canines,  or  bicuspids  a  short  canal,  and  lining  it  with  a  gold  tube. 
Corresponding  pins  soldered  to  the  plate  keep  it  in  place  much  as  stays 
do  ;  if  the  roots  permit  deep  canals  they  may  retain  it  with  consider- 


FlG.  1069. 


able  force.  Such  a  pin  may  be  used  in  combination  with  a  clasp  or 
stay.  Directions  given  in  chapter  on  crown  and  bridge-work  easily 
explain  how  to  prepare  and  attach  such  pins.  In  some  cases  it  may 
be  desirable  to  use  such  a  pin  in  place  of  a  clasp  or  stay,  but  the  plate 
must  cover  enough  mucous  surface  to  give  stability.  We  question  the 
propriety  of  subjecting  the  roots  of  two  incisors  to  the  strain  of  five 
or  six  teeth  on  a  plate  of  this  kind. 

When  the  teeth  have  recently  been  extracted  and  it  is  designed  to 
construct  an  artificial  denture  before  much  change  has  occurred  from 
absorption,  the  front  portion  of  the  plate  should  terminate  within  the 
outer  border  of  the  alveolar  ridge,  and  the  edge  be  scalloped  to  cor- 
respond with  the  festooned  surface  of  the  gum  over  the  cavities  from 
which  the  natural  teeth  have  been  removed. 

She  and  Outline  Fortn  of  Special  Cases. — It  is  impossible  to  enu- 
merate all  varieties  of  clasp  pieces,  nor  could  we  delineate  under  each 
variety  any  one  form  as  absolutely  best  for  all  its  sub-varieties.  The 
more   philosophical   course   is   to   find   if  possible   what   principles, 


956 


MECHANICS — DENTAL    PROSTHESIS. 


mechanical  and  physiological,  determine  the  best  form  in  any  case, 
and  to  illustrate  by  a  few  examples  the  application  of  these  principles. 

Upper  Incisors. — The  plate  must  not  cover  the  front  of  the  alveolus, 
so  that  on  front  or  side  views  of  the  mouth  its  presence  can  be  detected. 
This  rule  applies  also  to  canines  and  front  edges  of  bicuspids.  The 
model  at  these  points  should  be  scraped,  so  that  the  corresponding  die 
shall  give  a  shape  which  will  sink  into  the  gum.  The  plate  must  also 
be  filed  to  a  thin  edge  before  grinding  the  tooth.  With  these  pre- 
cautions a  tooth  or  block  may  have  the  support  of  the  plate  under  the 
center  of  its  base.  Otherwise  it  becomes  necessary  to  cut  the  plate 
along  the  line  of  the  backings  ;  and  this  is  in  some  cases  the  best  plan. 
Incisor  teeth,  if  firmly  bedded  in  the  gum,  may  trust  for  stability  to 
their  hold  in  the  standards,  provided  they  have  been  properly  fitted 
and  soldered. 

The  size  and  shape  of  plate  between  teeth  and  clasps  will  depend 
upon  the  number  of  incisors,  position  of  clasps,  presence  or  absence 


Fig.  1071. 


Fig.  1072 


of  other  teeth,  and  upon  peculiarities  of  the  mouth  or  of  the  patient. 
For  the  api^lication  of  the  principles  already  given  to  these  several 
conditions  we  shall  select  a  itv^  particular  cases. 

One  Incisor. — A  central  or  lateral  should  not  be  attached  to  a  first 
molar  on  the  same  side  by  a  plate  clasped  as  in  Fig.  1072  without  an 
additional  clasp  or  partial  stay  around  one  of  the  bicuspids,  as  in  Fig. 
1 07 1,  in  order  that  the  leverage  between  the  clasped  and  supporting 
tooth  or  teeth  may  be  lessened.  It  is  also  desirable  to  have  the  plate 
extend  some  distance  back  of  the  tooth  around  which  the  clasp  passes. 
When  three  or  more  natural  teeth  intervene  between  the  clasp  and  ar- 
tificial teeth  the  latter  form  is  preferable,  because  there  is  no  possibil- 
ity of  irritating  the  teeth  by  the  plate  or  by  mucous  deposits.  It  will 
be  noticed  that  the  curve  of  the  plate  is  opposite  that  of  the  dental 
arch,  thus  giving  proximity  to  the  teeth  only  where  it  is  unavoidable. 
A  lateral  incisor,  cuspid,  or  bicuspid  may  be  applied  in  the  same  way ; 


RETENTION    OF    BASE    PLATES.  957 

and  if  the  second  bicuspid  or  first  molar  is  unfit,  from  its  shape  and 
from  decay,  to  be  clasped,  the  plate  may  be  extended  to  the  second 
molar,  or  it  may  be  even  carried  across  the  mouth  and  clasped  to  a 
plate  on  the  opposite  side;  but  these  modifications  are  suggested  only 
in  cases  of  necessity.  Such  plates  may  be  made  very  narrow  if  strength 
is  given  by  increased  thickness ;  but  too  narrow  plates  are  open  to  the 
objection  of  allowing  the  attached  tooth  to  bed  itself  too  deeply  under 
the  pressure  of  mastication.  When  the  form  in  Fig.  1071  is  adopted 
it  is  usual  to  direct  soldering  a  wire  or  band  along  the  festooned  edge 
to  give  strength.  A  much  better  plan  is  to  gain  strength  by  thickness 
of  plate,  and  to  chamfer  the  plate  along  this  edge.  The  thin  edge 
protects  the  gum  equally  well,  does  not  wear  the  teeth  more  than  the 
thick  one,  and  has  the  decided  advantage  of  giving  no  space  for 
lodgment  of  food. 

This  plate  will  permit  attachment  of  clasp  to  the  molar  and  to 
either  of  the  bicuspids,  accordingly  as  one  or  other  of  these  may  be 
best  for  clasping.  Decision  in  this  case  is  based  on  principles  which 
apply  to  many  other  cases.  Supposing  the  three  teeth  well  shaped 
and  sound,  the  molar  is  firmly  implanted  by  its  trifid  root,  and  permits 
complete  encircling  with  the  clasp;  but  it  is  further  from  the  incisor; 
hence  there  is  more  strain  upon  tooth  and  clasp.  With  the  clasp  to 
the  second  bicuspid,  the  plate  having  the  same  length  as  before,  we 
have  the  best  possible  application  of  its  retentive  power;  it  cannot, 
however,  pass  around  the  outside  or  front  angle  of  either  bicuspid, 
consequently  the  clasp  does  not  have  so  firm  a  hold  on  the  tooth. 
The  same  remarks  apply  with  even  more  force  to  the  first  bicuspid. 
There  will  usually  be  some  modifying  circumstances  to  determine  in 
this  class  of  cases  choice  of  the  clasp  tooth. 

Two  or  Four  Incisors. — Two  incisors  may  be  attached  to  a  plate 
shaped  as  for  one  (Fig.  1071),  with  the  addition  of  a  second  clasp,  or 
partial  stay,  when  the  teeth  will  not  permit  of  a  full  clasp.  But  much 
the  best  practice  is  to  select  the  second  tooth  on  the  opposite  side. 
Fig.  1073  gives  the  form  when  it  is  decided  to  run  the  plate  up  to  the 
intervening  teeth.  With  four  incisors  and  clasps  on  second  bicuspids, 
the  form  represented  by  Fig.  1073  is  best,  because  only  two  teeth  lie 
between  the  incisors  and  clasp ;  and  it  is  better  to  carry  the  plate  up 
to  the  teeth  than  to  expose  so  small  a  portion  of  gum.  For  four  teeth 
the  plate  should  be  rather  wider  than  for  two. 

In  these  cases  a  closely-fitting  plate  assists  so  much  in  its  own  reten- 
tion that  bicuspid  stays  will  often  suffice  to  retain  them,  or  a  clasp  on 
one  side  and  a  stay  on  the  other.  When  the  adhesion  of  the  plate  to 
the  gum  is  thus  partly  relied  upon  it  is  not  necessary  to  make  the  plate 
for  four  incisors  larger  than  in  Fig.  1073. 


958 


MECHANICS DENTAL    PROSTHESIS. 


When  the  four  incisors  and  the  cuspids  are  to  be  replaced  the  con- 
struction of  the  plate  (Fig.  1073)  is  upon  precisely  the  same  principle 
as  the  preceding,  the  only  difference  being  that  the  plate  should  be 
rather  larger  and  extend  further  back  than  the  clasped  teeth.  When 
the  teeth  on  one  side  of  the  mouth  are  too  much  decayed,  or  are  inca- 
pable of  affording  a  secure  attachment,  or  are  missing,  even  this  num- 


FlG.  1073. 


Fig.  1074. 


ber  of  teeth  may  be  held  by  a  double  clasp  on  one  side  of  the  mouth 
and  a  stay  on  the  other.  But  the  plate  should  be  extended  half  or 
three-fourths  of  an  inch  back  of  the  tooth  to  which  it  is  clasped.  If 
this  precaution  is  neglected,  the  piece,  from  its  weight,  may  act  as  a 
lever  upon  the  tooth  and  loosen  it  or  cause  periostitis.  It  sometimes 
happens  that  a  piece  made  originally  with  clasps  on  both  sides  of  the 

mouth  loses  the  benefit  of  one  clasp 
from  the  loss  of  the  tooth  ;  and  yet 
the  patient  retains  it  in  place  as  well 
as  before.  The  piece  is  then  in  part 
retained  by  the  fit  of  the  plate  to  the 
gum;  from  which  we  learn  that  if 
only  one  clasp  or,  what  is  better,  a 
double  clasp  can  be  attached  to  a 
plate  with  from  four  to  six  teeth,  it  is 
advisable  to  cover  rather  more  of  the 
surface  of  the  mouth.  In  this  com- 
bination the  clasp  and  stay  gives 
steadiness,  and  the  close  fit  of  the  plate  to  the  gum  gives  adhesion. 

Upper  Bicuspids. — One  or  two  bicuspids  on  one  side  are  often  at- 
tached to  a  plate  about  the  size  of  a  half  dollar,  clasped  to  the  bicus- 
pid or  molar  behind.  But  such  pieces  are  not  of  much  service  in 
mastication.  It  is  better  practice  to  leave  such  a  space  unfilled  than 
endanger  the  durability  of  a  good  tooth  by  clasping  it.  If  there  is  a 
bicuspid  space  on  either  side  the  plate  crosses  the  mouth.     Fig.  1075 


Fig.  1075. 


RETENTION    OF    BASE    PLATES.  959 

represents  such  a  plate  clasped  to  the  first  molars  and  fitted,  as  is  very 
commonly  done,  closely  to  the  incisors.  But  in  this  and  all  other 
cases  where  the  four  or  six  front  teeth  remain,  if  the  plate  does  not  fit 
closely  to  the  palatal  necks  of  the  natural  teeth,  it  is  decidedly  better 
to  leave  as  large  a  space  between  the  plate  and  the  teeth  as  possible. 
The  strength  of  the  plate  is  preserved  by  giving  less  curve  to  the  back 
edge,  or  by  doubling  the  plate  in  the  middle.  The  design  of  this  form 
is  to  leave  uncovered  as  much  of  the  roof  of  the  mouth  as  is  possible. 

An  important  point  is  gained  by  having  the  plate  fit  closely  to  the 
teeth  and  mucous  membrane  immediately  back  of  the  natural  front 
teeth,  and  also  by  having  the  edge  of  the  plate  made  thin.  The  ar- 
ticulation of  the  dental  letters  (the  mutes  T,  D,  Th,  the  nasal  N  and 
the  liquid  L)  is  thickened  by  a  plate  which  is  left  thick  at  such  a  part, 
or  not  well  adapted  to  the  mucous  membrane  and  the  teeth. 

When  the  loss  of  bicuspids  is  accompanied  by  that  of  the  six  front 
teeth,  and  the  first  molars  alone  remain,  a  good  form  of  plate  is  shown 
in  Fig.  1074.  The  backward  extension  of  the  plate,  curving  partly 
over  the  alveolus,  is  designed  to  prevent  the  weight  of  the  piece  from 
acting  injuriously  on  the  molars  and  to  assist  their  retentive  power. 
If  the  second  molars  are  also  in  the  mouth,  the  extended  plate  must 
be  differently  shaped.  If  the  molars  are  well  shaped  and  firm  the 
plate  may  be  narrower  than  here  represented,  being  careful  to  make  it 
thicker  also.  But  if  the  presence  of  adjacent  molars  prevents  the  use 
of  complete  clasps,  or  if  their  form  renders  stays  necessary  instead  of 
clasps,  the  plate  may  be  rather  wider.  Be  careful,  however,  not  to 
cover  the  hard  floor  of  the  palate,  or  to  attempt  giving,  by  a  cross 
band  at  the  back  of  the  plate,  the  stiffness  which  is  best  gained  by 
thickness  of  metal. 

Plates  of  this  class  are  kept  in  place  as  much  by  the  adhesion  of 
contact  with  the  gum  as  by  the  clasps.  In  many  cases  the  force  of 
adhesion  is  such  that  the  lateral  support  of  stays  is  quite  as  effectual 
as  clasps.  Hence,  after  a  clasp  piece  of  this  kind  has  been  worn  for 
some  time  and  become  perfectly  set  to  the  mouth,  it  may  be  advisable 
to  shorten  the  clasps  into  stays;  indeed,  it  is  better  practice,  in  all 
cases,  to  anticipate  this  ultimate  fit  of  these  plates  and  make  stays  at 
first  instead  of  clasps.  This  applies  with  still  more  force  to  the  loss 
of  twelve  teeth,  the  second  molars  remaining,  which  should  in  no  case 
be  clasped ;  stays  may  very  properly  be  used  to  prevent  lateral  or 
backward  motion  of  the  plate.  The  presence  of  these  second  molars, 
by  giving  lateral  steadiness  to  the  plate,  prevents  all  necessity  for 
covering  the  hard  palate,  and  makes  a  vacuum  cavity  wholly  uncalled 
for.  A  solitary  molar  should  never  be  clasped,  nor  should  it  be 
allowed  to  remain  in  the  mouth. 


960 


MECHANICS — DENTAL    PROSTHESIS. 


Alternate  Spaces. — It  remains  to  consider  the  forms  of  plates  for 
vacancies  alternating  with  natural  teeth.  The  forms  given  for  four 
incisors  will  answer  for  all  alternating  vacancies  anterior  to  the  second 
bicuspids,  remembering  to  make  the  plate  wider  in  proportion  to  the 
number  of  teeth,  and  thicker  in  proportion  as  it  is  made  narrow ;  also, 
that  a  first  bicuspid  may  in  many  of  these  cases  be  clasped  with  belter 
effect  than  a  second  or  than  the  first  molar.  Fig.  1076  is  a  good  type 
for  cases  where  the  vacancies  include  the  bicuspids;  notice  in  this  cut 
the  backward  extension  of  the  plate.  Where  the  natural  teeth  are  in 
groups  of  two,  it  is  best  to  carry  the  plate  close  up;  if  as  many  as 
three  or  four  are  together,  the  plate  may  be  cut  awav,  especially  if 
they  are  incisors.  Fig.  1077  represents  an  exceptional  case,  in  which 
two  laterals  and  two  left  bicuspids  are  attached  by  clasping  to  the 
right  first  bicuspid  and  molar.  The  left  molars  are  supposed  to  be 
loose,  or  sockets  much  absorbed,  or  from  some  other  cause  forbidding 


Fig.  1076. 


Fig.  1077. 


clasps  or  stays.  In  this  case  the  undue  strain  on  the  clasp  teeth  will 
ultimately  cause  their  loss.  Whenever  an  unavoidable  strain  of  this 
kind  is  thrown  upon  a  tooth  a  clasp  may  be  used  in  preference  to 
covering  the  i)alate,  provided  the  patient  is  content,  for  the  sake  of 
the  firmness  which  it  gives,  to  risk  the  loss  of  the  tooth.  Teeth  are 
more  firmly  retained  by  clasps  than  by  atmospheric  pressure,  and  this, 
with  many  patients,  outweighs  all  considerations  of  injury  to  the 
other  teeth. 

Partial  pieces  with  alternating  spaces  do  not  acquire  that  adhesion 
by  contact  found  in  cases  where  the  lost  teeth  lie  together.  The 
interrupted  margin  between  the  teeth  so  readily  admits  air  under  the 
plate  on  the  slightest  motion  that  the  atmospheric  pressure  is  imper- 
fectly applied.  Hence  there  is  continued  demand  for  the  retentive 
power  of  the  clasps.  The  vacuum  cavity  does  not  correct  this  diffi- 
culty or  suj)ply  the  place  of  clasps,  since,  as  will  be  explained  in  the 


RETENTION    OF    BASE    PLATES. 


961 


next  section,  the  vacuum  acts  on  soft  membrane  and  has  necessarily  a 
temporary  force. 

When  the  six  or  eigiu  front  teeth  remain,  a  plate  holding  bicuspids 
and  molars  cannot  be  retained  by  clasps.  In  the  first  place  the  cus- 
pids could  not  be  clasped,  nor  would  it  be  proper  even  to  carry  stays 
against  them.  In  the  latter  case  the  weight  and  leverage  of  the  piece 
would  be  too  great  for  the  slight  clasp  that  a  first  bicuspid  permits; 
but  two  stays,  with  the  points  passing  as  far  to  the  front  of  the  bicus- 
pids as  the  cuspids  allow,  would  tend  to  prevent  the  slipping  of  the 
plate  backward. 

Lower  Partial  Pieces. — These  do  not  properly  come  under  the  head 
of  clasp  work.  Fig.  1078  represents  a  reinforced  partial  lower  plate 
for  supplying  bicuspid  and 
molar  teeth  on  both  sides,  the 
six  anterior  natural  teeth  re- 
maining in  the  mouth.  The 
anterior  portion  of  the  plate 
is  extended  upward  on  the 
lingual  surface  of  the  natural 
teeth,  which  adds  to  the 
strength  and  acts  as  partial 
stays  for  the  retention  of  such 
dentures.  Additional  strength 
may  also  be  given  by  doub- 
ling the  anterior  portion  of 
such  a  plate.  In  replacing 
one  or  more  incisors  lost  by  accident  or  calcic  deposits  half  clasps  may 
be  applied  to  the  bicuspids.  For  such  cases  the  best  style  of  work, 
beyond  all  question,  is  a  vulcanite  plate,  made  on  a  model  from  a 
plaster  imi)ression.  Fitting  with  great  accuracy  the  inner  surfaces  of 
the  bicuspids,  it  is  firmly  held  without  injury  to  the  retaining  teeth. 
Partial  pieces  filling  bicuspid  and  molar  vacancies  should  not  clasp 
cuspids  or  bicuspids;  the  position  of  remaining  molars  seldom  permits 
clasping;  even  stays  cannot  always  be  applied.  Artificial  crowns  may 
be  inserted  to  support  a  clasped  plate  and  gold  crowns  may  be  attached 
to  roots  and  badly  decayed  teeth  to  support  clasped  plates,  and  thus 
save  more  valuable  teeth  from  the  strain  and  wear  of  clasps. 

In  chapter  fourth,  on  Preparatory  Treatment  of  the  Mouth,  the 
question  of  extracting  molar  or  bicuspid  teeth  which  might  otherwise 
be  used  for  clasping  is  considered.  The  importance  of  permanence 
of  the  work  outweighs  any  temporary  advantage  resulting  from 
clasping  one  or  two  such  teeth.  In  chapter  third,  and  in  the  section 
on  Retention  by  Clasps,  are  many  remarks  which  it  is  unnecessary  to 
61 


Fig.  1078. 


962  MECHANICS — DENTAL   PROSTHESIS. 

repeat,  but   which  are  important  for   the  full   understanding  of  the 
details  of  construction  given  in  this  section. 

PLATES    RETAINED    BY    ATMOSPHERIC   PRESSURE. 

Of  the  two  methods  of  retaining  a  dental  appliance  already  con- 
sidered, the  first,  by  springs,  is  suited  only  to  entire  dentures ;  the 
second,  by  clasps,  is  adapted  only  to  partial  cases.  The  principle 
of  retention  now  to  be  considered  is  applicable  to  both  ;  where  prac- 
ticable it  is  the  most  perfect  way  of  retaining  a  set  of  artificial  teeth. 
If  the  pressure  of  the  atmosphere  could  be  removed  from  the  mucous 
side  of  a  plate,  allowing  its  full  force  to  be  exerted  upon  the  lingual 
surface,  the  smallest  plates  would  adhere  with  a  force  of  four  pounds, 
the  largest  forty.  But,  for  reasons  to  be  given,  plates  seldom  have 
one-fourth  of  this  resistance  to  displacement.  There  are  two  methods 
in  present  use  for  securing  the  service  of  atmospheric  pressure.  One 
is  by  close  adaptation  of  the  plate;  the  other  by  construction  of  a 
cavity  of  definite  form.  Both  act  by  the  more  or  less  perfect  exclu- 
sion of  air  from  between  the  plate  and  the  mouth.  The  first  will  be 
considered  as  the  Adhesion  of  Contact ;  the  second  as  the  power  of 
the  Vacuum  Cavity.  Before  describing  the  separate  application  of 
these  to  dental  plates,  a  iew  remarks  are  necessary  in  addition  to  what 
has  already  been  said  in  the  last  section  of  the  third  chapter,  in 
exposition  of  the  general  principles  of  atmospheric  pressure. 

The  surfaces  of  two  pieces  of  highly  polished  ground  glass,  if 
pressed  together,  will  adhere  firmly ;  so  much  so,  sometimes,  as  to 
resist  every  attempt  at  separation.  Surfaces  less  smooth  and  close- 
grained  will  also  adhere  with  great  tenacity  if  their  pores  or  irregu- 
larities are  filled  by  wetting  with  water.  If  both  surfaces  are  rigid 
they  may  be  made  to  slide  upon  each  other,  but  will  resist  a  force  of 
five  to  fifteen  pounds  for  every  square  inch  if  applied  at  right  angles 
to  the  surface ;  if  one  surface  is  soft  and  pliant  it  becomes  difficult 
to  keep  it  in  contact  around  the  edges.  Traction  upon  the  center,  as 
in  the  case  of  a  disk  of  wet  leather  upon  a  flat  stone,  will  draw  in  the 
edges  and  create  a  vacuum  in  the  centre.  It  might  be  supposed  that 
in  this  vacuum  space  lies  the  power  that  raises  the  stone  :  whereas  it 
lessens  the  power  by  reducing  the  area  of  stone  in  contact  with  the 
leather,  even  if  the  vacuum  is  perfect.  Still,  if  the  entire  circum- 
ference is  in  contact  no  air  enters  the  cavity  except  what  passes 
through  the  porous  leather,  and  for  a  time  the  lifting  power  of  the 
disk  is  sufficient  to  raise  the  stone.  If  traction  be  made  upon  the 
disk  anywhere  but  in  the  center  the  flexible  edge  will  be  raised  ;  air 
enters  between  the  surfaces  and  counteracts  that  pressure  on  the  under 
side  of  the  stone  which  was  the  lifting  force. 


RETENTION    OF    BASE    PLATES.  963 

Hence  between  two  surfaces  adhering  by  simple  contact,  one  of 
which  is  soft  and  pliant,  adhesion  is  not  so  persistent  as  where  both 
are  rigid,  because  of  the  liability  to  separation  around  the  edges 
admitting  air  between  the  surfaces.  Applying  this  to  dental  plates 
we  may  understand  their  liability  to  become  detached  by  a  degree 
of  motion  which  separates  them  from  the  gum  at  any  one  point 
around  the  edge.  We  learn  also  that  so  long  as  absolute  contact  is 
maintained  we  have  the  most  perfect  exclusion  of  air  practicable; 
hence  no  force  of  adhesion  in  a  limited  vacuum  cavity  (the  perfect 
exhaustion  of  which  is  impossible)  is  comparable  to  the  adhesion  of 
the  entire  surface  of  the  plate,  provided  this  is  made  as  perfect  as 
possible  by  accurate  workmanship  and  is  not  weakened  by  the  admis- 
sion of  air  around  the  edges. 

If  we  exhaust  the  air  from  the  barrel  of  a  key  and  apply  the  lip, 
it  will  be  drawn  in  and  held  with  a  force  sufficient  to  support  the 
weight  of  the  key  for  some  time.  This  simple  experiment  will 
prove,  on  examination,  very  instructive.  The  mucous  and  sub- 
mucous tissues  are  pressed  into  the  key  because  the  fluids  pervad- 
ing these  parts,  being  under  pressure  in  every  other  direction,  tend 
toward  the  point  from  which  the  pressure  is  wholly  or  partially  re- 
moved. The  extent  to  which  the  lip  is  drawn  into  the  key  will  depend 
upon  two  conditions:  First,  the  softness  and  mobility  of  the  tissue; 
secondly,  the  shape  of  the  edge  of  the  orifice.  If  in  addition  to  these 
two  points  we  inquire,  thirdly,  why  the  key  after  a  time  drops  off, 
we  shall,  from  this  simple  illustration,  have  fully  explained  the 
rationale  of  the  vacuum  cavity,  as  applied  for  the  retention  of  a 
piece  of  dental  mechanism. 

First :  the  extent  to  which  or  rapidity  with  which  a  partial  vacuum 
becomes  filled  up  by  any  yielding  tissue  with  which  it  is  brought  in 
contact  depends  upon  the  mobility  of  its  structure.  We  say  partial 
vacuum,  because  the  process  of  mechanical  exhaustion  can  never  pro- 
duce a  perfect  vacuum.  If  the  water  which  gives  softness  to  mucous 
tissues  was  perfectly  free  to  move,  the  cavity  would  be  instantly  filled, 
however  deep.  Parts  as  mobile  as  the  tongue  and  lips  yield  readily  to 
this  fluid  pressure ;  but  the  mucous  membrane  of  the  alveolar  ridge 
and  palate,  being  more  or  less  tied  down  to  the  bone,  fills  the  cavity 
more  slowly ;  if  too  deep  it  will  not  fill  it  at  all,  except  by  hyper- 
trophy. Reverting  to  the  experiment  of  the  key  :  if  violent  suction 
is  made  a  purple  spot  is  left  upon  the  lip  ;  the  mucous  tissues  being 
prevented  by  their  structure  from  filling  the  vacuum,  the  fluids  still 
feel  the  impulse  of  atmospheric  pressure  ;  the  blood,  thus  impelled 
with  a  force  which  the  thin  capillary  walls  cannot  resist,  is  extrava- 
sated,  as  takes  place  also  in  the  application  of  "dry  cups."      Hence, 


964  MECHANICS — DENTAL    PROSTHESIS. 

where  a  dental-plate  cavity  is  so  deep  that  the  tissues  cannot  fill  it,  if 
the  degree  of  exhaustion  is  such  as  still  to  draw  upon  the  surface,  the 
tissues  are  in  danger  of  being  ruptured.  Such  a  source  of  irritation 
will  in  many  persons  develop  morbid  action  and  should  forbid  the  use 
of  deep  cavities  in  any  plate. 

Secondly  :  The  shape  of  the  edge  modifies  the  rapidity  with  which 
the  cavity  fills.  If  the  edge  of  a  cupping  glass  is  rounded  the  skin 
glides  under  it  and  is  drawn  from  the  adjoining  parts  into  the  glass  ; 
but  if  the  glass  is  ground  so  as  to  present  a  sharp  edge  on  the  inside, 
this  beds  itself  in  the  surface  and  prevents  so  much  of  the  adjacent 
skin. from  being  drawn  in.  It  rises  to  a  less  height  in  the  cup,  and  the 
remaining  force  of  the  vacuum  is  spent  upon  the  capillary  vessels, 
which  are  ruptured.  Hence  we  learn  that  sharp-edged  cavities  fill 
less  rapidly,  but  act  with  more  power  upon  the  tissues  ;  they  are  con- 
sequently more  apt  to  excite  disease  if  the  cavity  has  sufificient  depth 
to  allow  continued  action. 

Thirdly  :  As  to  the  cause  of  the  final  dropping  off  of  the  key : 
water  and  all  the  moist  tissues  of  the  body  contain  atmospheric  air 
which  they  yield  up  under  a  vacuum.  Hence  a  mucous  membrane, 
although  at  first  drawn  strongly  into  a  cavity,  will  make  the  vacuum 
less  complete  by  giving  out  of  the  air  contained  in  its  tissue  and  in  the 
blood  constantly  circulating  through  it.  The  adhesion  of  a  vacuum, 
therefore,  over  mucous  membranes  requires  renewal  by  occasional  suc- 
tion, since  the  blood  is  constantly  circulating  through  the  surface  and 
supplies  air  to  the  cavity.  Mucous  membranes  have  also  the  property 
of  absorbing  air,  as  is  seen  in  the  lining  of  the  bronchial  cells  con- 
stantly and  in  the  power  of  the  mucous  membrane  of  the  intestines 
to  absorb  the  gases  there  generated.  This  property  acts  an  important 
part  in  absorbing  small  quantities  of  air. unavoidably  caught  between 
the  plate  and  the  mouth  ;  thus  partly  explaining  the  well-known  fact 
that  plates  adhering  by  simple  contact  become  tighter  after  being 
worn  awhile. 

Thus  the  double  action  of  mucous  membrane,  absorbing  minute 
portions  of  air  pressed  against  it,  and  giving  out  its  contained  air  to 
a  vacuum,  favors  the  retention  of  simple  contact,  whilst  it  acts  against 
the  efficacy  of  the  vacuum.  In  either  case  it  prevents  the  full  force  of 
pressure  theoretically  possible.  The  practical  inference  from  the  lesson 
of  the  key  is  that  the  Vacuum  Cavity  acts  well  at  first,  and  may  be 
useful  for  the  temjjorary  purpose  of  retaining  a  plate  until  the  changes 
of  which  the  mouth  is  capable  adapt  it  more  perfectly  to  the  plate; 
but  for  permanent  adhesion  the  only  reliable  application  of  the  atmos- 
pheric-pressure principle  is  the  Adhesion  of  Contact,  which  is  fully 
developed  only  when  the  contact  of  the  plate  is  complete.     A  vacuum 


RETENTION    OF    BASE    PLATES. 


965 


cavity,  acting  as  such,  gradually  draws  the  gum  into  it  and  finally  fills 
it  by  a  more  or  less  permanent  enlargement ;  when  thus  filled  the 
plate  is  retained  solely  by  the  adhesion  of  contact.  When  a  cavity 
intended  to  hold  up  a  plate  leaves  no  prominence  or  mark  in  the 
mouth,  it  unmistakably  proves  that  it  is  exerting  no  force  ;  so  far  from 
aiding  in  the  retention  of  the  plate  it  diminishes  the  force  of  adhesion 
by  the  presence  of  air,  and  has  no  compensating  advantage  except  in 
removing  pressure  from  a  hard  palate  membrane.  There  are,  however, 
other  and  better  ways  of  obtaining  an  air  space,  as  elsewhere  explained, 
without  the  presence  of  a  cavity,  which  marks  the  failure  of  its  original 
purpose. 

ADHESION    OF    CONTACT. 

Full  plates,  which  are  designed  to  adhere  by  force  of  contact,  differ 
from  those  retained  by  spiral  springs  in  that  the  former  are  larger 
than  the  latter,  covering  more  of  the  palate,  so  as  to  give  a  larger 
surface  for  the  pressure  of  the  atmosphere.  They  may  cover  the  whole 
of  the  outer  surface  of  the  alveolar  ridge  and  a  considerable  ])ortion 
of  the  roof  of  the  mouth ;  but  should  not  go  as  far  back  nor  run  so 
high  up  as  some  dentists  are  in  the 
habit  of  extending  them.  If  al- 
lowed to  cover  those  parts  of  the 
bone  where  the  cheek  muscles  on 
the  outside  of  the  ridge  or  the 
palate  muscles  at  the  back  of  mouth 
are  inserted,  the  gums  will  be 
chafed  or  ulcerated,  the  patient 
nauseated,  and  the  piece  rendered 
unstable  by  the  action  of  the  mus- 
cle. It  is  not  always  necessary  to 
employ  a  very  wide  plate  to  give 
secure  retention,  for  a  compara- 
tively narrow  one  will  often  adhere 
with  very  great  tenacity  to  the 
gums.  But  such  a  plate  is  more  liable  to  be  bent  and  lose  its  perfect 
adaptation  to  the  parts  than  a  wide  one,  unless  made  thicker  in  pro- 
portion as  it  is  narrower.  As  it  is  never  necessary  to  make  an  upper 
plate  so  narrow  as  a  lower  one,  there  can  be  no  difficulty  in  giving  the 
requisite  strength,  either  by  increasing  the  thickness  throughout  or  by 
doubling  the  anterior  half. 

The  diagram  (Fig.  1079)  represents  half-section  outlines  of  six 
modifications  of  form  in  the  posterior  margin  of  the  plate,  where  it  is 
proposed  to  overcome  the  difficulties  incident  to  a  hard  palatine  mem- 
brane by  cutting  out  the  plate.     The  line  P,  curving  forward  from  a 


Fig.  1079. 


966  MECHANICS DENTAL    PROSTHESIS. 

little  behind  the  termination  of  the  top  of  the  ridge  (dotted  line),  is 
the  extreme  limit  of  any  plate  not  complicated  with  cleft  palate.  The 
curve  a  or  a!  will  give  surface  sufficient  for  the  retention  of  most  plates, 
except  in  small  arches.  This  form  is  more  agreeable  to  the  patient 
than  the  first,  and  is  less  apt  to  produce  nausea ;  it  removes  the  plate 
from  all  action  of  the  palate  muscles,  and  lessens  the  liability  to  dis- 
lodgment  often  caused  by  the  forcible  action  of  the  tongue  against  the 
back  of  the  palate  in  certain  eff'orts  of  deglutition.  The  curve  b  or  (/ 
may  often  be  used  solely  to  avoid  unnecessary  covering  of  the  palate. 
In  mouths  of  average  size  and  having  moderate  and  regular  softness 
such  shape  will  prove  quite  as  firm  as  one  following  the  line  P.  But 
these  lines  are  more  frequently  to  be  followed,  for  the  same  reason 
that  we  take  the  curve  c  or  c'  to  keep  the  plate  off  the  hard  central 
ridge.  When  this  ridge  is  narrow  we  give  greatest  width  to  the  plate 
by  following  the  curves  on  the  side  R  of  the  diagram ;  but  if  the  sur- 
face is  broad  the  space  must  be  widened,  as  on  the  side  L,  and  the 
plate  made  thicker. 

This  method  of  relieving  the  central  bearing  of  plates  gives  them 
great  steadiness  in  the  ridge,  and  has  an  advantage  over  other  methods 
in  having  no  band  or  ridge  of  plate  pressing  along  the  line  P — a  point 
very  often  as  hard  as  any  other  part  of  the  palate.  It  is  advisable  in 
those  cases  where  a  vacuum  cavity  has  been  tried  with  unsatisfactory 
results  to  cutout  the  cavity  and  part  behind  it,  and  thus  try  the  effect 
of  a  plate  following  curve  b  or  c. 

There  are  other  methods  of  taking  off"  the  central  bearing  of  plates. 
When  the  ridge  is  soft  a  wax  impression  does  this  by  compressing  the 
gum.  Models  from  plaster  impressions  are  scraped  on  the  ridge  for 
the  same  purpose;  but  this  is  not  so  good  a  plan,  as  it  is  difficult  to 
do  it  uniformly.  A  much  better  expedient  is  to  brush  some  thin 
plaster  over  the  central  part  of  the  model,  being  careful  to  mark  the 
line  of  the  back  edge  of  the  plate,  and  put  no  plaster  there  ;  this  layer 
must  not  be  thicker  than  a  card,  and  should  have  no  abrupt  edges.  A 
thin  layer  of  wax  may  be  added  in  the  same  manner  to  plaster  models 
before  molding  in  sand  to  obtain  the  die  for  swaged  metal  plates.  In 
deep  arches  the  shrinkage  of  the  zinc  die  accomplishes  the  same  ob- 
ject ;  if  the  model  is  carefully  scraped  along  the  back  edge  of  the 
plate  this  part  will  fit  closely,  while  the  central  portions  will  stand  off"; 
this  is  far  better  than  the  attempt  to  adjust  the  edge  with  pliers. 

In  adapting  atmospheric-pressure  plates  the  form  and  fit  of  the  alveo- 
lar margin  must  be  considered.  Close  adaptation  of  this  edge  is  by 
no  means  so  essential  to  firm  retention  of  a  fiill  upper  piece  as  hi  the 
posterior  margin  ;  for  the  reason  that,  in  most  cases,  the  loose  mucous 
folds  which  lie  against  the  }>late  prevent  the  access  of  air.     But  close- 


RETENTION    OF    BASE    PLATES.  967 

ness  of  fit  is  very  desirable  for  other  reasons :  to  prevent  lateral 
motion  ;  to  avoid  unnecessary  fullness ;  to  prevent  irritation  of  the 
soft  parts  by  projecting  edges  of  metal.  The  form  of  the  alveolar 
edge  is  not  essential  to  adhesion,  provided  it  rises  high  enough  to  give 
steadiness  to  the  plate.  Esthetic  considerations,  however,  often  com- 
pel us  to  run  the  plates  up  as  high  as  the  muscular  attachments  will 
permit,  either  for  the  support  of  an  artificial  gum  or  to  restore  sunken 
features.  In  both  jaws,  especially  the  lower,  the  effort  to  get  the 
deepest  possible  edge  often  gives  instability  by  subjecting  the  piece  to 
the  action  of  the  facial  and  lingual  muscles.  In  any  case  of  doubt 
make  the  plate  too  shallow  rather  than  too  deep ;  especially  when  the 
edge  is  turned  over,  which  makes  it  impossible  to  take  off  any  excess 
without  spoiling  the  plate. 

Full  lower  plates  are  held  by  adhesion  of  contact ;  but  in  these  the 
weight  of  the  piece  increases  the  adhesion.     The  surface  is  so  small 
that  every  part  of  such  plates  should  fit  the  gum  with  accuracy.     The 
simpler  rule  for  the  form  of  lower  plates  is 
to   extend    them  as  far  on  the  inner  and 
outer   edges   as  the  muscular  attachments 
will  permit.     The   outer  and  inner  edges 
are  often  rounded  by  soldering  a  gold  wire 
after  determining  the  exact  outline.  Thick- 
ness of  the  edge  is  also  given  by  doubling 
the  plate  necessary  for  the  strength  of  nar- 
row  plates.     The   second    plate  is   to   be 
swaged  precisely  as  the  first;    then,  after 
partial  trimming,  the  two  plates  are  swaged 

together  over  a  new  die.  One  should  be  wider  than  the  other  on 
the  outer  or  inner  edge,  to  give  a  place  for  the  solder ;  the  borax  cream 
should  be  free  from  granules,  and  the  blowpipe  flame  directed  on  the 
edge  opposite  the  solder.  A  simple  and  convenient  clamp  for  binding 
plates  together  or  holding  rims  while  being  soldered  is  made  of  iron 
(or  nickel)  wire  (Fig.  1080).  a,  the  first  bend  ;  b,  the  second  bend; 
c,  a  side  view  of  the  same;  d,  side  view  of  clamp,  open  and  grasping 
two  pieces  of  plate.  The  curves  should  be  so  adjusted  that  the  points 
of  contact  with  the  plates  will  be  just  opposite,  else  clamp  or  plates  are 
liable  to  change  position. 

Partial  pieces  may  also  be  retained  by  closeness  of  adaptation  ;  but 
there  are  two  elements  of  instability  which  usually  will  prevent  them 
from  having  the  security  of  full  sets  or  of  partial  clasp  pieces — lateral 
movement  and  extent  of  margin,  admitting  air  on  slightest  motion. 
All  such  pieces  should,  if  possible,  have  two  stays,  one  on  each  side 
of  the  mouth,  to  prevent  lateral  motion  ;  they  should  cover  an  extent 


968  MECHANICS — DENTAL    PROSTHESIS. 

of  surface  proportioned  to  the  number  of  teeth  ;  the  edges  of  the  plate 
should  fit  with  great  accuracy.  If  the  exact  outline  of  the  plate  is 
determined  on,  a  good  plan  is  to  paint  the  model  with  a  coat  of  thin 
plaster,  keeping  one-eighth  inch  inside  the  margin  and  laying  an  extra 
coating  over  very  hard  places  ;  this  causes  the  edge  to  sink  slightly  into 
the  gum;  yet  if  carefully  done  it  will  not  change  the  general  contour 
of  the  surface.  Partial  i)lates,  holding  the  eight,  ten,  or  twelve  an- 
terior teeth,  if  assisted  by  stays  against  the  remaining  molars,  are 
nearly  or  quite  as  firm  as  full  plates.  But  in  either  partial  or  full 
pieces,  whenever  the  plate  has  to  be  cut  off  for  setting  the  six  front 
teeth  directly  on  the  gum,  this  dentated  margin  is  more  apt  to  admit 
air  than  the  upturned  rim,  which  has  the  folds  of  the  lip  lying  against 
it.  Partial  lower  plates  are  unstable,  not  from  any  admission  of  air, 
but  because  of  the  small  extent  of  surface,  inadequate  to  the  pressure 
of  mastication. 

Plates  for  partial  dentures  to  be  held  in  place  by  clasps  or  bands 
are  generally  made  narrow,  and  the  posterior  line  or  edge  within 
the  depression  of  the  rugae,  so  as  to  be  out  of  the  way  of  the  tongue, 
but  such  plates  must  not  be  made  too  small,  or  they  will  cause  pain 
by  being  forced  into  the  mucous  membrane.  -  Partial  lower  plates  for 
artificial  bicuspids  and  molars,  the  six  natural  anterior  teeth  remain- 
ing in  the  mouth,  should  extend  up  on  the  lingual  surfaces  of  the 
natural  teeth  to  prevent  the  too  great  pressure  of  the  plate  against 
the  inner  surface  of  the  alveolar  ridge,  and  also  to  give  greater 
strength  by  the  increased  width  and  form  of  the  plate  back  of  the 
natural  teeth,  which  would  otherwise  have  to  be  made  very  narrow 
and  thick.  The  lower  inner  edge  of  full  and  partial  lower  plates 
should  extend  so  far  down  as  to  be  out  of  the  way  of  the  tongue. 
Carrying  the  edge  of  such  a  j^late  over  the  projecting  surface  of  the 
ridge,  which  is  generally  present,  into  the  receding  underspace,  will 
prevent  the  tip  of  the  tongue  from  getting  under  it ;  at  the  same  time 
the  plate  should  not  extend  so  far  down  as  to  interfere  with  the  frenum 
of  the  tongue. 

A  tongue  or  catch  may  be  swaged  as  part  of  a  partial  lower  })late 
to  extend  slightly  over  the  angle  of  the  crown  of  a  posterior  natural 
tooth,  such  as  a  molar  or  bicuspid,  and  catch  on  the  grinding  surface, 
and  thus  prevent  a  partial  lower  denture  from  pressing  painfully  on 
the  gum.  This  tongue  or  catch  should  be  adapted  to  the  grinding 
surface  of  the  natural  tooth  at  a  point  where  it  will  not  interfere  to 
any  great  degree  with  the  occlusion  of  the  natural  teeth.  Partial 
stays  fitting  as  far  as  possible  into  the  interspaces  betweensuch  natural 
front  teeth  as  remain  in  the  month,  will  prevent  partial  lower  dentures 
containing  artificial  bicuspids  and   molars  from  sliding  backward,  as 


RETENTION    OF    BASE    PLATES.  969 

all  such  dentures  have  a  tendency  to  do.  Such  stays  will  also  prevent 
the  plate  from  being  raised  from  its  place  by  the  cheeks  and 
muscles. 

THE    VACUUM    CAVITY. 

In  some  mouths  the  base  plate  of  a  full  upper  piece  adheres 
from  the  beginning  with  great  firmness.  When  the  gum  is  moder- 
ately and  regularly  soft,  the  palatine  arch  deep,  and  the  mouth  of 
average  size,  want  of  adherence,  on  trial  of  the  plate,  is  positive 
evidence  of  defect  in  construction.  But  very  hard  or  very  small 
or  very  shallow  mouths  usually  require  time  for  the  perfect  adapta- 
tion of  the  best  made  plates.  Dr.  Dwinelle  thus  explains  the  tem- 
porary failure  of  a  simple  atmospheric  pressure  plate  to  fit  firmly 
when  first  inserted.  When  the  plate  is  applied  and  an  effort  made 
to  exhaust  the  air  the  gums  are  drawn  down  so  as  to  meet  it  along 
the  line  and  behind  the  edge  of  the  plate,  thus  resisting  every  effort 
made  from  without  to  withdraw  the  air  from  the  central  part  of  the 
plate;  so  that  the  pressure  of  the  atmosphere  is  exerted  upon  only 
a  small  breadth  of  surface  along  its  edge,  where  the  adhesion  is  con- 
stantly liable  to  be  disturbed  in  mastication. 

With  the  view  of  obviating  this  difficulty  the  idea  of  constructing 
a  plate  with  a  cavity  suggested  itself  to  the  author  as  early  as  1835,  and 
was  mentioned  at  the  time  to  several  of  his  professional  brethren. 
The  construction  of  the  chamber  then  devised  was  found  objection- 
able and  he  abandoned  its  use ;  and  it  was  not  until  the  early  part  of 
1848,  when  he  had  the  opportunity  of  seeing  a  cavity  plate  upon  a 
plan  contrived  by  Dr.  J.  A.  Cleaveland  two  or  three  years  previously, 
that  he  was  again  induced  to  construct  a  base  plate  of  this  kind.  Dr. 
Dwinelle  made  a  cavity  plate  with  an  external  opening  and  valve  for 
exhausting  the  air  in  the  winter  of  1845  J  ^^^  ^^  '^'"'^  summer  of  1847 
or  1848  Dr.  Jahial  Parmly  exhibited  to  the  author  a  plate  with  a  simple 
cavity  struck  into  it  by  swaging.  Some  months  after  he  heard  for  the 
first  time  of  a  cavity  plate  patented  by  Mr.  Gilbert,  of  New  Haven. 
The  cavity  now  generally  employed  is  formed  on  the  median  line, 
either  far  back  for  full  plates  (Fig.  1081),  or  immediately  behind  the 
alveolar  ridge  for  some  partial  plates.  Dr.  Flagg  adds  two  lateral 
cavities  on  the  slope  of  the  palate  with  a  view  to  prevent  the  plate  from 
rocking  and  to  give  it  increased  stability.  Dr.  Levett's  lateral  cavities 
are  placed  directly  upon  the  ridge  (Fig.  1082).  With  this  brief  his- 
tory of  cavity  plates  we  shall  proceed  to  give  a  concise  description  of 
the  manner  of  constructing  them.  The  following  is  the  mode  of  con- 
struction of  Dr.  Cleaveland's  cavity  plate,  which,  for  reasons  given 
below,  is  now  seldom  used. 

A  metallic  die  and  counter-die  having  been   obtained,  a  plate  is 


970  MECHANICS DENTAL    PROSTHESIS. 

swaged,  covering  the  entire  alveolar  border  and  extending  back  as 
far  as  the  line  P  (Fig.  1080).  This  done,  it  is  placed  in  the  mouth, 
and  if  found  to  be  accurately  adapted  to  the  parts  it  is  removed ;  a 
half-round  gold  wire  about  the  size  of  a  common  knitting  needle  is 
then  soldered  to  the  lingual  side  of  the  plate,  enclosing  a  space  shaped 
somewhat  as  is  shown  in  Fig.  1081,  varying  in  size  and  form  with  the 
differences  in  shape  and  size  of  the  plate  and  alveolar  ridge.  The 
part  within  the  wire  is  next  cut  out  with  punch-forceps  or  saw  and  the 
plate  placed  on  the  model ;  a  piece  of  wax  about  a  tenth  or  twelfth 
part  of  an  inch  in  thickness,  having  a  circumference  one-fourth 
greater  than  the  hole  in  the  plate,  is  then  placed  over  the  opening, 
extending  a  short  distance  beyond  the  wire  on  every  side.  The  wax 
at  the  outside  is  brought  to  a  thin  edge  and  is  also  made  thinner  in 
the  center  than  where  it  covers  the  wire  surrounding  the  opening  in 
the  plate.  From  this  model  with  plate  and  wax  upon  it,  die  and 
counter-die  are  obtained  with  which  to  swage  a  thin  plate  of  gold, 
large  enough  to  cover  the  wax  ;  its  edge  is  chamfered  off,  and  it  is  then 


Fig.  loSi.  Fig.  1082. 

soldered  to  its  place  on  the  plate,  where  it  may  be  secured  during 
soldering  either  by  iron  wire  clamps  or  by  gold  rivets.  A  sectional 
view  of  the  cavity  is  represented  in  Fig.  1083  A.  The  Cleaveland 
cavity  causes  the  plate  to  adhere  with  great  tenacity,  as  from  its  shape 
it  is  impossible  for  the  mucous  membrane  entirely  to  fill  it ;  the  trac- 
tion of  this  cavity  is  constant.  A  serious  objection  to  its  use  is  the 
great  irritation  it  excites  in  the  mucous  membrane  in  the  majority  of 
cases. 

The  simpler  cavity  plate  used  by  Dr.  Jahial  Parmly,  of  New  York, 
and  patented  by  Mr.  Gilbert,  of  New  Haven,  may  be  formed  with 
nearly  as  much  ease  as  a  plain  plate.  Fig.  1083  B  represents  a  sectional 
view  of  this  description  of  plate.  If  it  is  desired  to  have  lateral  cav- 
ities, three  pieces  of  wax  or  metallic  forms  are  placed  on  the  plaster 
model — one  in  the  center,  as  already  described,  and  one  on  the  slope 
of  the  alveolar  ridge  on  each  side.  When  it  is  desirable  to  make  a 
cavity  with  sharply  defined   border,   D,  a  second  plate  a  little  larger 


RETENTION    OF    BASE    PLATES. 


971 


than  the  projection  should  be  swaged  over  the  base  plate.  From  the 
base  plate  the  projection  is  to  be  cut  out  and  the  smaller  plate  soldered 
over  the  opening.  For  hard  mouths  the  thickness  of  the  main  plate 
will  give  sufficient  depth  of  cavity,  C  ;  in  this  case  no  projection  is  to 
be  placed  on  the  model. 

Should  the  usual  method  of  exhausting  air  from  these  cavities  be 
thought  insufficient,  the  valve  of  Dr.  Dwinelle  (Fig.  1083  ^)  ^^Y  ^^ 
inserted  in  the  plate  covering  the  cavity.  The  conical  portion  is 
neatly  fitted  by  grinding ;  the  stem  is  soldered  to  a  spring  on  the 
palatine  surface.  A  valve  of  easier  construction  is  given  at  V ;  a 
small  rubber  pad  acts,  by  the  spring,  upon  the  outside  of  the  hole. 
The  size  of  valves  and  thickness  of  plate  are  exaggerated,  the  better 
to  illustrate  the  details  of  construction.  By  means  of  either  of  these 
valves  a  vacuum  may  be  created,  which  will  draw  with  great  force  upon 
the  membrane  over  the  cavity. 

The  forms  B  and  D,  Fig.   1083,  necessitate  a  prominence  in  the 


die  which  is  variously  formed.  When  the  die  is  made  by  sand  mold- 
ing, a  corresponding  one,  formed  of  wax,  lead,  tin,  or  plaster,  is  put 
on  the  model ;  a  die  made  by  dipping  or  pouring  or  by  the  fusible 
metal  process  requires  plaster.  Dies  made  by  pouring  into  the  impres- 
sion require  the  cavity  to  be  cut  in  the  impression  itself.  A  variety 
of  shapes  in  tin  and  alloy  are  furnished  by  the  depots,  chiefly  for  vul- 
canite work  ;  but  they  may  be  used  also  for  the  sand  molding  model. 
Plates  made  by  the  metallo-plastic  processes  require  plaster  promi- 
nences. 

The  size,  depth,  form,  and  position  of  the  cavity  are  important 
considerations.  In  size  it  must  be  proportioned  to  the  plate.  Fig. 
1084  gives  a  fair  average  size  and  is  excellent  in  form,  except  that  it  is 
unnecessarily  pointed ;  all  angles  and  sharp  corners  should  be  avoided, 
and  fanciful  shapes  are  esthetic  blunders ;  the  form  should  appear  to 


972  MECHANICS DENTAL    PROSTHESIS. 

grow  out  of  some  necessity  ;  and  hence  it  should  be  modified  to  suit 
the  form  of  plate.  Shallow  cavities  maybe  larger  than  deep  ones; 
partial  pieces  usually  have  a  cavity  larger  in  proportion. 

Fig.  1085  represents  the  usual  forms  of  vacuum  cavities  (the  shield 
form  being  objectionable  on  account  of  its  sharp  angles),  which  may 
be  metal,  such  as  block  tin,  that  will  not  discolor  the  rubber  ;  vacuum 
cavities  made  of  sheet  lead  are  objectionable  on  that  account. 

In  depth  the  cavity  must  vary  with  the  softness  of  the  membrane. 
If  soft  it  quickly  fills  a  shallow  cavity  and  is  less  liable  to  injury 
by  a  deep  one.  Sharp-edged  cavities  fill  less  quickly  than  round-edged 
ones.  They  may  vary  in  thickness  from  No.  14  to  No.  24  gauge  plate, 
page  826.  When  the  cavity  is  designed,  after  a  temporary  retaining 
power,  to  act  permanently  in  relieving  the  pressure  on  central  hard 
parts,  it  should  be  very  shallow.  When,  in  very  flat  mouths,  it  is 
proposed  to  prevent  lateral  motion  by  the  mucous  prominence  the 
cavity  should  be  deeper.  Extreme  depth,  with  a  view  to  keep  up 
constant  action,  makes  a  most  unsightly  piece  and  injures  the  mouth. 

When  the  center  of  the  palate  is  very  hard  and  unyielding,  as  is 


Fig    1085. 


generally  the  case,  and  not  subject  to  change  of  form  by  pressure, 
while  the  alveolar  ridge  and  some  other  parts  are  subject  to  absorption, 
if  the  i)alate  is  permitted  to  rest  on  the  hard  central  portion,  the 
result  will  be  its  rocking.  This  may  be  prevented  and  good  adhesion 
secured  by  covering  the  entire  hard  palate  on  the  plaster  model  from 
near  the  anterior  margin  to  within  one-fourth  of  an  inch  (or  in  some 
cases  even  less)  of  the  posterior  margin  of  the  plate,  when  to  be  of 
metal,  with  a  thin  film  of  wax  (about  one-half  the  thickness  of  a  wax 
base  sheet),  with  the  edge  all  round  reduced  even  with  the  surface  of 
the  model.  In  vulcanite  plates  or  sets  adhesion  can  be  secured  on  the 
same  principle,  by  removing,  with  a  large  cone  bur  in  the  lathe,  the 
same  amount  from  the  palatal  surface  of  the  plate. 

As  to  position  there  would  seem  to  be  much  difference  of  opinion, 
if  we  judge  by  the  various  points  selected.  We  have  never  had  but 
one  opinion  on  this  subject,  and  that  is  in  favor  of  the  central  cavity. 
The  cavity  resists  the  greatest  force  of  displacement  when  applied  at 
right  angles;  as  this  force  is  always  nearlv  or  quite  vertical,  it  follows 


RETENTION    OF    BASE    PLATES. 


973 


that  the  most  effective  cavities  are  horizontal ;  hence  they  should  only 
be  on  the  roof  of  the  palate  and  limited  to  its  level  portion.  Cavities 
covering  the  rugae  or  sloping  walls  of  the  palate  act  at  disadvantage. 
A-gain,  after  the  cavity  ceases  to  act  its  secondary  use  in  relieving 
pressure  can  be  available  only  in  this  position.  The  very  worst  posi- 
tion for  a  cavity  is  on  the  ridge  of  either  upper  or  lower  jaw.  Firm 
pressure  on  the  ridge  is  one  of  the  most  important  elements  of  stability 
in  a  plate.  If  is  difficult  to  comprehend  what  compensation  for  the 
loss  of  this  is  found  in  the  cavity. 

Partial  plates  require,  when  the  cavity  is  used,  a  modification  of 
form  to  enable  the  cavity  to  be  placed  on  the  roof  of  the  palate.  Yet 
the  shapes  elsewhere  given  may  be  used  in  connection  with  Flagg's 
lateral  cavities  as  represented  by  the  oval  in  Fig.  1086.  If  no  stays 
can  be  used,  as  in  a  piece  of  artificial  bicuspids  and  molars  with  natu- 
ral incisors  and  canines,  a  central  or  two  lateral  sharp-edged  cavities 
may  be  of  service  to  prevent  lateral  motion.  In  all  other  partial  cases 
stays  may  be  used ;  these,  combined  with  accurate  fitting,  will  give  as 


Fig.  1086. 


Fig.  1087. 


firm  a  piece  as  any  form  of  cavity.  The  vacuum  cavity  may  also  be 
formed  in  the  impression  by  adapting  a  form  of  wax  to  the  roof  of  the 
mouth  in  the  proper  position  before  inserting  the  tray. 

Dr.  C.  H.  Land  has  recently  suggested  a  vacuum  cavity  pattern 
(Fig.  1087),  which  is  claimed  to  be  of  such  a  form  as  to  secure  the 
greatest  advantage  from  atmospheric  pressure  without  injury  to  the 
mouth ;  also  to  serve  as  a  relief  to  the  hard  portions  of  the  arch  by 
being  of  sufficient  depth  to  allow  for  continued  absorption  of  the 
alveolar  ridge  in  the  case  of  first  sets;  it  is  also  claimed  that  its  shape 
avoids  interference  with  the  organs  of  speech. 

Dr.  Joseph  Spyer  has  devised  an  automatic  suction  cavity  which,  he 
claims,  permits  of  the  construction  of  a  narrow  plate  with  perfect 
adhesion. 

Fig.  1088  is  a  view  of  Spyer's  Suction  Cavity  as  it  comes  ready  for 
use.  Fig.  1090  shows  the  Automatic  Suction  Cavity  secured  in 
position  on  the  plaster  model.     Fig.  1089  gives  a  view  of  the  palatal 


974 


MECHANICS DENTAL    PROSTHESIS. 


surface  of  a  finished  plate,  with  metal  form  removed.  While  the 
Automatic  Suction  Cavity  comes  already  shaped  for  the  model,  it  is 
necessary  to  trim  it  down  with  curved  scissors  to  meet  the  require- 
ments of  each  particular  case,  always  leaving  a  slight  space  between 
the  slots  or  openings,  A  A,  Fig.  1090,  and  the  outer  margin  of  the 
metal  form.  The  Suction  Cavity  is  then  secured  by  means  of  pins, 
or  by  varnish  or  mucilage  or  any  sticky  substance,  to  the  plaster  model 
on  the  palatal  surface  inside  of  the  alveolar  ridge,  leaving  the  alveolar 
ridge  uncovered.  A  sharp  instrument  is  then  passed  through  the  slots, 
A  A,  Fig.  1090,  in  the  manner  indicated  in  Fig.  1090,  and  carried 
their  entire  length,  forming  parallel  grooves  in  the  plaster  model. 
Then  the  metal  form  is  covered  by  the  wax  base  plate,  which  should  be 
the  size  of  the  finished  plate,  and  in  most  cases  approximating  to  the 
form  of  finished  plate,  shown  in  Fig.  1089.  Upon  the  base  plate  the 
teeth  are  set  up  as  usual,  and  the  case  flasked,  packed,  and  vulcanized 
in  the  usual  way.  After  vulcanizing,  the  metal  form  (the  "  Automatic 
Suction   Cavity")  is  removed.     If  the    parallel  ridges  are  too   high 


Fig.  1088. 


Fig.  I 


Fig.  1090. 


after  the  plate  is  vulcanized,  file  them  down  to  the  desired  height. 
The  finished  plate  will  have  along  the  edge  of  its  palatal  surface 
two  parallel  ridges,  as  shown  in  Fig.  1089,  besides  the  form  of  the 
suction,  which  provides  strong  adhesion  from  end  to  end  of  the 
plate. 

Dr.  Joseph  Spyer  has  also  devised  for  plastic  work  a  thin  metallic 
form,  the  surface  of  which  is  covered  with  minute  papilliform  promi- 
nences— shown  in  Fig.  1092  magnified  four  diameters — which  by  dis- 
placement of  mucus  at  the  points  of  gum  contact  effect  surface  cohe- 
sion as  if  the  denture  were  glued  to  the  gums,  yet  cause  no  irritation 
and  leave  no  marked  indentations.  Adapted  for  either  upper  or  lower 
plates.  By  the  aid  of  this  device  it  is  claimed  that  strong  cohesion 
can  be  had  with  a  narrow  plate,  and  thus  the  sense  of  taste  be  left 
unimpaired,  and  that  lower  plates  so  made  are  very  firm.  They  are 
put  up  in  packages  containing  one  dozen  forms  size  of  Fig.  1091, 
which  can  be  cut  for  either  upper  or  lower  plates.  These  forms  are 
also  made  of  gold  with  a  thin  covering  of  pure  silver;  the  sulphur  in 


RETENTION    OF    BASE    PLATES. 


975 


the  rubber,  when  set  free  by  the  action  of  vulcanizing,  sulphurizes  the 
surface,  and  to  this  the  rubber  adheres. 

Fig.  1093  represents  Dr.  Wiinsche's  metal  adhesion  form,  which 
consists  of  a  strong  white  metal  plate,  the  material  being  hard  enough 
to  prevent  the  flattening  of  the  convexities  under  any  necessary 
pressure. 


Fig.  1091. 

Silver  Plate  and  Solder. — The  processes  heretofore  described 
and  the  rules  laid  down  have  been  considered  mainly  in  their  relation 
to  artificial  teeth  mounted  upon  gold  plate  by  the  operation  of 
soldering.  But  other  metals  may  be  swaged  by  the  same  processes,  as 
platinum,  aluminium,  and  silver. 

Silver  is  the  least  valuable  of  these,  and  has  nothing  to  recommend 


Fig.  1092. 


Fig.  1093. 


it  except  its  cheapness,  in  which  questionable  merit  it  has  aluminium 
and  vulcanite  as  its  competitors,  and  hence  it  is  now  not  very  much 
used.  It  is  manipulated  in  all  respects  like  gold,  except  in  the  opera- 
tions of  refining  by  acids,  the  composition  of  solders  used,  and  the 
care  necessary  in  soldering,  from  the  fusibility  of  the  plate. 

For  plates  inne  silver  alloyed  with  platinum  possesses    advantages 


976  MECHANICS DENTAL    PROSTHESIS. 

over  coin  silver,  which  oxidizes  greatly  in  the  mouth.     The  formula 
for  such  a  plate  is — 

Pure  silver, *.i  ounce. 

Platinum, I  pennyweight. 

Some  prefer  gold  clasps  for  silver  plates. 
A  good  silver  solder  is  composed  of — 

Pure  silver, 6  parts. 

Pure  copper, 3  parts. 

Pure  zinc, 2  parts. 

In  the  preparation  of  such  a  solder  the  silver  and  copper  should  be 
melted  together  and  then  the  zinc  added,  pouring  the  molten  mass 
into  the  ingot-mold  before  the  zinc  volatilizes. 

Fine  silver  alloyed  with  one-third  its  weight  of  brass  also  gives  a 
good  silver  solder,  as  the  zinc  in  the  brass  reduces  the  fusing  point  of 
the  alloy  and  makes  it  easy-flowing.  If  ^  to  i  grain  of  zinc  is  added 
to  the  above  formula,  the  fusing  point  is  still  further  reduced.  After 
pouring  the  alloy  into  the  form  of  an  ingot,  it  should  be  rolled  to  No. 
26  or  27,  annealed,  and  its  surface  cleansed  by  placing  it  in  the  acid- 
bath. 

Aluminium  can  be  rolled  into  plate  and  swaged.  It  requires  ex- 
treme care  in  annealing,  but  makes  a  rigid,  strong,  and  very  light 
plate.  It  does  not  withstand  the  buccal  secretions  as  well  as  twenty- 
carat  gold,  nor  is  it  as  good  as  eighteen-carat  gold.  The  obstacle  to 
its  general  use  also  lies  in  the  fact  that  as  yet  there  is  no  good  solder 
for  it.  Hence  it  is  necessary  to  attach  the  teeth  by  vulcanite.  This 
can  be  very  successfully  done,  as  vulcanized  rubber  adheres  more  closely 
to  this  metal  than  to  any  other,  excepting,  perhaps,  pure  gold  or  pure 
platinum.  The  process  will  be  described  in  the  section  on  Vulcanite  ; 
it  is  equally  applicable  to  twenty-carat  gold  and  to  platinum,  but  not 
at  all  to  silver.  An  alloy  of  aluminium  which  is  cast  directly  upon 
the  teeth  is  referred  to  under  Metallo-plastic  Work. 

Platinum,  if  alloyed  with  five  to  ten  per  cent,  of  gold,  has  stiffness 
sufficient  to  be  used  as  a  base  plate,  in  the  manner  previously  given 
t'or  gold.  As  it  has  no  advantage  over  gold  when  used  in  this  way  its 
less  cost  is  not  a  sufficient  offset  to  the  inconveniences  attending  its  use 
and  to  the  color,  which  is  so  objectionable  to  most  persons  that  they 
are  unwilling  to  pay  as  much  as  for  the  same  work  in  gold.  Platinum 
has,  however,  one  remarkable  property  possessed  by  no  other  metal 
used  by  dentists  except  palladium,  which  is  now  scarcely  at  all,  if  ever, 
used  ;  it  cannot  be  fused  in  the  highest  heat  of  the  forge  or  porce- 
lain-baking furnace.     Hence  it  is  the  only  metal  used  for  the  metallic 


CONTINUOUS-GUM   WORK.  977 

pins  and  other  fastenings  inserted  into  porcelain  teeth,  requiring  for 
its  fusion  the  flame  of  the  oxyhydrogen  blowpipe.  It  is  also  the  only 
metal  used  in  a  remarkably  beautiful  style  of  work  known  as  the  Con- 
tinuous-Gum Work,  which  forms  the  subject  of  the  next  section. 

CONTINUOUS-GUM   WORK. 

The  idea  of  uniting  porcelain  teeth  to  a  metallic  base  by  means  of  a 
fusible  silicious  composition  originated  in  France,  where  the  method 
has  to  some  extent  been  practiced  since  1820.  But  Dr.  Fitch,  who 
spent  much  time  in  Paris  and  was  well  acquainted  with  the  French 
method  and  Delabarre's  formulae,  stated  that  the  latter  never  perfected 
his  recipes  or  brought  them  into  practical  use.  The  composition  em- 
ployed there,  judging  specimens,  cannot  be  used  in  connection  with 
porcelain  teeth  containing  as  large  a  proportion  of  feldspar  as  those 
manufactured  in  this  country.  Delabarre's  compound,  according  to 
Dr.  Locke,  required  3761°  Fahrenheit  to  fuse  it  completely.  Below 
this  it  fused  imperfectly  and  was  found  too  fragile. 

The  process  now  known  as  the  Continuous  Gum  consists  essentially 
of  a  silicious  paste,  similar  (except  more  fusible)  in  composition  to 
that  of  which  the  teeth  are  made,  which  is  applied  around  the  bases 
and  fastenings  of  teeth  previously  soldered  upon  a  plate  of  purest 
platina,  and  then  fused  at  a  temperature  of  about  2200°  Fahrenheit. 
It  takes  its  name  from  the  fact  that,  unlike  blocks  or  single  gum  teeth, 
it  presents  an  unbroken  continuous  gum 
outside  the  alveolar  ridge,  as  is  shown  in 
Fig.  1094.  It  is  applied  in  two  layers — 
a  yellowish-white  body,  giving  the  gen- 
eral contour  of  the  gum,  and  an  enamel, 
to  produce  that  correct  imitation  of  the 
natural  gum  for  which  nothing  but  cera- 
mic materials  have  as  yet  been  found  fig.  1094. 
suitable.      Dr.   Allen    covered    with    the 

same  material  the  entire  lingual  surface  of  the  plate,  and  also  certain 
projections  outside  of  the  molars  and  above  the  cuspids,  designed  by 
him  for  the  restoration  of  the  natural  fullness  of  the  face. 

This  falling  in  of  the  features  is  due  to  the  absorption  of  the  alveo- 
lar ridge,  and  cannot  be  fully  restored  by  an  artificial  set  of  teeth  as 
usually  made;  since  if  the  molars  were  set  out  to  the  original  width 
of  the  teeth  the  force  of  mastication  would  fall  outside  the  absorl)ed 
alveolus  and  render  it  practically  useless.  Dr.  Allen's  device  corrects 
this  sinking  under  the  malar  prominence  of  the  superior  maxilla  and 
in  the  canine  fossa,  and  thus  greatly  aids  in  the  restoration  of  the  face 
to  its  original  appearance. 
62 


978  MECHANICS — DENTAL   PROSTHESIS. 

This  process  was  patented  by  Dr.  John  Allen  in  1S51  ;  but  the 
priority  of  invention  was  contested  by  Dr.  William  H.  Hunter  in  a 
suit,  the  progress  and  result  of  which  were  published  in  the  dental 
periodicals  of  that  period.  Dr.  Allen  surrendered  his  patents  of  1851, 
owing  to  certain  defects  in  the  same,  and  in  1856  a  new  patent  was 
issued  to  him  for  the  process  as  then  improved.  The  process  is  very 
generally  known  as  "  Allen's  Continuous  Gum."  The  formulae  given 
in  this  chapter  are  those  of  Dr.  Hunter,  and  the  earlier  ones  of  Dr. 
Allen.  As  all  such  materials  are  more  perfectly  prepared  on  a  large 
scale,  we  think  it  much  better  to  purchase  than  to  make  them. 

A  "  continuous  gum"  piece  made  in  the  most  perfect  manner  is 
only  surpassed  in  point  of  beauty  by  the  occasional  productions  of  a 
very  few  block  carvers ;  but  so  rare  are  these  specimens  of  perfection 
in  block  work  that  we  may  safely  say  of  the  continuous-gum  work  that 
when  properly  made  it  is  the  most  beautiful,  as  it  certainly  is  the 
purest  and  sweetest,  that  can  be  worn  in  the  mouth,  so  long  as  the 
porcelain  covering  maintains  its  integrity.  It  was  thought  when  this 
method  of  mounting  artificial  teeth  was  first  adopted  that  the  spring- 
ing of  the  plate  in  the  act  of  mastication  would  cause  the  gum  to 
crack  and  scale  off,  which  did  occur  in  a  large  proportion  of  the  cases. 
Although  the  injury  could  be  repaired  by  replacing  the  loss  with  fresh 
composition  and  fusing  it  to  the  fractured  edges  of  the  remaining  por- 
tions and  to  the  plate,  yet  this  at  one  time  formed  a  very  serious  ob- 
jection to  its  use.  But  later  improvements  in  the  strength  of  the 
compound  and  also  in  the  rigidity  of  the  plate  and  soldered  backings, 
or  long  pins,  have  so  far  corrected  this  evil  that  it  is  perhaps  no  more 
liable  to  accident  while  in  the  mouth  than  any  other  kind  of  work. 
But  out  of  the  mouth  its  weight  renders  it  peculiarly  exposed  to  acci- 
dent; a  fall  is  almost  certain  to  break  one  or  more  teeth  or  crack  the 
silicious  covering  of  the  plate.  Hence  it  is  necessary  to  impress  upon 
the  patient  the  great  importance  of  the  most  careful  handling. 

By  uniting  the  teeth  to  each  other  near  their  base  and  to  the  plate 
with  a  glazed  porcelanic  material,  the  cleanliness  of  the  substitute  is 
most  perfectly  secured  ;  as  all  the  openings  beneath  and  around  them 
are  completely  closed,  excluding  the  secretions  of  the  mouth  and 
particles  of  food,  which  have  no  affinity  for  or  action  upon  the  porce- 
lain. In  this  respect  they  are  superior  to  the  most  perfectly  mounted 
block-teeth,  while  the  labor  of  putting  u})  a  set  of  the  former  can  be 
performed  in  half  the  time  required  for  making  and  mounting  a  set 
of  the  latter.  A  person  who  can  mount  single  teeth  well  may  acquire 
a  knowledge  of  this  method  with  proper  instruction  in  a  few  weeks  ; 
although  much  of  the  peculiar  talent  required  in  block-carving  is 
needed  in  arranging  the  teeth  and  shaping  the  gum  for  this  process, 


CONTINUOUS-GUM   WORK.  979 

the  details  are  comparatively  simple  and  may  soon  be  taught.  Of 
course,  much  practice  will  be  required,  especially  in  the  management 
of  the  furnace  heats.  The  necessity  for  such  practice,  to  enable  one 
successfully  to  manage  the  furnace,  is  the  chief  obstacle  to  its  casual 
use  by  the  practitioner.  Unless  he  makes  it  a  specialty,  and  does  all 
his  own  work  and  some  for  his  neighbors,  he  will  be  certain  to  meet 
with  many  discouraging  failures  in  the  final  process  of  baking  an  other- 
wise perfectly  constructed  piece. 

We  therefore  advise  the  dentist  to  swage  the  platina  plate,  select 
and  arrange  and  articulate  the  teeth  ;  for  no  one  should  be  so  com- 
petent to  do  this  as  the  one  whose  intercourse  with  the  patient  enables 
him  to  judge  exactly  what  form,  color,  and  arrangement  of  teeth  are 
best  suited  to  the  case  ;  and  only  he  can  decide  upon  the  correctness 
of  the  fit  of  the  plate.  But  when  all  this  is  done  the  piece  should  be 
securely  packed  and  sent  by  express  or  mail  to  some  experienced 
w^orker  in  the  continuous-gum.  The  piece  w^ill  be  returned  with  the 
plate  unchanged  in  shape,  and  the  porcelain  work  executed  in  such 
style  as  can  be  reached  only  by  constant  practice  and  familiarity  with 
the  special  details  of  this  work. 

The  artificial  gum  consists,  as  we  have  stated,  of  two  parts ;  the 
first  is  termed  the  base  or  body,  as  this  constitutes  the  principal  part  of 
the  cement,  and  is  used  for  filling  in  between  the  teeth  and  building 
up  the  gum  on  the  plate ;  the  other  is  gum  enamel.  The  materials 
employed  by  Dr.  Hunter  in  the  composition  of  his  compounds  are 
silex,  fused  spar,  calcined  borax,  caustic  potash,  and  asbestos.  The 
silex  and  spar  should  be  of  the  clearest  and  best  quality,  and  ground 
very  fine.  The  asbestos  should  be  freed  from  talc  and  other  foreign 
substances  and  reduced  to  a  fine  powder.  He  gives  the  following 
formulae  and  directions  :  — 

Flux. — Take  of  silex,  8  oz.  ;  calcined  borax,  4  oz.;  caustic  potash, 
I  oz.  The  potash  is  first  ground  fine  in  a  wedgewood  mortar,  and 
the  other  materials  gradually  added  until  they  are  thoroughly  mixed. 
Line  a  Hessian  crucible  (as  white  as  can  be  had)  with  pure  kaolin, 
fill  with  the  mass,  and  lute  on  a  cover  of  a  piece  of  fire-clay  slab  with 
the  same.  Expose  to  a  clear,  strong  fire  in  a  furnace  with  coke  fuel 
for  about  half  an  hour,  or  until  it  is  fused  into  a  transparent  glass, 
which  should  be  clear  and  free  from  stain  of  any  kind.  This  is  broken 
and  ground  until  it  will  pass  a  bolting  sieve. 

Granulated  Body. — Spar,  3  oz. ;  silex,  \\  oz. ;  kaolin,  \  oz. ;  com- 
pletely fused.  Break  and  grind  so  that  it  will  pass  through  a  wire  sieve  No. 
50,  and  again  shift  off  the  fine  particles,  which  pass  through  No.  10  bolt- 
ing cloth,  which  leaves  it  in  grains  about  the  size  of  the  finest  gunpow- 
der.    It  may  be  made  of  hard  porcelain,  fine  china,  or  Wedgwood  ware. 


980  MECHANICS — DENTAL   PROSTHESIS. 

Body. — Take  flux,  i  oz.  ;  asbestos,  i  oz.  ;  grinding  together  very 
finely,  completely  intermixing.  Add  granulated  body,  i^  oz.  ;  and 
mix  with  a  spatula,  to  prevent  grinding  the  granules  of  body  any  finer. 

Enamels. — No.  i.  Flux,  i  oz.  ;  fiased  spar,  i  oz.  ;  English  rose  red, 
40  grains.  Grind  English  rose  red  extremely  fine  in  a  mortar,  and 
gradually  add  the  flux  and  then  the  fused  spar,  grinding  until  the 
ingredients  are  thoroughly  incorporated.  Cut  down  a  large  Hessian 
crucible,  so  that  it  will  slide  into  the  muffle  of  a  furnace,  line  with  a 
mixture  of  equal  parts  silex  and  kaolin,  put  in  the  material,  and  raise 
the  heat  to  the  point  of  vit)'ification,  not  fusion,  then  withdraw  from 
the  muffle.  The  result  will  be  a  red  cake  of  enamel  which  will  easily 
leave  the  crucible,  which,  after  removing  any  adhering  kaolin,  is  to  be 
broken  down  and  ground  tolerably  fine.  It  may  now  be  tested,  and 
if  of  too  strong  a  color  tempered  by  the  addition  of  covering.  This 
is  the  gum  which  flows  at  the  lowest  heat,  and  is  never  used  before 
soldering. 

No.  2.  Flux,  I  oz.  ;  fused  spar,  2  oz.  ;  English  rose  red,  60  grains. 
Treat  the  same  as  No.  i.  This  is  a  gum  intermediate  and  is  used 
upon  platina  plates. 

No.  3.  Flux,  I  oz.  ;  fused  spar,  3  oz.  ;  English  rose  red,  80  grains. 
Treat  as  the  above.  This  gum  is  used  in  making  pieces  intended 
to  be  soldered  on,  either  in  full  arches  or  in  the  sections  known  as 
block  work.  It  is  not  necessary  to  grind  very  fine  in  preparing  the 
above  formulae. 

Covering. — What  is  termed  covering  is  made  by  the  same  for- 
mulas as  for  the  enamel,  omitting  the  English  rose  red.  Being  with- 
out any  coloring  whatever,  it  is  used  for  tempering  the  above  enamels 
when  too  highly  colored,  which  may  be  done  by  adding,  according  to 
circumstances,  from  one  to  six  parts  of  covering  to  two  of  enamel,  thus 
procuring  the  desired  shade.  When  it  is  to  be  used  for  covering  the 
base  prior  to  applying  the  enamel  it  may  be  covered  with  titanium, 
using  from  two  to  five  grains  to  the  ounce. 

Investment. — Take  two  measures  of  Avhite  quartz  sand,  mix  with 
one  measure  of  plaster-of-Paris,  using  just  enough  water  to  make  the 
mass  plastic,  and  apply  quickly.  The  slab  on  which  the  piece  is  set 
should  be  saturated  with  water  to  keep  the  material  from  setting  too 
.soon,  and  that  it  may  unite  with  it. 

Memoranda. — In  preparing  material  always  grind  dry  and  use  the 
most  scrupulous  cleanliness  in  all  the  manipulations.  In  all  cases 
where  heat  is  applied,  it  should  be  raised  gradually  from  the  bottom 
of  the  muffle,  and  never  run  into  a  heat.  Where  it  is  desired  to 
lengthen  any  of  the  teeth,  or  to  mend  a  broken  tooth,  it  may  be  done 
with  covering,  properly  covered  with  platina,  cobalt,  or  titanium. 


CONTINUOUS-GUM   WORK.  981 

In  repairing  a  piece  of  work  wash  it  with  great  care,  using  a  stiff 
brush  and  pulverized  pumice  stone.  Bake  over  a  slow  fire  to  expel  all 
moisture  and  wash  again,  when  it  will  be  ready  for  any  new  application 
of  the  enamel.  Absorption  occurring  after  a  case  has  been  some  time 
worn,  by  allowing  the  jaws  to  close  nearer  causes  the  lower  jaw  to 
come  forward  and  drive  the  upper  set  out  of  the  mouth.  By  putting 
the  covering  on  the  grinding  surfaces  of  the  back  teeth  in  sufficient 
quantity  to  make  up  the  desired  length,  this  difficulty  may  be  to  some 
extent  remedied. 

Any  alloy  containing  copper  or  silver  should  not  be  used  for  solder 
or  plate,  if  it  is  intended  to  fuse  a  gum  over  the  lingual  side  of  the 
teeth,  as  it  will  surely  stain  the  gum.  Simple  platinum  backs  alone  do 
not  possess  the  requisite  stiffness,  and  should  always  be  covered — on 
platinum  with  the  enamel,  and  on  gold  with  another  gold  back.  In 
backing  the  teeth  lap  the  backs  or  neatly  join  them  up  as  far  as  the 
lower  pin  in  the  tooth,  and  higher  if  admissible,  and  in  soldering  be 
sure  to  have  the  joint  so  made  perfectly  soldered. 

The  compositions  originally  employed  by  Dr.  Allen  consist  of — 
Body:  Silex,  2  oz.  ;  flint  glass,  i  oz.  ;  borax,  i  oz.  ;  wedgewood 
ware,  i^  oz.  ;  asbestos,  2  drams;  feldspar,  2  drams;  kaolin,  i  dram. 
Enamel:  Feldspar,  ^  oz.  ;  white  glass,  i  oz. ;  oxid  of  gold,  ij^ 
grains.  Since  the  publication  of  the  early  editions  of  this  work  great 
improvements  have  been  made  in  the  composition  and  preparation  of 
both  the  body  and  gum  enamel,  which  are  furnished  by  the  manufac- 
turers, and  may  be  obtained  at  any  of  the  dental  depots  at  a  very 
moderate  price. 

The  metals  which  may  be  employed  for  the  base  in  this  method  of 
mounting  artificial  teeth  are  platinum  or  pure  palladium.  The  common 
commercial  article  of  palladium  is  not  pure,  and  is  never  used  in  this 
country.  Platinum,  alloyed  with  from  i  to  10  per  cent,  of  pure  gold, 
may  also  be  used  ;  but  it  is  objectionable  from  its  liability  to  spring  or 
warp.  It  makes  a  stiffer  plate,  and  so  far  has  the  advantage  over  pure 
platinum,  but  for  the  reason  given  the  purest  metal  should  be  selected. 
Because  of  its  softness  it  must  be  used  thicker  than  gold  plate.  The 
process  of  swaging  the  plate  is  the  same  as  before  given.  It  must  be 
often  annealed  and  gradually  carried  into  any  deep  depressions,  for 
its  softness  makes  it  more  liable  than  gold  to  be  torn,  made  thin,  or 
punched  through.  A  narrow  rim,  partially  turned  up,  is  to  be  left 
around  the  outside.  The  process  of  articulating,  etc.,  is  similar  to 
that  for  gold.  In  adjusting  the  teeth  accurate  grinding  is  unnecessary  ; 
but  each  tooth  should  touch  the  plate.  Part  of  each  backing,  where 
the  teeth  are  lined,  should  lap  over  the  adjoining  ones,  and  behind  the 
six  front  teeth  should  also  be  lapped  over  an  additional  narrow  band, 


982 


MECHANICS — DENTAL    PROSTHESIS. 


to  give  greater  rigidity  to  the  plate.  Continuous  gum  teeth  with  long 
pins  are  now  used,  the  ends  of  the  pins  being  bent  down  to  the  plate, 
to  which  they  are  soldered  with  pure  gold ;  hence  backing  the  teeth  is 
not  necessary.  In  this  process  there  is  great  opportunity  to  give  to 
the  teeth  that  irregularity  of  arrangement  which  forms  one  of  the 
characteristics  of  natural  teeth,  neglect  of  which  gives  to  many  other- 
wise excellent  pieces  of  work  an  unnatural,  artificial  appearance,  that 
shows  great  deficiency  in  the  cultivation  of  dental  esthetics. 

Before  applying  the  body  the  piece  may  be  tried  in  the  mouth  and 
any  inaccura«.y  of  articulation  readily  corrected ;  careful  articulation 
makes  this  trial  unnecessary ;  but  if  from  any  causes  changes  are  found 

on  trial  to  be  needed,  they  can 
be  made  more  readily  in  this 
work  before  the  gum  is  added 
than  in  any  other;  since  no 
joints  or  neat  fitting  to  the  plate 
are  disturbed  by  changes  in  the 
position  of  a  tooth.  After  this 
the  piece  s?iould  be  set  in  a  mix- 
ture of  plaster  and  asbestos  or 
plaster  and  sand,  resting  on  a 
muffle  slide  and  coming  up 
around  the  outside  of  the  teeth 
to  keep  them  in  place.  The 
solder  used  must  contain  no 
trace  of  either  silver  or  copper, 
as  such  metals  will  stain  the  gum 
enamel  and  body,  but  must  be 
either  pure  gold  or  alloyed  with 
about  5  per  cent,  platina.  Borax 
may  be  used,  not  in  this  case  as 
a  flux — for  where  there  is  no 
oxidation  no  flux  is  required — but  to  hold  the  pieces  of  solder  in  place 
until  ready  to  flow.  The  slide  is  then  gradually  carried  in  to  the 
muffle,  and  the  whole  piece  raised  to  the  melting  point  of  the  solder. 
Figs.  1095,  1096,  and  1097  represent  three  of  the  most  approved 
forms  of  furnaces. 

The  Combination  Gas  and  Gasoline  Furnace  of  Dr.  Land  is  repre- 
sented by  Fig.  1096,  in  which  is  shown  this  furnace  thrown  open, 
being  swung  on  hinges  at  the  back,  exposing  the  muffle  E.  The 
groove  P  P  is  packed  with  asbestos  fibre,  so  that  when  the  sections 
are  brought  together  the  furnace  will  be  perfectly  air  and  gas  tight. 
It  is  claimed  that  with  gasoline  gas  porcelain  teeth  can  be  enameled 


Fig.  1095. 


CONTINUOUS-GUM   WORK. 


983 


in  from  ten  to  fifteen  minutes,  with  ordinary  illuminating  gas  in  from 
fifteen  to  twenty  minutes,  according  to  quality. 

Fig.  1097  represents  Dovvnie's  Continuous  Gum  Furnace,  in  which 
it  is  claimed  that  a  full  case  can  be  baked  in  from  fifteen  to  twenty- 
five  minutes. 

The  tempering  ovens  are  on  each  side  of  the  opening  into  the  mufile. 


Fig.  1096. 


and  the  hearth  is  provided  with  two  sides,  so  the  case  can  be  brought 
out  on  to  the  hearth  and  put  into  the  tempering  oven  by  simply 
shoving  the  slide  to  one  side  by  the  small  porcelain  knob  seen  at  the 
bottom  of  the  hearth. 

The  rules  for  the  management  of  the  heat  are  the  same  as  hereafter 
given  for  block  work.     The  heat  required  for  this  is  not,  however,  so 


984 


MECHANICS  —  DENTAL    PROSTHESIS. 


great  as  that  required  in  block  work ;  the  gold  and  the  continuous- 
gum  materials  fusing  at  about  2200°  Fahrenheit. 

Having  thus  soldered  and  cooled  off  the  piece  very  gradually,  it 


Fig.  1097, 


must  be  thoroughly  washed,  so  as  to  remove  every  particle  of  invest* 
ment.  Then,  with  a  camel's-hair  brush  and  small  knife,  such  as  ^re 
used  in  block  carving,  the  spaces  between  the  teeth  and  nlate  are  to 


CONTINUOUS-GUM   WORK.  985 

be  perfectly  filled  with  a  finely  compacted  paste  of  body  and  rain 
water.  The  paste  must  be  applied  very  moist,  so  as  to  exclude  the  air 
and  run  into  all  the  spaces;  then  dried  with  cloth  or  bibulous  paper 
and  compressed  with  the  knife.  If  the  lingual  surface  of  the  plate  is 
to  be  covered,  this  should  be  made  rough  by  either  etching  the  surface 
or  by  soldering  small  clippings  of  platina  over  it  at  the  time  the  teeth 
are  soldered.  The  natural  rugae  of  the  palate  should  be  imitated  in 
the  thin  layer  of  body  which  is  applied. 

The  work  must  then  be  slowly  and  thoroughly  dried  and  the  piece 
put  on  a  slide  with  the  coronal  ends  of  the  teeth  downward,  and  im- 
bedded to  the  depth  of  an  eighth  of  an  inch  in  a  thick  batter  of  plaster 
and  asbestos.  But  if  the  teeth  are  very  securely  soldered  it  will  be 
best  to  flow  the  body  with  the  plate  resting,  teeth  upward,  on  the 
plaster  and  asbestos  or  sand  model  on  which  the  soldering  was  done. 
The  slide  is  then  gradually  introduced  into  the  muffle  and  subjected 
to  a  heat  sufficiently  high  to  fuse  the  compound — sav  twentv-two 
hundred  and  fifty  degrees.  It  is  then  withdrawn  slowly  and  com- 
pletely cooled.  Usually  there  will  be  cracks  and  flaws  which  need 
filling  with  paste.  The  outside  rim  is  also  to  be  turned  down  over 
the  edge  of  the  body  with  hammer  and  pliers,  and  any  defects  at  this 
point  filled  up;  then  heat  a  second  time  with  the  same  care  as  at  first. 

The  piece,  now  ready  for  enameling,  should  present  a  semi-vitrified 
appearance  ;  if  too  highly  glazed  it  is  too  much  done,  and  the  enamel 
will  not  take  so  firm  a  hold;  if  too  dull  looking  it  is  not  sufficiently 
baked,  and  will  be  deficient  in  strength.  The  enamel  must  be  applied 
moist,  and  is  best  put  on  with  a  brush  ;  much  plastering  with  a  knife 
makes  it  apt  to  fly  off  in  baking,  and  for  the  same  reason  it  must 
be  heated  z'^rj^  gradually.  The  layer  of  enamel  should  be  thin  and 
irregular,  the  yellowish  white  of  the  body  showing  more  or  less 
through  it,  so  as  to  give  the  variations  of  tint  observed  in  the  natural 
gum.  If  a  thick  and  even  layer  is  applied  the  result  will  be  an  unnat- 
ural uniform  color,  which  will  destroy  much  of  the  peculiar  beauty  of 
this  work. 

The  greatest  care  is  necessary  in  applying  the  paste  to  remove  every 
particle  from  the  parts  of  the  teeth  and  plate  which  are  not  to  be 
covered,  as  it  adheres  with  great  tenacity  and  roughness,  and  dis- 
figures these  parts.  Much  experience  is  also  necessary  in  determining 
the  exact  heat  necessary  to  develop  the  full  beauty  and  strength  of 
the  work.  Repeated  heatings,  either  for  the  first  making  or  for 
repairs,  do  not  injure  the  plate  or  teeth,  provided  proper  care  is  taken 
to  heat  and  cool  gradually ;  and  provided,  in  case  of  repair,  the  piece 
is  thoroughly  cleansed  in  strong  soda  to  remove  all  trace  of  the  buccal 
secretions. 


986  MECHANICS DENTAL    PROSTHESIS. 

The  work  is  peculiarly  adapted  to  full  lower  dentures.  The  princi- 
ples of  construction  are  precisely  the  same,  only  the  plate  should  be 
very  heavy,  and  the  extra  band  behind  the  six  or  eight  front  teeth 
very  thick  and  strong.  Many  use  it  for  partial  cases  ;  for  which,  how- 
ever, it  is  not  as  well  suited  as  for  entire  dentures.  The  three  distin- 
guishing advantages  of  the  continuous-gum  work  are  its  ready  adapta- 
bility to  every  variety  in  shape  of  gum  and  arrangement  of  teeth,  its 
extreme  beauty,  and  its  great  cleanliness;  its  three  disadvantages  are 
its  weight,  its  liability  to  be  broken  by  accident,  and  its  comparative 
inapplicability  to  partial  cases. 


CHAPTER  XIV. 
MOLDED  PLATES  OF  PLASTIC  MATERIALS. 

In  the  classification  of  operations  for  the  Replacement  of  Teeth 
given  on  pages  655  and  656,  difference  in  the  order  of  these  operations 
was  made  the  groundwork  of  a  division  of  all  base  plates  into  two 
classes :  Swaged  and  Plastic.  In  describing,  up  to  the  point  of 
completion  of  the  model,  the  operations  common  to  both  classes,  the 
modifying  requirements  of  each  were  duly  considered.  The  special 
order  and  details  of  swaged  work  were  then  taken  up,  with  incidental 
allusions  to  plastic  work,  by  way  of  comparison  or  contrast.  Opera- 
tions, materials,  and  apparatus  peculiar  to  the  latter  will  form  the 
subjects  of  this  and  succeeding  chapters. 

Plastic  work  includes  all  dental  substitutes  in  which  the  base 
plate  is  brought  into  contact  with  the  teeth  and  the  model  of  parts 
to  be  fitted  whilst  in  a  fluid,  softened,  or  plastic  condition,  then 
hardened,  during  continuance  of  this  contact,  either  by  the  application 
or  the  withdrawal  of  heat.  Plasticity,  as  thus  used,  is  the  property  of 
being  molded,  and  has  already  been  spoken  of  as  an  essential  quality 
of  impression  materials.  In  them  it  is  associated  with  other  qualities 
especially  fitting  them  for  this  particular  use  ;  so  in  plastic  work  mere 
plasticity  is  of  no  avail,  if  other  properties  do  not  give  to  the  material 
the  qualities  essential  to  a  base  plate.  It  must  have  strength  and 
durability,  and  must  be  in  harmony  with  the  parts  to  which  it  is 
applied.  This  harmony  implies  that  it  shall  not  act  injuriously  upon 
the  mouth  or  receive  injury  from  it ;  that  it  shall  not,  in  form,  color, 
taste,  or  smell,  be  repulsive  to  patients.  It  ought  not,  if  possible,  to 
be  even  objectionable  ;  but  tastes  are  so  variable  that  this  contingency 


MOLDED    PLATES    OF    PLASTIC    MATERIALS.  987 

cannot  be  a  positive  ground  for  exclusion  of  an  otherwise  valuable 
material. 

As  in  swaged  work  there  are  four  metals  of  which  plates  may  be 
formed — gold,  platinum,  aluminium,  and  silver — in  plastic  work  there 
are  five  varieties  of  plastic  material  of  which  plates  may  be  molded  : 
I,  Porcelain  clay;  2,  tin  and  its  alloys;  3,  sulphurated  gum;  4, 
celluloid  and  modifications;  5,  aluminium  and  its  alloys;  6,  electro- 
metallic.  The  first  two  have  been  longest  in  use;  the  third  and 
fourth  have  become  the  most  important  in  modern  dentistry  ;  the 
fifth  and  latest  has  yet  to  pass  the  ordeal  of  experience.  The  first  is 
molded  by  tools,  not  in  flasks,  as  are  the  other  four  ;  it  also  requires 
intense  heat  to  vitrify  or  harden  it.  The  second  is  made  plastic  by 
fusion,  requiring  a  flask,  hot,  to  prevent  cracking  of  teeth,  and  tight, 
to  prevent  escape  of  metal ;  these  plates  harden  by  cold.  The  third 
3^\di fourth,  less  plastic,  demand  force  in  the  act  of  molding;  they  are 
hardened  by  heat ;  but  the  temperature  to  which  the  teeth  are  sub- 
jected is  less  than  in  the  other  three.  The  fifth  is  made  plastic  by 
fusion  ;  but,  though  more  plastic  than  the  third,  in  its  pure  state  it 
does  not  flow  as  readily  as  the  second  ;  its  extreme  lightness  and 
sluggish  flow  necessitate  peculiar  apparatus  in  molding  ;  but  some  of 
these  disadvantages  have  been  overcome  by  alloying  it  with  other 
metals.  The  sixth  is  a  process  by  which  gold  and  silver  are  deposited 
upon  the  surface  of  the  plaster  model  prepared  for  the  purpose. 

Comparing  them  in  respect  of  certain  other  properties — weight, 
durability,  strength,  and  necessary  thickness  of  plate ;  amount  of 
change  in  shape,  from  contraction  ;  resistance  to  change  by  the  action 
■  of  the  buccal  fluids — vulcanite  and  celluloid  are  lightest ;  aluminium 
being  thinner,  is  very  nearly  as  light ;  porcelain,  though  a  light  sub- 
stance, requires  such  bulk  that  it  is  heavier  than  either  ;  tin  and  its 
alloys  are  heaviest.  Vulcanite  plates,  properly  made,  are  strong,  dur- 
able, and  may  be  as  thin  as  any,  except  aluminium ;  aluminium  plates 
are  thinnest  and  strongest ;  the  durability  of  pure  aluminium  plates  is 
still  an  open  question  ;  tin  alloys  are  variable,  some  being  tough  and 
strong,  others  stiff  and  brittle,  others  soft  and  flexible  ;  they  have 
about  the  same  bulk  as  gum,  and  the  best  are  perhaps  nearly  or  quite 
as  durable.  Porcelain  plates  contract  very  much ;  aluminium  much 
less,  but  still  very  considerably ;  tin  alloys  contract  very  slightly ;  gum 
has  no  contraction.  Porcelain  most  perfectly  resists  the  buccal  secre- 
tions and  substances  taken  into  the  mouth  ;  vulcanite  nearly  or  quite 
as  effectually  ;  tin  alloys  undergo  some  change  ;  aluminium  is  not 
changed  by  sulphur,  as  silver  is,  but  will  probably  be  found,  in  some 
mouths,  to  undergo  slight  change. 

To  give  uniformity  to  nomenclature,  the  four  varieties  of  plastic 


988  MECHANICS DENTAL    PROSTHESIS. 

work  will  be  classed  under  four  heads,  i.  Ceramo-plastic,  or  porce- 
lain. 2.  Metallo-plastic,  including  tin,  cheoplastic  metal,  other  tin 
alloys,  aluminium,  and  gold  alloy.  3.  Vulcano-plastic,  including 
caoutchouc,  gutta-percha,  and  all  vegetable  substances  that  by  com- 
bination with  sulphur,  iodin,  etc.,  have  the  property  of  hardening  by 
heat  under  the  process  known  as  "vulcanizing."  4.  Celluloid  and 
its  modification,  zylonite,  which  are  molded  by  heat. 

CERAMO-PLASTIC  WORK. 

Porcelain  plates  are  remarkable  for  cleanliness,  and  in  the  hands  of 
a  skillful  worker  in  the  ceramic  art  may  have  great  artistic  beauty. 
There  are,  however,  several  considerations  that  must  prevent  their 
extensive  use.  Like  continuous-gum  work,  ceramic  plates  are  best 
adapted  to  full  sets.  They  are  frail,  occasionally  breaking  under  the 
force  of  powerful  mastication  ;  they  will  inevitably  break,  falling  on 
any  very  hard  surface.  It  is  but  just,  however,  to  state  that  the  few 
who  make  porcelain  plates  a  specialty  claim  that  they  are  no  more 
liable  to  accident  than  other  pieces;  that  the  teeth  of  all,  especially 
continuous-gum,  are  as  apt  to  break  as  this  work  ;  and  that  a  broken 
tooth  or  plate  is  more  easily  and  quickly  mended  in  porcelain-plate 
work  than  in  any  other. 

A  second  objection  is  the  great  shrinkage  of  any  strong  porcelain 
substance.  Efforts  to  correct  in  the  material  itself  this  shrinkage 
make  it  proportionately  weak.  Correction  by  enlargement  of  the 
model  is  not  only  troublesome,  but  it  is  uncertain  ;  the  same  is  true 
of  the  correction  by  grinding  with  corundum  wheels,  which  is  very 
tedious  and  cannot  be  exact.  When  base  plates  were  made  of  ivory 
and  fitted  to  the  mouth  by  carving,  this  imperfection  of  porcelain 
plates  was  not  objected  to  because  the  former  fitted  no  better,  if  as 
well ;  but  in  contrast  with  the  exact  adaptation  of  other  forms  of 
plastic  work  and  of  swaged  plates  it  becomes  very  manifest.  There 
are  many  mouths  in  which  a  porcelain  plate  could  not  be  retained  at 
all ;  there  are  others  which  adapt  themselves  so  readily  to  moderate 
inaccuracies  that  such  a  plate  is  worn  with  entire  satisfaction. 

A  third  objection  is  the  necessity  of  constant  practice  to  keep  up 
that  skill  in  ceramic  art  which  is  essential  to  an  artistic  piece,  and  to 
insure  uniformity  of  result  by  proper  control  of  the  furnace.  This 
difficulty,  however,  can  be  met  in  the  same  way  as  in  continuous-gum 
work.  If  the  dentist  will  make  the  model,  select  and  articulate  the 
teeth,  arrange  them  on  a  temporary  plate  with  wax  to  give  the  fullness 
of  gum,  and  a  sample  tooth  to  show  its  color,  then  ])ack  securely  and 
send  to  any  block  carver  or  porcelain  teeth  manufacturer,  he  can  have 
a  porcelain  plate  made  better  and  with  more   certainty  than  only  an 


METALLO-PLASTIC   WORK.  989 

occasional  practice  will  enable  him  to  do  for  himself.  If  it  is  desired 
that  the  teeth  and  plate  shall  be  carved  at  the  same  time,  it  will  be 
sufficient  to  send  correct  model  and  articulation,  with  directions  as  to 
the  style,  color,  etc.,  of  the  teeth.  We  think,  however,  that  it  will 
be  safer  for  the  dentist  to  select  and  arrange  the  teeth,  as  he  can  better 
judge  what  is  appropriate  than  one  who  does  not  see  the  patient. 

For  details  of  construction  the  reader  is  referred  to  other  chapters. 
Impression  and  model  are  made  like  any  other  work ;  articulating  pro- 
cesses are  the  same  as  for  other  forms  of  plastic  work ;  grinding  the 
teeth  is  very  simple,  as  in  continuous-gum  work  ;  enlargement  of  the 
"furnace  model  "  and  manipulation  of  the  porcelain  mixture  will  be 
described  in  the  chapter  on  Porcelain. 


CHAPTER  XV. 
METALLO-PLASTIC   WORK. 

The  use  of  a  fusible  metal  in  the  construction  of  base  plates  is  by 
no  means  new ;  but  many  of  the  metallic  compounds  suggested  or  now 
used  for  this  purpose  are  of  quite  recent  introduction.  Except 
aluminium,  none  of  them  fuse  above  the  melting  point  of  tin,  442°. 
Pure  tin  is  the  oldest  form  of  metallo-plastic  base  plate,  and  was  used 
exclusively  for  the  lower  jaw.  It  is  objectionable  on  account  of  its 
softness ;  even  in  a  heavy  lower  rim  it  is  apt  to  bend,  and  for  an  upper 
plate  it  is  wholly  unsuited.  In  its  resistance  to  chemical  change  in 
the  mouth  it  stands  next  to  gold  and  platinum ;  is  superior  to  silver 
and  probably  to  pure  aluminium  ;  superior  also,  in  this  respect,  to  any 
of  its  own  alloys.  The  process  of  constructing  a  lower  plate  of  pure 
tin  is  the  same  as  for  any  of  the  tin  alloys. 

Tin  may  be  made  harder  and  more  rigid  by  alloying  with  Gold, 
Silver,  Copper,  Antimony,  Zinc,  Lead,  Bismuth,  or  Cadmium.  Cop- 
per and  lead  make  it  unfit  for  the  mouth ;  antimony,  zinc,  and  bis- 
muth make  it  brittle,  unless  used  in  very  moderate  proportion.  Silver 
gives  it  hardness,  also  cadmium,  without  imparting  the  objectionable 
properties  named.  Probably  the  best  of  all  alloys  for  tin  is  cadmium. 
Closely  resembling  tin  in  its  physical  properties,  it  hardens  it  without 
making  it  too  brittle  or  imparting  increased  liability  to  the  action  of 
fluids  of  the  mouth.  The  majority  of  tin  alloys  at  present  recom- 
mended for  base  plates  contain  cadmium,  with  some  zinc,  antimony, 
or  bismuth  ;  they  ought  not  to  contain  copper  or  lead. 


990  MECHANICS^DENTAL    PROSTHESIS. 

Chcoplastic,  Wood' s,  IVes/on's,  and  Watt' s  Metals. — The  Cheoplastic 
Metal  was  patented  by  Dr.  A.  A.  Blandy  in  1856,  together  with 
certain  processes  used  in  the  construction  of  dental  plates.  The 
manipulations  since  so  familiar  in  the  working  of  vulcanite  were  then 
as  unknown  as  vulcanite  itself.  The  peculiar  merits  of  plastic  work 
were  at  once  recognized  by  many  of  the  profession,  and  the  Cheo- 
plastic process  would  have  passed  into  very  general  use,  with  such 
modifications  as  experience  may  have  dictated,  had  it  not  been  for  the 
introduction  of  Hard  Rubber.  After  some  years'  contest  the  profes- 
sion decided  in  favor  of  rubber.  Dr.  Blandy's  departure  from  the 
States  in  1862  and  the  failure  of  the  supply  of  his  metal  led  to  a  total 
disuse  of  the  cheoplastic  metal. 

The  abuses  of  vulcanite  and  the  gross  mismanagement  of  rubber 
patents  during  their  continuance  urged  many  advocates  of  plastic  work 
to  revert  to  various  tin  alloys  which  are,  in  their  principle  of  compo- 
sition and  in  the  essential  character  of  the  processes  employed,  iden- 
tical with  Dr.  Blandy's  patents.  The  name  chosen  by  him  (signifying 
the  making  of  plates  by  pouring  a  metal  made  plastic  by  heat)  is 
equally  applicable  to  all  alloys  of  tin  now  used.  The  alloy  of  the 
cheoplastic  metal  was  silver  with  some  bismuth  and  a  trace  of  antimony. 
The  exact  proportions  are  not  known,  but  may  be  learned  by  refer- 
ence to  the  patents.  The  alloy  imparted  no  taste  whatever  to  the 
mouth  ;  and  its  purity,  so  far  as  its  capability  of  resisting  the  action 
of  the  secretions  of  the  buccal  cavity  is  concerned,  was  said  to  be 
equal  to  eighteen-carat  gold.  Its  color  became  slightly  darker  after 
being  worn  some  weeks,  but  could  be  restored  by  placing  it  in  a  strong 
solution  of  caustic  potash. 

The  cheoplastic  metal  was  the  pioneer  of  the  numerous  alloys  of  tin 
(stannum)  which  are  now  claiming  the  attention  of  the  profession. 
We  have  elsewhere  spoken  of  the  necessity  of  testing  all  such  alloys  in 
the  crucible  of  "practice."  We  shall  mention  those  of  Drs.  B. 
Wood,  H.  Weston,  and  George  Watt, — the  first  because  next  to  the 
cheoplastic  metal  it  has  been  longest  known  to  the  jjrofession,  particu- 
larly those  alloys  adapted  to  the  filling  of  teeth  ;  the  last  because  they 
are  very  strong,  flow  well,  and  retain  their  color  well.  The  formula 
of  Watt's  metal  is  given  as  "tin,  40  dwt.  ;  silver,  8  dwt.  ;  bismuth, 
16  grains." 

Of  the  composition  of  Dr.  Weston's  alloy  we  know  nothing  beyond 
an  assurance  that  it  contains  no  copper,  antimony,  zinc,  or  lead.  It 
may  be  better  than  any  of  its  competitors  closely  resembling  it ;  but, 
in  ignorance  of  the  formulae  of  any  of  them,  we  can  only  say  what, 
perhaps,  if  we  knew  these  formulcg  we  might  still  say — submit  to  the 
test  of  experience  that  which  seems  to  be  the  best.     Dr.  Wood's  alloys 


METALLO  PLASTIC    WORK. 


991 


are  the  result  of  an  elaborate  series  of  very  careful  experiments  made 
some  ten  years  ago.  His  plate  alloys  consist  mainly,  perhaps  alto- 
gether, of  tin  and  cadmium  ;  they  vary  in  fusibility,  hardness,  and  rigid- 
ity, but  are  nearly,  if  not  all,  more  fusible  than  Weston's  metal.  Dr. 
Watt's  metal  is  said  to  withstand  the  chemical  action  within  the  mouth 
as  well,  if  not  better,  than  i8-carat  gold,  and  to  be  strong  and  to  run 
sharp.  Molds  may  be  made  in  almost  any  flask,  but  a  special  flask 
known  as  Watt's  molding  flask  (Fig.  1098)  is  better  adapted  to  the 
use  of  this  metal  than  the  ordinary  flask.  The  following  instructions, 
in  connection  with  what  remain  to  be  given  for  vulcanite,  will  be  a 
sufficient  guide  in  the  construction  of  plates  made  of  Wood's,  Wes- 
ton's, Watt's,  or  any  other  stannic  alloy. 


WZ^06ART-STILLmN.cmj^ 

Fig.   1098. 


Teeth  for  rubber  work  are  best  suited  for  this  with  the  following 
precautions :  First  :  Grind  off  the  thin  upper  edge  of  gum  teeth  or 
sections;  the  anterior  band  is  useful  in  rubber  and  does  no  harm  ;  if 
of  metal  it  is  apt  to  crack  the  block  and  is  unnecessary,  as  teeth  are 
rather  more  firmly  set  in  metal  than  in  rubber ;  hence  no  metal  should 
overlap  the  upper  edge  of  the  gum.  Secondly :  In  jointing  blocks  do 
it  as  squarely  as  possible  \  if  merely  the  edges  of  gums  touch,  the 
slight  contraction  of  the  alloy  may  cause  them  to  scale  or  break.  If, 
however,  from  accident  or  necessity  this  last  kind  of  joint  occurs,  do 
as  in  soldering  blocks  to  gold  plate — place  a  thin  piece  of  paper  in  the 
joint  before  securing  it  to  the  wax  plate.  Before  drying  the  flasks  this 
slight  space  caused  by  the  paper  may  be  closed  with  plaster  and  solub'e 


992  MECHANICS — DENTAL    PROSTHESIS. 

glass,  to  prevent  metai  from  running  in  and  making  a  metallic  seam  on 
the  front  of  the  block.  Thirdly :  Be  careful  to  cover  the  pins  with 
the  wax  which  gives  shape  to  the  metal,  so  that  in  finishing  up  the 
latter  they  will  not  be  exposed. 

The  Weston's  improved  flask  consists  of  two  rims  without  top  or 
bottom,  to  permit  rapid  escape  of  moisture.  It  is  much  larger  than  the 
ordinary  flasks,  so  as  to  allow  room  for  the  gate  and  reservoir  posterior 
to  the  plate.  It  closes  with  two  small  bolts  with  nuts,  and  stands  on 
feet.  It  is  very  important  to  screw  the  flask  up  well  before  pouring, 
that  the  weight  of  fluid  metal  may  not  separate  the  halves  of  the  flask; 
the  slightest  space  will  allow  much  or  all  the  metal  to  flow  out. 

The  plaster  may  be  mixed  with  soapstone  powder,  pumice  powder, 
or  clean  white  sand.  Asbestos  would  prevent  shrinkage,  but  its  fibres 
would  interfere  with  the  free  flowing  of  the  batter.  The  same  care  in 
heating  the  flask  is  necessary  as  before  stated,  remembering  that  plaster 
confined  in  metal  flasks  takes  longer  to  become  dry.  It  is  not  safe  to 
pour  under  less  than  three  hours'  drying  ;  and  this  must  never  be  done 
in  direct  contact  with  flame.  Moisture  is  one  of  the  products  of  com- 
bustion in  all  flame,  and  is  largely  absorbed  by  the  plaster ;  hence 
plaster  over  flame  can  never  be  made  perfectly  dry,  unless  contained 
in  some  box,  say  of  sheet  iron,  excluding  this  vapor. 

Directions  for  heating,  pouring,  cooling  off",  and  finishing  are  as 
follows  : — 

All  necessary  trimming  of  the  plaster  is  done  before  the  wax  is 
removed,  to  prevent  small  pieces  from  falling  in  the  matrix  by  the 
sides  of  the  teeth.  All  of  the  wax  is  now  removed,  as  the  absorp- 
tion of  any  considerable  portions  left  in  the  matrix  has  a  tendency 
to  roughen  the  surface,  and  thus  to  prevent  the  metal  from  running  as 
smoothly  as  it  would  otherwise  do.  After  removing  the  wax  each 
half  of  the  matrix  may  be  held  over  the  flame  of  a  tallow  candle  until 
a  slight  coating  of  lampblack  forms  on  it.  The  two  parts  are  now 
screwed  firmly  together. 

The  flask  may  now  be  placed  in  a  kitchen  range  or  bake  oven  and 
exposed  to  a  bread-baking  heat,  say  from  300°  to  400°  Fahr.,  for  from 
three  to  five  hours,  or  until  every  particle  of  moisture  is  driven  from 
it ;  then  placed  in  an  upright  position  and  the  melted  metal  poured 
quickly  into  the  matrix.  If  there  is  no  ebullition  and  the  metal 
comes  up  into  the  vents  freely,  the  piece  will  come  from  the  matrix  in 
a  perfect  condition.  If  it  bubbles  it  may  be  lightly  tapped  several 
times  on  some  hard  surface.  When  perfectly  cold  the  two  parts  of 
the  matrix  are  separated,  exposing  one  of  the  surfaces  of  the  plate. 

Dr.  A.  Allen  describes  the  method  of  using  Watt's  metal  as  follows:  — 

"The  method  of  constructing  a  case  is  the  same  as  for  any  of  the 


METALLO-PLASTIC   WORK. 


99: 


fusible  alloys,  or  as  follows:  After  securing  the  impression  in  the 
usual  manner,  give  it  a  thin  coat  of  shellac,  then  a  thin  coat  of  sand- 
arac  varnish ;  after  the  varnish  is  dry,  soak  in  water  and  pour  model 

without    oiling    impression,  

using  a  mixture  of  two  parts 
plaster  and  one  part  Spanish 
whiting,  or  a  mixture  of  two 
parts  of  plaster  and  one  of 
finely  ground  asbestos. 

' '  The  plate  may  be  cast 
directly  on  to  the  teeth,  or 
the  base  plate  may  be  cast 
and  the  teeth  attached  in 
the  usual  manner  of  making 
rubber  attachments. 

"Teeth  intended  for  rub- 
ber are  most  suitable  for  this  work.  If  gum  sections  are  used,  grind 
square  joints  and  slip  a  strip  of  writing  paper  into  each  joint  while 
waxing  up,  removing  just  before  flasking. 

"  If  simply  a  base  plate  is  to  be  cast,  a  piece  of  ordinary  base  plate 
wax  is  carefully  molded  over  the  model  and  trimmed  to  the  gum  line 
and  dovetailed  lugs  added  to  secure  the  rubber  (Fig.  1099).  A  rim 
with    an  under-cut   edge   may  also  be  added  if  desired  (Figs,    iioo 


Fig.  1099. 


Fig.  iioo. 


Fig.  iioi. 


and  iioi).     If  for  upper  case  the  base  plate  should  be  of  much  thinner 
wax  (Fig.  IIOO). 

"  If  the  case  is  to  be  cast  directly  on  to  the  teeth,  set  them  up  as  an 

ordinary  case   for  rubber,  using  care  to  make   the  base  plate  smooth 

and  just  as  you  want  the  plate  to  be  when  finished.     This  will  save 

much  time  in  finishing.     Invest  the  case  in  the  half  of  the  flask  having 

63 


994 


MECHANICS  —  DENTAL    PROSTHESIS. 


the  guide  pins,  leaving  only  the  base  plate  or  base  plate  and  teeth 
exposed  (Fig.  iioi). 

"  For  the  investment,  use  plaster  three  parts,  and  pulverized  pumice 
stone  one  part.  After  hardening,  trim  carefully,  and  cut  a  groove 
from  each  heel  to  the  pouring  gates,  dust  the  surface  with  powdered 
soapstone,  then  add  other  half  of  flask,  and  bolt;  place  pledgets  of 
cotton  in  the  pouring  gates  and  fill,  being  careful  to  avoid  air  bubbles. 

"When  the  investment  has  hardened,  warm  slightly,  not  enough  to 
melt  the  wax,  separate  and  carefully  remove  the  wax.     Cut  grooves  at 


Fig.  II02. 


heel  corresponding  with  grooves  in  lower  half,  indicated  by  projec- 
tions made  by  lower  grooves  (Fig.  1102). 

"Place  parts  of  flask  together  and  carefully  dry  in  oven  or  otherwise 
until  moisture  will  not  condense  on  a  cold  mirror  placed  over  the  vents. 
"While  the  flask  is  still  warm,  melt  an  ingot  of  the  metal  in  the 
ladle  without  stirring  or  shaking  it.  Do  not  heat  the  metal  very  hot. 
Simply  watch  the  ingot  until  it  is  entirely  melted  and  pour  in  a  gentle, 
steady  stream,  stopping  the  instant  it  appears  in  the  other  opening. 

Do  not  jar  or  handle  the  flask 
until  it  has  cooled,  and  use  the 
melting  ladle  for  nothing  else. 

"It  is  a  good  plan  to  pack 
molding  sand  around  the  flask, 
or  lute  the  joint  with  moistened 
kaolin  just  before  pouring,  to 
prevent  the  possibility  of  the 
metal  escaping  between  the  two 
parts  of  the  flask. 

"When  nearly  cold  place  the 
flask  in  warm  water  for  a  (ew  minutes  and  remove  the  j)late  from  the 
investment,  cut  off  the  surjilus  metal  with  a  fine  saw  and  finish  in  the 


Fig.  1 103. 


METALLO- PLASTIC    WORK. 


995 


usual  manner.  Fig.  1103  illustrates  a  lower  case  ready  for  mounting 
teeth,  and  shows  the  manner  of  roughening  the  plate  so  the  rubber 
will  attach  itself  more  firmly.     Fig.   1104  illustrates  a  finished  case 


Fig.  1 104. 


and  Fig.  1105  a  finished  case  with  rim.     Figs.  1106  and  1107  finished 
cases  cast  on  to  gum  sections. 


Fig.  1105. 


"To  repair,  cut  away  metal  enough  to  let  the  new  tooth  or  block 
go  in  place,  touch  the  margins  with  chlorid  of  zinc,  invest  as  for  a 


Fig.  no6. 


new  piece,  and  pour.    When  the  break  is  very  slight,  some  mend  with 
a  blowpipe,  using  beeswax  as  a  flux,  with  the  metal  as  a  solder,  or, 


996 


MECHANICS— DENTAL    PROSTHESIS. 


make  an  undercut  in  the  region  of  the  pins,  fill  with  rubber,  warm  the 
tooth  or  block,  press  to  place,  and  vulcanize.  It  may  also  be  repaired 
with  a  small  soldering  iron,  using  wax  for  a  flux  and  Watt's  metal  for 
the  solder.  In  repairing  the  metal  should  be  made  hotter  than  for 
casting  a  new  case. 

"  Most  beautiful  upper  or  lower  plates  may  be  made  by  combining 


Fig.  1107. 

it  with  rubber  or  celluloid,  when  there  would  be  too  much  weight  in 
using  the  metal  alone." 

When  the  process  of  constructing  artificial  dentures  of  these  alloys 
is  properly  conducted  from  the  beginning  up  to  the  point  of  pouring 
the  metal,  the  piece  will  come  from  the  matrix  perfect  in  all  its  parts. 
But  when  the  metal  fails  to  flow  freely  around  the  teeth,  and  to  cover 
perfectly  the  alveolar  border  and  palatine  arch,  it  is  better  to  replace 


Fig.  1 108. 


the  removed  half  of  the  matrix ;  then,  turning  the  gate  down,  heat  it 
up  to  the  melting-point  of  the  metal,  place  again  in  the  sand-bath,  and 
pour  a  second  time.  Attempts  are  sometimes  made  to  patch  the  plate 
where  the  defects  are  small ;  but  it  will  prove  far  more  satisfactory  in 
the  end  to  pour  it  entirely  anew.  The  matrix  should  become  entirely 
cold  before  any  attempt  is  made  to  remove  the  piece ;  otherwise  there 


METALLO-PLASTIC   WORK.  997 

will  be  danger  from  the  sudden  exposure  of  warm  teeth  to  the  air. 
The  plaster  mixture  is  easily  cut ;  dipping  it  in  water  will  make  it 
softer  and  more  easily  removed. 

If  care  has  been  used  in  shaping  the  wax  plate,  if  the  plaster  has 
been  kept  free  from  air-bubbles,  and  if  the  joints  between  gum  teeth 
or  blocks  have  been  nicely  jointed  and  filled  on  their  front  edge,  with 


Fig.  1109. 

the  plaster  moistened  with  soluble  glass,  the  piece  may  be  finished 
with  little  trouble.  The  gates  and  vents  and  irregular  edges  of  the 
plate  may  be  sawed  off  or  removed  with  coarse  files  ;  fine-cut  files  be- 
came clogged  with  the  metal.  Scrapers  (Fig.  1108)  may  be  employed 
for  removing  the  roughness  of  surface — curved  or  rounded  for  the 
inner  surface,  flat,  straight-edged,  and  pointed  for  outer  surfaces  or 


dental  interstices.  If  carelessness  in  making  the  wax  plate  renders  it 
necessary  to  cut  away  much  thickness  of  metal  the  lathe  burs  used  for 
vulcanite  will  be  found  useful.  In  reducing  the  thickness  of  plates" 
frequent  use  of  calipers  (Figs.  1109,  11 10)  is  necessary  to  avoid  the 
accident  of  cutting  through  the  plate.  This  is  especially  apt  to  hap- 
pen in  the  use  of  lathe  burs.  Fig.  11 10  should  have  the  tips  on  one 
side  pointed,  as  in  Fig.  1 109,  and  they  should  be  occasionally  exam- 


99S  MECHANICS — DENTAL    PROSTHESIS. 

ined  to  see  if  both  sides  come  together  alike.  It  will  make  the  use  of 
calipers  more  easy  if  the  arms  are  kept  permanently  open  by  an  elastic 
band,  closing  by  pressure  of  the  fingers  at  each  trial  of  the  plate. 
Graduated  calipers  are  useful  also  for  measuring  the  depths  of  articulat- 
ing rims,  the  length  of  teeth,  etc.,  and  are  quite  indispensable.  This 
done,  the  surface  is  rubbed  first  with  coarse  and  afterward  with  fine 
emery  cloth,  then  washed  in  soap  and  water  with  a  hard  brush,  after- 
ward burnished  and  finished  by  polishing  with  chalk  on  a  brush  wheel ; 
coarse  Scotch  stone  may  be  used  in  place  of  the  emery  cloth.  The 
upper  surface  of  its  plate  must  neither  be  scraped  nor  polished,  as  the 
accuracy  of  the  adaptation  to  the  gums  and  palatine  arch  would  be 
injured  ;  it  should  simply  be  washed  well  with  a  brush,  using,  perhaps, 
a  little  whiting.  Every  other  part  ought  to  be  finished  in  the  neatest 
and  most  perfect  manner  ;  the  piece  is  put  in  a  strong  solution  of 
caustic  potash,  boiled  for  two  or  three  minutes,  then  washed  in  pure 
water,  wiped  dry,  and  finished  with  chalk  and  the  brush  wheel. 

Under  no  circumstances  should  the  tin  alloy  be  gilded.  The  least 
imperfection  of  the  electrotype  deposit,  or  the  abrasion  of  any  edge 
of  prominence,  or  the  removal  of  the  coating  by  trimming  the  plate 
at  any  point,  presents  to  the  fluids  of  the  mouth  two  metals  having 
widely  different  galvanic  relations ;  electric  action  is  inevitable, 
causing  decomposition  of  the  plate,  annoyance  to  the  patient,  and 
often  ulceration  of  the  gum.  The  tin  alloys  are  quite  harmless  in  the 
mouth.  They  all  slightly  tarnish,  but  the  surface  oxid  seems  to  pro- 
tect from  further  action,  except  where  abraded  by  the  mastication  of 
food.  The  brilliant  polish  of  new  work  cannot  be  kept  so  long  as  on 
a  gold  plate,  because  it  is  much  softer ;  this,  however,  is  of  secondary 
importance,  provided  the  metal  is  hard  enough  to  resist  wearing  away 
under  the  necessary  operations  of  use  and  of  cleansing. 

In  mounting  a  set  of  teeth  for  the  lower  jaw  the  gate  through 
which  the  metal  is  poured  into  the  matrix  should  have  two  lateral 
l)raiiches,  one  on  each  side,  to  admit  the  metal  more  freely.  The 
wax  plate  should  also  be  thicker,  to  give  sufficient  strength  and  sta- 
bility to  the  base ;  in  other  respects  the  process  is  the  same  as  that 
described  for  an  upper  set.  For  a  partial  lower  set  of  molars  and 
bicuspids  on  each  side  the  wax  plate  should  be  extended  behind  the 
remaining  front  teeth  ;  and  two  or  three  thicknesses  should  be  applied 
here,  giving  stiffness  sufficient  to  prevent  breaking  or  bending  under 
the  pressure  of  mastication. 

In  making  an  antagonizing  model  for  an  entire  set  of  teeth  the  wax 
plate  for  the  lower  jaw  is  stiffened  by  the  adjustment  of  a  stout  iron 
wire,  bent  to  the  curvature  of  the  arch,  and  made  fast  to  and  partly 
bedded  in  the  plate.     The  rim  of  wax  is  now  arranged  on  the  ridge. 


METALLO-PLASTIC   WORK. 


999 


and  after  being  properly  trimmed  it  is  taken  from  the  model.  Upper 
and  lower  plates  are  then  adjusted  in  the  mouth,  the  articulation  is 
obtained,  and  the  articulator  (Fig.  iiii)  made  in  the  manner  de- 
scribed for  a  full  set  of  teeth  mounted  on  gold  plate.  Fig.  1112 
represents  a  double  set  of  teeth  arranged  in  wax  upon  a  plaster  articu- 
lation, ready  to  be  placed  upon  their  respective  models  preparatory  to 
the  formation  of  the  remaining  halves  of  the  matrices.  The  cast  base 
process  is  also  applicable  to  partial  sets  of  teeth  ;  a  single  tooth  or 
several  teeth  situated  in  different  parts  of  the  arch  can  be  replaced, 
and  retained  so  as  to  occasion  no  inconvenience  or  annoyance  to  the 
patient.  The  only  precaution  necessary  to  be  observed  in  their  con- 
struction, in  addition  to  that  of  accuracy  of  adjustment  and  neatness 
of  execution,  is  to  thicken  the  projections  of  the  wax  plate  between 
the  remaining  natural  teeth  sufficiently  to  give  strength  to  the  metal 
at  these  points.  These  portions,  when  very  narrow,  should  have  twice 
the  thickness  of  the  other  parts  of  the  plate.     Clasps  cannot  be  used, 


Fig.  iiii. 


Fig.  1112. 


as  the  metal  itself  has  no  elasticity,  and  gold  clasps  could  not  be  con- 
nected to  such  plates.  With  this  exception  the  forms  of  partial  pieces 
for  this  work  are  the  same  as  for  vulcanite  work,  hereafter  described. 
After  having  adjusted  the  artificial  teeth  and  made  them  fast  to  the 
wax  plate  the  teeth  of  the  model  should  be  cut  off  before  making  the 
other  half  of  the  matrix,  as  it  would  be  almost  impossible  to  separate 
the  two  halves  without  breaking  the  teeth  and  other  important  parts. 

But  if  proper  flasks  are  used  it  is  not  necessary  to  cut  off  the  teeth. 
In  the  same  manner  as  hereafter  described  for  that  work,  the  model 
may  be  set  in  the  deep  half  of  the  flask  until  the  edges  of  the  teeth  are 
nearly  or  quite  level  with  the  edge  of  the  flask ;  the  investing  plaster 
supports  the  outside  of  the  teeth  and  prevents  breakage  on  separating 
the  flask. 

A  piece  from  which  one  or  more  teeth  have  been  broken  can  be 
easily  repaired.  If  any  portion  of  the  tooth  remain  it  is  removed, 
and  the  metal  that  united  it  to  the  base  filed  away ;  a  new  tooth  is 


lOOO  MECHANICS — DENTAL    PROSTHESIS. 

selected  and  ground  until  it  corresponds  with  the  adjoining  teeth  ;  it 
is  then  put  in  place  and  wax  applied  on  the  outside  and  inside  of  the 
tooth,  smoothing  it  with  the  warm  wax-knife  evenly  with  the  plate. 
The  apex  of  a  conical-shaped  roll  of  wax  about  an  inch  and  a  half  in 
length  is  united  to  the  wax  on  the  back  part  of  the  tooth ;  the  apex 
should  be  little  more  than  an  eighth,  and  the  base  half  an  inch  in 
diameter,  which  latter  should  be  half  an  inch  above  the  edge  of  the 
teeth.  A  small  stem  of  wax  is  united  to  the  wax  on  the  outside  of  the 
tooth  with  the  free  extremity  half  an  inch  above  its  edge.  The  one- 
half  of  the  flask  is  now  filled  full  of  the  plaster  mixture,  and  the  piece 
put  immediately  io  it  with  the  base  downward,  first  filling  the  irregu- 
larities of  the  plate  with  the  plaster  ;  the  top  or  other  half  of  the  flask 
is  then  put  on  and  a  thin  mixture  of  the  same  composition  is  poured 
on  top,  filling  the  ring  and  covering  the  edges  of  the  teeth  about  a 
quarter  of  an  inch.  When  hard  the  projecting  stems  of  wax  are  with- 
drawn ;  the  wax  on  each  side  of  the  tooth  and  between  it  and  the  base 
will  be  melted  and  absorbed  during  the  drying  process.  The  matrix 
is  dried  in  a  stove  or  furnace,  being  careful  not  to  heat  it  up  to  the 
point  of  fusion  of  the  plate.  The  alloy  is  then  melted  and  poured 
into  it  through  the  gate  behind  the  tooth,  and  if  it  flows,  filling  the 
vent  in  front  without  bubbling,  the  piece  will  come  from  the  matrix 
perfectly  restored.  When  cold  the  plaster  mixture  is  broken  from  the 
teeth  and  the  metal  around  the  new  tooth  finished  according  to  the 
direction  given  for  full  sets.  In  repairing  pieces  the  heating  of  the 
matrix  and  metal  must  be  done  very  carefully.  If  the  matrix  is  too 
hot,  the  plate  may  fuse  ;  if  too  cool  and  the  melted  metal  too  hot,  the 
porcelain  may  be  cracked.  In  using  tin  alloys  in  connection  with 
platina  pins  it  should  be  remembered  that  the  exposure  of  a  single 
rivet  to  the  action  of  the  buccal  fluids  forms  a  galvanic  battery,  which 
will  cause  an  unpleasant  taste  and  render  the  ])iece  liable  to  slow  de- 
composition; hence  all  pins  must  be  carefully  covered  with  metal,  so 
as  not  to  be  exposed  in  the  finishing  processes. 

Sets  of  teeth  may  be  made  of  these  alloys  which,  after  cutting  off" 
the  gate  and  vents,  are  ready  for  the  emery-cloth  and  brush-wheels. 
This  result  can  be  uniformly  secured  by  care  in  shai)ing  the  wax  and 
proper  attention  to  temperature  in  pouring.  These  alloys  have  a  slight 
shrinkage,  not  sufficient  to  break  blocks  or  chip  the  edges  if  the  direc- 
tions above  given  are  observed.  The  slight  shrinkage  may  give  these 
plates  an  advantage  over  vulcanite  in  point  of  adaptation. 

The  strength  of  the  Wood  or  Weston  metals  permits  their  use  for 
partial  pieces  and  allows  stays  to  be  formed  on  the  plate ;  but  full 
clasps  cannot  be  made  because  alloys  of  this  class  are  not  sufficiently 
elastic.     The  form  of  such  plates  will  be  discussed   in  the  next  chap- 


METALLO-PLASTIC   WORK.  lOOI 

ter.  In  preparing  the  above  directions  we  have  discarded  some  inno- 
vations upon  other  processes  as  being  anything  but  improvements  ; 
such,  for  instance,  as  the  recommendation  to  heat  to  210°,  or,  "so 
that  it  can  hardly  be  held  in  the  hand,"  a  flask  containing  teeth  on 
to  which  a  metal  is  to  be  suddenly  poured  at  a  temperature  of  440°. 
This  temperature  may  be  quite  sufficient,  however,  for  some  of  Dr. 
Wood's  alloys.  The  safest  rule  in  all  cases,  except  for  repairs,  is  to 
heat  up  to  the  fusion  point  of  the  alloy.  As  an  offset  to  this  error  we 
notice  a  good  suggestion  for  removing  small  remnants  of  wax  by  wash- 
ing out  with  hot  water.  It  has  an  advantage  over  the  plan  of  allowing 
the  hot,  dry  plaster  to  absorb  the  wax,  in  permitting  examination  of 
the  pins  and  joints  and  allowing  closure  of  front  joints  with  plaster  ; 
also  by  enabling  the  mold  to  be  thoroughly  cleansed  just  before  clos- 
ing it  prevents  the  accidental  retention  of  small  particles  of  plaster 
which  may  interfere  with  the  flow  of  the  metal. 

Aluminum  or  Alu7ninium  Work. — This  metal  is  in  nearly  all  works 
on  chemistry  called  Aluminium,  making  it  similar  in  termination  to 
twenty-three  other  metallic  bases  discovered  by  modern  science  and 
known  by  Latinized  names  ending  in  tum.  None  of  these,  however, 
have  any  practical  value  in  the  arts  as  metals,  except  cadmium,  mag- 
nesium, palladium,  rhodium,  and  iridium. 

Sir  Humphrey  Davy  inferred  from  his  discovery  of  sodium  and 
potassium  that  alumina  was  the  oxid  of  a  metallic  base.  This  con- 
jectural metal,  named  Aluminium,  was  subsequently  discovered  by 
Wohler,  but  remained  for  more  than  twenty  years  a  mere  chemical 
curiosity,  until  in  1854  St.  Clair  Deville  succeeded  in  manufacturing 
it  in  large  ingots  by  the  action  of  sodium  upon  the  chlorid  of  alu- 
minium ;  but  the  cost  of  metallic  sodium  made  this  an  expensive  pro- 
cess. He  subsequently  obtained  it  by  the  action  of  chlorid  of  potas- 
sium upon  the  once  rare  mineral.  Cryolite — an  alumino-fluorid  of 
sodium,  large  deposits-of  which  have  been  discovered  in  Greenland. 

It  is  the  lightest  metal  known  except  magnesium  (excei)ting  also, 
of  course,  sodium  and  potassium)  ;  its  specific  gravity  is  2.56  for  cast 
metal  and  2.67  for  hammered  metal,  about  the  weight  of  glass  or  porce- 
lain. Its  point  of  fusion  is  somewhere  near  1000°  Fahrenheit.  It 
is  malleable,  laminable,  and  ductile  in  a  high  degree  ;  has  a  hardness 
equal  to  silver  and  excels  it  in  point  of  tenacity ;  it  is  eight  times 
better  than  iron  as  a  conductor  of  electricity,  being  nearly  equal  to 
silver.  Unlike  silver,  it  wholly  resists  the  action  of  sulphur,  also  of 
nitric  acid,  unless  it  is  boiling.  Sulphuric  acid  does  not  affect  it,  nor 
do  the  vegetable  acids,  as  citric,  oxalic,  and  tartaric.  Its  proper  sol- 
vents are  hydrochloric  acid  and  chlorin.  It  is  somewhat  affected  by 
the  caustic  alkalies,  soda,  and  potash  ;  also,  perhaps,  by  ammonia  and 


I002  MECHANICS — DENTAL    PROSTHESIS. 

quicklime.  A  solution  of  salt  and  vinegar  is  said  to  affect  it,  possibly 
due  to  a  liberation  of  the  chlorin  in  the  salt. 

Its  record  of  resistance  to  change  by  acid  and  alkali  is  a  very  fair 
one,  and  gives  rise  to  the  conjecture  of  possible  impurity  of  metal  in 
explanation  of  the  cases  reported  in  which  aluminium  plates  undergo 
change  in  the  mouth.  The  conjecture  is  strengthened  by  the  pecu- 
liarity of  this  change  ;  it  occurs  in  spots,  seeming  to  indicate  some 
local  impurity  or  alloy,  not  by  a  general  discoloration  of  the  plate, 
such  as  we  see  on  eighteen-carat  gold,  or  silver,  and  on  the  stannic 
alloys.  The  subject  of  aluminium  alloys  in  connection  with  the  mouth 
and  as  solders  is  an  open  field  of  inquiry,  and  researches  may  some 
day  be  crowned  with  the  discovery  of  an  aluminium  base  plate  equal 
in  all  respects  to  gold  plate,  with  the  peculiar  advantage  of  its  remark- 
able lightness.  Present  experience  is  unfavorable  to  its  power,  in  its 
pure  state,  of  resisting  the  buccal  secretions. 

Aluminium  plates  may  be  swaged,  teeth  backed  and  soldered  by  the 
blowpipe,  just  as  in  gold  work,  but  its  soldering  requires  great  care. 
For  many  years  all  formulae  of  solders  for  this  metal  proved  very  un- 
satisfactory, and  but  recently  it  was  discovered  that  the  chlorids  of 
silver  and  cadmium  acted  well  as  fluxes  in  soldering  aluminium.  The 
most  successful  solder  which  has  attained  any  extensive  use  is  that  of 
Joseph  Richards,  of  Philadelphia,  which  can  be  used  with  the  blow- 
pipe or  with  a  soldering  iron. 

When  used  with  the  blowpipe  or  soldering  iron,  the  surfaces  to  be 
united  are  first  scraped  clean  and  then  tinned  with  the  solder  itself  by 
rubbing  it  on  hard  with  the  copper  soldering  iron  ;  the  prepared  edges 
can  then  be  easily  soldered  together,  using  the  hot  copper  iron  and  no 
flux.  This  solder  consists  of  an  alloy  of  zinc,  tin,  aluminium,  and 
phosphorus,  the  zinc  and  tin  constituting  the  bulk  of  the  mass.  When 
this  solder  is  to  be  used  with  the  blowpipe,  a  little  silver  can  be  added 
to  it  to  give  a  better  color.  The  swaging  of  aluminium  is  done  just 
as  in  the  case  of  gold  or  platinum,  except  that  frequent  annealing  is 
necessary.  The  annealing  must  be  done  with  extreme  care,  since  the 
fusion  point  of  the  metal  is  so  little  above  red  heat  that  the  slightest 
excess  of  heat  will  warp,  blister,  or  melt  the  plate.  For  the  purpose 
of  annealing  it  is  suggested  to  coat  the  surface  of  plate  with  oil,  and 
then  pass  it  over  the  flame  of  a  spirit-lamp  until  the  oil  is  burned  off 
and  the  plate  becomes  white,  when  it  is  instantly  withdrawn.  The 
extreme  lightness  of  this  metal  permits  the  use  of  a  plate  two  or  three 
times  the  thickness  of  gold  plate  ;  hence  aluminium  plates  may  be  the 
very  strongest  that  can  be  made  in  any  given  case.  The  best  method 
yet  proposed  for  attaching  the  teeth  to  such  a  plate  is  by  vulcanite, 
the  details  of  which  process  will  be  given  in  the  next  chapter.     It  is  a 


AJETALLO-PLAbTlC    WuK...  1003 

peculiarity  of  pure  aluminium  that  vulcanized  rubber  adheres  to  it  with 
great  tenacity.  A  set  of  well-chosen  block  teeth,  skillfully  arranged 
and  secured  to  an  accurately  fitting  aluminium  plate,  may  safely  be 
offered  to  the  most  fastidious  and  critical  patient.  It  has,  moreover, 
the  great  advantage  that  ■'  sixty-minute"  dentists  will  not  care  to  imi- 
tate work  which  takes  "  several  "  hours  to  do  even  passably  well. 

Another  form  of  aluminium  work,  and  that  which  has  led  to  the 
present  classification  of  this  metal  under  the  head  of  Plastic  work, 
was  the  molded  or  cast  aluminium  plate.  No  experiments,  however, 
seem  to  us  to  have  been  conducted  with  such  care  as  those  of  the  late 
Dr.  James  B.  Bean,  of  Baltimore,  who  perished  under  an  avalanche, 
in  the  summer  of  1870,  while  ascending  Mont  Blanc;  and  his  process 
was  not  only  a  difficult  one  to  pursue,  but  was  very  uncertain  in  its 
result ;  hence  the  use  of  aluminium  is  not  at  the  present  time  attempted 
except  in  the  form  of  swaged  plates  to  which  the  teeth  are  connected 
by  vulcanized  rubber,  and  which  is  referred  to  in  the  article  on 
Vulcanite. 

Aluminium  Cast  Base. — Dr.  C.  C.  Carroll  uses  a  prepared  form  of 
aluminium  which  he  describes  as  being  first  made  pure  to  prevent  dis- 
integration, and  then  alloyed  with  a  small  per  cent,  of  noble  metals 
that  expand  in  cooling  and  thus  compensate  the  contraction  of  the 
aluminium.     He  describes  his  method  as  follows  :  — 

^^  JFor  a  Jiubber  Attachment. — Base  No.  i:  Take  an  accurate  im- 
pression in  plaster,  or  modeling  composition,  outline  on  the  impression 
the  limit  to  be  covered  by  the  denture  as  intended  to  be  worn.  Place 
a  strip  of  our  No.  i  base  plate  wax,  ^  inch  wide,  across  the  posterior 
palatine  arch  of  the  impression,  terminating  and  shading  out  at 
the  alveolar  palatine  border.  This  wax  strip,  when  reproduced  in 
aluminium,  closes  the  posterior  palatine  arch  of  the  cast  denture, 
which  by  virtue  of  the  slight  contraction  of  -^^  part  impinges 
firmly  on  the  alveolar  ridge,  while  it  lifts  slightly  from  the  central 
posterior  arch,  making  a  denture  that  rests  firmly  in  place  without 
rocking.  Pour  the  impression  thus  prepared  with  our  investing 
compound  mixed  to  the  consistency  of  thick  cream,  and  get  a 
"model,  on  which  cut  a  narrow  line  -^  inch  deep  and  the  same  width, 
extending  from  the  wax  strip  imprint  around  the  alveolar  palatine 
f^border,  to  constitute  all  the  air  chamber  that  should  ever  be  made  in 
an  aluminium  cast  denture. 

"Take  a  thin  sheet  of  our  No.  i  wax  base  plate,  about  No.  23 
standard  gold  gauge  in  thickness,  and  shape  neatly  on  the  model  a 
temporary  base  plate  as  intended  to  be  worn.  Surround  the  entire 
palatine  and  labial  alveolar  border,  near  to  the  line  that  the  teeth  are 
to  occupy,  with  a  thin  strip  of  paraffin  wax  about  }i  inch  in  width ; 


ioo4 


MECHANICS DENTAL    PROSTHESIS. 


fasten  and  smooth  down  the  outer  edge  of  this  strip  with  melted  wax  ; 
then  with  a  thin  wax  knife  raise  the  inner  edge  all  around  next  where 
the  teeth  are  to  be  arranged,  which  wax  strip,  when  reproduced  in  the 
metal  base  plate,  will  be  a  flange  or  undercut,  surrounding  the  teeth  to 
hold  the  celluloid  or  rubber  attachment  for  fastening  the  teeth  to  the 
permanent  metallic  base  plate. 

"  Contour,  carve,  and  smooth  neatly  to  the  form  desired.  Now 
make  the  matrix  by  imbedding  the  model  with  the  temporary  base 
plate  upon  it,  in  the  female  part  of  the  flask,  allowing  the  investing 


MooOk 


Fig.  1 1 13. 


material  to  come  up  to  the  edge  of  the  base  plate.  When  set,  smooth 
the  investing  material  and  cut  a  gate  from  the  middle  edge  of  the  base 
plate  to  the  pouring  point  of  the  flask  ;  also  cut  short  gates  about  one 
inch  long  in  a  perpendicular  line  from  the  heels.  The  gates,  when 
finished,  should  be  nearly  round,  about  ^  inch  in  diameter.  Connect 
one  gate  with  the  vent  cut  in  the  flask. 

"  Dust  the  surface  of  the  matrix  with  inilverized  suapstone,  and  polish 
the  surface  by  rubbing  with  the  finger.       Mix  enough  investing  mate- 


METALLO-PLASTIC    WORK.  I005 

rial  to  fill  the  other  half  of  the  flask  ;  pour  first  so  as  to  cover  the 
base  plate  and  matrix,  jar  to  expel  the  air,  and  then  pour  into  the 
male  part  of  the  flask,  place  the  two  parts  carefully  together,  and  force 
into  place,  squeezing  the  excess  through  the  perforated  back  of  the 
flask.  When  set  and  hard  separate  and  remove  the  temporary  base 
plate,  washing  out  the  wax  with  hot  water.  Take  great  care  that  the 
wax  is  not  melted  before  separating,  and  absorbed  into  the  matrix  to 
generate  gas  that  will  prevent  a  perfect  cast  of  aluminium. 

"  Cut  the  gates  in  the  male  part  of  the  matrix,  as  indicated,  to 
correspond  to  the  female  part.  Cut  out  the  plaster  from  the  pouring 
point.  Bolt  the  flask  firmly  together.  Coat  the  thread  of  flask  with 
soapstone.  Screw  the  retort  firmly  to  flask.  Place  the  fine  copper 
wire  in  the  vent.  Then  lute  the  seam  of  the  flask  and  where  retort 
joins  the  flask,  also  around  the  bolts,  with  investing  material,  to  pre- 
vent the  escape  of  air  or  metal  in  casting.  Test  with  the  rubber  bulb 
and  clamping  lever.  See  if  matrix  is  air-tight.  Soapstone  sprinkled 
over  suspected  leak  will  determine  the  test.  Withdraw  the  wire  from 
the  vent  and  test  again  to  see  that  only  the  vent  is  open.  Place  the 
flask  in  the  slot  of  the  burner,  turn  on  low  flame,  and  dry  out  thor- 
oughly, as  will  be  shown  if  no  moisture  appears  on  the  surface  of  a 
mirror  held  over  the  retort. 

"  When  the  piece  is  dry,  place  the  flask  on  the  bottom  of  the 
burner;  put  two  ingots  of  Aluminium  Base  No.  i  in  the  retort,  place 
the  hood  over  it,  and  turn  on  full  flame,  and  with  use  of  foot  bellows 
attached  to  air  tube  of  the  burner  proceed  to  melt  the  metal,  which 
will  usually  require  from  six  to  ten  minutes. 

"  When  melted,  remove  the  hood,  turn  off"  the  gas,  and  clamp  the 
retort  cover  in  place  with  clamping  tongues,  slipping  the  ring  over 
handles,  then  with  the  rubber  bulb  pressed  gently  but  firmly  force  the 
melted  metal  into  the  matrix,  until  metal  is  forced  through  the  matrix 
at  the  vent ;  chill  the  metal  with  piece  of  wet  sponge  tied  to  a  stick  as 
soon  as  it  appears  at  the  vent.  Press  three  seconds  to  condense  the 
metal  under  pressure  in  the  matrix.  Make  an  ingot  mold  by  filling  a 
pepper  box  with  investing  and  boring  a  tapering  hole  of  less  diameter 
than  the  retort.  With  the  handles  of  the  clamping  tongs  unscrew  the 
retort  from  the  flask  as  it  stands  in  the  burner,  and  with  bulb  blow  out 
all  excess  aluminium  from  the  retort,  so  that  the  opening  through  the 
bottom  is  clear. 

"  For  Casting  Directly  on  Teeth. — When  it  is  desired  to  cast  directly 
on  plain  teeth,  which  are  preferable  to  section  teeth,  place  the  model 
prepared  as  above  described  upon  the  articulator,  after  obtaining  a 
correct  articulation  in  the  usual  manner.  Mount  the  teeth  on  the  No. 
I   wax  base  plate,  as   is  usual  for  rubber  work,  except  that  the  teeth 


IOo6  MECHANICS DENTAL    PROSTHESIS. 

must  be  spaced  so  that  a  postal  card  will  pass  between  them  when 
mounted.  Wax  up  contour  and  carve  neatly,  with  a  double  curved 
end  wax  knife,  exactly  as  intended  to  be  worn,  leaving  the  lingual 
surface  of  the  wax  base  plate  unmarred  as  you  would  have  the  aluminium 
plate  come  out  finished,  remembering  that  the  wax  form  will  be  accu- 
rately reproduced  in  aluminium. 

"  If  it  is  necessary  to  have  an  artificial  gum,  which  very  rarely  happens 
if  plain  teeth  of  the  proper  pattern  are  selected,  then  place  a  narrow 
strip  of  base  plate  wax,  ^  inch  wide,  around  the  alveolar  border  only, 
for  a  flange,  between  which  flange  and  the  ends  of  the  teeth  a  pink 
rubber  facing  may  be  attached. 

"Remove  the  model  with  the  mounted  denture  and  proceed  to 
invest  as  described  for  a  base  plate  alone.  After  washing  out  the 
wax,  make  a  thin  cream  of  equal  parts  carbonate  of  magnesia  and 
prepared  chalk,  with  water,  and  with  a  small  camel's-hair  pencil  cover 
the  alveolo-labial  edge  of  the  teeth  with  a  thin  coating  of  this  cream, 
to  prevent  the  metal  from  flowing  over  the  edge  and  possibly  checking 
the  teeth. 

"Bolt  the  flask  together  and  dry  out  the  case,  and  make  castas 
directed  for  base  plate. 

"  If  the  gum  section  teeth  are  used,  grind  the  feather  edge  slightly 
beveled,  leaving  the  labial  edge  of  the  gum  highest,  and  mount,  spac- 
ing slightly  by  placing  heavy  writing  paper  between  the  joints.  Before 
investing,  remove  the  paper  and  flow  between  the  joints  the  magnesia 
and  chalk  cream  above  given.  Then  invest  the  same  as  for  plain  teeth. 
After  washing  out  the  wax,  flow  a  thin  film  of  the  above  cream  along 
the  beveled  edge  of  the  gum,  close  the  flask,  dry  out,  and  proceed  to 
cast  as  directed. 

"If  at  any  time  the  crucible  passage  becomes  stopped,  before  mak- 
ing another  cast  heat  the  crucible  to  a  bright  red  and  blow  out  the 
obstruction  ;  otherwise  metal  being  left  near  the  outlet  of  the  passage 
would  form  a  siphon,  and  empty  the  chamber  of  any  metal  in  it  de- 
signed for  a  subsequent  cast. 

"Let  the  cast  cool  slowly  ;  separate  the  flask  and  remove  the  cast 
from  the  investment.  With  a  fine  saw  and  cutting  pliers,  trim  away 
all  surplus  metal  from  the  cast.  Coarse  finish  with  files,  cone  burs, 
and  sand  paper.  Burnish  and  remove  scratches  with  pumice  and  water, 
and  finish  with  polishing  compound  on  brush  and  buff  wheels. 

"  If  a  base  plate  has  been  cast,  use  this  finished  base  plate  for  a  trial 
plate ;  with  wax  placed  along  the  flanged  alveolar  border,  obtain  the 
correct  bite  and  articulation.  Mount  the  teeth  as  desired,  waxing  up 
for  celluloid  or  rubber  attachment,  and  proceed  as  in  celluloid  or  rubber 
work. 


METALI  0-PLASTIC    WORKl.  TOO/ 

''  Directions  for  Base  No.  2.  —  Proceed  in  all  respects  as  if  for  rubber 
work,  using  thin  parafifine  wax  for  temporary  base  plate  until  the  teeth 
are  mounted  on  the  model.  Trim  and  wax  up  neatly  and  light  as 
intended  to  be  when  finished  for  the  mouth.  Then  invest  the  model 
and  the  teeth  in  perforated  flask  and  proceed  as  directed  for  Base  No. 
I  up  to  the  point  of  making  the  cast.  When  the  matrix  is  dry  and 
ready  to  make  the  cast,  place  two  ingots  of  Base  No.  2  in  the  retort 
with  the  larger  opening.  Stop  the  opening  with  an  old  plugger  to 
prevent  the  metal  escaping  as  it  melts.  When  all  is  melted  withdraw 
the  stopper  and  chill  the  metal  when  it  appears  at  the  vent.  Turn  on 
flame  enough  to  melt  the  metal  in  eight  to  ten  minutes,  which  requires 
not  over  half  the  flame  needed  for  Base  No.  i.  If  there  should  be  any 
point  of  leakage  of  metal  it  can  be  stopped  at  once  by  touching  it 
with  a  wet  cloth,  and  any  escaped  metal  can  be  immediately  remelted 
and  poured  into  the  matrix  without  producing  any  flaw  or  imperfec- 
rion  in  the  piece  to  be  cast.  Let  the  piece  cool  slowly,  remove  from 
the  flask,  and  finish  as  directed  for  Base  No.  i.  Never  use  the  same 
retort  for  melting  Base  No.  i  and  Base  No.  2. 

*■'  For  Aluminium  Crown  and  Bridge  Work. — Shape  the  roots  or  teeth 
to  which  attachment  is  to  be  made  for  crowns  or  bridges  the  same  as 
for  a  gold  crown  and  bridge  work.  Then  take  an  accurate  impression 
in  plaster,  if  possible,  from  which  make  a  model  of  investing  of  the 
part  to  be  supplied.  Mold  upon  the  supporting  roots  or  teeth  in  thin 
parafifine  wax  the  crown  or  bridge  as  intended  to  be  worn,  and  mount 
the  teeth  desired  to  supply  the  needed  deficiency  with  proper  occlu- 
sion, in  the  same  manner  as  if  a  partial  plate  were  to  be  made,  taking 
care  to  space  the  teeth  so  they  shall  not  touch  each  other  if  the  bridge 
is  to  be  cast  from  Base  No.  i.  Carve  neatly  as  intended  to  be  worn, 
allowing  the  bridge  or  saddle  to  rest  narrowly  on  the  alveolar  border, 
which  should  be  slightly  scraped  on  the  model  so  as  to  fit  firmly  on 
the  soft  parts  and  thus  distribute  the  force  over  the  supporting  roots 
and  the  alveolar  border  alike,  at  the  same  time  precluding  food  from 
getting  under  the  bridge  or  saddle.  Now  invest  or  proceed  with  the 
subsequent  steps  as  already  described  for  casting,  according  as  the  case 
may  be  for  Base  No.  i  or  No.  2.  Finish  and  adjust  to  the  mouth 
either  for  detachable  or  cemented  bridge,  as  may  be  desired — giving 
the  preference  to  detachable  bridge  work  when  practicable.  If  it  is 
to  be  cemented,  use  oxyphosphate  of  zinc,  mixed  as  if  to  be  used  in 
filling  ;  dry  the  roots  or  teeth  to  be  crowned  ;  fill  the  crowns  ;  press 
the  bridge  firmly  to  place,  keeping  dry  until  fully  set,  which  operation 
may  be  expedited  by  the  use  of  hot  air.  Removable  bridges  and 
partial  dentures  are  securely  held  in  place  by  the  Carroll  Spiral  Alu- 
minium Coil  Spring. 


xoo8 


MECHANICS DENTAL    PROSTHESIS. 


"  Directions  for  Using  Gasoline  Furnace. — Use  74  degree  specific 
gravity  gasoline,  fill  the  tank  about  half  full,  close  all  the  openings, 
pump  in  air,  open  vent  to  the  dripping-pan,  S^  (see  Gasoline  Furnace, 
Fig.  1 113),  swing  around  the  cut-off  to  the  dripping  pan  (C),  and  fill 
about  two-thirds  full,  which  you  light  to  heat  the  lower  generator ; 
when  dripping-pan  is  burned  out,  swing  cut-off  back  and  open  lower 
generator  and  light  the  gas  under  large  generator  B^,  which  let  run  for 
about  five  minutes,  then  open  upper  generator  at  S^  and  light  the  gas 
at  the  burner  B^,  keeping  the  lower  generator  burning  just  high  enough 
to  heat  the  upper  generator  while  in  use.  Keep  water  in  the  reservoir 
above  the  tank  in  order  that  the  tank  may  not  heat.  Mount,  invest, 
and  cast  as  directed  for  gas  outfit." 

Gold  Alloy  Cast  Base. — Dr.  G.  F.  Reese  has  recently  devised  an 
alloy  composed  of  gold,  one  part;  silver,  two  parts;  and  tin,  twenty 
parts,  which  is  manipulated  by  a  special  method,  as  a  base  for  artificial 
dentures,  and  which    has  met   with    considerable    favor.      A    brief 

description  of  Dr.  Reese's 
method  is  as  follows  :  A  plas- 
ter model  is  first  obtained 
from  a  plaster  impression  of 
the  mouth,  and  on  the  model 
a  trial  plate  is  made  of  gutta- 
percha, paraffin,  and  wax,  or 
of  modeling  composition. 
Upon  this  trial  plate  the  teeth 
are  arranged  and  tried  in  the 
mouth.  If  satisfactory  the 
waxing  about  the  teeth  is 
completed,  and  the  portion 
of  the  trial  plate  covering  the 
palatine  surface  is  removed  to 
such  a  degree  as  to  nearly  ex- 
pose the  pins  of  the  teeth,  the  wax  under  the  gums  being  allowed  to 
remain.  For  the  portion  of  the  trial  plate  removed  two  thicknesses  of 
French  flower  wax  is  substituted,  being  carefully  adapted  to  the  model. 
Fig.  1 1 14  represents  a  case  carried  to  the  stage  described,  the  dotted 
lines  showing  the  edges  of  the  thin  wax  substitute  portion,  and  B,  A, 
and  C  prominences  of  wax  attached  to  the  posterior  border  and  portion 
of  the  plate  covering  the  maxillary  tuberosities,  A  and  C  being  de- 
signed for  the  escape  of  the  alloy,  which  is  poured  in  at  B.  The  case 
is  then  placed  in  a  brass  flask,  which  has  been  oiled  to  render  its  re- 
moval from  the  investment  easy.  Fig.  11 15  represents  the  case  in  the 
fiask  ready  for  investment.     To  invest  the  case  each  section   is  placea 


Fig    I I 14 


METALLO-PLASTIC    WORK. 


1009 


upon  a  plate  of  glass  and  plaster  poured  in  until  it  is  half  filled,  when 
the  model,  which  has  been  saturated  with  water,  is  pressed  into  the 
plaster  batter  until  the  teeth  and  gums  alone  remain  uncovered.  The 
counterpart  of  the  flask  is  then  set  on  and  sufficient  plaster  poured  in 
until  the  prominences  of  wax  along  the  posterior  border  of  the  trial 
plate  are  slightly  covered.  After  the  plaster  has  set  the  upper  section 
of  the  flask  is  removed  and  the  surface  of  the  plaster  coated  with  shel- 
lac varnish.  The  section  of  the  flask  is  then  returned  to  its  place  and 
the  investment  completed  by  filling  it  up  to  the  edges  with  additional 
plaster.  When  this  has  set  the  flask  is  placed  in  hot  water  in  order  to 
separate  the  sections  easily.     The  wax  is  then  removed  and  also  the 


Fig.  1115. 


sections  of  the  flask  by  gently  tapping  them,  and  communication  made 
from  the  outer  surface  with  the  cavities  left  by  the  wax  prominences 
along  the  posterior  border  of  the  plate;  or,  if  this  is  impossible,  the 
vents  and  gates  may  be  formed  at  the  line  of  division  between  the  sec- 
tions, as  represented  by  the  dotted  lines  in  Figs.  11 16  and  1117.  Ex- 
ternally the  openings  D,  E,  and  F,  Fig.  1117,  should  be  enlarged  by 
reaming  out  the  plaster  and  varnished  with  shellac,  to  receive  the 
cylinders,  which  latter  are  made  of  wax,  rolled  thin,  and  wrapped 
around  a  cone-shaped  piece  of  wood.  These  cylinders  are  about  one 
and  a  half  inches  long  and  about  half  an  inch  in  diameter  at  the  base, 
tapering  to  an  eighth  of  an  inch  at  the  apex. 
64 


lOIO  MECHANICS DENTAL    PROSTHESIS. 

The  pouring-cylinder  is  usually  made  somewhat  smaller  at  its  base 
than  the  others,  but  some  two  inches  long.  Wax  covers  are  attached 
by  a  warm  sjjatula  to  the  larger  ends  of  the  cylinders,  so  as  to  make 
them  water-tight.  Fig.  1116,  d,  e,  f,  shows  the  cylinders  thus  pre- 
pared and  attached.  In  case  the  openings  have  been  made  through 
the  plaster  investment  of  the  lower  section,  as  represented  in  Fig. 
1 1 16,   then   the  upper  section,  Fig.  1117,   need  not  be  united  to  it 


until  the  openings  have  been  formed  upon  the  line  of  division,  when 
the  sections  must  be  joined  before  the  cylinders  can  be  attached.  The 
case  is  then  placed  in  a  larger  flask.  Fig.  11 18,  and  invested  as  before, 
allowing  the  end  of  the  pouring-cylinder  to  rest  in  the  opening  of  the 
posterior  border  of  the  flask.  In  this  investment  there  is  no  division 
of  the  sections  after  the  parts  of  the  flask  are  filled.     The  case  is  then 


METALLO-PLASTIC   WORK. 


lOI  I 


dried  in  an  oven,  all  of  the  wax  being  absorbed  by  the  heated  plaster, 
until  all  moisture  is  expelled.  Several  grades  of  the  alloy  are  used  by 
Dr.  Reese,  which  melt  at  600°  to  700°  F.,  but  a  higher  temperature  is 


Fig.  1 1 18. 


necessary  before  the  metal  is  ready  to  pour.     A  temperature  of  000° 
F.,  however,  will  cause  rapid  oxidation,  which,  of  course,  should  be 


MECHANICS  —  DENTAL    PROSTHESIS. 


— s 


avoided.  An  ordinary  ladle  may  be  employed  to  melt  the  alloy,  which 
is  poured  at  the  proper  temperature  into  the  opening  of  the  flask  and 
investment.     When  sufficient  time  has  elapsed  for  the  metal  to  cool, 

the  flask  is  opened  and  the 
case  presents  the  appear- 
ance represented  by  Fig. 
1 1 19,  when  it  is  ready  for 
finishing,  the  surplus  alloy 
being  removed  by  a  saw, 
and  the  surface  of  the  plate 
polished  by  pumice  on  a 
wheel  and  brush. 

To  repair  this  work  all 
edges  are  scraped  clean, 
and  a  space  cut  between 
them  of  about  one-eighth 
of  an  inch,  which  is  filled 
with  wax  when  the  set  is 
adjusted  on  the  model.  At 
each  end  of  the  space  two 
cones  of  wax,  each  about 
one-eighth  of  an  inch  in 
diameter,  are  attached, 
standing  perpendicularly 
to  the  palatal  surface,  and 
the  whole  invested  with  plaster  to  the  depth  of  an  inch.  The  two  sec- 
tions thus  made  are  then  separated,  and  the  wax  is  washed  out  by 
boiling  in  hot  water.  The  external  ends  of  the  spaces  left  by  the  wax 
cones  are  then  countersunk  and  a  larger  wax  cone  is  inserted  into  each 
opening,  the  one  to  form  a 
pouring-gate  and  the  other  to 
act  as  a  vent  for  surplus  metal, 
this  last  being  entirely  covered 
by  the  plaster  of  the  invest- 
ment. The  entire  piece  is  then 
invested  in  a  repair-flask,  and 
the  plaster  thoroughly  dried  and 
heated  up  before  the  alloy  is 
poured. 

Fig.  1 1 20  represents  a  dental 
mold   designed  by  Dr.  Hayford  for  use  in   manipulating  Weston's, 
Watt's,  and  Hayford's  alloys  and  by  which  it  is  claimed  all  imperfec- 
tions caused  by  air  bubbles  or  failure  of  the  material  to  cast  sharply 


Fig.  1120. 


VULCANO-PLASTIC   WORK.  IOI3 

are  overcome.  The  metal  is  introduced  with  the  flask  partly  open, 
and  just  before  crystallization  commences  pressure  is  applied  by  means 
of  the  lever,  which  closes  the  flask  and  forces  the  material  into  every 
portion  of  the  mold,  producing  a  sharp,  perfect  casting. 

Ward' s  Electro-Metallic  Dentures. — A  process  of  depositing  by  the 
action  of  a  battery  gold  and  silver  directly  upon  the  surface  of  the 
plaster  model  obtained  from  the  impression  of  the  mouth,  and  thus 
securing  perfect  adaptation,  has  recently  been  introduced.  The  sur- 
face of  the  plaster  model  is  prepared  for  the  deposit  of  gold  by  coating 
it  with  plumbago.  A  definite  thickness  of  gold  is  first  deposited  on 
the  plumbago-covered  surface  of  the  plaster  model,  and  upon  the  gold 
a  deposit  is  then  made  of  silver,  which  in  like  manner  is  then  covered 
by  another  deposit  of  gold.  The  object  of  using  silver  as  an  inter- 
mediate layer  between  the  two  gold  layers  is  to  give  strength  to  the 
plate,  as  all  deposited  metals  are  deficient  in  that  respect,  but  silver 
less  so  than  gold.  Sometimes  a  thin  silver  plate  is  swaged  and  the 
gold  deposited  upon  it.  Any  desired  thickness  of  gold  can  be  de- 
posited. If  a  rim  is  desired  on  the  plate  the  edges  of  the  impression 
are  cut  down  and  shaped  accordingly  before  the  model  is  poured.  A 
plate  so  constructed  must  not  be  soldered,  as  the  heat  will  anneal  it  to 
such  a  degree  as  to  render  it  too  pliable;  hence  in  a  set  of  full  metal 
the  teeth  are  attached  by  depositing  gold  about  and  around  their  pins, 
and  the  backings  are  portions  of  the  deposited  metals  and  continuous 
with  the  plate.  This  process  is  applicable  for  full  and  partial  dentures 
of  all  metal  finish  and  for  combination  with  rubber  or  celluloid,  in 
which  case  a  portion  of  the  surface  of  the  plate — that  covering  the 
alveolar  ridge — is  so  formed  as  to  present  projections  of  the  metal  in 
the  form  of  retaining-points  for  securing  the  vulcanite  or  celluloid 
which  attaches  the  teeth  and  forms  the  gum  portion.  It  can  also  be 
applied  to  capping  crowns  or  cusps  and  to  removable  bridge-work. 

VULCANO-PLASTIC   WORK. 

Under  this  name  are  included  all  vegetable  materials  which  have 
been,  or  may  hereafter  be,  incorporated  with  sulphur,  iodin,  or  other 
substances  for  the  development  of  those  peculiar  properties  so  well 
known  in  hard  rubber.  Inspissated  linseed  oil,  amber,  and  gum  copal, 
etc.,  have  thus  been  experimented  with,  but  with  results  thus  far  very 
unsatisfactory.  They  are  here  mentioned  because  it  is  by  no  means 
improbable  that  among  the  vegetable  oils,  resins,  or  gums,  now  known 
or  to  be  discovered,  there  will  be  found  one  which  shall  excel  any  yet 
known  in  those  remarkable  qualities  imparted  by  sulphur  to  the 
resinous  gums,  gutta  percha,  and  caoutchouc.  These  differ  from 
some  other  resins  in  an  opacity  which  follows   them    through  their 


IOI4  MECHANICS — DENTAL   PROSTHESIS. 

combinations  with  sulphur,  making  it  impossible  to  obtain  even  a 
tolerable  imitation  of  mucous  membrane.  Possibly  some  as  yet 
unknown  vulcanizable  transparent  resin  may  be  found  carrying  into 
its  combinations  enough  of  translucency  to  give  that  peculiar,  life-like 
animation  which  now  characterizes  porcelain-gum  colors  alone.  The 
history  of  caoutchouc  teaches  us  that  it  is  not  impossible  we  may  be 
in  daily  use  of  some  such  gum  or  resin.  The  only  compounds  of  gum 
(more  strictly,  resin)  and  sulphur  that  have  been  tried  to  any  extent 
are  corallite  and  vulcanite — the  trade  names  of  sulphuretted  gutta- 
percha and  sulphurated  caoutchouc ;  also  spoken  of  as  sulphid  of 
caoutchouc,  because  the  new  properties  developed  by  the  union  are 
such  as  make  it  appear  to  be  a  true  chemical  compound,  and  not,  like 
the  vermilion,  etc.,  often  incorporated  with  it,  a  mechanical  mixture. 

Corallite. — Gutta-percha  is  the  resinous  exudation  of  a  forest  tree, 
the  Isonandra  Gutta,  found  extensively  in  Sumatra,  Borneo,  and  the 
Malayan  Peninsula.  It  was  first  brought  to  the  notice  of  the  Euro- 
peans by  Dr.  Montgomerie,  of  Bengal,  in  1842,  and  in  a  few  years 
attracted  much  attention  for  those  valuable  properties  which  have  since 
made  it  so  indispensable  to  the  dentist.  Twelve  years  ago  experi- 
ments were  made  with  it  in  combination  with  sulphur.  Combined 
with  half  its  weight  of  sulphur,  and  the  compound  then  mixed  with 
half  its  weight  of  vermilion,  it  formed  a  substance  known  as  "  Coral- 
lite," which  hardened  under  the  same  conditions  as  vulcanite,  and  of 
which  it  promised  to  become  a  formidable  rival. 

Unfortunately,  one  property  of  crude  gutta-percha  followed  it  into 
this  combination — its  tendency  to  become  brittle.  It  is  well  known 
that  sheets  of  this  substance,  whether  the  pure  crude  gum  or  that  pre- 
pared for  dental  use  by  large  admixture  of  foreign  matter,  will  become 
in  time  so  brittle  as  to  break  almost  at  a  touch.  The  vulcanized 
gutta-percha  has  the  same  property  in  less  marked  degree,  but  quite 
enough  so  to  be  fatal  to  its  pretensions  as  a  rival  of  vulcanite.  Hence 
corallite  is  no  longer  avowedly  used,  and  even  its  name  is  almost  for- 
gotten. So  persistent  is  this  injurious  property  that  it  will  affect  any 
rubber  compounds  with  which  it  may  be  mixed.  Any  suspicion  of  the 
presence  of  gutta-percha  should  condemn  sulphurated  caoutchouc  for 
dental  use  ;  this  last-named  gum,  however,  may  be  brittle  and  worth- 
less from  admixture  of  other  substances  besides  gutta-percha,  as  will 
be  hereafter  stated. 

VULCANITE. 

Caoutchouc,  formerly  known  as  elastic  resin,  and  still  more  uni- 
versally known  as  India-rubber,  was  discovered  by  certain  French 
Academicians  in  Cayenne  in  the  year  1735.  For  many  years  its  only 
known  value  was  as  an  eraser  of  lead-pencil  marks.     Dr.  Priestley,  the 


VULCANO-PLASTIC   WORK.  IO15 

distinguished  discoverer  of  oxygen,  in  the  preface  to  his  work  on 
Perspective,  published  in  1770,  speaks  of  it  as  being  excellently- 
adapted  to  the  purpose  of  wiping  from  paper  the  marks  of  a  black-lead 
pencil.  It  was  still  many  years  after  this  that  it  was  confined  to  this 
use  and  to  the  making  of  rubber  shoes  and  bottles  by  South  American 
and  East  Indian  natives,  who  formed  them  on  clay  molds  from  the 
fresh  exudation  of  the  Siphonia  cahuca  Jatropa  elastica,  or  Ficus 
elastica.  Upon  discovery  of  a  solvent,  its  uses  were  extended  by 
bringing  to  bear  the  skilled  labor  of  civilization  ;  but  the  fact  of  its 
becoming  hard  and  rigid  (yet  not  brittle)  at  48°  greatly  limited  its 
value.  The  principal  solvents  of  caoutchouc  are  spirits  of  turpentine, 
bisulphid  of  carbon,  benzol,  ether,  chloroform,  naphtha,  and  the 
essential  oils. 

Mr.  Charles  Goodyear's  discovery  of  the  remarkable  effects  of  sul- 
phur in  combination  with  caoutchouc  has,  since  1840,  extended  the 
application  of  this  gum  to  an  almost  infinite  variety  of  uses.  In  cer- 
tain proportions  and  at  certain  temperatures  the  sulphur  does  not  much 
impair  the  remarkably  elastic  and  flexible  property  of  the  native  gum, 
but  preserves  it  at  low  temperatures.  Subsequent  experiments  led  to 
the  discovery  of  hard  rubber,  which  at  first  was  made  into  combs, 
buttons,  etc.  It  was  thus  used  for  a  number  of  years  before  its  appli- 
cation to  dental  purposes.  This  was  first  attempted  as  early  as  1853. 
Mr.  Bevan,  a  former  employee  of  the  Goodyear  Company,  Dr.  Put- 
nam, of  New  York,  and  Dr.  Mallett,  of  New  Haven,  were  the  first 
persons  known  to  the  writer  as  engaged  in  these  experiments  ;  possibly 
others  were  at  the  same  time  thus  occupied.  But  owing  to  the  exceed- 
ingly cumbrous  vulcanizing  apparatus  (Dr.  Putnam's  weighing  twelve 
hundred  pounds),  and  the  absence  of  that  knowledge  of  the  material 
and  those  appliances  for  its  manipulation  which  experience  alone  could 
give,  it  made  very  slow  progress  for  the  first  few  years.  It  has  been 
estimated  that  in  1858  not  more  than  three  hundred  dentists  made  any 
use  of  it ;  in  1863  it  was  conjectured  by  Dr.  Franklin  (then  dental 
agent  for  the  American  Hard  Rubber  Company)  that  nearly,  if  not 
quite,  three  thousand  employed  it  in  their  practice.  At  the  present 
time,  the  patents  restricting  its  use  having  expired,  it  is  universally 
employed. 

Hard  rubber  possesses,  when  prepared  in  greatest  perfection,  many 
qualities  which  fit  it  for  use  as  a  base  plate.  It  is  impervious  to  the 
buccal  secretions  and  unchanged  by  them  ;  it  has  very  considerable 
strength,  great  lightness,  and,  when  properly  vulcanized,  a  high  degree 
of  elasticity.  For  some  purposes  in  prosthetic  dentistry  it  has  no 
equal  and  for  some  few  it  is  indispensable  ;  but  the  merit  of  superior 
adaptation  is  shared  by  other  plastic  substances,  and  ff)r  many  cases 


IOl6  MECHANICS — DENTAL    PROSTHESIS. 

we  have  shown  that  the  fit  of  an  old-fashioned  gold  plate  is  much  to 
be  preferred. 

Dental  vulcanite  is  usually  incorporated  with  vermilion,  to  give  it  a 
color  more  generally  acceptable  than  the  dark  brown  of  the  simple 
sulphurated  gum.  But  rubber,  sulphur,  and  vermilion  are  all  opaque 
substances,  and  can  never  themselves,  or  by  combination  with  other 
materials,  be  made  to  assume  any  resemblance  to  the  natural  gum, 
which  porcelain  alone  has  thus  far  been  able  to  imitate.  The  incor- 
poration of  such  substances  for  this  purpose  has  no  other  effect  than 
seriously  to  impair  the  strength  of  the  material.  Experiments  in  vul- 
canite are  much  more  troublesome  than  those  with  stannic  alloys,  and 
probably  few  will  take  the  trouble  of  making  them.  A  common  formula 
for  the  red  vulcanite  is  caoutchouc,  48  parts;  sulphur,  24  parts  ;  vermil- 
ion, 36  parts.  The  formula  for  a  dark-brown  vulcanite  is  caoutchouc, 
48  parts  ;  sulphur,  24  parts  ;  this  gives  the  strongest  rubber.  The  for- 
mula for  a  jet  black  vulcanite  is  caoutchouc,  48  parts ;  sulphur,  24  parts; 
ivory,  or  drop  black,  48  parts.  All  colored  rubbers  are  weakened  by 
the  addition  of  foreign  matter,  as  English  pink  vulcanite'  which  con- 
tains 48  per  cent,  of  white  clay.  White  oxid  of  zinc  in  the  propor- 
tion of  47  per  cent,  will  give  to  vulcanite  mixed  with  sulphur  and 
vermilion  a  deep  pink  color.  The  pink  rubbers  are  so  much  weakened 
by  the  admixture  of  foreign  matter  that  care  must  be  taken  when  they 
are  used  to  produce  a  more  natural  color  of  the  gum  portion  of  a 
denture,  to  prevent  the  pins  of  the  artificial  teeth  from  being  covered 
by  such  rubber.  From  an  extended  series  of  very  careful  experiments 
by  the  late  Prof.  Wildman  we  condense  the  following  statements :  — 

Caoutchouc  two  parts,  sulphur  one  part,  form  a  dark-brown  rubber, 
which  is  the  strongest  of  the  vulcanites.  Of  all  additions  for  modifi- 
catio-n  of  color,  purest  vermilion  is  best ;  it  withstands  heat,  resists 
the  action  of  sulphur,  and  has  an  intensity  of  color  that  soonest  over- 
comes the  darkness  of  the  rubber.  Being  a  sulphuret,  it  appears  to 
have  much  less  effect  in  weakening  the  texture  of  the  sulphid  of  caout- 
chouc than  an  equal  quantity  of  any  other  substance  ;  yet  it  does 
diminish  its  strength  in  proportion  to  its  use.  English  deep  red  and 
American  Hard  Rubber  Company's  red  contain  by  weight  two  parts 
sulphid  of  caoutchouc  and  one  part  of  vermilion.  To  the  red  and 
brown  rubbers  white  oxid  of  zinc  or  white  clay  are  added  in  propor- 
tions varying  from  .20  to  .57  per  cent.,  to  produce  grayish-white  or 
pink  rubber.  Of  these  the  best  is  Ash  and  Sons'  pink  rubber  (S.  P.), 
containing  gum  sulphur  and  vermilion,  in  same  proportion  as  English 
deep  red,  with  one-fourth  this  weight  of  white  oxid  of  zinc  added  to 
tone  the  deep  color.  Black  rubber  is  made  by  adding  to  six  parts  of 
the  brown  sulphid  from  two  to  four  parts  of  the  ivory  black. 


VULCANO-PLASTIC    WORK.  I017 

In  the  selection  of  rubbers  we  unhesitatingly  decide  in  favor  of  the 
brown  vulcanite,  not  from  any  absurd  idea  of  the  injurious  action  of 
vermilion,  which  we  shall  presently  show  to  be  perfectly  harmless,  but 
because  of  its  superior  lightness  and  strength.  We  are  not  justified  in 
sacrificing  these  valuable  qualities  for  the  sake  of  colors,  which  not 
only  have  no  greater  esthetic  harmony  with  the  mouth,  but  which  by 
the  brilliancy  of  their  color  attract  attention  to  this  defect.  We  use 
white  platinum  and  aluminium  and  yellow  gold  ;  ivory,  in  old  times, 
soon  darkened,  and  a  tobacco  chewer  will  blacken  any  vulcanite  plate. 
Why  not,  then,  use  a  brown  base  plate  from  the  beginning?  If  the 
vermilion  rubber  is  used  let  it  by  all  means  have  its  natural  rich 
mahogany  color,  and  not  the  glaring  brilliancy  with  which  students 
delight  to  invest  their  specimens.  This  does  very  well  in  show  cases, 
and  is  eminently  adapted  to  those  captivating  exhibitions  of  high  art 
where  a  lovely  wax  face  opens  and  closes,  revealing  alternately  an  ach- 
ing void  and  acheless  grinders ;  but  in  the  mouth  such  bright  colors 
are  monstrous  violations  of  good  taste. 

Vermilion  combined  with  rubber  cannot  have  any  deleterious 
effect.  In  no  case  coming  under  our  observation  have  we  seen  a 
single  symptom  of  local  or  constitutional  action  peculiar  to  vulcan- 
ite, except  a  sensation  of  heat ;  this  we  take  to  be  an  electric  action, 
due  to  the  fact  that  rubber,  like  sealing  wax,  is  a  powerful  negative 
electric.  It  is  common  to  brown,  red,  pink,  and  white  rubbers,  and 
there  is  no  remedy  for  it.  It  is  not  a  constant  symptom  ;  some 
patients  never  feel  it,  some  often,  some  occasionally — dependent, 
perhaps,  upon  the  state  of  the  electric  element  entering  into  the  com- 
position of  vital  force. 

Pure  sulphuret  of  mercury  is  reckoned  by  Orfila  as  medicinally 
inert.  Fumigation,  by  vaporizing  the  mercury,  gives  it  a  medicinal 
activity;  but  this  requires  a  temperature  of  600°  Fahrenheit.  There- 
fore, for  the  development  of  constitutional  symptoms,  we  must  have 
the  presence  of  arsenic  or  of  red  lead,  as  impurities  of  the  sulphuret 
or  the  existence  of  free  mercury. 

First,  as  to  the  impurities  of  arsenic  or  red  lead  :  they  are  not 
found  in  pure  vermilion.  But  even  if  present  such  poisonous  impurity 
would  be  rendered  harmless,  because  completely  invested  by  an  insol- 
uble coating  of  India-rubber.  A  piece  of  vulcanite  is  impervious  to 
the  fluids  of  the  mouth  ;  hence  no  part  of  its  substance  can  be  dis- 
solved and  thus  taken  into  the  stomach.  Any  supposed  medicinal 
action  must,  therefore,  come  from  such  minute  particles  as  may  possibly 
be  worn  off  the  lingual  surface  near  the  teeth,  where  bread  crusts  01 
other  hard  particles  of  food  impinge.  White,  gray,  and  pink  rubbers 
have  so  large  a  proportion   of  foreign  matter   that    they  are   easily 


lOlS  MECHANICS — DENTAL    PROSTHESIS. 

abraded  ;  but  in  the  pure  red  rubbers  we  have  thus  an  almost  infini- 
tesimally  small  quantity  of  vulcanite  taken  into  the  stomach,  one-third 
of  which  is  inert  vermilion,  adulterated  (we  will  suppose)  with  three 
per  cent,  of  arsenic,  and  this  coated  with  a  layer  of  rubber,  which,  as 
previously  stated,  is  insoluble  in  water,  alcohol,  alkalies,  or  weak 
acids.  This  very  minute  trace  of  arsenic,  even  if  divested  of  its 
envelope  of  rubber,  would  have  a  purely  homeopathic  (and,  by  con- 
sequence, not  poisonous)  action  ;  while,  if  encased  in  rubber,  which 
pervades  every  part  of  the  material,  it  is  absolutely  inert.  The  same 
may  be  said  of  the  less  poisonous  adulteration,  red  lead. 

Secondly,  as  to  the  mercury  :  the  researches  of  Prof.  C.  Johnston, 
with  the  microscope,  and  Prof.  Alfred  Mayer,  by  chemical  analysis, 
have  failed  to  discover  the  slightest  trace  in  samples  of  the  best  rubber 
used.  Prof.  Wildman  found  sulphur  sublimed  during  vulcanization, 
but  not  the  smallest  trace  of  mercury.  We  have  failed  by  any 
mechanical  force  to  press  out  any  globules,  nor  have  we  ever,  in  any 
manipulations,  seen  the  slightest  particle  of  this  metal,  or  been  able 
with  the  microscope  to  detect  it  upon  the  surface  of  any  finished 
piece.  This  question  of  the  presence  of  free  mercury  in  the  vulcanized 
material  may  perhaps  require  a  more  extended  series  of  experiments. 
It  is  the  only  agent  that  can  possibly  exert  any  deleterious  action  upon 
the  system.  That  its  presence  is  rare  is  proven  ;  that  it  is  never  found 
can  be  confidently  asserted  or  denied  only  after  the  extended  ob- 
servations recommended,  the  observers,  however,  being  careful  not  to 
confound  the  minute  crystals  of  sulphur  with  globules  of  mercury,  as 
some  have  done. 

Impressions  for  vulcanite  work  may  be  taken  in  plaster,  wax,  gutta- 
percha, or  modeling  composition.  The  minute  accuracy  of  plaster  is 
not  so  essential  in  swaged  work,  since  the  very  fine  lines  of  the  model 
are  partly  lost  in  the  die  and  could  not  be  impressed  on  the  plate ;  but 
m  the  vulcanite  the  faintest  scratch  is  faithfully  copied.  The  finest 
plaster  must  be  used  and  stirred  until  all  air  bubbles  are  removed. 
Although  fine  plaster  will  give  the  minutest  lines,  yet  many  prefer 
for  all  laboratory  use  a  moderately  coarse  plaster,  which  becomes  hard 
and  strong  when  it  sets,  and  recommend  in  all  cases  admissible  plaster 
to  be  mixed  as  thick  as  it  will  work  well,  as  thin-mixed  plaster  expands 
more  than  the  thick-mixed.  The  fracture  of  the  teeth  of  a  plaster 
model  may  be  prevented  by  inserting  small  pieces  of  wire  or  brass 
pins  in  the  impressions  of  such  teeth  before  pouring  the  plaster. 
The  absolute  necessity  of  plaster  impressions,  in  most  partial  cases 
where  vulcanite  is  used,  led  the  late  Prof.  Austen  to  devise  the  method, 
elsewhere  described,  of  taking  impressions  with  gutta-percha  trays. 
The  advantages  of  a   partial  plaster  impression    thus   obtained  are  : 


VULCANO-PLASTIC    WORK.  IOI9 

first,  the  exact  shape  of  the  outside  of  the  teeth  adjoining  the  space 
to  be  filled  permits  correct  adjustment  upon  the  model ;  secondly,  the 
accurate  shape  of  the  inside  of  the  molars  and  bicuspids,  at  the  point 
where  wax  or  modeling  composition  impressions  drag,  allows  the  stays 
or  half-clasps  to  be  closely  fitted  to  the  teeth.  But  it  must  be  borne 
in  mind  that  partial  impressions  in  plaster  and  partial  pieces  in  vul- 
canite demand  for  their  success  the  utmost  care  and  nicety  of  manipu- 
lation, a  care  which  the  result  will  fully  reward.  The  absolute  non- 
contraction  of  rubber  may  make  wax,  modeling  composition,  or  gutta- 
percha in  some  cases  a  better  impression-material  for  full  sets  than 
plaster  ;  in  fact,  we  recommend  plaster  less  often  for  full  vulcanite 
plates  than  for  base  plates  of  any  other  material ;  while  in  partial 
cases,  for  reasons  just  given,  we  prefer  its  most  exclusive  use. 

Vulcanite  models  require  no  particular  shaping  except  the  extension 
of  the  back  part  an  inch  or  more,  so  that  the  model  itself  may  serve 
as  one-half  of  the  articulator.  This  not  only  saves  time  and  plaster, 
but  gives  more  accurate  results,  since  there  is  no  transfer  of  the  teeth 
and  wax  plate  to  a  new  wax  model.  When  the  teeth  are  set  in  the  wax 
plate  the  model  is  then  separated  with  a  saw  from  the  back  part  and 
placed  in  the  flask.  In  double  sets  the  back  part  of  one  model  is 
smoothed  and  the  T-shaped  groove  cut  and  soaped  or  covered  with  tin 
foil ;  the  extension  of  the  other  model  is  left  rough,  and  when  the 
articulating  plates  are  made  the  models  are  set  into  their  respective 
plates  and  the  space  at  the  back  part  filled  with  plaster.  Partial 
models  containing  a  number  of  teeth  require  no  other  antagonizer 
than  a  model  made  from  a  simple  impression  in  wax  of  the  lower  teeth, 
which  will  fit  the  irregularities  of  th?  teeth  of  the  upper  model. 
Models  for  vulcanite  may  be  coated  with  very  dilute  soluble  glass 
(liquid  silex),  collodion,  or  tin  foil.  The  late  Prof.  Austen,  in  1858, 
sent  his  earliest  experiments  in  rubber  to  Dr.  Putnam,  of  New  York, 
to  be  vulcanized.  The  Doctor  wrote  to  know  "what  the  varnish  was 
which  prevented  the  rubber  from  sticking."  It  was  this  soluble  glass, 
used  originally  for  the  purpose  of  hardening  the  surface,  to  prevent 
injury  from  subsequent  manipulations. 

Antagonizing  plates  are  made  by  molding  a  piece  of  gutta-percha 
over  the  model,  kept  very  wet  to  prevent  adhesions.  The  central  part 
should  be  not  less  than  one-eighth  of  an  inch  thick,  to  give  stiffness 
to  the  plate ;  the  rim  on  the  edge  should  be  the  exact  length  of  the 
teeth  required  and  trimmed  very  carefully  on  the  outside  to  give  the 
proper  fullness.  The  gutta-percha  should  be  first  worked  into  a  ball, 
using  from  one  to  two  sheets,  according  to  the  size  of  the  mouth  ; 
then,  pressing  from  the  centre  outward,  the  articulating  rim  is  formed 
at  the  same  time  that  the  material  is  turned  over  the  ridge.     It  is 


I020  MECHANICS — DENTAL   PROSTHESIS. 

quickly  done,  will  not  injure  the  most  delicate  ridge,  and  gives  a  plate 
as  unyielding  as  any  gold  plate.  In  a  lower  set  the  rim  may  be  stiff- 
ened with  a  piece  of  heavy  iron  or  copper  wire.  In  a  full  or  nearly 
full  upper  set  the  impress  of  the  lower  teeth  is  to  be  received  in  a  thin 
rim  of  wax  set  on  the  gutta-percha.  In  a  double  set  the  rims  are 
trimmed  till  they  touch  uniformly,  and  then  their  relation  marked  by 
decided  indentations  across  the  line  of  contact.  It  is  quite  possible 
with  these  gutta-percha  plates  to  take  the  articulation  in  every  case 
with  such  absolute  accuracy  that  no  trial  of  the  teeth  is  necessary,  nor 
any  grinding  of  the  teeth  upon  inserting  them  in  the  mouth.  Metallic 
articulating  plates  swaged  for  the  case  are  much  more  troublesome  and 
are  no  better.  The  usual  method  of  making  them  of  sheet  gutta- 
percha, wax,  or  tin  foil  can  never  give  one  that  full  confidence  in  his 
articulation  which  enables  him  habitually  to  dispense  with  the  trial 
of  the  piece  after  grinding.  As  vulcanite  articulations  are  often 
taken,  it  would  be  as  well  simply  to  look  at  the  mouth  and  guess  at 
them. 

The  modeling  composition  is  an  excellent  material  for  a  base  plate 
in  securing  the  articulation.  After  being  softened  and  adapted  to 
the  cast  a  roll  of  softened  wax  is  placed  upon  the  base  plate  over 
the  alveolar  ridge  and  shaped  to  the  form  of  the  arch.  After  being 
tried  in  the  mouth  and  added  to  or  trimmed  oft"  if.  too  short  or  too 
long,  the  patient  is  directed  to  bite  into  the  wax.  To  prevent  secur- 
ing too  long  or  too  short  a  bite,  one  or  more  small  blocks  of  soft  pine 
wood,  about  half  an  inch  square  and  thicker  than  the  required  bite, 
may  be  attached  to  the  base  plate  with  melted  wax  and  trimmed  off" 
until  the  necessary  length  is  obtained.  The  wax  rim  is  then  applied 
over  the  block  and  the  proper  articulation  secured.  For  an  entire 
denture  the  articulating  rims  may  be  made  of  modeling  composition. 

Preparatory  to  the  selection  and  grinding  of  teeth  or  blocks  the 
thick  articulating  plates  must  be  removed  and  the  model  covered  with 
thin  druggist's  foil,  and  the  space  inside  the  ridge  filled  with  a  mass 
of  soft  wax  pressed  out  until  it  meets  the  probable  inside  line  of  the 
teeth  to  be  fitted  ;  this  aff"ords  a  much  firmer  support  to  the  teeth 
during  grinding  than  the  usual  practice  of  using  the  thin  wax  or  gutta- 
percha matrix  plate.  The  top  and  outside  of  the  ridge  are  left  cov- 
ered with  foil  alone.  When  blocks  like  Fig.  1122  are  to  be  ground, 
passing  over  the  front  of  ridge  and  surmounted  with  a  rubber  band,  it 
is  essential  that  the  block  shall  not  quite  touch  the  model  at  any 
point;  this  contact  is  prevented  by  placing  between  the  foil  plate  and 
the  model  a  strip  of  foil  having  four,  six,  or  eight  thicknesses,  as  may 
be  desired.  But  when  blocks  such  as  Figs.  11 23  and  11 24  or  teeth  like 
Fig.  1 1 21  are  ground  resting  directly  upon  the  gum,  with  no  rubber 


VULCANO-PLASTIC   WORK.  I02I 

above  or  under  the  upper  part  of  the  gum,  the  tin  foil  is  retained  only 
during  the  process  of  grinding,  so  as  to  receive  the  paint  used  in 
accurate  fitting  of  blocks;  the  foil  is  then  removed  and  the  plaster 
scraped,  so  as  to  slightly  bed  the  front  blocks  or  teeth  in  the  natural 
gums.  As  the  teeth  are  ground  they  should  be  attached  to  the  wax 
mass  with  softened  or  melted  wax. 

In  grinding  the  greatest  care  must  be  taken  to  make  close  joints  ; 
but  the  fitting  of  the  base  requires  none  of  the  accuracy  demanded  in 
fitting  gold  plates,  except  when  the  tooth  is  to  be  set  directly  upon  the 
gum.  It  is,  however,  a  mistake  to  suppose  that  a  space  of  half  an 
inch  can  with  perfect  impunity  be  left  between  the  teeth  and  plate  ; 
for  vulcanite  has  a  slight  shrinkage  on  cooling.  Unlike  the  shrinkage 
of  metal,  which  is  irresistible,  that  of  vulcanite  is  controlled  by  the 
matrix,  so  that  it  results  in  no  change  in  the  shape  of  the  plate.  This 
is  proved  by  the  closeness  with  which  it  is  seen  to  adhere  to  the  model 
on  opening  the  matrix.     But  it  takes  place  in  the  direction  of  the 


Fig.  II2I. 


Fig.  1 1 23 


Fig.  1 124. 


thickness  of  the  plate.  If,  therefore,  a  large  bulk  of  material  is  inter- 
posed between  the  teeth  and  ridge,  it  will  shrink  perceptibly  either 
from  the  ridge  or  from  the  teeth  ;  in  the  first  case  impairing  the  fit  of 
the  piece,  in  the  latter  case  loosening  the  hold  of  the  rubber  upon  the 
tooth.  Thick  masses  of  vulcanite  are  also  apt  to  be  porous  or  honey- 
combed, owing  to  the  evolution  of  sulphur.  That  sulphur  is  evolved 
in  all  cases  is  evident  from  the  staining  of  the  plaster,  blackening  of 
the  flasks  and  inside  of  the  vulcanizer,  and  from  the  peculiar  smell 
whenever  there  is  escape  of  steam.  We  sometimes  find  it  makes  the 
rubber  porous,  especially  in  lower  cases,  in  spite  of  every  precaution 
taken  to  prevent  it.  It  is  not  impossible  that  subsequent  modifications 
in  the  time  and  manner  of  vulcanizing  may  correct  this  and  several 
other  difficulties  attendant  on  the  hardening  of  thick  masses  of  rubber ; 
meanwhile  it  is  safer  to  avoid  all  unnecessary  thickness  of  material. 
jVIany  cases  will  permit  the  use  of  a  stout  aluminium  wire  behind  and 
under  the  pins,  running  along  the  incisors  and  bicuspids  ;  if  so,  it  will 


I032  MECHANICS — DENTAL    PROSTHESIS. 

reduce  the  bulk  of  rubber  and  strengthen  the  piece.  We  often,  run  a 
heavy  platinum  wire  or  strip  of  doubled  plate  behind  the  entire  arch 
in  lower  sets  to  add  to  their  weight  and  strengthen  them  ;  when  care- 
fully done  it  makes  a  very  strong  piece,  and  removes  the  objection  of 
lightness  which  prevents  the  use  of  rubber  in  many  lower  cases. 

When  the  teeth  or  blocks  are  ground,  and  the  joints  and  outside 
fitting  carefully  examined  with  a  Coddington  lens  or  some  other  strong 
magnifying  glass,  the  next  point  is  to  make  guiding  grooves  or  holes 
in  the  plaster  articulator  below  the  teeth;  then  place  the  lead  band 
and  pour  the  temporary  investing  rim,  as  has  been  already  described 
in  the  investment  of  teeth  for  gold  plate  preparatory  to  backing  (see 
p.  921).  If  it  is  a  partial  piece  we  often  prefer  to  make  this  rim  with 
a  roll  of  gutta-percha,  previously  wetting  the  model  to  prevent  its  ad- 
hesion. An  elastic  band  or  string  will  hold  this  rim  in  place  while 
the  wax  is  being  removed  and  substituted  by  the  matrix  plate,  that  is, 
the  wax  plate  which  is  to  be  replaced  by  the  rubber.  The  use  of  the 
rim  permits  an  examination  of  the  blocks  or  teeth  on  the  inner  side 
and  the  correction  of  any  irregularity  in  the  pins  or  in  the  inner  edge 
of  porcelain  where  it  meets  the  rubber,  also  the  grinding  off  of  any 
point  where  a  block  may  come  unnecessarily  near  the  model. 

A  small  roll  of  soft  wax  is  then  to  be  pressed  against  the  pins  and 
model,  holding  the  rim  firmly  to  prevent  the  slightest  displacement  of 
the  blocks.  A  wax  matrix  plate  is  then  slightly  softened  and  pressed 
gently  over  the  face  of  the  model  and  the  other  wax  up  to  the  tooth. 
Be  careful  not  to  thin  the  wax  unequally,  and  yet  to  press  it  into  all 
the  natural  irregularities  of  the  model  and  to  bring  out  the  tracings  of 
the  rugae  and  the  central  raphe.  If  the  first  wax  is  trimmed  so  as  to 
just  clear  the  tips  of  the  pins  and  have  a  slight  curve  where  it  joins  the 
model,  very  little  trimming  of  the  wax  plate  will  be  necessary  when 
blocks  are  used.  This  method  also  enables  the  operator  to  know  ex- 
actly the  thickness  of  the  plate  at  all  points.  Gutta-percha  does  not 
answer  so  well  as  wax,  as  it  cannot  so  readily  be  smoothed  where  it 
joins  the  blocks.  After  using  the  wax-knife  around  the  edges  it  is 
well  to  go  over  the  surface  with  a  strip  of  oiled  buckskin. 

The  wax  plate  should  vary  in  thickness  from  No.  14  to  No.  18 
gauge  plate  (Fig.  921),  according  to  the  depth  of  the  palatine  arch. 
Vulcanite  cannot  safely  be  reduced  to  the  thinness  of  gold  or  alu- 
minium plates,  or  even  of  the  best  stannic  alloys.  The  elasticity  of 
the  best  made  vulcanite  is  often  thought  to  justify  great  thinness  of 
plate,  and  this  may  be  allowed  in  some  partial  pieces  ;  but  in  full  sets, 
or  where  many  teeth  lie  grouped  together,  elasticity,  with  thinness 
such  as  permits  bending  of  the  palate,  is  very  apt  to  cause  opening  of 
joints   or   breaking   of  blocks.     Elasticity  of  vulcanite   lessens   the 


vmjCAXo-PLAsnc  wobk. 


1023 


chance  of  injorv  firom  an  accidental  ^1 ;  but  ssan  dement  of  strengdi 
it  is  principally  valnable  as  imjHOTing  its  rigiditv  and  toogliness :  and 
the  plate  of  all  fiill  sets  shoold  be  thick  enoqgh  to  be  unyielding  under 
the  force  of  mastication. 

Fig.  112:;  represents  Dr.  R.  WQnsches'  perforated  metal  plate,  by 


\ 


the  use  of  which,  it    :  ^  may  be 

made  much  thinner  ..  ".ri 

that  these  platKgiv  7  .  -  f 

countersunk,  forming  a     t.i     -  1 

thus  preventing  any  dar  _   - 

Fig.  1 1 26  represents 
In   flowing  wax  with   *. 
around  the  teeth,  after 
curately   arranged    upcr.  r 

must  be  taken  to  kee 

and  the  wax  plate  i„ -.    — .  ..„ „ 

smoothed  with  either  the  blowpipe  f.ir.:e. 
benzine  applied  on  a  piece  of  soft  cl : : 
by  the  repeated  and  careful  applicai. : : 
the  warm  spatula. 

The  wax  plate  should   be  as  perfect   a  P:;  ::.75. 

counterpart  of  the  vulcanite  plate  as  it  is 

pcssible  to  make  it.  Fig.  1 1 27  represents  a  set  of  carving  instruments, 
designed  by  Dr.  W.  W.  Evans,  for  modeling  wax  in  vulcanite,  zyio- 
nite,  and  celluloid  work. 

When   the    inside  wax    plate    has  been   completely  finished   the 


I024 


MECHANICS — DENTAL    PROSTHESIS. 


outside  plaster  rim  is  removed,  having  provided  for  its  easy  removal 

by  a  break  or  section  opposite  the 
incisors.  Again  examine  all  joints 
with  the  glass  to  see  that  they  have  not 
i|,  li  II  ■*  been  accidentally  opened  ;  then  apply 
one  or  more  strips  of  wax  to  give  the 
required  form  of  edge,  outside  the  ridge 
and  above  the  blocks.  Plain  or  gum 
teeth  or  blocks,  resting  directly  on  the 
gum,  must,  of  course,  have  no  wax  in 
front  of  incisors,  canines,  and  first  or 
even  second  bicuspids ;  in  all  such  cases 
be  careful,  just  before  investing  in  the 
flask,  to  see  that  the  teeth  set  closely 
down  upon  the  model.  Vulcanite  blocks 
have  a  shoulder  designed  to  receive  the 
margin  of  the  external  rubber  band ; 
when  the  blocks  have  been  chosen  with 
such  care  that  no  grinding  of  the  upper 
edge  is  necessary,  this  gives  the  best 
finish.  But  it  often  happens  that  the 
exigencies  of  the  case  require  thinning 
or  shortening  of  the  blocks;  a  thin  edge 
of  wax  should  then  slightly  overlap  the 
blocks.  If  the  porcelain  edge  has  suffi- 
cient thickness  it  is  sometimes  a  good 
plan  to  bevel  it ;  the  rubber  may  then  be 
finished  continuously  with  the  porcelain, 
and  }et  have  a  retaining  edge.  It  is 
well  to  pass  a  very  fine  corundum  slab 
over  the  gum  just  before  placing  the  wax 
rim;  it  removes  accidental  roughness 
and  makes  the  finishing  process  easier. 
Superfluous  wax  should  be  avoided  out- 
side as  well  as  inside ;  but  every  undercut 
must  be  filled,  else  there  will  be  danger 
of  breaking  thin  or  prominent  ridges  in 
separating  the  matrix.  Outside  surplus 
is  more  easily  removed  than  inside; 
hence  there  is  no  objection  to  running 
the  wax  further  up  on  the  ridge  than  the 
finished  ])late  ;  but  unnecessary  thickness 
Fig.  1 127.  is  to  be  avoided  for  reasons  before  given. 


\| 


VULCANO-PLASTIC   WORK.  IO25 

If  the  original  model  has  been  extended  tor  articulation  caretully 
remove  the  plate  and  saw  off  this  portion  of  the  model,  and  trim  so  as 
to  fit  the  half  flask  in  which  it  is  to  be  set.  This  trimming  done, 
replace  the  plate  and  fasten  it  around  the  edges  with  a  hot  wax-knife. 
It  is  now  ready  for  the  vulcanizing  flask. 

All  forms  of  teeth  may  be  used  with  the  vulcanite  base,  and,  unlike 
most  other  work,  may  be  used  again  and  again.  Continuous-gum  teeth 
can  be  strongly  and  handsomely  arranged,  provided  the  patient  shows 
but  little  of  the  tooth;  and  also  where  celluloid  is  used  in  connection 
with  vulcanite.  Single  teeth,  plain  or  gum,  require  either  to  be  backed 
with  gold  strips  and  soldered,  or  simply  to  have  the  pins  lengthened. 
For  this  purpose  heavy  platina  wire,  say  No.  20,  should  be  cut  into 
lengths  from  one-fourth  to  three  fourths  of  an  inch  long,  set  between 
the  pins  in  the  required  direction  and  soldered  with  pure  gold.  Plate 
teeth  backed  with  a  narrow  platina  strip,  similar  to  Fig.  11 28,  may 
also  be  used,  and  are  required  in  certain  cases  that  will  not  admit  of 
thick  vulcanite  teeth.  The  projecting  tang  strengthens  the  rubber  in 
case  of  isolated  teeth  and  may  be  serrated  with  a  file  ;  but  a  pair  of 


Fig.  1128.  Fig.  1129. 

forceps  with  serrated  beaks  may  do  this  better  and  more  quickly  than 
the  file.  Occasionally  some  one  or  more  under  teeth  strike  so  closely 
against  the  gum  as  almost  to  touch  ;  if  rubber  is  used  in  such  cases 
these  teeth  must  be  plate  teeth  with  the  usual  soldered  gold  backing, 
having  a  serrated  extension  into  the  rubber. 

The  assortment  of  vulcanite  teeth  now  offered  to  the  profession  is, 
in  variety  of  color,  size,  and  shape,  such  as  to  meet  almost  every 
possible  case.  In  fact,  we  doubt  if  the  manufacturer's  esthetic  skill 
in  making  is  not  sometimes  in  advance  of  the  dentist's  esthetic  taste 
in  selecting.  Certainly  the  stiff  uniformity  and  monotonous  expres- 
sion which  so  frequently  meet  the  eye  is  an  injustice  to  the  present 
high  de\elopment  of  the  dento-ceramic  art.  In  the  .next  chapter  we 
shall  illustrate  by  wood-cuts,  kindly  provided  for  us  by  the  S.  S.  White 
Co.,  some  of  the  delicate  forms  which  so  exactly  imitate  Nature. 
Figs.  1122,  1123,  1124,  1125,  1128,  and  1129  will  give  a  correct  idea 
of  the  special  form  and  shape  of  the  ping  of  vulcanite  teeth  as  at 
present  manufactured. 
65 


I026 


MECHANICS DENTAL    PROSTHESIS. 


Vulcanizers. — A  sixteen-horse-power  boiler,  communicating  bv 
twenty  feet  of  pipe  with  a  thirt3^-inch  cubical  steam  chest,  was  the 
vulcanizer  of  1S57. 

The  first  one  which  was  at  all  practicable  as  an  office  fixture  was 
a  two -chambered  affair  of  cast  iron,  as  large  as  a  soda  fountain  reser- 
voir, heated  by  a  coal  stove.     Successive  improvements  have  since 

been  made,  and  the  vul- 
canizer  of  to- day  is  a  very 
different  thing  from  the 
huge,  clumsy  affair  from 
which  it  originated. 

The  proper  working  of 
the  vulcanizer  and  the  sat- 
isfaction with  which  it  is 
used  depend,  in  a  great 
measure,  upon  the  perfec- 
tion of  the  workmanship 
put  upon  it ;  and  a  saving 
of  a  dollar  or  two  in  first 
cost,  coupled  with  the  pos- 
session of  a  poorly-made 
machine,  will  prove  an  ex- 
pensive investment  in  the 
long  run. 

Copper  is  now  almost 
universally  emplo}ed  as 
the  material  from  which 
the  boiler  or  body  of  the 
vulcanizer  is  made,  a  ring 
of  brass  being  brazed  to 
the  edge  to  form  the  jxTck- 
ing  joint  and  the  attach- 
ment for  the  cover.  The 
flexibility  of  these  mate- 
rials renders  it  important 
that  the  cover  fastening 
should  support  the  whole 
circumference  of  the  edge  of  the  boiler  and  bring  the  strain  uniformly 
upon  it  in  order  to  preserve  the  truth  of  the  face  of  the  packing  joint. 
If  the  strain  is  brought  to  bear  upon  the  circumference  of  the  joint  at 
intervals,  the  result  is  that  the  boiler  gradually  yields  to  the  strains  at 
the  points  where  it  is  unsupported,  the  joint  is  drawn  out  of  true,  and 
in  a  short  time  the  vulcanizer  is  leaky  and  comparatively  worthless. 


VULCANO-PLASTTC   WORK. 


1027 


Figs.  1130,  1131,  and  1132  represent  the  improved  vulcanizers  in  use 
at  the  present  time.  Steam  gauges  are  attached  to  the  first  two,  and  a 
thermometer  to  the  other. 

Fig.  1133  represents  a  dry  steam  vulcanizer  for  hardening  vulcanite 
by  dry  steam,  which,  it  is  claimed,  saves  time  and  rubber,  and  gives 
to  thin  plates  sufficient  strength. 


Fig.  1131. 

The  "New  Mode  Heater,"  Fig.  1134,  invented  by  Dr.  John  S. 
Campbell,  presents  many  points  of  difference  when  compared  with 
other  vulcanizers.  It  is  made  of  phosphor-bronze,  in  a  single  casting, 
with  two  chambers,  the  one  in  which  the  flask  is  placed  being  sur- 
rounded by  an  outer  steam-chamber.     It  has  screws  for  closing  the 


I028 


MECHANICS — DENTAL    PROSTHESIS. 


flask  as  it  is  being  heated,  and  is  adapted  to  working  celluloid  as  well 
as  for  vulcanizing  rubber.  Steam  may  be  admitted  to  the  vulcanizing 
chamber  or  not,  as  may  be  desired,  and  either  "wet"  or  "dry" 
heat  used.  The  use  of  the  New  Mode  Heater,  it  is  claimed,  will  pre- 
vent the  rubber,  when  being  vulcanized,  from  shrinking  from  the  teeth, 
and  also  permit  of  the  use  of  plain  teeth  with  rubber  for  the  base  and 
celluloid  for  the  gum,  a  form  of  work  to  which   the  name  of  "New 


Fig.  1132. 


Mode  Continuous  Gum  "    has  been  given   by  Dr.    Campbell,  the  in- 
ventor (see  Celluloid). 

The  vulcanizer  is  usually  heated  by  either  gas,  alcohol,  or  kerosene. 
Gas,  if  used  in  a  burner  which  will  mix  the  proper  quantity  of  air 
with  it  before  burning  is  the  most  convenient,  cleanest,  and  probably 
the  cheapest  fuel  for  the  purpose.     The  flame  should  be  a  clear  blue, 


VULCANO-PLASTIC   WORK. 


1029 


with  no  streaks  of  yellow.  A  yellow  flame  results  from  an  insufficient 
mixture  of  air,  and  makes  smoke,  soot,  and  a  bad  smell  from  the  pro- 
duction of  acetylene.  The  use  of  gas  also  admits  of  the  employment 
of  the  gas  regulator  (Fig.  1132),  an  attachment  which  automatically 
keeps  the  temperature  of  the  vulcanizer  at  the  exact  point  required. 
The  steam  pressure  acts  upon  a  valve  to  control  the  flow  of  gas  to  the 
burner,  lessening  the  flow  as  the  pressure  rises  and  keeping  it  at  the 


Fig.  1133. 


point  for  which  it  is  set.  It  is  not  liable  to  get  out  of  order  and  with 
it  the  supervision  of  the  dentist  over  the  vulcanizing  process  is  not 
required  ;  and  if  the  time  cut-off  is  also  used  the  dentist  is  at  liberty 
to  go  to  his  patients  in  the  operating  room  without  the  necessity  of 
giving  a  thought  to  the  vulcanizer,  knowing  that  the  temperature  will 
be  kept  exactly  right  and  that  the  gas  will  be  turned  off  at  the  right 
time.     The  results  will  thus  be  uniform  ;  much  more  so  than  is  possible 


MECHANICS — DENTAL    PROSTHESIS. 


Fig.  1134. 


with  the  use  of  the  ther- 
mometer, as  the  regulator, 
operating  by  steam  pres- 
sure, is  more  sensitive  and 
exact  than  the  thermome- 
ter can  possibly  be.  After 
gas  the  alcohol  flame  is  pre- 
ferable for  vulcanizing  pur- 
poses. It  is  clean  and  inof- 
fensive. Many  use  the  kero- 
sene stove,  but  taking  into 
account  itssmoke  and  smell 
it  may  be  doubted  whether 
the  economy  secured  by  its 
use  is  not  dearly  bought. 

The  following  tables, 
carefully  collected  from  ex- 
periments of  the  French 
Academy,  the  Franklin  In- 
stitute, Ure,  Dalton,  and 
others,  will  serve  as  a  guide 
in  the  use  of  either  the 
steam-guage  or  the  mercu- 
rial thermometer:  — 


No.  I.                                 No.  2. 

Pressure  per  Square  Inch. 

Temperature. 

Pounds. 

Temperature. 

Inches  of 
Mercury. 

Atmo- 
spheres. 

Pounds 
Avoirdupois. 

Scale 
Fahrenheit. 

Differences. 

30 

60 

90 

120 

150 
180 
210 
240 
270 
300 

360 
420 
480 
540 
600 
660 
720 
1 

I 

3 

4 
5 
6 

7 
8 

9 
10 

12 

14 
16 
18 
20 
22 
24 

15 

30 
45 
60 

75 
90 
105 
120 
135 
150 

180 
210 
240 
270 
300 

330 
360 

212° 
250° 
275° 
294° 
309° 

321° 
332° 
342° 

352° 
360° 

374° 
387° 
398° 

40q° 
419° 
428° 
436° 

38° 
25° 
19° 

15° 
12° 
11° 

10° 
10° 

8° 

14° 

13° 
11° 

11° 

10° 
9° 
8° 

•  63 

73 
80 

87 
95 
102 
no 
117 
124 
131 

300° 
310° 

315° 
320° 

325° 
330° 

335° 
340° 

345° 
350° 

VULCANO-PLASTIC    WORK.  I03I 

These  tables  show  the  increase  of  steam  pressure  with  the  tempera- 
ture up  to  a  point  much  higher  than  the  dental  vulcanizer  should  ever 
be  called  upon  to  bear.  The  second  table  is  prepared  especially  to 
show  the  pressure  due  to  the  temperature  at  diiTerent  vulcanizing 
points,  and  attention  is  especially  called  to  the  rapid  increase  of  pres- 
sure with  equal  increments  of  heat  as  the  temperature  rises.  The  last 
column  in  Table  No.  i  shows  the  additional  temperature  required  for 
equal  increments  of  pressure,  and  it  will  be  seen  that  while  it  requires 
38°  to  raise  the  pressure  15  pounds  at  212°,  only  4°  is  required  for  the 
same  increase  from  430°.  The  pressure  nearly  doubles  with  the 
addition  of  each  50°  of  heat,  and  allowing  a  vulcanizer  to  run  up 
to  400°  or  420°  is  shown  to  be  a  piece  of  unpardonable  carelessness 
and  a  proceeding  fraught  with  the  greatest  danger  to  life  and 
property. 

Every  vulcanizer  should  be  provided  with  some  means  by  which  the 
steam  will  be  allowed  to  escape  before  the  danger-point  is  reached. 
Safety-valves  have  been  thoroughly  tried  and  have  proved  unsatisfac- 
tory from  their  constant  leakage.  The  fusible  plug, 
consisting  of  an  alloy  of  soft  metal  filling  a  hole  in  the 
vulcanizer,  which  would  melt  and  blow  out  at  350°  or 
360°,  was  at  one  time  much  used,  but  it  has  the  fatal 
detect  of  hardening  after  repeated  heating,  so  that  its 
melting  point  is  raised  to  400°  or  even  more  ;  so  that 
after  being  used  a  short  time  it  is  wholly  untrustworthy. 
A  most  satisfactory  device  for  the  purpose  is  the  copper 
disc  (Fig.  1 135),  made  of  metal  thin  enough  to  give 
way  under  an  extreme  pressure.  It  is  secured  upon  the 
end  of  a  small  stud,  screwed  into  the  vulcanizer  cap  by  means  of  a 
washer  and  screw-cap. 

Flasks. — Of  flasks  there  are  many  varieties,  made  of  iron  and  brass. 
The  essentials  of  a  good  flask  are  :  i.  It  must  have  depth  and  width 
for  the  largest  cases.  2.  Both  ends  should  be  separate  for  greater 
convenience  of  placing  the  model  in  either  ring.  3.  The  guide- 
fingers,  about  one-quarter  of  an  inch  long,  should  work  straight  and 
true,  be  strong,  and  yet  not  unnecessarily  break  the  regularity  of  inside 
and  outside  surfaces  ;  cover  flanges  may  be  very  short.  4.  Inside  and 
outside  should  present  as  unbroken  a  surface  as  possible  for  facility  in 
removing  and  cleaning  off  surplus  plaster.  Both  rings  should  taper, 
partly  to  give  greatest  breadth  to  the  line  of  junction,  partly  for 
easier  delivery  of  plaster. 

Figs.  iT36and  1 137  represent  the  "Star"  and  "Anchor"  flasks, 
the  first  being  reversible ;  other  flasks  are  also  self-locking  by  means 
of  flat  springs  on  the  outside  of  the  lugs. 


1032 


MECHANICS  —  DENTAL    PROSTHESIS. 


Fig.  1 1 38  represents  the  "  box  flask,"  designed  for  extra  large  cases, 
splints  for  fractures,  artificial  jialates,  etc. 

Making  Mafrix,  Rejnoviiig  Wax,  and  Packing  the  Ruhber. — The 
model  of  a  full  set  is  placed  in  the  shallow  half,  A,  of  the  flask  (Fig. 
1139),  with  wax  plate  and  teeth  attached,  as  before  described.  The 
model  must  be  saturated  with  water,  to  prevent  the  too  rapid  setting 
of  the  plaster  batter  with  which  the  flask  is  partly  filled,  and  which, 
on  placing  the  model,  rises  to  the  edge  of  flask  and  edge  of  the  wax 
plate.  The  plaster  should  be  mixed  as  thick  as  will  pour  readily  and 
the  lower  section  of  the  flask  partly  filled  with  it,  when  the  model  and 


teeth  should  be  placed  in  it,  bottom  down,  as  shown  in  Fig.  1139,  A, 
and  slightly  inclining  in  front  so  as  to  exclude  all  air  bubbles  when 
forcing  it  into  place.  In  the  case  of  an  entire  upper  or  lower  set  the 
l)laster  should  extend  up  to  the  wax,  as  this  will  allow  the  teeth  to  be 
imbedded  in  the  plaster  filling  the  upper  .section  of  the  flask.  As 
soon  as  the  plaster  has  become  moderatel\-  firm  trim  smoothly  up  to 
the  model  with  spatula  or  sponge;  then  soap  this  surface,  or  varnish 
and  oil  it,  or  cover  it  with  tin  foil.  When  shellac  varnish  is  used, 
care  should  be  taken  that  the  teeth  or  gums  are  not  coated  with  it. 


VTJLCANO- PLASTIC    WORK. 


1033 


Some  prefer  the  soap  solution,  white  soap,  sj,  soft  water,  Oj,  for  sepa- 
rating plaster  surfaces.     Some  are  in  the  habit  of  placing  the  lower 


Fig.  1137. 


I034 


MECHANICS — DENTAL    PROSTHESIS. 


half  of  the  flask  in  water,  that  it  may  absorb  as  much  as  possible  before 
the  upper  half  is  poured.  Mix  a  fresh  lot  of  rather  stiff  batter,  and 
brush  it  carefully  over  the  wax  and  into  all  the  interstices  of  the  teeth. 
Then  place  the  upper  half-flask,  C,  accurately  upon  the  lower  half,  and 
quickly  pour  the  batter,  stirring  it  well  with  a  feather  or  small  brush, 
into  the  space  between  the  teeth  and  sides  of  the  flask.  Set  on  the 
cover  D  and  apply  the  clamp  B,  or  a  heavy  weight.  Before  it  fully 
hardens  wash  off  the  plaster  with  a  sponge  from  the  outside  of  the 
flask,  and  let  it  get  quite  hard  before  separating  the  two  halves.  The 
object  of  making  the  batter  stiff  is  to  give  it  greater  hardness  for 
supi^ort  of  the  blocks  under  pressure  of  packing.  These  are  often  dis- 
placed and  the  joints  opened  under  moderate  pressure ;  because,  first, 
the  batter  is  too  thin,  and,  secondly,  time  is  not  allowed  for  it  prop- 
erly to  harden  before  packing.  The  flask  should  be  set  in  water  at 
about  120°  for  five  minutes  before  separation,  so  that  in  case  of  under- 
cut or  of  a  thin  or  prominent  ridge  there  shall  be  no  danger  of  break- 
ing the  model.     Dry  heat  may  also  be  used  to  separate  the  flask,  but 


Fig.  1 139. 


the  wet  is  preferable,  as  the  former  may  melt  the  wax  and  cause  it  to 
be  absorbed  by  the  plaster;  and  if  the  base  plate  is  gutta-percha  it 
will,  if  made  too  hot,  adhere  to  the  model.  The  wax  or  gutta-percha 
model  i?.late  should  be  removed  entire  if  possible,  and  also  the  wax 
around  the  pins,  by  means  of  a  small  excavator,  and  what  remains  may 
be  washed  away  by  pouring  over  the  surface  a  stream  of  boiling  water 
from  a  height  of  about  one  foot.  All  wax  should  be  carefully  removed 
in  order  to  prevent  deterioration  of  the  rubber,  and  as  much  of  it  as 
possible  be  preserved  for  the  purpose  of  determining  the  quantity 
of  rubber  necessary  to  use  in  packing  the  piece.  After  the  wax  is 
entirely  removed  vents  or  gates  are  cut  in  the  plaster  surface  of  the 
investments,  as  shown  in  Fig.  1143,  to  allow  the  excess  of  rubber  to 
escape  when  the  flask  is  closed.  The  flask  will  then  present  the  appear- 
ance shown  in  Fig.  11 40;  the  model-half,  E,  separating  from  the 
teeth  and  wax  contained  in  the  dental-half,  H.  Should  the  joints  not 
be  very  closely  fitted,  place  a  little  dry  plaster  over  each  and  touch 
with  a  drop  of  water  or  diluted  soluble  glass,  and  when  hard  trim  off 


VULCANO-PLASTIC   WORK. 


1035 


the  surplus  plasier.  Some  prefer  to  pack  with  tin  or  gold  foil.  The 
zinc  cement  in  the  form  of  the  oxychlorid  or  oxyphosphate  is  also 
serviceable,  and  when  used  for  such  a  purpose  should  be  mixed  quite 
thin  and  allowed  to  become  as  hard  as  possible.  Without  some  such 
precaution  the  rubber  will  press  into  open  joints  and  present  an  un- 
sightly appearance ;  of  course,  closely-ground  joints  are  preferable  to 
any  of  these  expedients  ;  but  neither  the  tightest  joints  nor  any  pre- 
cautions will  avail  if  strong  pressure  is  used  in  packing,  for  this  invari- 
ably opens  the  joints  and  admits  the  gum. 

In  partial  cases,  or  where  no  vulcanite  is  required  outside  the  arch 
and  above  the  teeth  (where  plain  teeth  are  used,  resting  directly  upon 
the  gum),  the  deep  half,  H,  must  be  used  for  the  model  and  the  line 
of  separation  be  made  at  the  cutting-edges  of  the  teeth,  so  that  the 
plaster  around  the  teeth  may  come  nearly  or  quite  level  with  the  edge 
of  the  flask.  The  teeth  are  thus  firmly  fixed  in  their  exact  position 
and  resist  displacement,  which  the  separation  of  the  flasks  or  the 
pressure  of  the  rubber  might  possibly  occasion.     In  this  way,  should 


Fig.  1140. 


the  flasks  chance  not  to  come  perfectly  together,  the  result  will  be  an 
extra  thickness  of  plate,  but  no  displacement  of  teeth.  We  consider 
this  use  of  the  deep-half  of  the  flask  in  all  partial  cases  as  of  the 
utmost  importance.  The  teeth  are  never  disturbed  in  their  position  on 
the  model  given  them  in  the  wax  plate  ;  also,  there  is  no  breaking  of 
plaster  teeth  or  splitting  of  the  model  by  pressure  of  the  rubber. 

To  prevent  the  rubber  from  adhering  to  the  surface  of  the  plaster 
model  and  mold,  which  gives  a  rough  surface  to  the  palatine  portion 
of  the  plate,  this  surface,  as  before  remarked,  should  be  coated  with 
^either  liquid  silex,  collodion,  or  tin  foil.  When  liquid  silex  is  used,  a 
thin  coat  upon  a  moist  plaster  surface  answers  best;  collodion  is 
applied  like  liquid  silex  ;  tin  foil  is  attached  to  the  plaster  surface  by 
means  of  shellac  varnish  and  carefully  adapted  by  pressure  with  a  soft 
cone  of  leather  to  all  the  inequalities,  and  its  surface  is  coated  with 
collodion,  which  is  allowed  to  dry,  when  it  is  again  coated  with  the 
soap  solution.     Such  a  method  will  render  it  easy  to  remove  the  tin 


1036 


MECHANICS DENTAL    PROSTHESIS. 


from  the  vulcanized  rubber  and  give  a  polished  surface.  Withnut 
such  precaution  the  use  of  muriatic  acid  may  be  necessary  in  order  to 
remove  the  tin  foil.  Gilding  the  surface  of  the  model  with  gold  foil 
is  also  done. 

Clean  hands  and  instruments  are  very  necessary  in  packing  rubber, 
otherwise  the  color  and  even  the  texture  of  this  material  are  impaired. 
The  mold  as  well  as  the  rubber  should  be  warm  during  the  packing 
process,  and  the  latter  should  be  cut  in  different  sized  pieces,  using  a 
large  piece  of  the  proper  shape  to  cover  the  palatine  surface  of  the 
model,  and  which  may  be  applied  by  pressure  with  the  thumb  and 
fingers,  first  dipping  them  in  water.  Fig.  1141  represents  a  boiler 
suitable  for  heating  the  flasks,  and  having  a  flat  top  on  which  the 
rubber  may  be  softened.     In  packing  the  smaller  pieces  of  rubber, 


Fig.  1141. 

and  especially  the  long  strips  suitable  for  the  rim  of  the  plate,  care  is 
necessary  that  all  particles  of  plaster  be  excluded,  and  also  that  too 
much  rubber  is  not  pressed  against  thin  margins  of  the  gum;  other- 
wise fracture  of  the  porcelain  blocks  may  result  when  the  flask  is 
being  closed.  It  is  safer  to  pack  the  rubber  thicker  in  the  center,  and 
as  it  yields  to  the  pressure  it  will  flow  around  weak  points  without 
danger  of  fracturing  them.  Each  piece  of  rubber  as  it  is  added 
should  be  consolidated ;  and  if  any  tooth  or  block  has  become  loos- 
ened in  the  plaster  a  drop  of  liquid  silex  placed  in  the  bottom  of  its 
plaster  cavity  will,  after  it  becomes  dry,  hold  it  firmly  in  place. 

It  is  desirable  in  all  cases  and  quite  essential  in  most  that  the  flasks 
should  come  perfectly  together.  This  is  accomplished  by  attention 
to  three  points:    i.   Softening  the  rubber;   2.   Using  a  proper  quan- 


VULCANO-PLASTIC   WORK. 


1037 


tiiy;  3.  Having  vents  for  the  surplus.  First,  for  softening  the  rubber 
use  a  deep,  covered  saucepan  capable  of  holding  the  flask-press  and 
containing  two  or  three  inches  of  water.  When  the  flask  is  thor- 
oughly heated  by  the  steam,  the  rubber  is  placed  over  the  cover  of  the 
saucepan  or  on  a  small  shelf  attached  to  the  inside  of  the  saucepan  ; 
then  while  soft  let  it  be  packed  with  the  help  of  a  pointed  stick  or 
the  smooth  end  of  a  straight  excavator  flattened  for  the  purpose  into 
the  dental  half  of  the  matrix.  Around  the  teeth  the  rubber  may  be 
packed  in  the  form  of  very  narrow  strips,  somewhat  as  foil  is  inserted 
into  the  cavity  of  a  tooth,  with  instruments  made  from  excavators 
with  blunt  points  bent  at  a  right  angle.  The  remainder  is  packed 
either  in  large  strips  or  in  one  piece  cut  to  the  shape  of  the  wax  plate. 
Secondly.  It  is  important  to  use  the  proper  quantity  of  rubber; 
too  little  vulcanite  spoils  the  piece  ;  too  much  requires  a  pressure  which 
may  break  the  blocks, 
displace  the  teeth,  and 
force  rubber  into  the 
joints,  or  else  requires 
a  long  time  for  a  safe 
degree  of  pressure  to 
bring  the  flask  to- 
gether. In  some  cases 
the  quantity  can  be 
correctly  found  by 
having  the  sheets  of 
vulcanite  exactly  as 
thick  as  the  wax  plate, 
removing  the  latter  as 
carefully  as  possible, 
and  marking  off  its 
size  on  the  former. 
But  for  some  irregu- 
larly-shaped cases  and 
most  lower  cases  the 
following  simple 
method  will  be  found 
better.  Let  the  plate 
be  entirely  of  wax ; 
remove  it  all  from  the 
matrix  and  roll  it  into 
a  sheet   the  thickness  t,.,^  ,,_ 

rlG.    II42. 

ot'  the  rubber  ;    make 

the  rubber  a  little  larger  than  the  wax  ;   then  cut  into  conveniently- 


f038 


MECHANICS — DENTAL   PROSTHESIS. 


sized  strips  and  pack,  putting  most  at  those  points  where  the  wax 
was  thickest.  Starr's  measuring  glass,  which  determines  the  quantity  of 
rubber  by  "  displacement,"  is  a  convenient  instrument  for  this  pur- 
pose.    (Fig.  1 142.) 

For  ascertaining  the  quantity  of  rubber  required  for  any  given  case  : 
The  vessel  being  about  half  filled  with  water,  set  the  lower  pointer 
to  the  level  of  the  water ;  throw  in  every  particle  of  the  model  plate ; 
set  the  upper  pointer  to  the  rise  of  the  water  ;  empty  the  vessel  and 
again  fill  with  water  to  the  lower  pointer  ;  add  a  sufficient  quantity  of 
rubber  to  cause  the  water  to  rise   to  the  upper  pointer  and  there  will 


Fig.  1 143. 


be  just  enough  to  fill  the  mold.     Allowance  can  then  be  made  for 
surplus. 

Thirdly.  Since  the  error  in  quantity  should  always  be  on  the  safe 
side  of  excess,  provision  must  be  made  for  the  escape  of  this  surplus 
by  cutting  vents,  that  the  halves  of  the  matrix  may  come  together 
without  too  great  pressure.  Fig.  1143,  taken  from  Prof.  Wildman's 
monograph,  is  a  fine  illustration  of  the  best  method  of  cutting  these 
vents.  The  radiating  vents  might,  however,  stop  at  the  circular 
groove,  taking  care  to  make  this  large  enough  for  any  possible  excess 


VULCANO-PI.ASTIC    WORK. 


1039 


of  rubber.  If  these  leaders  are  too  large  next  the  plate  the  rubber 
niav  not  pack  so  firmly  as  is  desirable;  also  the  generation  of  gas 
while  vulcanizing  may  force  rubber  too  freely  into  the  groove,  and 
so  make  it  porous. 

A  good  form  of  flask  press  is  that  of  Messrs.  Snowden  and  Cowman, 
Fig.  1 144.  As  soon  as  the  rubber  is  packed  the  halves  of  the  flask 
are  carefully  brought  together,  placed  in  the  press,  and  a  moderate 
force  applied  ;  the  press  and  flask  are  then  placed  in  the  heater.  A 
piece  of  pure  "rubber-packing,"  about  an  inch  thick,  placed  under 
the  screw,  will,  as  before  stated,  insure  a  constantly  acting  force 
whilst  in  the  heater.     Avoid  using  the  full  power  of  even  one  hand 


Fig.  1144. 


Fig.  1 145. 


upon  the  lever;  if  the  vents  are  free  and  great  excess  of  material  is 
avoided,  moderate  pressure  acting  steadily  in  the  heater  will  safely 
bring  any  flask  together  in  from  ten  to  forty  minutes. 

Fig.  1145  represents  Dr.  Donham's  Spring  Clamp,  which  utilizes  the 
tension  of  a  spring  for  closing  the  flasks  in  vulcanizing.  It  gives  con- 
tinuous pressure  and  dispenses  with  flask-bolts. 

In  all  cases  use  a  flask  press  first  and  the  small  screw  bolts,  except  in 
the  Donham  clamp,  when  the  case  is  ready  for  the  vulcanizer.  If  pres- 
sure is  applied  suddenly,  before  the  rubber  is  sufficiently  plastic,  there 
is  great  danger  of  fracturing  the  teeth,  especially  sectional  blocks. 
When  the  screw  bolts  alone  are  used  to  bring  the  sections  of  the  flask 


I04O  MECHANICS — DENTAL   PROSTHESIS. 

together,  no  more  pressure  should  be  applied  at  first  than  can  be  made 
with  the  fingers,  after  which  the  flask  is  placed  in  boiling  water  for  a 
few  minutes,  when  a  gentle  turning  of  the  screws  will  suffice  to  bring 
the  parts  together.  Clean  flasks  are  essential  to  successful  packing, 
for  soiled  fingers  stain  the  rubber,  which  interferes  with  perfect  union 
of  the  pieces ;  hence  all  apparatus  handled  in  packing  should  be  so 
simple  in  form  as  to  be  readily  cleaned  ;  also,  it  is  well  to  keep  them 
constantly  covered  with  a  coating  of  varnish. 

Dr.  T.  F.  Chupein,  referring  to  some  valuable  suggestions  of  Dr. 
Geo.  B.  Snow  concerning  the  Physical  Properties  of  Vulcanite, 
sa\  s  :  * — 

"  The  writer,  after  giving  many  good  points  and  making  many 
valuable  suggestions  about  vulcanite  work  and  the  behavior  of  vul- 
canite dental  plates,  recommends  that  when  from  the  nature  of  the 
case  it  is  found  impracticable  to  make  the  plate  of  equal  thickness, 
the  places  where  the  plate  will  be  unduly  thick  be  filled  with  small 
pieces  of  rubber  which  has  been  already  vulcanized  (an  old  rubber 
plate,  for  example,  cut  up  and  cleanly  filed  into  small  pieces  about  the 
size  of  duck-shot),  to  compensate  for  the  undue  thickness  of  the  plate 
at  these  points  and  to  control  the  expansion  or  contraction  of  the 
material. 

"  If  a  set  of  teeth  be  waxed  up  and  flasked  in  the  usual  way,  it  will 
be  extremely  difficult  to  know  where  to  place  these  pieces  of  vulcanized 
rubber;  the  memory  being  the  only  guide  as  to  where  they  are  to  be 
put,  the  procedure  is  reduced  to  guesswork. 

"To  overcome  this  difficulty  (recognizing  the  value  of  the  sugges- 
tion) we  proceed  as  follows :  After  the  case  has  been  waxed  up  as 
usual,  whether  gum  section  or  plain  teeth  are  used,  the  wax  is  care- 
fully removed  from  the  front  part  of  the  sections  or  from  the  front 
part  of  the  plain  teeth,  so  that  these  are  held  in  place  only  by  the  wax 
on  the  palatal  surface.  Those  parts  of  the  sections  or  plain  teeth  and 
the  plaster  model  are  then  painted  with  rubber  solution  (red  rubber 
dissolved  in  chloroform),  and  when  this  dries  small  pieces  of  red  rubber 
are  packed  next  the  sections  to  form  the  rim ;  or  small  pieces  of  pink 
rubber  are  packed  next  the  plain  teeth  to  form  an  imitation  of  the 
gum.  This  being  done,  the  case  is  flasked  so  that  the  plaster  of  in- 
vestment is  brought  all  over  the  front  part  of  the  teeth  as  shown  in  the 
figure.  Thus  the  small  pieces  of  vulcanized  rubber  may  be  placed  just 
where  they  are  needed  to  compensate  for  the  extra  thickness  or  volume 
of  rubber  at  these  points. 

"  Fig.  1 1 46  indicates  the  extent  of  such  extra  thickness  under  the 

*  Physical  Properties  of  Vulcanite,  Denial  Cosmos,  Aug.  No.,  1888. 


VULCANO-PLASTIC   WORK. 


1 041 


bicuspids  and  molars,  for  which  spaces  the  vulcanized  pieces  are  to  be 
prepared  in  the  present  instance. 

"  Incidentally  it  may  be  observed  that  by  this  mode  of  flasking  the 
teeth  are  kept  in  their  exact  posi- 
tions relatively  to  the  cast,  and, 
the  gates  being  freely  cut  in  the 
other  part  of  the  flask,  the  articula- 
tion will  be  found  undisturbed  even 
though  the  flask  should  not  have 
been  accurately  and  completely 
closed. 

"  It  is  well  to  say  that  in  remov- 
ing the  wax  from  the  front  part  of 
the  case  this  should  be  all  removed 
before   the    case    is   painted   with 

rubber  solution,  and  the  small  pieces  of  red  or  pink  vulcanite  that  are 
put  in  place  of  the  wax  that  was  removed  should  be  added  to  the 
painted  surface  with  a  clean  wax  spatula,  free  from  all  grease,  wax,  or 
dirt,  and  heated  (for  easier  manipulation  of  these  pieces)  in  the  blaze 
of  a  spiril-lamp.  If  there  is  any  grease  on  the  spatula  the  rubber  will 
not  stick  to  the  places  where  it  is  wanted." 

Time  of  Vulcanizing. — When  the  halves  of  the  flask  are  brought  into 
contact  it  is  taken  from  the  press,  the  screws  are  adjusted,  and  it  is 
placed  in  the  vulcanizer,  which  is  then  filled  two-thirds  full  of  boiling 
water,  the  cover  adjusted,  the  gas  or  lamp  lighted,  and  time  reckoned 
from  the  moment  of  closing  the  cover. 

The  time  occupied  in  heating  up  and  vulcanizing  varies  with  differ- 
ent varieties  of  rubber  from  fifteen  minutes  to  an  hour  and  a  half.  As 
thermometers  vary  much,  and  the  rubber  used  also  varies,  the  best  plan 
is  for  every  one  to  vulcanize  trial  pieces  until  the  required  hardness, 
toughness,  and  elasticity  are  obtained.  It  should  curl  under  the 
scraper  like  horn,  permit  bending  at  an  angle  of  at  least  45°,  and  re- 
turn to  its  original  shape  unchanged. 

When  the  heat  is  too  great,  or  the  time  too  long,  the  rubber  becomes 
dark  and  brittle.  For  the  black  rubber  a  longer  time  is  necessary 
than  for  the  red  rubber,  and  the  best  method  is  to  heat  up  very  slowly 
unti  it  has  reached  320°  F.,  or  to  use  a  less  heat  and  longer  time.  The 
more  foreign  matters  rubber  contains  the  less  time  is  required  to  vul- 
canize it ;  and  where  the  adulteration  is  considerable,  as  in  the  case 
of  the  pink  rubber,  the  heat  may  be  raised  more  rapidly,  but  such 
rubbers  are  weak  and  unfit  for  forming  any  more  of  the  plate  than  the 
gum  portion.  In  using  the  red  rubbers  the  heat  should  not  rise  higher 
than  320°,  and  the  piece  should  be  allowed  to  stand  until  it  is  cold. 
66 


I042  MECHANICS — DENTAL    PROSTHESIS. 

In  a  very  large  proportion  of  vulcanite  pieces  the  full  strength  of  the 
material  is  lost  by  overheating;  in  others  by  the  opposite  error  of 
giving  too  much  elasticity  and  throwing  undue  strain  in  full  cases  upon 
the  blocks  and  the  rim  of  rubber  behind  them.  If  some  of  the  time 
spent  in  polishing  up  vulcanite  and  bringing  out  the  offensively  glaring 
brilliancy  of  its  color  were  devoted  to  careful  management  of  the  vul- 
canizer,  to  making  proper  record  of  heatings,  so  as  to  arrive  at  uniform 
results,  and  to  the  cultivation  of  those  habits  of  accuracy  which  alone 
can  give  success,  there  would  be  fewer  broken  pieces  returned  to  the 
laboratory  for  repair. 

Slow  heating  and  a  perfectly  tight  vulcanizer  full  of  water,  with 
flask  well  bound  together  and  vents  not  too  free,  are  the  best  safe- 
guards against  porous  rubber,  except  where  an  unusual  thickness  is  re- 
quired, when  the  small  pieces  of  hard  vulcanite  may  be  used  in 
packing. 

It  sometimes  happens,  when  large  and  thick  masses  are  built  upon 
the  plate,  as  in  cases  of  excessive  absorption,  that  the  thick  portions 
of  the  plate,  when  vulcanized,  prove  to  be  soft  and  spongy  in  the 
center.  This  is  the  result,  first,  of  bringing  the  plate  up  to  the  vul- 
canizing point  too  quickly  and  the  retention  of  the  sulphurous  gas.  A 
long  time,  even  two,  three,  or  four  hours,  the  time  depending  upon 
the  thickness  of  the  mass  of  rubber  to  be  hardened,  should  be  taken  to 
raise  the  temperature  of  the  vulcanizer  from,  say  250°  to  320°,  if  no 
pieces  of  hard  rubber  are  used  in  i)acking.  Second.  Different  samples 
of  rubber  act  differently  when  vulcanized  in  thick  masses,  depending 
somewhat  upon  the  amount  of  earthy  matter  contained  in  them.  It  is 
very  difficult  to  vulcanize  a  mass  of  pure  rubber  and  sulphur  even 
three-eighths  of  an  inch  thick  and  insure  its  solidity.  On  the  other 
hand,  some  of  the  English  pink  rubbers,  which  contain  large  amounts 
of  oxid  of  zinc  and  vermilion,  can  be  vulcanized  in  thick  masses  with 
but  little  trouble.  It  is  to  be  remarked,  also,  that  rubbers  which  are 
"loaded"  with  earthy  matter  have  less  shrinkage  than  those  which 
are  purer. 

So  the  expedient  may  be  resorted  to  of  packing  the  inside  of  thick 
portions  of  the  plate  with  some  one  of  the  rubbers  containing  more 
earthy  matter  than  those  usually  employed,  or  using  the  same  pieces 
of  hard  vulcanite  as  befpre  described.  The  expedient  of  filling  in 
parts  of  the  mold  where  the  thickness  of  rubber  is  excessive  with  a 
mixture  of  small  fragments  of  old  vulcanite  and  new  rubber  will  answer 
every  purpose  as  a  safeguard  against  porosity.  If  the  pieces  are  freshly 
filed  all  over  their  adhesion  with  the  new  material  will  be  perfect,  and 
the  plate  will  be  as  strong  as  though  wholly  of  new  material. 

There  seems  to  be  a  point  beyond  which,  if  rubber  twice  passes. 


VULCANO-PLASTIC   WORK.  I043 

it  becomes  inevitably  brittle  ;  hence  no  confidence  can  be  placed  in 
the  old  material  of  a  repaired  piece.  Two  flasks  in  the  same  vul- 
canizer  cannot  give  the  same  results ;  loss  of  heat  by  radiation  is 
greatest  from  the  cover,  and  the  supply  of  heat  is  from  below ;  hence, 
necessarily,  the  lower  half  of  the  oven  is  hotter  than  the  upper. 
Uniformity  of  texture  can  be  obtained,  therefore,  only  by  vulcaniz- 
ing one  piece  at  a  time.  One  who  is  systematic  in  the  arrangement 
of  his  work  will  separately  vulcanize  the  pieces  of  a  double  set  in 
very  nearly  the  same  time  required  if  both  are  done  at  once  ;  for 
one  piece  may  be  in  the  oven  while  the  other  is  in  preparation  for  it. 

Removal  from  Vulcanizer  and  Finishing. — Upon  expiration  of  the 
time  determined  upon  the  flame  is  to  be  at  once  extinguished  ;  the 
vulcanizer  may  be  cooled  gradually  as  it  stands,  or  rapidly  by  the 
escape  of  the  steam,  or  by  setting  the  lower  three-fourths  of  the  vul- 
canizer in  cold  water.  The  last  method  of  rapid  cooling  is  preferable, 
running  the  heat  five  minutes  longer  than  when  slow  cooling  is  prac- 
ticed. Letting  off  steam  is  a  very  disagreeable  process  and  makes 
the  plaster  of  the  flasks  very  hard  to  cut  out.  Flasks  may,  with  per- 
fect safety,  be  cooled  by  setting  the  vulcanizer  containing  them  in 
snow  or  pounded  ice  if  desired  ;  but  in  no  case  should  the  flasks  them- 
selves be  cooled  by  contact  with  cold  water,  as  some  might  chance  to 
penetrate  to  the  blocks  and  crack  them.  The  flask  should  be  opened 
and  the  piece  removed  from  its  plaster  investment  within  two  or  three 
hours  after  vulcanizing.  After  that  time  the  plaster  assumes  a  sand- 
like, granular  state,  and  adheres  with  great  tenacity  to  the  plate,  no 
matter  what  separating  varnish  may  be  used.  Tapping  the  edges  of 
the  flask  after  separation  will  dislodge  their  contents  in  mass  ;  the 
plaster  can  then  be  trimmed  from  the  piece,  taking  care  that  it  is 
perfectly  cold.  The  adherent  plaster  in  the  dental  half  of  the  flask 
can  easily  be  washed  from  the  piece  with  a  stiff  brush ;  but  the  model 
half  leaves  a  coating  that  clings  very  tenaciously,  unless  means  are 
taken  to  prevent  it ;  soluble  glass,  a  dilute  ethereal  solution  of  collo- 
dion, or  a  layer  of  thin  foil  have  been  already  mentioned  as  the  proper 
preventives. 

The  process  of  finishing  is  more  troublesome  than  in  the  case  of 
gold  work,  unless  great  care  is  used  in  the  formation  of  the  wax  plate. 
Several  sizes  of  round  and  half-round  files  are  necessary  for  finishing 
up  the  edges  and  convex  surfaces  ;  for  the  concave  surfaces,  scrapers, 
graving  chisels,  and  curved  files.  Fig.  1147  represents  common  forms 
of  rubber  files. 

Fig.  1 1 48  represents  several  sizes  of  a  form  of  scraper  or  finisher, 
suggested  by  Dr.  Kingsley,  with  convex  back  and  thin  edges,  which 
do  not  dull  readily  and  are  easily  sharpened. 


I'  K 


MECHANICS DENTAL    PROSTHESIS. 


Lathe  burs  and  file-cut  wheels  will  be  found  very  useful  if  there  is 
to  be  much  reduction  of  thickness— Figs.  1149  and  1150  represent 
one  of  each— the  burs  in  sets  of  four  and  the  wheels  in  sets  of  three. 


Fig.  11.17. 


Fig.  1150. 


Sufficient  thickness  must  be  left  in  the  body  of  the  plate  for  strength, 
but  the  edges  should  be  chamfered  off.     A  pair  of  calipers  (Figs.  1 109, 


VULCANO-PLASTIC   WORK.  I045 

1 1 10)  are  required  to  measure  the  thickness  of  the  plate  if  it  is  to  be 
reduced  by  files  and  scrapers,  and  the  use  of  this  instrument  will  lessen 
the  danger  of  cutting  through  the  plate.  Some  operators  next  use 
sand-paper  or  emery  cloth  ;  others  use  pumice  stone  on  cork  wheels  ; 
many  prefer  Scotch  stone.  The  third  step  is  the  use  of  rotten  stone 
(not  Tripoli,  which  cuts  with  too  keen  a  grit),  either  on  a  brush 
wheel  with  tallow  or  oil,  which  is  the  more  rapid  process,  or  on  a 
stick  of  some  hard  wood,  with  water,  which  is  the  more  cleanly.  A 
little  oxid  of  zinc  on  a  soft  wheel  or  on  the  finger  will  give  a  brilliant 
finishing  polish,  but  is  not  essential,  as  the  rotten  stone  can  be  made 
to  polish  very  highly.  After  trying  the  piece  and  finding  that  no 
part  of  the  edge  requires  alteration,  a  bright  surface  color  may  be 
given  by  placing  the  piece  in  alcohol  and  exposing  to  the  sun's  rays 
for  six  or  twelve  hours.  Some  regard  this  as  an  improvement ;  it 
certainly  does  not  injure  the  quality  of  the  plate,  but  the  original  ma- 
hogany color  of  the  vulcanite  is  in  much  better  taste  than  the  bright 
vermilion  tint  thus  given.  In  finishing  partial  cases  it  will  prevent 
accident  if,  after  filling  the  edges,  plaster,  or  modeling  composition, 
or  gutta-percha  is  fitted  to  the  palatine  surface  of  the  plate ;  the 
subsequent  operations  can  be  conducted  more  rapidly  and  with  less 
danger  in  delicately  shaped  pieces.  Vulcanite  is  softened  by  heat ; 
hence  a  piece  is  sometimes  bent  by  revolving  the  brush-wheel  too 
rapidly.  A  piece  that  has  been  in  any  way  bent  or  warped  may 
be  restored  by  heating  either  in  boiling  salt  water  or  in  oil  to  about 
250°.  While  soft  it  may  be  bent  with  the  fingers  ;  but  as  this  guess- 
work method  is  hazardous  it  is  much  better  to  bind  it  down  upon  a 
model  and  heat  to  the  point  of  softening. 

By  pouring  plaster  upon  the  palatal  surfaces  of  thin  partial  plates 
and  allowing  it  to  harden,  the  danger  of  changing  the  shape  when 
polishing  with  a  revolving  wheel  is  avoided.  To  give  a  polished  sur- 
face to  a  vulcanite  plate  and  dispense  with  the  usual  finishing  up  and 
polishing  process,  the  surface  of  the  wax  may  be  covered  with  tin  foil, 
which  is  lightly  but  smoothly  burnished  to  the  surface  of  the  wax.  To 
insure  a  polished  surface  to  the  palatal  surface  of  a  vulcanite  plate  also 
the  surface  of  the  model  may  be  varnished  with  shellac  and  then  cov- 
ered with  tin  foil,  evenly  applied  ;  but  a  better  method  is  to  obtain  a 
block  tin  or  other  suitable  metal  die  from  the  plaster  model  and  vul- 
canize upon  it.  When  tin  foil  is  applied  to  the  surface  of  a  wax  plate 
all  the  wax  may  be  removed  without  injury  to  the  foil  by  pouring 
boiling  water  upon  it.  By  the  use  of  the  improved  heaters  to  vulcanize 
rubber,  although  a  longer  time  is  necessary  than  with  the  common 
vulcanizers,  yet  the  strength  and  color  of  rubber  so  manipulated  are 
improved.     To  vulcanize  red  rubber  with  these  heaters  the  flask  may 


1046  MECHANICS — DENTAL    PROSTHESIS. 

be  heated  and  packed  in  the  oven  ;  and  when  this  process  is  com- 
pleted the  machine  is  closed,  and  the  steam  valve  is  then  raised  to 
admit  the  steam  to  the  packing  chamber.  When  the  heat  has  been 
raised  to  320°  the  case  is  allowed  to  remain  in  the  hot  box  at  that 
temperature  for  one  and  a  half  hours. 

To  produce  a  pure  jet-black  rubber  plate,  perfectly  pure  black 
rubber  should  be  used,  and  vulcanized  by  the  dij  process.  The 
model  and  investment  should  be  thoroughly  dried  before  packing  the 
black  rubber,  and  no  steam  be  allowed  to  enter  the  packing  chamber 
during  the  operation.  The  time  required  for  vulcanizing  black  rubber 
by  the  dry  process  is  five  hours  at  320°.  To  construct  a  vulcanized  set 
with  a  celluloid  gum,  see  chapter  on  Celluloid. 

A  modification  of  the  vulcanite  process  was  patented  in  1868  by 
Dr.  Stuck.  Briefly  described,  it  is  the  vulcanizing  of  rubber  between 
two  polished  tin-foil  plates,  the  articulating  plate  being  formed  upon 
a  block-tin  model  made  directly  from  the  impression.  The  plate 
comes  out  highly  polished,  provided  the  tin  foil  has  been  carefully 
burnished  into  shape.  On  the  palatine  surface  this  polish  is  objec- 
tionable ;  hence  we  should  prefer  to  vulcanize  directly  upon  the 
block-tin  model,  the  granulated  surface  of  which  is  better  for  adhesion. 
The  plate,  thus  made  smaller  than  the  mouth  by  the  shrinkage  of  the  tin, 
would  in  most  cases  fit  better  ;  the  difficulty  is  in  removing  the  finished 
plate  from  the  metal  in  case  of  a  deep  arch  or  slight  undercut,  an 
objection,  however,  which  is  now  overcome  by  using  shell  or  sectional 
tin  models.  A  second  peculiarity  of  Dr.  Stuck's  plates  is  their  elas- 
ticity, compared  with  pieces  as  ordinarily  prepared  and  vulcanized  in 
the  same  oven.  This,  we  suggest,  is  due  to  the  retention  of  the  sul- 
phur by  the  foil  plates  on  either  side.  We  think  these  elastic  plates 
are  usually  made  too  thin,  under  the  idea  that  elasticity,  like  rigidity, 
compensates  for  diminished  thickness.  This  method,  though  open  to 
some  objection,  is  worthy  of  careful  investigation  by  every  worker  in 
vulcanite. 

It  sometimes  happens  that  the  rubber  shrinks  from  the  teeth,  leaving 
a  space  in  which  particles  of  food  and  saliva  collect.  The  cause  of 
such  shrinkage  has  been  ascribed  to  the  fact  that  the  rubber  in  cooling 
from  a  temperature  of  320°  to  that  of  the  atmosphere,  contracts  more 
than  any  metal,  and  the  plaster  of  the  model  and  investment  after 
boiling  in  sulphuretted-hydrogen  water  for  sixty  minutes  is  rendered 
very  soft,  and  has  not  strength  sufficient  to  hold  the  vulcanite  in  form 
while  cooling ;  but,  on  the  contrary,  yielding  to  pressure,  allows  the 
rubber  to  draw  away  from  the  teeth.  It  is  claimed  that  any  method 
which  will  prevent  the  plaster  model  and  investment  from  becoming 
soft  will  overcome  this  objection. 


VULCANO-PLASTIC    WORK.  IO47 

Repairing  and  Refitting  Plates. — Vulcanite  work  maybe  repaired  by 
removing  the  broken  tooth  or  block,  cutting  dovetails  in  the  rubber, 
and  then  fitting  the  new  teeth,  arranging  the  wax,  and  vulcanizing  as 
at  first.  To  describe  this  method  of  repairing  more  in  detail  :  if  a 
tooth  or  block  has  been  broken  the  fractured  parts  should  be  removed 
and  a  dovetail  or  groove  formed  in  the  base  covering  the  space  occu- 
pied by  the  tooth  to  be  replaced.  The  tooth  or  block  is  then  fitted 
by  grinding  and  supported  by  wax,  the  dovetail  being  also  filled  up 
rather  fuller  than  is  necessary  to  restore  the  surface  in  order  to  allow  for 
finishing.  All  of  the  set,  except  the  portion  of  the  lingual  surface  over 
the  wax,  is  then  imbedded  in  the  lower  half  of  the  flask,  and  the 
plaster  surface  varnished  and  oiled  to  prevent  adhesion  when  the  upper 
section  of  the  flask  is  adjusted  and  filled  with  the  plaster  investment. 
When  the  plaster  has  set  and  the  two  halves  of  the  flask  are  separated, 
all  of  the  wax  is  removed,  the  piece  heated  up,  and  rubber  packed  into 
the  cavity  around  the  tooth  or  block.  The  sections  of  the  flask  are 
then  heated  and  screwed  together  and  the  process  of  vulcanizing  com- 
pleted. Another  method  of  repairing  rubber  plates,  and  by  which 
pressure  is  avoided,  is  to  first  cleanse  the  piece  thoroughly,  and  to 
coat  the  inner  surface  with  a  little  oil  to  prevent  the  plaster  which  is 
poured  upon  this  surface  in  order  to  form  a  new  model  from  adhering. 
When  the  plate  is  separated  from  the  model  dovetails  are  cut  into  the 
plate,  and  it  is  returned  to  the  model  and  the  teeth  adjusted  by  grind- 
ing, after  which  the  surface  under  them  is  coated  with  the  rubber 
solder  or  liquid  rubber,  as  are  also  such  parts  uf  the  teeth  and  pins 
that  are  to  come  in  contact  with  the  rubber.  The  teeth  being  replaced, 
warm  rubber  is  packed  under  them  and  into  the  dovetails,  and  the 
case  is  then  invested  in  one  mass  of  plaster,  no  flasks  being  used,  and 
vulcanized  in  the  ordinary  manner.  Where  the  plate  is  cracked  or 
broken  into  two  pieces  the  parts  should  be  carefully  adjusted  and 
secured  in  place  by  either  wax  or  ligatures  and  covered  with  plaster 
on  its  inner  surface  so  as  to  form  a  model.  The  plate  is  removed  from 
the  plaster  when  it  has  set  and  a  groove  cut  out  the  entire  length  of 
the  crack  or  fracture,  on  either  side  of  which  dovetails  are  formed. 
When  the  pieces  are  returned  to  the  model,  the  case  is  placed  in  the 
lower  half  of  the  flask  and  invested  with  plaster,  all  portions  of  the 
plate  being  covered  except  where  the  new  rubber  is  to  be  packed. 
The  rubber  solder  is  then  applied  to  the  prepared  surface  and  the  rub- 
ber packed  firmly  into  the  groove  and  dovetails.  The  upper  half  of 
the  flask  is  then  adjusted  and  the  investment  completed,  when  the  case 
is  ready  for  vulcanizing.  Instead  of  cutting  dovetails,  which  are  often 
disfiguring  and  sometimes  impracticable,  a  liquid  preparation  may  be 
used  known  as  Rubber  Solder.     The  surface  of  the  old  plate  should 


1048  MECHANICS DENTAL    PROSTHESIS. 

be  brushed  over  with  it  just  before  packing.  The  adhesion  is  so  perfect 
that  the  plate  will  break  through  old  or  new  rubber  sooner  than  separate. 
Before  cutting  out  the  old  rubber  the  part  of  the  plate  under  the  broken 
teeth  should  be  filled  with  plaster  and  then  removed,  so  as  to  preserve 
the  shape  of  the  ridge  ;  in  case  the  process  of  repair  requires  that  the 
plate  shall  be  cut  entirely  through  at  this  point,  it  is  to  be  replaced 
before  applying  the  wax.  The  second  heating  darkens  the  old  rubber 
and  makes  it  more  brittle  ;  full  cases  may  admit  of  one,  possibly  two, 
such  heatings.  Partial  cases  should  be  repaired  by  replacing  the  entire 
plate  with  new  rubber,  although  many  repair  as  in  full  pieces.  We 
decidedly  prefer  in  both  full  and  partial  cases  the  entire  replacement 
of  the  rubber.  In  doing  this  there  are  various  ways  of  securing  the 
correct  relation  of  the  teeth  to  the  new  model.  To  replace  a  broken 
partial  or  full  plate,  the  teeth  being  uninjured,  attach  the  broken  parts 
firmly  by  resinous  cement  on  the  lingual  surface  ;  soap  the  rubber,  or 
very  slightly  oil  it,  and  make  a  new  model ;  then  surround  it  with  a 
plaster  rim,  as  explained  on  page  921,  coming  fully  to  the  edges  of 
the  teeth.  Remove  the  resinous  cement  from  the  lingual  side  of  the 
plate  and  take  a  plaster  copy  of  this  surface  and  of  the  inside  of  the 
teeth,  being  careful  in  partial  cases  to  slope  the  plaster  so  that  it  may 
be  readily  drawn.  The  plaster  now  enveloping  the  piece  is  in  three 
or  four  parts  ;  remove  the  plaster  from  the  lingual  surface ;  remove  the 
rim  in  one  or  in  two  pieces  ;  then  carefully  remove  the  plate  from  the 
model.  Soften  the  rubber  plate  and  remove  the  teeth  ;  replace  the 
plaster  rim  around  the  model  and  set  the  teeth  or  blocks  in  position, 
pressing  a  little  wax  under  each  to  keep  it  in  place.  Now  set  model, 
rim,  and  teeth  in  the  half-flask,  first  soaking  in  water  to  prevent  too 
quick  setting  of  the  batter.  Soap  or  cover  with  foil  the  plaster  surface  ; 
then  saturate  and  put  in  place  the  remaining  lingual  piece  of 
plaster  ;  set  the  other  half-flask  and  pour  the  remaining  half-matrix. 
Separate  flask,  pick  out  the  pieces  of  wax  ;  the  case  is  then  ready  for 
packing  and  vulcanizing.  By  this  process  the  new  plate  has  the  exact 
shape  of  the  old  one,  and  there  is  no  necessity  for  molding  a  ntw 
wax  plate.  If  the  plate  is  of  such  form  as  to  endanger  the  model  in 
detaching,  soften  it  by  cautious  use  of  the  blowpipe  flame. 

If  new  teeth  or  block  be  required,  let  this  be  first  fitted  and  wax 
properly  shaped  around  it ;  then  proceed  as  above.  But  if  some  modi- 
fication in  the  shape  or  thickness  of  the  plate  is  required,  do  not  fill 
the  lingual  surface  with  plaster;  but  after  making  model  and  rim  re- 
move plate,  reset  teeth,  adjust  a  new  wax  plate,  and  then  proceed  as 
in  a  new  piece.  .  If  the  vulcanite  rim  outside  and  above  the  teeth 
needs  modification  the  plaster  rim  must  be  removed  and  wax  placed 
there  also,  as  in  a  new  piece. 


VULCANO  PLASTIC    WORK.  I049 

The  black  deposit  which  collects  on  vulcanite  plates  from  long  use, 
or  from  the  smoke  of  tobacco,  can  be  removed  by  applying  a  small 
quantity  of  a  solution  composed  of  aqua  ammonia,  alcohol,  and  chlo- 
roform, equal  parts,  and  then  adding  pulverized  pumice  stone.  After 
scouring  with  this  mixture,  the  surface  may  be  polished  in  the  usual 
manner. 

Dr.  George  B.   Snow,  in  an  excellent  article  on  "  Repairing  Vul 
canite  Plates,"  gives  the  following  suggestions:  — 

"  It  is  not  unusual  to  see  vulcanite  plates  which  have  been  cracked 
or  broken,  and  repaired  by  what  may  be  termed  the  '  hole  and  plaster  ' 
system.  Holes  are  drilled  through  the  plate  along  the  edges  of  the 
crack,  and  a  new  thickness  of  rubber  superimposed  upon  a  mass  which 
possibly  is  already  too  thick  for  comfort  or  convenience,  the  old  crack 
still  remaining  as  a  weak  point  to  occasion  further  breakage.  No  ad- 
vantage was  taken  of  any  possibility  of  union  between  the  old  and 
new  material,  the  dentist  having  been  obviously  ignorant  of  the  fact 
that  perfect  union  can  be  obtained  in  such  cases  if  the  surfaces  of 
contact  are  freshly  cut,  absolutely  clean,  and  properly  roughened. 

"  The  great  point  to  be  remembered  in  repairing  or  making  any 
addition  to  a  vulcanite  plate  is  that  the  new  and  old  material  will 
unite  perfectly,  and  with  such  firm  adhesion  that  the  plate  will  be 
practically  as  good  as  new  if  the  surfaces  of  the  old  plate  where  union 
with  the  new  material  is  desired  are  freshly  filed,  absolutely  clean, 
properly  roughened,  and  of  sufficient  area.  To  insure  these  results 
wax  should  not  be  melted  upon  the  surfaces  of  union  in  waxing  up, 
and  removal  of  the  wax  from  the  mold  should  be  accomplished  by 
means  of  instruments  and  not  by  hot  water,  unless,  possibly,  for  the 
removal  of  very  small  particles  which  cannot  otherwise  be  got  rid  of. 
Any  amount  of  the  old  material  desired  may  be  cut  away  and  its  place 
supplied  by  new,  and  thus  any  change  wished  may  be  eff'ected.  In 
case  of  breakage  or  cracking  the  plate  should  be  cut  away  so  that  the 
old  defects  will  be  wholly  obliterated  and  new  material  supplied. 

"  As  a  first  instance,  suppose  a  partial  lower  plate  supplying  the  loss 
of  the  bicuspids  and  molars  on  both  sides  of  the  mouth  to  be  broken 
through  the  bar  which  extends  from  one  side  of  the  mouth  to  the 
other  behind  the  incisors.  The  fracture  is  generally  a  clean  one,  re- 
sembling that  of  glass  or  porcelain,  and  the  two  pieces  maybe  brought 
into  apposition  with  certainty.  The  dentist  holding  the  parts  together 
in  exactly  the  right  position,  the  assistant  covers  the  lingual  side  of  the 
plate  at  the  point  of  fracture  with  a  few  drops  of  hot  shellac  from  a 
shellac  stick.  A  little  cold  water  follows,  and  the  two  parts  of  the 
plate  are  firmly  cemented  together.  A  brace  is  now  extended  across 
from  the  molars  on  one  side  to  those  on  the  other  by  laying  a  burnt 


1050  MECHANICS DENTAL    PROSTHESIS. 

match  on  the  grinding  surfaces  of  the  respective  teeth  and  fastening 
both  ends  with  a  few  drops  of  hot  wax.  By  this  means  sufficient 
strength  is  obtained  to  allow  of  the  plate  being  safely  handled.  A 
piece  of  paper  or  sheet-wax  is  cut  to  fit  and  reach  across  the  lingual 
space  at  the  lower  edge  of  the  plate  and  fastened  therein  with  wax,  a 
coat  of  shellac  varnish  is  applied  to  the  paper,  the  surface  lathered 
with  soap-suds  and  rinsed,  and  a  model  run  in  the  same  manner  as 
in  filling  an  impression. 

"After  this  has  hardened  the  plate  is  removed  from  the  model, 
which  is  then  given  a  coating  of  liquid  silex.  This  is  always  prefer- 
ably done  in  repairing  plates  at  the  time  when  the  plate  is  first  re- 
moved from  the  model.  The  bar  may  be  now  wholly  cut  away  close 
to  the  body  of  the  plate  on  either  side  by  a  jeweler's  saw,  the  cut 
being  made  diagonally  so  as  to  make  what  is  termed  a  "  scarf"  joint. 
The  surfaces  should  be  further  roughened  by  making  a  series  of  shallow 
parallel  cuts  across  them  with  the  saw,  a  thick  separating  file,  or  a  thin- 
wheel  engine  bur.  The  parts  of  the  plate  are  placed  upon  the  model, 
waxed  up,  and  flasked ;  the  model  and  buccal  surfaces  of  the  teeth 
being  covered  with  plaster,  and  the  parting  made  so  that  the  plate  will 
be  retained  upon  the  model,  while  the  pieces  of  the  bar  can  be  readily 
removed.  After  the  flask  is  opened  the  pieces  are  removed,  the  usual 
gateways  cut,  and  the  packing,  vulcanizing,  and  finishing  done  as  usual. 

"  In  the  case  of  an  entire  lower  set  broken  through  the  center,  it 
will  be  seen  that  the  same  directions  will  apply,  excepting  as  to  the 
amount  of  rubber  to  be  cut  away.  A  free  cut  should  be  made  on  the 
lingual  side,  extending  through  under  the  teeth,  to  and  including  the 
labial  band  ;  so  that  the  broken  surfaces  will  be  entirely  obliterated 
and  at  least  one-eighth  inch  in  width  of  new  rubber  supplied  between 
the  cut  surfaces.  An  engine-bur  will  do  much  of  this  work  nicely,  and 
a  wheel-bur  is  very  convenient  for  the  purpose  of  scoring  the  surface. 
The  making  a  model,  flasking,  and  packing  will  be  done  as  before. 

"If  one  of  the  incisor-blocks  be  broken  and  needs  replacement,  a 
new  one  can  be  fitted  after  the  model  is  obtained,  and  the  remaining 
steps  of  the  process  followed  as  has  been  described. 

"  Upper  plates  are  sometimes  cracked  in  the  center,  the  crack  ex- 
tending from  under  and  between  the  incisor  teeth  backward  over  the 
palate.  This  often  happens  from  the  amount  of  rubber  just  behind 
the  incisors  being  insufficient.  It  is  not  unusual  to  see  it  cut  away  at 
this  point,  so  that  the  pins  are  almost  or  quite  exposed,  the  plate  hav- 
ing its  usual  thickness  at  a  very  short  distance  behind  the  teeth.  A 
much  larger  amount  of  material  will  be  tolerated  here  than  is  usually 
employed,  and  often  with  benefit,  not  only  to  the  strength  of  tht 
plate,  but  to  the  articulation  of  the  wearer.     The  curve  of  the  surface 


VULCANO-PLASTIC    WORK.  I05I 

of  the  plate  should  be  made  to  resemble  that  of  the  palate  before  the 
removal  of  the  teeth,  and  it  will  be  found  that  the  extra  thickness  may 
extend  for  half  an  inch  behind  the  teeth  without  annoyance  to  the 
patient. 

'"A  proper  curvature  to  the  surface  of  the  plate  just  behind  the 
incisors  will  do  much  to  prevent  the  disagreeable  whistling  in  making 
the  s  sound,  and  will  assist  in  giving  the  correct  enunciation  to  s/i,  zh, 
and  other  Unguals. 

"  If  the  cracked  plate  fits  a  flat  mouth  a  model  can  often  be  drawn 
from  it  as  it  is;  but  if  the  arch  is  high  and  the  gums  projecting  it  is 
better,  after  thoroughly  cleaning  and  drying  the  plate,  to  finish  the 
cracking  by  breaking  the  plate  entirely  in  two.  The  two  halves  may 
now  be  fastened  together  by  dropping  shellac  upon  the  lingual  side, 
and  a  model  secured  from  which  either  half  of  the  plate  can  be  easily 
removed.  The  whole  palatal  portion  of  the  plate  can  then  be  re- 
moved by  a  saw-cut,  leaving  only  a  narrow  margin  on  the  lingual 
surface  inside  the  teeth.  The  remainder  of  the  surfaces  of  fracture 
are  cut  away  as  directed  in  case  of  the  lower  plate,  the  new  surfaces 
roughened,  the  pieces  of  the  old  plate  replaced  upon  the  model  (which 
has  received  its  coating  of  liquid  silex),  waxed  up,  flasked,  packed, 
and  vulcanized,  the  teeth  being  retained  upon  the  model  as  before 
described.  The  plate,  when  finished,  will  show  the  old  rim  and  a 
margin  of  the  old  rubber  inside  the  teeth. 

"  It  is  sometimes  desirable  to  change  the  substance  of  the  plate 
entirely,  as  in  case  of  supposed  mercurial  poisoning  by  red  rubber ;  or 
at  least  to  put  what  red  rubber  there  may  be  about  the  plate  entirely 
out  of  sight  and  to  reduce  its  quantity  to  a  minimum.  If  this  is  to 
be  done  to  the  plate  last  under  consideration,  it  should  be  prepared 
for  flasking  as  described,  excepting  that  the  labial  band  should  be  cut 
away,  and  everything  arranged  so  that  the  plate  can  be  separated  from 
the  model  when  flasked.  The  parts  cut  away  should,  of  course,  be 
replaced  by  wax.  The  case  is  now  set  in  the  flask  so  as  to  leave  the 
parting  at  the  upper  edges  of  the  gums.  The  plaster  is  varnished  and 
oiled  and  more  plaster  built  on  against  the  labial  sides  of  the  teeth, 
extending  from  their  cutting-edges  to  the  edge  of  the  flask,  and  again 
varnished  and  oiled,  so  that  the  appearance  will  now  be  precisely 
similar  to  a  plate  flasked  so  as  to  be  retained  upon  the  model.  The 
ring  of  the  flask  is  now  put  in  place  and  filled,  and  the  plaster  allowed 
to  harden. 

"When  the  flask  is  separated  the  teeth  will  be  found  in  its  ring- 
section.  A  i^w  blows  of  the  hammer  will  dislodge  them,  with  the  piece 
of  plaster  built  against  their  labial  surfaces.  This  is  carefully  broken 
away  in  two  pieces  if  possible,  which  are  preserved,  and  the  teeth  and 


1052  MECHANICS DENTAL    PROSTHESIS. 

rubber  encasing  them  is  left.  The  rubber  is  now  filed  away  as  much 
as  is  practicable,  leaving  none  of  the  old  rubber  in  sight  and  removing 
enough  from  the  palatal  surface  to  make  a  new  fit  to  the  model.  The 
teeth  and  plaster  are  replaced  in  the  flask  and  the  case  is  ready  for 
packing  and  vulcanizing,  and  when  finished  none  of  the  old  rubber 
will  be  seen,  and  the  plate  will  be  practically  as  good  as  though  the 
teeth  had  been  removed  from  the  old  plate  and  reset. 

"It  is  sometimes  difficult  to  prevent  the  rubber  from  showing  at 
the  joint  between  the  incisors ;  great  care  should  be  exercised  in 
bringing  the  sections  together  properly  and  in  holding  them  in 
position  while  flasking.  If  there  is  room  a  small  wisp  of  loose  cotton, 
not  larger  than  a  thread,  may  be  tucked  into  the  joint  on  its  palatal 
side,  the  edges  of  the  blocks  being  beveled  to  admit  of  this  being 
done. 

"  It  is  evident  that  the  change  from  red  to  black  rubber  just  de- 
scribed can  be  made  with  a  whole  plate  or  a  broken  one  indifferently. 
If  a  change  of  articulation  and  a  new  fit  to  the  mouth  is  also  desired 
on  account  of  shrinkage  of  the  gums,  the  plate  should  be  prepared  so 
as  to  draw  from  the  model,  and  a  few  small  pieces  of  wax  put  in  the 
palatal  side  to  bear  upon  the  alveolar  ridge,  and  give  the  right  articu- 
lation by  trial  in  the  mouth,  the  center  of  the  plate  being  cut  away 
to  facilitate  the  fitting  of  the  plate  to  the  model.  A  fresh  model  of 
the  mouth  being  secured  from  an  imj^ression,  the  plate  is  waxed  on  to 
it,  the  case  is  flasked  with  a  false  piece  of  plaster  built  against  the 
labial  sides  of  the  teeth  as  has  been  before  described,  and  the  plate 
afterward  removed  and  cut  away  as  much  as  desired,  a  considerable 
amount  always  being  taken  from  its  palatal  surface. 

"  This  process  not  only  gives  a  new  fit,  but  allows  the  material  of 
the  plate  to  be  substantially  changed.  Holes  and  dovetails,  it  will  be 
seen,  are  wholly  unnecessary,  and  the  fine  serrated  edge  left  by  cross- 
cutting  the  surfaces  of  union  will  be  found  an  excellent  guide  in 
scraping  the  plate  to  avoid  overlaps.  The  use  of  shellac  as  a  cement 
is  strongly  advised  in  repairing,  as  it  is  rigid  and  brittle  when  cold, 
and  the  broken  parts,  if  once  properly  brought  together,  cannot  get 
out  of  adjustment  without  at  once  attracting  attention  by  the  break- 
age of  the  cement.     Wax  does  not  answer  the  purpose  nearly  so  well. 

"The  amount  of  shrinkage  in  vulcanite  from  cooling  after  vul- 
canization is  not  so  generally  noticed  and  provided  for  as  it  should 
be.  Plates  composed  of  single  teeth  do  not  give  trouble  from  this 
cause,  but  full  plates  on  which  sections  are  mounted  are  often  very 
vexatious  to  the  dentist  from  the  change  of  shape  they  undergo  from 
shrinkage. 

The  reason  of  this  is  that  the  ends  of  the  sections  abutting  form  an 


VULCANO-PLASTIC   WORK.  IO53 

arch  of  porcelain,  which  expands  or  contracts  but  slightly  from  changes 
of  temperature.  The  rib  of  vulcanite  immediately  inside  this  arch, 
and  in  which  the  pins  are  imbedded,  forms  a  second  arch  closely  at- 
tached by  the  pins  to  the  first  one.  The  plate  is  molded  to  the  model 
and  hardened  at  a  temperature  of  about  320°,  and  is  afterward  placed 
in  the  mouth,  where  the  temperature  is  in  the  neighborhood  of  90°. 
Under  these  circumstances  the  contraction  of  the  rubber  which  ensues 
has  the  effect  of  lessening  the  radius  of  the  arch,  drawing  the  heels 
of  the  plate  together,  thus  rendering  it  a  little  too  narrow  to  fit  the 
mouth  accurately.  This  has  the  further  effect  of  elevating  the 
palatal  portion  of  the  plate,  which,  when  tried  in  the  mouth,  will 
usually  be  found  to  rock  slightly,  often  so  much  as  to  interfere  with  its 
fitting. 

"If  the  plate  has  been  made  upon  a  model  taken  from  the  mouth 
the  difficulty  is  overcome  by  warming  the  back  part  of  its  palatal  por- 
tion, pressing  it  down  slightly,  and  cooling  it  while  the  pressure  is 
continued,  the  narrowing  of  the  plate  being  too  small  in  amount  to 
be  itself  objectionable. 

"  This  change  can  be  accomplished  with  more  certainty  by  making 
a  small  plaster  cast  of  the  palatal  portion  of  the  plate,  placing  upon  the 
part  where  the  change  is  desired  a  small  piece  of  folded  paper,  folded 
so  as  to  present  a  thick  center,  and  forcing  the  plate  down  upon  it 
after  its  palatal  portion  has  been  warmed. 

"The  shrinkage  here  alluded  to  becomes  a  more  serious  matter 
when  the  plate  is  re-vulcanized  in  the  course  of  repairing  it.  It  is 
flasked  when  the  change  in  form  by  its  shrinkage  has  already  once 
manifested  itself,  and  again  heated  to  320°  ;  and  in  cooling  a  second 
shrinkage  takes  place,  it  becomes  still  narrower,  and  its  fit,  already 
defective,  is  made  perceptibly  worse.  It  now  often  becomes  a  matter 
of  necessity  to  bring  it  back  to  its  proper  shape  before  it  can  be  worn 
with  comfort.  To  provide  for  this  a  small  dot  should  be  made  with 
a  pointed  instrument  on  each  side  of  the  plate  immediately  behind 
the  molars,  and  a  pair  of  dividers  set  to  the  distance  between  these 
points.  After  vulcanization  the  dividers  can  be  applied  to  the  marks, 
and  they  will  indicate  the  amount  ^f  shrinkage  the  plate  has  experi- 
enced. Let  the  plate  now  be  warmed  just  behind  the  incisors  and  in 
the  mesial  line  by  repeated  short  puffs  of  a  blowpipe  flame.  This  must 
be  done  carefully  and  the  heat  not  allowed  to  extend  over  an  area 
much  exceeding  half  an  inch  in  diameter.  When  the  rubber  is  suffi- 
ciently softened  the  plate  should  be  taken  by  the  heels,  a  pull  made 
upon  it  sufficiently  forcible  to  expand  the  arch,  and  a  stream  of  cold 
water  applied.  The  dividers  will  at  once  show  if  the  change  made  is 
sufficient. 


1054  MECHANICS — DENTAL    PROSTHESIS. 

"  When  the  plate  is  now  tried  in  the  mouth  it  may  be  that  the  back 
.  edge  will  not  touch  the  roof,  and  air  will  be  admitted  under  the  plate, 
in  which  case  the  back  edge  should  be  warmed  and  forced  up  to  its 
proper  position. 

"  The  same  remarks  apply  to  full  lower  plates  as  well,  which  often 
are  found  to  have  lost  their  fit  in  a  measure,  after  having  been  re- 
vulcanized.  The  process  above  detailed  will  suffice  to  restore  them  to 
their  former  fit  and  render  them  again  comfortable  to  the  wearer." 

If  the  teeth  are  to  be  reset  because  of  change  from  absorption,  or 
because  of  some  inaccuracy  in  the  fit  of  the  plate,  it  will  perhaps  be 
best,  in  most  cases,  to  proceed  just  as  for  a  new  piece,  grinding  the 
joints  again  for  any  change  of  arrangement.  Sometimes  rejointing  the 
blocks  may  be  saved  by  bedding  their  cutting  edges  and  cusps  in  a 
gutta-percha  rim  before  detaching  from  the  plate ;  this  will  permit 
their  adjustment  to  the  new  wax  plate  in  a  continuous  arch.  Some- 
times the  old  plate  may  with  advantage  be  used  as  an  impression  cup 
by  roughening  the  rubber  and  using  a  very  thin  layer  of  wax  or  plaster, 
whichever  best  suits  the  case.  In  making  the  model  extend  it  bark- 
ward,  as  before  described  under  Articulation  of  Plastic  Work.  Before 
removing  the  piece  complete  the  articulator,  making  the  plaster  cover 
the  edges  and  crowns  of  the  teeth  one-eighth  of  an  inch.  By  setting 
the  blocks,  when  removed  from  the  old  plate,  into  their  depressions  on 
the  articulator  the  exact  relations  of  blocks  to  the  model  is  preserved  ; 
also,  if  the  plaster  of  the  impression  is  made  accidentally  too  thick  the 
articulator  may  be  slightly  closed.  The  wax  plate  is  arranged  first  on 
the  outside  ;  the  half-articulator  is  then  removed  and  the  inner  part 
of  the  plate  shaped.  The  articulating  portion  is  then  cut  off,  the 
model  set  in  the  flask,  and  the  process  completed  in  the  usual  manner. 

Gold,  platina,  or  aluminium  plates  may  also  be  re-fitted  to  suit  a 
mouth  changed  by  absorption.  Perforate  the  plate  with  holes  about 
size  No.  22  (Fig.  921),  countersunk  on  lingual  side,  regularly  arranged 
and  about  half  an  inch  apart.  Fill  the  lingual  surface  between  teeth 
with  plaster;  remove  this  when  hard  and  make  countersinks  in  it 
opposite  each  hole  in  the  plate.  Set  the  plate  on  model  and  fasten  it 
with  wax  around  the  entire  edge;  then  place  in  half  flask  as  usual. 
Replace  the  countersunk  pieces  of  plaster  and  pour  second  half  matrix  ; 
this  piece  of  plaster  and  the  wax  around  the  edge  prevent  the  batter 
of  the  matrix  from  getting  between  plate  and  model.  Separate  flask, 
cut  vents,  put  in  a  sheet  of  prejjared  rubber  of  proper  size,  press  matrix 
together,  and  vulcanize.  The  imj^ression  may  be  taken  in  the  usual 
cups  or  in  the  plate  itself,  and  with  either  plaster  or  wax,  as  the  case 
may  require;  if  taken  in  the  plate,  cleanse  this  carefully  after  making 
the  model.     The  adhesion  of  the  rubber  may  be  increased  by  cutting 


VULCANO-PLASTIC    WORK.  IO55 

the  palatine  surface  of  the  metallic  plate  with  a  sharp  graver  ;  it  should 
be  carefully  cleansed  just  before  packing  the  rubber. 

Dr.  Richardson  gives  the  following  method  of  refitting  gold  or  vul- 
canite plates  with  a  new  vulcanite  lining:  "  Perforate  the  palatal  por- 
tions of  the  plate  with  from  eight  to  twelve  holes  at  different  points, 
and  also  the  extreme  borders,  from  heel  to  heel  of  the  plate,  at  inter- 
vals of  one-eighth  to  half  an  inch  apart  and  near  the  edges.  These 
holes  may  be  enlarged  to  the  dimensions  of  a  medium-sized  knitting- 
needle ;  or,  if  the  piece  is  of  vulcanite,  to  twice  or  three  times  that 
size.  On  the  lingual  and  buccal  surfaces  the  holes  are  well  counter- 
sunk with  a  bur  drill.  The  plate  is  employed  as  a  cup  or  holder  to 
take  an  impression  of  the  mouth  in  plaster,  being  pressed  up  closely  to 
the  parts.  The  plaster  forced  through  the  holes,  and  filling  the  coun- 
tersinks on  the  opposite  side  of  the  plate,  will  serve  to  bind  the  plaster 
to  the  plate  and  prevent  the  two  from  separating  as  they  are  detached 
from  the  mouth.  When  removed  the  plaster  impression  lining  the 
plate  is  trimmed  even  with  the  borders  of  the  latter  and  varnished  and 
oiled.  The  lower  section  of  the  vulcanizing  flask  is  now  filled  with  a 
batter  of  plaster  on  a  level  with  its  upper  surface,  and  the  impression 
filled  witli  the  same  is  turned  over  and  placed  in  the  center  of  the  flask, 
with  the  edges  of  the  plate  touching  the  surface  of  the  plaster.  The 
plate  and  adhering  plaster  are  now  carefully  separated  from  the  model. 
After  cutting  out  the  plaster  from  the  holes  and  countersinks  in  the 
plate  the  plaster  forming  the  impression  is  detached  from  the  plate  and 
the  holes  and  countersinks  filled  with  wax.  The  plate  is  then  re- 
adjusted over  the  model  and  (the  surrounding  surface  of  the  plaster  in 
the  flask  having  been  varnished  and  oiled)  plaster  is  poured  in  upon 
the  upper  surface  of  the  plate  and  teeth,  filling  the  upper  ring.  When 
the  plaster  is  sufficiently  hard  the  two  sections  of  the  flask  are  separated 
and  grooves  formed,  running  out  from  the  matrix  to  the  margins  of  the 
flask.  A  sufficient  quantity  of  vulcanizable  rubber  is  now  either  placed 
upon  the  model  or  packed  in  upon  the  palatal  surface  of  the  plate  ;  be- 
fore doing  which,  however,  the  wax  filling  the  holes  and  countersinks 
in  the  plate  (and  which  was  placed  there  to  prevent  portions  of  plaster 
last  poured,  in  forming  the  matrix,  from  filling  them  up)  should  be 
worked  out  with  a  small  instrument.  The  whole  being  sufificientlv 
heated,  the  two  sections  of  the  flask  are  forced  together,  expelling  re- 
dundant material.     The  piece  is  then  vulcanized." 

The  late  Dr.  Wildman  suggested  the  following  method  of  forming  a 
new  plate  without  changing  the  articulation  of  the  teeth  :  "  Roughen 
the  palatal  surface  of  the  rubber  plate  to  cause  the  plaster  to  adhere 
to  it;  then  use  it  as  an  impression  cup  to  take  a  plaster  impression, 
being  careful,  when  it  is  in  the  mouth,  to  preserve  the  articulation. 


1056  MECHANICS — DENTAL    PROSTHESIS. 

In  this  impression  cast  the  model ;  trim  and  cut  conical  holes  at 
several  points  in  its  outer  face.  Now,  before  separating  the  impres- 
sion from  the  model,  make  a  cast  of  the  face  of  the  teeth  in  two  or 
three  perpendicular  sections,  extending  to  the  base  of  the  model, 
using  a  solution  of  soap  or  other  parting  substance  on  the  plaster 
model.  Remove  this  mold  of  the  face  of  the  teeth,  which  indicates 
their  true  position  relative  to  the  model.  Then  take  the  impression 
from  the  model.  By  the  aid  of  heat  sufficient  to  soften  the  rubber 
remove  the  teeth  from  it.  Next  make  a  model  plate  with  prepared 
gutta-percha,  'wax  and  paraffin  (or  modeling  composition).'  Now 
secure  the  sections  of  the  mold  of  the  face  of  the  teeth  to  the  model 
(their  place  will  be  indicated  by  the  conical  holes  or  keys)  ;  adjust 
the  teeth  in  their  proper  positions  in  the  plaster  mold  of  them,  and 
build  up  with  wax  to  the  proper  form  of  the  model  set.  This  being 
done,  test  its  accuracy  of  contour  and  articulation  by  placing  it  in  the 
mouth.     Then,  using  the  model,  proceed  as  for  making  a  new  set." 

The  method  just  described  requires  the  presence  of  the  patient ;  but 
cases  occur  where  this  is  not  possible,  and  owing  to  accident  a  new 
plate  is  necessary  and  the  articulation  must  be  preserved.  Take  a 
case,  for  an  example,  where  the  plate  is  so  fractured  that  it  cannot  be 
repaired,  and  yet  is  capable  of  being  temporarily  adjusted  by  means 
of  hot  wax  dropped  from  a  spatula.  When  this  is  done  the  palatal 
surface  of  the  plate  is  coated  lightly  with  oil  and  plaster  batter  poured 
into  it  to  form  a  model.  Then  trim  the  edges  of  the  plate  and  sides 
of  the  model,  and.  form  holes  of  a  conical  shape  to  act  as  keys  for  the 
mold,  which  is  made  in  sections  of  the  outer  face  of  the  teeth. 
When  this  mold  has  become  hard  the  sections  of  it  are  removed,  as 
well  as  the  plate  from  the  plaster  model.  Undercuts  may  prevent  the 
ready  removal  of  the  old  vulcanite  plate,  and  in  such  a  case,  to  pre- 
vent injury  to  the  model,  the  old  plate  should  be  softened  by  heat. 
The  subsequent  manipulation  is  the  same  as  in  the  previous  method. 

When  the  plate  is  broken  in  half  a  rubber  plate  maybe  repaired  by  a 
method  suggested  by  Dr.  Gilbert:  "Remove  the  denture,  and  with 
a  fine  Swiss  saw  cut  away  the  palatal  portion  of  the  plate  to  within 
about  an  eighth  of  an  inch  of  the  inner  surface  of  the  teeth.  In  this 
remaining  portion  cut  dovetails  to  retain  the  new  rubber,  and  also 
form  an  undercut  channel  in  the  portion  which  fits  over  the  alveolar 
ridge  in  the  line  of  the  break,  as  far  as  the  edge  of  the  rim;  secure 
the  parts  to  the  model  with  wax.  The  cut-(nit  palatal  portion  may 
then  be  laid  back  in  place  to  aid  in  waxing  up  that  part.  Invest  in 
the  flask,  covering  the  labial  and  grinding  portions  of  the  teeth,  as  in 
other  repair  work.  After  separating  remove  the  part  desired  to  be  re- 
placed with  new  material  ;  pack  and  vulcanize  as  usual." 


VULCANO-PLASTIC    WORK.  IO57 

Partial  pieces  can  usually  be  retained  by  stays  and  the  fit  of  tne 
plate.  If  clasps  are  called  for  these  may  be  made  of  rubber  alone  if 
the  clasps  are  short  and  the  rubber  elastic ;  or  of  rubber  strength- 
ened by  a  gold  wire,  which  is  to  be  curved 
around  the  clasp  tooth  just  before  pack- 
ing. A  gold  clasp  may  also  be  fitted  and 
retained  in  the  rubber  either  by  a  pro- 
jecting slip  of  the  same  metal  or  by  sol-  '^  'p^^  ^^.^ 
dering  into  it  one  or  two  platinum  pins. 

Fig.  1 151,  taken  from  Prof.  Wildman's  monograph,  represents  these 
two  forms  of  clasp ;  but  in  cases  requiring  clasps  we  very  decidedly 
prefer  a  gold  plate.  The  larger  size  of  vulcanite  plates  necessary  for 
strength  will  usually  secure  adhesion  with  the  help  of  stays  or  half 
clasps;  in  none  of  these  cases  do  we  consider  the  vacuum  cavity  of 
any  service. 

Comlnnation  of  Vulcanite  atid  Metallic  Plates. — Section  or  single 
plain  and  gum  teeth  may  be  secured  to  gold  or  aluminium  plates  by 
vulcanite  instead  of  by  soldering.  Blocks  having  a  porcelain  gum  on 
the  inside,  finished  to  the  plate  and  having  a  countersunk  base  in 
which  are  platinum  pins,  present  a  very  handsome  appearance  when 
attached  to  gold  plate  by  vulcanite,  and  may  be  made  very  secure. 
The  hole  should  be  of  good  size,  but  must  not  come  so  near  the  trans- 
lucent front  of  the  tooth  as  to  permit  the  color  of  the  rubber  to  darken 
it.  In  this  and  the  subsequent  modes  of  attachment  the  swaging,  ar- 
ticulation, and  grinding  of  blocks  is  done  as  usual,  except  that  there 
is  less  necessity  for  close  fitting  to  the  plate  than  in  case  of  soldered 
work.  The  temporary  plaster  rim,  elsewhere  described,  must  in  all 
cases  be  used,  so  as  to  permit  removal  and  correct  replacement  of 
teeth.  Where  blocks  or  single  teeth  with  holes  in  the  base  are  to  be 
supported  by  pins  soldered  to  the  plate,  which  is  another  mode  of  at- 
tachment, press  each  block  into  place  over  a  thin  layer  of  wax  on  the 
gold  plate.  The  wax  projection  made  by  each  hole  shows  where  to 
drill  the  plate  for  the  pins;  then  remove  plate,  drill  holes,  and  solder 
rougliened  or  headed  pins  into  the  plate  opposite  each  hole  ;  fasten 
the  blocks  temporarily  with  wax,  then  invest  in  the  vulcanizing  flask, 
so  that  on  separating  the  matrix  the  plate  shall  come  away  in  one  half, 
the  teeth  in  the  other.  Fill  the  holes  with  rubber  and  place  a  strip 
over  the  base  of  the  blocks ;  warm  and  replace  the  two  halves  of  the 
matrix,  and  vulcanize.  Vulcanite  blocks,  such  as  those  in  Figs.  1152 
and  1 153,  may  be  very  firmly  attached  to  metal  plates  by  some  one  of 
the  methods  represented  in  Fig.  1154.  Set  the  teeth  or  blocks  in  the 
temporary  plaster  rim  and  distinctly  mark  a  line  around  the  ridge,  just 
under  the  head  of  the  pins  (C)  ;  mark  across  this  line  the  position 
67 


I058 


MECHANICS — DENTAL    PROSTHESIS. 


of  each  pin  {a,  b,  c,  d) ;  then  remove  blocks  and  prepare  the 
plate  for  the  different  plans  of  retaining  the  vulcanite,  ist.  For  an 
aluminium  plate  which  can  have  no  soldered  pins  drill  a  row  of 
small  holes  on  the  line  between  the  pins;  set  it  in  the  counter-die,  and 
v/ith  a  tapering  punch  enlarge  each  hole,  with  the  projecting  bur  next 


Fig.  1152. 


Fig.  1153. 


Fig.  1154. 


the  tooth  (C,  C-).  Let  each  hole  be  not  smaller  than  No.  20  (Fig.  921). 
In  some  cases  a  smaller  set  of  holes  may  be  punched  or  drilled  in  the 
outer  edge  above  the  gum  (C).  Swage  the  plate  again  to  correct  the 
effect  of  this  punching  ;  then  place  it  on  model,  replace  blocks,  ar- 
range wax,  and  prepare  for  vulcanizing.      2d.  Arrange  the  plate  firmly 

on  a  piece  of  charcoal, 
set  small  cups  of  gold  or 
platina  on  the  line,  be- 
tween the  pins  (A,  a),  with 
a  small  piece  of  solder  at 
each,  and  solder  them  all 
at  one  heating.  3d.  Or 
drill  small  holes  on  the 
line,  between  the  pins  of 
the  teeth  (B,  b),  and  insert  headed  platina  or  gold  pins  and  solder  them. 
4th.  Or  drill  two  holes  between  the  tooth-pins  (E,  e)  and  insert  a 
loop ;  only  one  hole  is  really  necessary,  as  the  other  end  of  the  loop 
may  be  shortened  so  as  just  to  touch  the  plate,  to  which  the  solder  will 
attach  it.  5th.  Lastly,  a  wire  may  be  bent  in  a  series  of  waves  (d),  so 
as  to  pass  under  each  tooth-pin  (or  just  behind  it  if  the  pin  is  too  close 
to  the  plate,  but  never  over  it)  and  rise  from  the  plate  between  the 
pins.  Adjust  this  wire  accurately,  with  the  blocks  in  place  ;  mark  the 
points  of  contact ;  then  remove  jilate  and  solder  the  wire.  The  last 
four  methods  are  applicable  to  gold  and  platinum,  which  admit  of 
soldering.  In  soldering  no  plaster  investment  must  be  used,  and  the 
plate  must  have  a  good  support  on  the  charcoal ;  with  these  precau- 
tions careful   soldering  will   not  warp  or  spring  the  plate.     If  sprung 


VULCANO- PLASTIC   WORK.  1059 

the  pins  and  loops  make  it  necessary  to  cut  a  deep  groove  in  the  lead 
counter-die  before  attempting  to  swage. 

After  completing  either  of  the  five  plans  here  described  re-adjust 
the  teeth  in  the  plaster  rim  and  fasten  them  in  place  with  wax,  trimmed 
to  the  shape  required  for  the  vulcanite ;  then  invest  in  the  flask  and 
vulcanize  as  before  described.  By  avoiding  excess  of  rubber,  using 
only  so  much  as  is  necessary  to  conceal  the  pins  or  loops,  the  vulcanite 
band  may  have  a  very  neat  appearance.  Some  dentists  partly  conceal 
the  rubber  by  an  inside  and  outside  band ;  but  if  concealment  is 
necessary,  we  should  prefer  to  do  it  by  the  form  of  blocks  above  given. 
If  the  inside  band  is  used  the  simplest  method  is  to  mark  the  line  of 
its  position  ;  then,  by  skillful  use  of  the  hammer,  a  strip  of  gold  can 
he  pa?ic{/  and  with  the  pliers  beiit  %o  as  to  have  a  uniform  slope  and  a 
close  fit  :  a  file  will  be  necessary  over  small  prominences ;  this  method 
of  paning  is  simpler  than  either  swaging  a  band  or  first  making  a  lead 
or  tin  pattern.  If  cast  plates  of  aluminium  or  other  metal  allovs  are 
used  it  is  only  necessary  to  drill  holes,  as  many,  and  of  such  size,  as 
may  be  thought  necessary,  in  that  part  of  the  plate  next  the  blocks ; 
they  may  pass  through  to  the  palatine  surface  if  necessary  and  be 
countersunk.  It  is  very  important  to  ascertain,  by  trial,  that  the 
closely  fitting  edge  of  aluminium  does  not  interfere  with  the  teeth  in 
separating  and  replacing  the  flask. 

A  method  of  attaching  porcelain  teeth  to  a  metal  base  with  vulcanite 
was  devised  by  Dr.  P.  G.  C.  Hunt,  and  a  process  very  similar  was 
afterward  introduced  by  Dr.  Engle.  It  is  described  by  Dr.  Hunt  as 
follows  :  "  Thus  far  we  proceed  as  we  do  for  ordinary  gold  plate  work. 
We  will  now  suppose  the  teeth  ground  and  jointed,  leaving  as  much 
space  between  the  teeth  and  plate  as  the  plate  will  admit  of.  We  next 
mark  with  a  sharp-pointed  instrument  on  the  labial  surface  of  the  plate 
each  point  where  it  is  necessary  to  place  a  loop  for  purposes  hereinafter 
described;  then  apply  wax  to  the  external  or  labial  parts  of  the  teeth 
and  plate,  in  any  manner  sufficient  to  retain  the  teeth  in  position  ; 
remove  the  wax  from  the  lingual  parts  of  the  teeth  and  plate,  and 
mark  the  position  on  the  metal  where  it  is  desirable  to  insert  the  loops ; 
remove  the  teeth  and  wax,  and  with  a  small  bow-drill  make  holes 
through  the  plate  at  the  several  points  previously  determined  on  for 
the  attachments  about  the  size  of  an  ordinary  plate-punch  hole;  take 
a  wire  or  ordinary  gold  plate  cut  in  strips,  say  from  a  half  to  one  line 
in  width,  being  governed  by  the  amount  of  room  there  is  under  the 
base  of  the  teeth,  and  with  small  round-nosed  pliers  bend  the  strip 
around  ;  grasp  both  ends  with  square-nosed  pliers  ;  draw  the  round- 
nnsed  pliers  from  the  loop,  still  grasping  the  square-nosed  pliers  with 
the  left  hand,  and  with  a  hammer  strike  the  top  of  the  loop  a  sufficient 


io6o 


MECHANICS — DENTAL    PROSTHESIS. 


blow  to  keep  the  ends  from  springing  apart ;  cut  off  the  ends  and 
dress  down  to  fit  the  holes  in  the  plate  ;  after  which  solder  on  charcoal 
or  other  suitable  substance  without  investment.  Fig.  1155  illustrates 
the  bent  or  hooked  wire  soldered  to  the  base.  Pickle,  dress,  and 
polish  that  portion  of  the  plate  to  be  exposed  to  view.  Bend  and 
flatten  the  pins;  arrange  the  teeth,  waxing  so  as  to  cover  up  the  loops 
if  practicable.  The  loops  should  be  placed  as  near  the  base  of  the 
teeth  as  possible,  the  rubber  forming,  when  finished,  a  part  of  the  gen- 
eral concave  shape  which  is  desirable  in  upper  dentures  and  which  it  is 


Fig.  1 156. 


not  possible  to  obtain  with  ordinary  soldered  work.  Then  with  silicate 
of  soda  paint  the  joints,  to  keep  the  rubber  from  forcing  in  where  it 
would  show  after  vulcanizing.     Flask,  vulcanize,  and  finish  as  usual. 

A  punch  for  forming  loops  in  metal  plates,  and  especially  for  alumi- 
nium plates,  is  represented  by  Fig.  1156.  The  size  of  the  loop  may 
be  regulated  by  a  thumbscrew. 

Celluloid  can  be  attached  to  a  metal  plate  with  the  same  loops  and 
hooks  by  sawing  out  the  palatal  portion  of  the  celluloid  blank,  and 


VULCANO-PLASTIC    WORK. 


I061 


trimming  awaj  as  much  of  the  remaining  portion  which  covers  the 
alveolar  ridge  as  is  necessary  to  avoid  having  an  excess  of  material. 
When  investing  the  piece  the  line  of  separation  is  made  at  the  edge 
of  the  wax  rim,  thus  permitting  the  plaster  to  cover  the  palatal  por- 
tion of  the  metal.  When  the  sections  of  the  flask  are  separated  the 
metal  plate  will  occupy  the  lower  and  the  teeth  the  upper  portions. 

The  attachment  of  vulcanite  to  metal  plates  is  an  extremely  useful 
and  important  application.  It  loses  one  of  the  peculiar  advantages 
claimed  for  vulcanite,  the  accurate  fit  of  the  plate;  but  it  makes  very 
strong  work,  and  is  more  cleanly  than  ordinary  swaged  work,  because 
all  interstices  are  completely  closed.  It  also  gives  a  shape  behind  the 
teeth  more  conformable  to  the  natural  shape  of  the  teeth  and  gum.  It 
obviates  two  of  the  principal  objections  urged  against  vulcanite — 
thickness  of  the  plate  and  contact  of  the  rubber  against  the  gum  and 
tongue.  It  dispenses  with  that  accurate  grinding  of  the  base  of  blocks 
required  in  ordinary  gold  work,  and  obviates  the  risks  of  the  soldering 
process.  It  is  applicable  to  full  sets,  or  to  partial  sets  where  the  teeth 
are  in  groups  of  three  or  more.  It  is  best  repaired  by  removing  the 
entire  vulcanite  attachment ;  but  those  who  patch  up  old  rubber  plates 
can,  with  greater  impunity,  patch  the  "  combination  work  ;"  since  the 
strength  of  the  piece  depends  mainly  on  the  plate,  the  brittleness  of 
second  heating  is  of  less  moment.  Another  argument  in  its  favor  is 
that  it  makes  available  to  gold-dentists  the  beautiful  forms  of  rubber 
blocks,  without  identifying  them  with  that  class  of  rubber-dentists 
who,  by  accommodating  the  style  of  their  work  to  the  cheapness  of 
the  material,  have  brought  much  discredit  upon  dental  mechanism. 
Dr.  R.  M.  Chase  has  invented  what  he  styles  "a  metallic-roof  plate," 
which  comprises  a  plate  of  gold  or  other  metal  to  cover  the  roof  of 
the  mouth  and  a  vulcanized  extension  attached  to  the  edges  of  such  a 
plate  and  extending  over  the  alveolar  ridge.  The  edge  of  the  metal- 
lic plate  is  serrated  or  notched,  and  bent  upward  at  an  angle  so  that 
the  vulcanite  portion  can  be  attached.  In  such  a  denture  the  metal 
portion  only  comes  in  contact  with  the  roof  of  the  mouth,  while  the 
vulcanite  is  restricted  to  the  under  and  outer  surfaces  of  the  alveolar 
ridge.  The  method  of  constructing  such  a  denture  is  described  by 
Dr.  Chase  as  follows  :  "  Shape  the  plaster  model  so  that  it  will  easily 
drop  from  the  sand  by  its  own  shape  and  weight  by  simply  raising  the 
flask  at  a  right  angle  from  the  table.  After  shaping  the  model  as 
described,  mold  wax  and  paraffin  base-plate  to  the  labial  and  buccal 
portion  of  the  alveolar  ridge  of  the  model,  filling  all  undercuts  and 
irregularities,  letting  it  extend  over  on  to  the  alveolar  ridge  to  the 
depth  of  from  one-eighth  to  one-quarter  of  an  inch.  This  should  be 
beveled  toward  the  palatine  aspect,  this  being  done  with  a  view  to 


Io62  MECHANICS — DENTAL   PROSTHESIS. 

where  the  turned-up  edge  of  the  plate  will  not  interfere  with  the  pins 
of  the  teeth.  The  whole  model,  including  the  wax,  should  be  shaped 
on  a  true  bevel  from  the  base  to  the  beveled  edge.  Varnish  the  model, 
including  the  paraffin  wax,  with  two  or  three  coats  of  white  shellac 
dissolved  in  alcohol.  A  model  when  prepared  in  this  manner  presents 
a  beveled  surface  at  all  points,  which  makes  sand-molding  simplicity 
itself.  When  the  shellac  varnish  is  dry  mold  in  fine  sand.  Do  not 
pack  the  sand  over  the  face  of  the  model  but  a  trifle,  rather  depend 
upon  the  weight  of  the  sand  to  do  this.  Pack  thoroughly  around  the 
side  and  top  of  the  flask,  so  that  when  it  is  leveled  off  and  reversed 
none  will  drop  out. 

"  Having  secured  the  impression  of  the  model,  melt  zinc  and  make 
a  die.  When  the  die  is  cool  reverse  it  and  pack  sand  around  it  nearly 
as  high  as  the  top  of  the  ridge,  so  that  only  the  palatine  surface  and 
the  beveled  edge  is  exposed.  Place  over  this  a  rim  of  iron  about  one 
inch  larger  in  diameter  than  the  die,  and  pour  melted  lead  into  the 
rim  to  the  depth  of  one  inch.  Remove  this  counter-die  and  make 
another,  but  do  not  let  the  sand  extend  up  higher  than  half  an  inch 
from  the  top  of  the  ridge.  The  first  counter  serves  to  shape  and 
partially  swage  upon.  When  this  is  done  trim  the  edge  of  the  plate 
where  it  bends  over  the  edge  of  the  die  to  the  proper  shape,  not  let- 
ting it  extend  beyond  the  top  of  the  beveled  edge.  The  second 
counter  serves  for  the  final  swaging.  It  is  seldom  necessary  to  make 
more  than  one  die  and  two  counter-dies  as  described.  When  the  plate 
is  shaped  upon  the  first  counter,  notch  the  turned-up  edge  about  one- 
eighth  of  an  inch  apart,  cutting  into  the  metal  to  about  one-thirty- 
second  of  an  inch — where  the  turned-up  edge  commences  or  where  it 
is  to  leave  the  cast,  place  back  upon  the  die  and  smooth  down  the 
notched  points,  which  will  curl  up  in  cutting.  Anneal  and  place  upon 
counter  No.  2  and  strike  the  die  with  two  or  three  dead,  pushing  blows ; 
this  will  finish  the  swaging  process.  Now  saw  or  trim  off  the  base  of 
the  model,  remove  the  wax  and  paraffin,  and  adjust  the  trial-plate. 
Secure  the  bite  or  articulation  ;  after  this  is  done  remove  the  trial-plate 
and  fasten  the  metallic  plate  to  the  cast  in  position  by  a  few  drops  of 
wax.  Soften  base  plate,  place  this  upon  the  labial  and  buccal  surface 
of  the  cast,  connecting  it  with  the  edge  of  the  plate.  Proceed  to 
wax  up  the  teeth  in  usual  manner,  letting  the  wax-backing  extend  on 
to  the  plate  as  far  as  desired  when  finished.  When  adjustment  of  the 
teeth  and  waxing  process  are  completed,  flask  the  same  as  for  rubber, 
except  the  plaster  should  cover  the  metallic  plate,  extending  a  little 
above  the  edge  or  border  of  the  wax.  Soap  the  plaster,  adjust  the 
upper  half  of  the  flask,  and  fill  with  plaster.  When  hard,  warm  the 
flask  and  open.     Remove  all  wax  by  pouring  boiling  hot  water  upon 


'.      VULCANO-PLASTIC   WORK.  I063 

it.  Now,  with  a  pair  of  narrow  beak  forceps,  bend  the  notched  parts 
every  other  one  in  opposite  directions.  This  gives  additional  security 
against  becoming  detached  when  the  extension  is  molded  to  it ;  vul- 
canize and  finish."  A  vulcanized  plate  may  be  bleached  by  placing 
it  in  a  glass  vessel  containing  alcohol,  and  exposing  to  the  sun's  rays 
for  from  four  to  six  hours  ;  covering  the  top  of  the  vessel  with  a  plate 
of  glass  will  prevent  rapid  evaporation.  The  pink  rubber  employed  to 
give  a  more  natural  color  to  the  gum  requires  to  be  bleached  in  order  to 
render  it  sightly.  To  remove  teeth  from  a  vulcanite  plate  the  piece 
may  either  be  passed  through  an  alcohol  flame  until  the  teeth  become 
hot,  or  the  set  may  be  boiled  in  oil  or  imbedded  in  hot  sand  of  such  a 
temperature  as  will  not  char  the  plate.  The  latter  method  is  prefer- 
able when  care  is  taken  to  have  the  sand  at  a  proper  temperature,  as 
the  teeth  or  sectional  blocks  can  be  readily  detached  and  all  rubber 
adhering  to  the  pins  be  removed  by  means  of  a  pointed  excavator. 
Any  slight  imperfections  in  a  vulcanite  plate  in  the  form  of  a  small 
hole  left  by  plaster  particles  can  be  repaired  by  melting  gum  shellac 
and  incorporating  it  with  vulcanite  filings.  A  cement  thus  formed  can 
be  introduced  in  a  plastic  state  and  made  smooth  with  a  heated  spatula 
or  burnisher. 

Rubber  can  be  made  liquid  for  use  as  a  rubber  solder  by  cutting  it 
into  small  pieces  and  dissolving  by  either  benzine,  turpentine,  chloro- 
form, ether,  or  bisulphid  of  carbon,  all  of  these  agents  being  solvents 
of  rubber.  The  shape  of  a  vulcanite  plate  can  be  changed  by  obtain- 
ing a  correct  impression  and  model  of  the  mouth,  upon  which  the 
plate,  having  been  previously  heated,  is  pres--ed  by  means  of  a  napkin 
or  piece  of  chamois  skin,  and  held  in  position  until  it  is  cold.  To 
soften  the  rubber  plate  the  set  may  be  immersed  in  boiling  water,  or 
placed  in  an  oven  with  the  teeth  downward  until  the  rubber  becomes 
pliable  ;  in  the  latter  method  care  should  be  taken  that  the  rubber  is 
not  blistered  or  charred.  A  more  certain  method,  however,  is  to  re- 
construct the  set. 

For  quick  repair  in  the  case  of  a  broken  tooth  or  sectional  block  a 
hard,  quick-setting  amalgam  is  sometimes  employed,  first  cutting  out 
a  suitable  cavity  about  the  space  to  be  filled,  and  after  the  tooth  is 
properly  adjusted  packing  the  amalgam  under  it  and  about  the  pins, 
the  tooth  being  firmly  held  in  place  during  the  operation.  Wood's 
fusible  metal  has  also  been  used  for  the  same  purpose  and  to  close 
holes,  the  latter  being  countersunk  on  both  surfaces  and  made  oblong. 

Spring  plates  consist  of  elastic  partial  pieces  which  are  so  constructed 
and  vulcanized  as  to  press  against  certain  natural  teeth,  and  thus  be 
retained  in  position.  After  securing  the  model  a  little  of  the  palatal 
surfaces  of  the  plaster  bicuspids  and  molars  is  scraped  away,  and  in 


1064  MECHANICS — DENTAL    PROSTHESIS. 

forming  the  trial  plate  tne  wax  is  allowed  to  extend  some  distance  from 
the  necks  of  the  retaining  teeth  upon  the  model,  toward  the  grinding 
surfaces,  in  the  form  of  partial  stays.  These  plates  are  so  shaped  as  to 
leave  the  central  portion  of  the  mouth  free,  no  air-chambers  or  clasps 
being  necessary.  As  the  tendency  of  spring  plates  is  to  press  the  re- 
taining teeth  outward,  they  are  not  generally  used.  For  mouths  having 
soft  places  Dr.  Land  recommends  an  air-chamber  covering  four-fifths  of 
the  palatine  arch  and  including  certain  parts  of  the  alveolar  walls  (pages 
973  and  974)  ;  and  the  same  writer  remarks  :  "  To  insure  a  comfortable 
adaptation  the  pressure  must  be  so  equalized  that,  as  the  alveolar  ridge 
recedes,  undue  stress  will  not  be  brought  on  the  palate.  For  this 
reason  an  air  space,  covering  almost  the  entire  surface  of  the  pala- 
tine arch,  is  desirable,  as  thus  the  pressure  is  better  distributed  and 
brought  to  bear  directly  on  the  alveolar  ridge,  where  there  will  be  the 
least  danger  of  injuring  the  mouth,  thus  avoiding  the  riding  or  rocking 
of  the  plate  on  the  hard  palate.  The  conventional  air  chamber,  with 
its  acute  angles  invariably  placed  on  the  most  rigid  portion  of  the  hard 
palate,  soon  outlines  itself  in  the  tissues,  demonstrating  a  failure  to 
properly  utilize  atmospheric  pressure  and  injuring  the  mouth  by  induc- 
ing absorption  unnecessarily." 

Dr.  Hurd  has  suggested  what  he  terms  a  "  flange  section  "  for  lower 
plates,  which  is  described  as  follows :  An  impression  is  first  taken  in 
wax,  and  this  is  used  to  obtain  a  plaster  impression.  The  extreme 
projecting  plaster  at  the  sides  of  the  tongue  is  cut  off,  and  the  surface 
varnished  and  filled  up,  so  as  to  make  a  full  model  across  from  heel  to 
heel,  running  far  back  upon  the  process,  to  keep  the  lip  from  pressing 
the  plate  back  when  the  force  of  the  muscles  and  lip  is  brought  to  bear 
upon  it.  After  obtaining  a  correct  articulation,  a  gutta-percha  plate 
being  used  for  the  purpose,  the  teeth  are  set  directly  upon  the  center 
of  the  margin,  perpendicular  in  front,  but  inclined  at  the  sides,  so  as 
to  allow  for  a  sufficient  space  to  form  an  outer  flange  for  the  lip  to 
press  down  upon.  This  flange  is  then  made  by  means  of  wax  about 
cne-third  of  an  inch  thick,  with  the  inner  surface  rounded  up  in  the 
same  manner  as  the  outside,  but  not  made  so  thick  and  high,  for  the 
tongue  to  rest  upon  and  keep  down,  thus  excluding  the  air,  the  saliva 
which  collects  under  the  tongue  also  aiding  in  making  the  vacuum. 
It  is  necessary  that  the  flange  should  rest  gently  against  the  cheek  to 
give  steadiness  to  the  plate,  and  the  teeth  must  be  so  arranged  that 
they  are  level  on  the  face.  After  vulcanizing,  the  piece  is  first  cut 
away  by  filing  at  the  hard  margin  on  the  under  side  of  the  outside 
flange,  and  increasing  it  near  the  edge  of  the  plate  at  the  cheek,  and 
making  a  chamber.  The  inside  of  the  plate  is  also  cut  away  to  free  it 
from  the  sublingual  muscles  and  glands,  which  tend  to  elevate  the  plate 


VULCANO-PLASTIC    WORK.  I065 

when  the  tongue  moves  upward.  In  cases  of  malformation  a  thin, 
flexible  rubber  flange  may  be  attached  to  the  plate  instead  of  the  hard 
flange,  so  as  to  hold  securely  and  conform  to  the  movements  of  the 
muscles. 

Lining  Vulcanite  Plates  with  Gold. — Vulcanite  plates  are  sometimes 
covered  with  a  gold  lining  on  the  palatine  surface  to  prevent  the  con- 
tact of  the  rubber  with  the  mucous  membrane.  What  is  known  as  the 
"vulcan  gold  lining"  is  composed  of  chemically  pure  gold,  with  a 
thin  covering  of  pure  silver.  The  flask  is  packed  as  usual  and  the  gold 
is  applied  in  one  piece  to  the  surface  to  be  covered.  The  union  between 
the  rubber  plate  and  the  gold  covering  is  mechanical ;  and  the  sulphur 
in  the  rubber  when  set  free  by  the  action  of  vulcanizing  attacks  the  sil- 
ver, sulphurizing  the  surface,  and  to  this  the  rubber  tightly  adheres. 

If  the  rubber  plate  is  covered  by  the  gold  on  both  sides  it  is  claimed 
that  the  vulcanite  becomes  tougher  when  vulcanized,  for  the  reason 
that  during  this  process  the  pressure  against  the  metal  gives  the  plate 
a  surface  more  dense  than  it  will  have  if  vulcanized  in  contact  with 
plaster.  The  sheets  of  this  form  of  gold  are  of  the  thickness  of  No.  20 
foil. 

Vulcanite  for  Irregularity  Appliances. — Of  the  peculiar  adaptation 
of  the  vulcanite  material  to  the  correction  of  irregularity  mention  has 
been  made  in  the  chapter  on  that  subject.  No  further  special  direc- 
tions are  required  except  on  two  points  :  first,  to  have  the  plaster  which 
makes  the  model  perfectly  smooth  and  free  from  air  bubbles  ;  secondly, 
to  coat  the  teeth  before  vulcanizing  with  soluble  glass  or  collodion  so- 
lution. Attention  to  these  two  points  will  give  a  plate  which,  if  the 
impression  is  correct,  will  fit  the  teeth  with  most  perfect  accuracy. 

Directions  to  Patient. — Upon  the  completion  and  insertion  of  a  vul- 
canite piece  the  patient  should  be  cautioned  to  cleanse  it  thoroughly 
at  least  once  a  day  ;  also  to  keep  it  in  water  when  not  worn  in  the 
mouth.  Extreme  cleanliness  is  advisable  in  all  kinds  of  artificial 
work,  and  many  patients  need  no  such  direction  ;  the  special  neces- 
sity for  care  in  the  case  of  vulcanite  arises  from  the  tenacity  with 
which  the  mucous  secretions  adhere  to  the  surface  if  from  neglect  they 
are  allowed  to  collect  upon  it.  This  coating  is  most  apt  to  collect  at 
those  points  where  the  friction  of  the  tongue  and  of  the  food  does  not 
remove  it ;  the  same  care  is  necessary  for  its  daily  removal  as  is  required 
to  keep  the  natural  teeth  in  good  order.  There  is,  however,  this  dif- 
ference between  cleanliness  of  the  teeth  and  of  the  plate,  that  while 
both  are  essential  to  purity  of  the  mouth,  the  secretions  have  no 
chemical  action  upon  the  plate,  as  they  have  upon  the  teeth. 

One  point  affecting  the  durability  of  vulcanite  plates  has,  perhaps, 
not  been  determined  by  a  sufficient  experience.     It  is  well  known  that 


Io66  MECHANICS  —  DENTAL    PROSTHESIS. 

silver  and  eighteen-carat  gold  undergo  a  change  in  the  mouth  which 
causes  them  to  become  more  or  less  brittle  ;  such  is  not  the  case  with 
twenty-carat  gold  and  with  platinum.  The  change  in  these  cases  is 
partly  the  effect  of  mastication,  acting  as  do  the  repeated  blows  of 
swaging  ;  partly  a  galvanic  action  between  the  molecules  of  the  alloyed 
metal.  A  similar  but  much  more  rapid  change  takes  place  in  the 
gutta-percha  which  is  used  for  impressions ;  also  in  the  vulcanized  gutta- 
percha and  in  all  those  preparations  of  vulcanized  rubber  with  which 
foreign  substances  are  largely  mixed  for  the  purpose  of  modifying  the 
brown  or  red  color.  The  brown  rubber,  being  purer,  will  probably 
retain  its  toughness  and  elasticity  longer  than  the  red  rubber.  We 
have  some  specimen  pieces  of  red  rubber  which  seem,  at  the  end  of 
twelve  years,  to  possess  their  original  strength  ;  and  we  know  of  one 
partial  piece  that  has  been  worn  constantly  for  ten  years,  which  has 
never  been  repaired,  and  seems  as  strong  as  when  first  made.  This 
point,  however,  requires  the  collected  experience  of  many  observers 
during  a  period  of  many  years,  carefully  distinguishing  between  the 
brittleness  of  over-baking  or  twice  vulcanizing,  and  that  which  may 
supervene  as  the  result  of  certain  molecular  changes  in  the  substance 
of  the  material.  It  is  a  change  which,  unlike  the  galvanic  action  in 
gold  and  silver  plate,  may  not  require  the  presence  of  the  buccal  fluids, 
but  which  will  probably  take  place  alike  out  of  the  mouth  as  in  ;  for 
such  is  shown  to  be  the  case  with  gutta-percha. 

CELLULOID. 

Celluloid,  like  vulcanized  rubber,  a  cheap  base  for  artificial  dentures, 
was  first  introduced  in  1869,  and  during  the  existence  of  the  '•  rubber 
patents"  was  much  used  by  those  who  objected  to  become  licensees  of 
the  Goodyear  Rubber  Company.  The  comparatively  recent  improve- 
ments made  in  the  material,  and  methods  of  manipulating  it,  have 
commended  celluloid  to  professional  favor  as  a  plastic  substance  more 
in  harmony  with  the  soft  tissues  of  the  mouth,  as  regards  natural  gum 
color,  than  rubber,  although  it  is  more  liable  than  the  latter  substance 
to  change  form  after  molding  and  to  absorb  the  oral  secretions  if  not 
properly  manipulated.  Celluloid  is  obtained  from  cellulose,  the 
woody  fibre  which  constitutes  the  framework  of  plants,  examples  of 
which  are  furnished  by  hemp,  linen,  cotton-wool,  etc.  In  the  manu- 
facture of  celluloid  the  cellulose  of  hemp,  which  is  the  strongest,  is 
first  converted  into  paper  by  the  usual  method,  its  chemical  properties 
during  this  process  remaining  unchanged.  The  hemp  paper  is  then 
converted  into  pyroxylin  (gun  cotton),  by  immersing  the  paper  in  a 
strong  mixture  of  nitric  and  sulphuric  acids,  afterward  being  thoroughly 
washed. 


CELLULOID.  1067 

This  process  increases  its  weight  about  seventy  per  cent,  and  renders 
it  highly  explosive,  taking  fire  at  300°  Fahrenheit. 

The  pyroxylin  is  then  reduced  to  a  pulp,  and  a  mixture  made  of  the 
following  ingredients  :  Pyroxylin,  100  parts  ;  camphor,  40  parts ;  oxid 
of  zinc,  2  parts;  vermilion,  0.6  part.  It  will  be  seen,  therefore,  that 
celluloid  is  composed  principally  of  pyroxylin,  with  camphor  (dis- 
solved in  alcohol)  as  a  solvent,  and  that  it  contains  less  vermilion  than 
the  red  vulcanizable  rubbers.  After  the  ingredients  are  thoroughly 
mixed  immense  pressure  is  brought  to  bear  upon  the  mass  by  means  of 
a  hydraulic  press  of  two  thousand  pounds  to  the  square  inch,  which 
squeezes  the  celluloid  through  a  small  orifice  in  the  side,  near  the  bot- 
tom of  a  strong  cylinder.  This  pressure  is  necessary  to  condense  and 
solidify  the  celluloid,  which,  as  it  presses  out  of  the  orifice  in  the 
cylinder,  is  cut  into  pieces  and  molded  by  heat  and  pressure  into  forms 
suitable  for  dental  use,  called  "  blanks,"  and  which  in  size  and  shape 
approximate  to  the  bases  of  upper  and  lower  dentures.  These  ' '  blanks  ' ' 
are  then  seasoned  for  some  two  months  in  a  room  kept  at  a  temperature 
of  160°  Fahrenheit,  when  they  are  ready  for  use.  To  manipulate  a 
celluloid  blank  into  a  proper  denture  is  by  no  means  as  easy  an  opera- 
tion as  the  working  of  vulcanizable  rubber,  celluloid  being  a  material 
that  is  liable  to  alteration  in  shape  and  character  under  different  cir- 
cumstances. Repeated  failures  are  the  result  of  manipulating  cellu- 
loid like  vulcanizable  rubber  ;  hence  perfect  molds,  equal  pressure,  and 
metal  dies  are  absolutely  necessary  for  the  usefulness  and  durability  of 
such  a  denture.  Experience  proves  that  metal  dies,  which  produce  a 
surface  proof  against  disintegration,  are  alone  reliable.  The  coating 
of  the  surface  of  a  wax  and  paraffin  plate,  and  also  of  the  plaster 
model,  with  tin  foil,  overcomes  somewhat  the  difificulty  of  preventing 
the  loss  of  too  much  of  the  camphor  solvent  by  absorption,  and  ob- 
viates the  necessity  of  removing  the  original  surface  possessed  by  a 
celluloid  plate  when  it  is  taken  from  the  heater. 

In  the  preparation  of  a  celluloid  denture  the  manipulations  are  the 
same  as  for  vulcanized  rubber  until  the  case  is  ready  to  invest  in  the 
flask.  The  plaster  used  for  working  celluloid  should  be  of  the  best 
quality,  and  not  mixed  too  thin.  The  pink  paraffin  and  wax  answers 
better  than  any  other  material  for  a  base  plate,  a  thin  paraffin-and  wax 
sheet  being  used  for  the  plate,  which  is  strengthened  by  adding  to  its 
surface  either  warmed  paraffin  or  modeling  composition,  first  covering 
jthe  paraffin  plate  with  No.  60  tin  foil  in  order  that  the  modeling 
composition  may  be  removed  without  injuring  the  smooth  surface 
of  the  thin  paraffin  base  plate.  The  teeth  are  arranged  upon  the 
base  plate  and  secured  by  dropping  melted  paraffin  and  wax  around 
their  roots.     A  stick-form  of  paraffin  and  wax  can  be  obtained,  which 


Tc68 


MECHANICS  — DENTAL    PROSTHESIS. 


is  \ery  convenient,    the  method   of  using   it   being   represented    in 
Fig.  II57- 


Fig,  1157. 


Fig.  II59- 


Fig.  1158. 


The  paraffin  and  wax  compound  is  then  carved  into  the  shaiie  of 
the  gum  desired  by  carving  instruments,  such  as  the  set  of  Dr.  W.  W. 
Evans,  represented  in  Fig.  1127  ;  or  a  simple  scraper   may  be  used. 


CELLULOID.  1069 

such  as  is  represented  in  Fig.  1158.  The  surface  of  the  paraffin  and 
wax  may  be  made  very  smooth  by  directing  upon  it  the  flame  of  an 
alcohol  lamp  with  a  blowpipe,  care  being  taken  to  preserve  the  out- 
lines of  the  carved  gum.  The  more  perfectly  the  wax  is  carved  and 
smoothed,  the  less  finishing  of  the  surface  of  the  celluloid  will  be  neces- 
sary. The  surface  of  the  wax  is  then  covered  with  heavy  tin  foil, 
which  is  burnished  down  lightly  and  smoothly. 

The  case  is  now  ready  for  investing  or  flasking,  after  which  the 
grooves  are  cut  for  excess  of  material ;  and  in  every  case  the  parting 
of  the  flask  should  be  at  the  edge  of  the  wax,  and  the  wax,  teeth,  and 
foil  removed  with  the  upper  half  of  the  flask,  so  that  the  surface  of  the 
model  or  cast  is  left  clean  and  entirely  exposed. 

To  prevent  breaking  a  plaster  cast,  in  cases  of  deep  undercut,  the 
method  of  investment  suggested  by  the  late  Dr.  Wildman  should  be 
followed.  "It  consists  simply  in  so  investing  the  cast  that  it  shall 
occupy  the  position  shown  in  Fig.  1159.  If  so  placed,  the  pressure 
applied  in  molding  is  brought  to  bear  upon  the  mass  of  plaster  sup- 
porting the  projection,  instead  of  upon  a  thin  section."  Cutting 
away  the  base  of  the  cast  at  the  heel  before  investing  it  will  elevate  the 
anterior  part  in  the  manner  referred  to.  After  the  sections  of  the 
flask  are  separated,  the  wax  is  removed  by  pouring  boiling  water  upon 
it  from  the  spout  of  a  kettle,  when  the  tin  foil  will  remain  upon  the 
plaster  surface.  In  some  cases  it  may  be  necessary  to  cut  away  the 
thin  edge  of  plaster  which  projects  over  the  mold  in  the  section  of  the 
flask  containing  the  teeth.  It  is  recommended  to  cut  a  groove  for 
excess  of  material  around  the  inside  of  the  flask,  about  one-eighth  of 
an  inch  from  the  model,  and  in  this  section  of  the  flask,  with  no  cross 
grooves  connecting  the  main  groove  with  the  model,  as  is  done  in  the 
case  of  vulcanite.  All  sharp  edges  of  plaster  liable  to  break  off  should 
be  removed  or  rounded,  and  many  prefer,  especially  when  gum  teeth 
are  used,  to  cut  away  the  plaster  between  the  model  and  the  edge  of 
the  flask  all  around,  about  the  thirty-second  of  an  inch,  to  allow  the 
surplus  celluloid  to  escape  without  pressing  too  much  upon  the  gums 
of  the  teeth.  In  using  a  celluloid  blank  care  should  be  taken  to  select 
one  as  near  the  size  of  the  surface  of  the  model  as  possible,  for  all 
folding,  owing  to  too  great  width  at  the  sides,  will  form  creases  in  the 
plate  ;  the  blank  may  be  reduced  to  a  proper  size  by  cutting  down. 
Celluloid  may  be  molded  with  steam,  glycerin,  or  oil,  and  by  dry 
heat,  the  latter  giving  the  most  perfect  results.  Fig.  1160  represents 
a  sectional  diagram  of  the  steam  molding  apparatus  of  the  Celluloid 
Manufacturing  Company. 

In  using  this  steam  apparatus  the  boiler  is  partly  filled  with  water, 
the  quantity  being  sufficient  to  cover  the  ribs  at  the  bottom.     The 


1070 


MECHANICS — DENTAL    PROSTHESIS. 


screw  is  turned  back  so  far  that  the  plunger  when  in  position  is 
resting  against  the  top  of  the  boiler,  so  that  the  model  may  not  be 
injured  by  pressure  upon  the  flask  while  the  cover  is  being  screwed 
down.  It  is  very  necessary  that  the  cover  should  be  well  turned 
down,  the  gland  turned  back,  and  the  screw  working  easily,  other- 
wise it  is  impossible  to  determine  how  much  pressure  is  exerted  ; 
for  if  too  much,  the  teeth  or  model  may  be  broken,  and  if  too  little, 
the  result  is  a  porous  plate.     After  the  flask  is  placed  in  the  appa- 


FiG.  1160. 


ratus  the  screw  is  turned  down  very  gently  with  the  thumb  and 
finger,  until  it  is  felt  to  touch  the  flask.  The  heat,  which  may  be 
generated  with  alcohol,  kerosene,  or  gas,  is  then  applied.  The  upper 
portion  of  the  safety  valve,  which  consists  of  two  parts,  may  be  sus- 
pended by  the  pins  in  the  lead  weight,  and  this  valve  should  not  allow 
the  steam  to  escape  at  a  temperature  of  225°  F.  When  the  steam 
begins  to  blow  off,  strict  attention  is  necessary,  as  the  plate  is  readily 


CELLULOID.  I07I 

injured  by  too  much  heat  without  the  required  pressure.  Tlie  time 
necessary  from  this  point,  with  the  properly  regulated  heat,  is  Uom 
fifteen  to  twenty  minutes.  When  the  steam  escapes  from  the  valve,  its 
upper  portion  being  suspended,  the  plate  begins  to  soften,  and  the 
screw  is  easily  turned  with  the  thumb  and  finger,  when  the  upper 
weight  should  be  dropped  down.  The  screw  is  again  turned  very  care- 
fully, the  pressure  ceasing  as  soon  as  resistance  is  felt,  and  continued 
when  it  again  yields.  This  careful  screwing  down  is  kept  up,  and 
the  pressure  somewhat  increased  as  the  steam  rises,  which  can  be  deter- 
mined by  raising  the  valve,  the  object  being  to  exert  an  equal  pressure 
over  the  entire  plate,  before  the  steam  blows  off  very  sharply  and 
continuously  on  raising  the  safety  valve.  At  this  point  in  the  mold- 
ing process  the  pressure  should  be  increased,  but  an  interval  elapse 
between  the  turns  of  the  screw  in  order  to  allow  the  celluloid,  which 
flows  very  slowly,  to  escape  under  the  pressure.  At  the  end  of  the 
process,  considerable  pressure  should  be  exerted  by  means  of  the 
screw,  as  much,  indeed,  as  can  be  applied,  or  until  the  screw  can  no 
longer  be  turned.  If  alcohol  is  used  to  generate  the  heat,  the  cup  of 
the  apparatus  is  of  such  a  size  that  its  contents  are  consumed  by  the 
time  the  steam  blows  off  from  the  safety  valve,  and  the  molding  is 
completed.  If  gas  or  kerosene  is  employed,  the  flame  should  be  so 
regulated  as  to  complete  the  molding  process  within  thirty  to  forty 
minutes,  otherwise  the  celluloid  may  be  injured. 

To  mold  celluloid  in  glycerin  or  oil  an  a]:)paratus  represented  by 
Fig.  1 161  is  employed.  It  consists  of  an  open  tank  to  contain  the 
glycerin,  with  a  thermometer  to  indicate  the  heat,  a  stand  on  detach- 
able legs,  and  a  screw-clamp  to  hold  the  flask.  In  the  use  of  the  gly- 
cerin apparatus,  when  the  case  is  ready  for  molding,  the  celluloid  blank 
is  placed  in  the  flask,  which  is  then  put  in  the  screw-clamp,  and  the 
screw  turned  until  it  lightly  presses  upon  the  top  of  the  flask.  The 
whole  case  is  then  placed  in  the  tank  and  sufficient  glycerin  poured 
in  to  cover  the  flask — about  one  and  a  half  pounds. 

The  heat  (which  may  be  generated  by  alcohol,  gas,  or  kerosene)  is 
then  applied,  and  as  soon  as  its  effect  is  felt  by  the  screw  yielding  to 
slight  pressure,  about  225°  F.,  the  molding  process  is  .commenced. 
The  screw  should  be  very  gently  turned  at  first,  and  the  pressure  regu- 
lated by  the  softening  of  the  celluloid,  and  increased  as  the  flask 
closes.  The  flask  in  the  clamp  can  be  removed  from  the  tank  at  times 
to  note  the  progress  of  closing  of  the  flask,  which  should  take  place 
evenly,  so  as  to  distribute  the  pressure  equally  over  the  entire  plate. 
The  heat  should  not  rise  above  280°  F.,  and  if  the  flask  is  not  closed 
completely  when  this  temperature  is  reached  the  flame  may  be  reduced. 
Olive  or  lard  oil  may  be  used  instead  of  glycerin,  but  the  latter  is 


IO-J2 


MECHANICS — DENTAL    PROSTHESIS. 


preferable  on  account  of  cleanliness.  In  using  sLeain  or  glycerin,  the 
flask  should  remain  in  the  clamp  until  it  has  become  coid  ;  the  cooling 
may  be  hastened   by  immersing  the  clamp  and  flask  in  cold  water. 

Where   the   plate    is   of  unusual 
2?  thickness,  or  the  blank  is  changed 

in  shape  to  accommodate  it  to 
the  case,  it  is  recommended  to 
place  the  flask,  secured  in  a 
clamp,  near  a  stove,  at  a  temper- 
ature not  exceeding  140°  F.,  for 
at  least  half  a  day,  in  order  to 


Fig.  1161. 


avoid  the  danger  of  warping  the  plate.  It  is  also  necessary,  in  the 
use  of  the  steam  apparatus,  to  put  sufficient  water  in  the  heater,  as  too 
small  a  quantity  maybe  entirely  converted  into  steam,  which  is  liable 
to  become  overheated,  a  result  which  is  not  only  dangerous,  but 
injurious  to  the  celluloid. 

In  molding  celluloid  by  means  of  hot,  moist  air,  several  forms  of 
apparatus  may  be  used,  one  of  the  most  prominent  of  which  is  the 
"  Best"  Hot  Moist  Air  Celluloid  Apparatus,  represented  in  Fig.  1162. 

In  using  the  "Best"  apparatus,  the  plaster  in  the  flask  should  be 
made  very  wet  by  placing  it  in  a  flask  of  water  before  it  is  put  into  the 
heater.  After  this  is  done  the  flask  is  placed  in  the  clamp,  the  top  of 
which  is  screwed  down  until  it  comes  in  contact  with  the  flask.  It  is 
then  placed  in  the  oven  of  the  heater  and  the  heat  applied,  the  degree 
of  which  is  determined  by  moistening  the  end  of  the  finger  and  apply- 
ing it  to  the  flask.  When  it  fizzles  on  contact,  as  a  sad-iron  does  to 
the  finger  of  a  washerwoman,  the  flask  is  screwed  together. 

The  point  of  a  knife  inserted  between  the  edges  of  the  flask  will 
also  determine  the  condition  of  the  celluloid  at  this  stage;  also  by 
experience  in  screwing  down  the  flask.  More  pressure  is  applied  as 
the  celluloid   softens   or  flows,  allowing  some  little   time   10   eiapse 


CELLULOID. 


1073 


between  the  turning  of  the  screws,  until  the  sections  of  the  flask  are 
brought  together,  when  the  heat  is  removed  in  order  to  avoid  injur- 


RIGGED  FOR  GAS. 


rigged  for  kerosene. 
Fig.  1162. 


68 


I074  MECHANICS — DENTAL    PROSTHESIS. 

ing  the  plate  by  making  it  porous.  In  the  use  of  this  apparatus  the 
edges  of  the  flask  must  not  be  pressed  together  until  the  celluloid  is 
sufficiently  softened  to  flow  ;  and,  on  the  other  hand,  the  sections  of 
the  flask  must  not  be  kept  apart  too  long  or  the  plate  will  become 
hard  from  the  evaporation  of  the  camphor  and  obstruct  the  proper 
closing.  The  case  is  then  removed  from  the  oven  of  the  heater  and 
allowed  to  cool  gradually,  until  it  becomes  quite  cold. 

For  molding  celluloid  by  dry  heat,  which  is  now  considered  to  be 
preferable  to  either  steam  or  glycerin,  the  New  Mode  Heater,  repre- 
sented by  Fig.  1 163,  was  the  first  apparatus  invented  which  possessed 
superior  advantages  over  the  others  used  for  the  purpose,  and  also  for 
vulcanizing  rubber.  It  is  a  cylindrical-cast  vessel,  having  two  cham- 
bers, one  within  the  other,  the  inner  one  being  supported  by  piers  or 
columns  connecting  its  sides,  top,  and  bottom  with  those  of  the  outer 
chamber,  the  whole  being  made  in  one  casting.  The  outer  compart- 
ment is  the  steam-chamber  or  boiler,  and  incloses  the  hot-air  or 
packing-chamber  on  all  sides  except  the  front,  where  the  walls  of  the 
two  chambers  converge  and  become  one,  for  the  purpose  of  permit- 
ting access  to  the  packing  chamber.  A  door,  made  of  the  same 
metal  as  the  boiler,  and  fitted  with  lead  packing  to  make  it  steam- 
tight,  is  held  in  place  by  a  bridge  secured  with  screws.  The  door  is 
also  provided  with  a  plate-glass  light  (shown  in  cut),  through  which 
the  operator  can  watch  the  progress  of  the  molding  in  the  oven.  The 
only  communication  between  the  two  chambers  is  by  means  of  a  valve 
having  its  seat  in  the  top  of  the  packing-chamber,  and  controlled  by 
a  hollow  stem  which  passes  through  the  top  of  the  machine. 

B  is  a  mercury  bath ;  C,  thermometer  ;  D,  screw  plug  ;  E,  lamnut ; 
F,  stem  of  steam-valve;  G,  screw-cap;  H,  large  screw  for  closing  the 
flask  ;  I,  I,  I.  smaller  screws  for  the  same  purpose ;  K.  K.  K.  L,  nickle- 
plated  caps  for  screws ;  O,  O,  steam-chamber. 

The  New  Mode  Heater,  Seabury's  and  Evans's  Vulcanizers  (Fig. 
1 163)  combine  in  one  apparatus  important  improvements  in  the  means 
of  working  both  celluloid  and  rubber,  that  cannot  fail  to  commerd 
them  to  the  favor  of  the  profession. 

It  is  the  conviction  of  the  inventors,  which  is  sustained  by  the  ex- 
perience of  many  experts  in  the  use  of  both  substances,  that  perfect 
work  in  either  can  only  be  made  in  a  dry  chamber,  and  that  where  a 
high  degree  of  heat  is  used,  such  as  is  absolutely  essential  in  the  mani- 
pulation of  celluloid,  the  temperature  must  be  kept  uniform  until  the 
work  is  complete,  and  must  not  be  allowed  to  change  suddenly. 

Steam  is  used  in  these  machines  to  heat  up  the  packing-chamber  and 
mvestment,  but  the  chamber  itself  can  be,  and  for  certain  kinds  of 
work   must  be,   kept  absolutely  dry  after   the  molding  commences, 


CELLULOID. 


1075 


while  the  complete  control  which  the  operator  has  over  the  workings 
of  the  machine  enables  him  to  maintain  the  heat  at  any  desired  tem- 
perature. The  hot-box  or  packing-chamber  is  nearly,  in  one,  and  in  the 
others  quite,  surrounded  by  the  boiler,  and  steam  may  be  admitted  to 


RIGGED  FOR  GAS. 

Can  be  adapted  for  alcohol  by  substituting  the 
lamp  lor  the  gas  burner. 


GAS    BURNER. 


ALCOHOL    LAMP. 


Fig.  1:63. 


or  excluded  from  the  packing-chamber  at  will.  A  case  may  be  removed 
from  the  heater  and  another  one  inserted  without  reducing  the  tem- 
perature or  letting  off  the  steam  from  the  boiler,  thus  accomplishing  a 
large  saving  of  time.  The  boiler  has  no  steam-packed  plunger  or  screw 


J076  MECHANICS — DENTAL    PROSTHESIS. 

to  cause  uncertainty  as  to  the  amount  of  pressure  applied.  The  top 
of  the  boiler,  in  the  case  of  the  New  Mode  Heater,  is  cast  in  one  piece 
with  the  boiler;  the  flask  is  closed  with  a  small  key-wrench  by  the 
thumb  and  finger,  the  screw-bolts  for  closing  the  flask  passing  through 
the  steam- chamber  in  piers  or  columns  ;  a  steam-tight  plate-glass  door 
permits  the  operator  to  examine  the  work  at  any  time  during  the  pro- 
cess of  molding,  enabling  him  to  apply  the  proper  pressure  at  the  right 
time,  thus  reducing  the  liability  to  break  the  cast,  investment,  or  teeth. 
The  descriptions  of  the  Seabury  and  Evans  machines,  in  the  article  on 
Vulcanite,  will  explain  their  manipulation. 

Dry  heat  has  no  injurious  effect  on  the  celluloid  material.  If  a 
piece  of  transparent  celluloid  be  passed  through  a  jet  of  steam,  the 
transparency  will  disappear  in  an  instant,  and  the  material  will  become 
opaque  and  lose  its  hardness.  A  piece  of  the  same  transparent  cellu- 
loid heated  in  a  dry  chamber  to  the  same  temperature  as  that  of  the 
jet  of  steam  is  not  affected,  its  transparency  and  hardness  remaining 
unchanged.  So,  too,  a  piece  of  black  rubber  vulcanized  by  dry  heat 
is  of  a  pure  jet-black  color  when  taken  out ;  while  a  piece  of  the  same 
black  rubber  vulcanized  in  the  ordinary  method  shows  brownish  dis- 
color.ations.  These  simple  experiments  show  conclusively  that  the  ac- 
tion of  the  steam  is  the  cause  of  the  loss  of  quality.  Dr.  Campbell 
gives  the  following  directions  for  the  molding  of  celluloid  in  his  appa- 
ratus, which  are  also  applicable  to  the  others:  — 

To  secure  the  best  practical  results,  celluloid  should  be  molded  or 
pressed  into  the  form  desired  at  the  highest  possible  temperature  which 
will  not  burn  it.  To  prove  this  it  is  only  necessary  to  mold  a  plate 
on  a  metal  cast  at  the  lowest  temperature  at  which  it  can  be  done, 
which  is  less  than  212°,  and  another  on  the  same  cast  at  the  highest 
temperature  possible,  say  310°  or  320°,  and  lay  the  two  aside  for  a  few 
days,  when  it  will  be  found  that  the  one  molded  at  the  lower  tempera- 
ture will  not  fit  the  cast,  while  that  molded  at  the  higher  temperature 
will  fit  as  well  as  when  first  made.  The  reason  is  that  the  low  tem- 
perature fails  to  overcome  the  tendency  of  the  plate  to  return  to  its 
original  form,  while  the  high  temperature  renders  it  so  thoroughly 
plastic  that  this  tendency  is  entirely  eradicated.  This  is  proportion- 
ally the  case  with  pieces  made  at  intermediate  temperatures ;  the  higher 
the  temperature  to  which  the  plate  is  subjected  in  molding,  the  more 
exactly  will  it  hold  its  new  form  and  the  less  will  be  its  tendency  to 
warp. 

Celluloid  may  be  readily  and  safely  manipulated  in  the  New  Mode 
Heater  at  320°,  a  temperature  many  degrees  higher  than  is  deemed 
safe  in  other  machines,  and  which  accomplishes  perfectly  the  result 
above  noted,  and  produces  a  plate  which  is  believed  to  be  absolutely 


CELLULOID.  1077 

unchangeable  in  color,  form,  and  texture.  When  this  very  high  tem- 
perature is  employed  the  celluloid  should  be  in  the  machine  only  long 
enough  to  permit  the  closing  of  the  flask ;  for  the  reason  that  heat 
vaporizes  the  camphor — the  solvent  of  the  material.  If  too  much  of 
this  is  driven  off  before  the  flask  is  closed  it  will  be  almost  impossible 
to  mold  the  blank  to  the  desired  form.  The  sooner  the  flask  is  closed 
after  being  placed  in  the  oven  the  more  readily  it  will  be  done  and  the 
better  will  be  the  result. 

The  molded  surface  of  a  piece  of  celluloid  is  much  more  durable 
than  its  interior,  and  will  retain  the  color  better.  It  is  obvious, 
therefore,  that  this  surface  is  essential  to  the  integrity  of  the  plate  and 
should  be  preserved  intact.  To  insure  this,  the  case  should  be  so  pre- 
pared that  the  plate,  wlien  taken  from  the  flask,  will  require  little  or 
no  labor  to  make  it  ready  for  use.  It  is  possible  that  some  surplus  ma- 
terial at  the  edges  may  have  to  be  trimmed  off  and  the  edges  smoothed, 
but  the  case  is  not  properly  prepared  if  more  than  this  is  necessary. 
The  care  and  trouble  involved  in  proper  preparation  will  really  save 
time,  will  absolutely  avoid  interference  with  the  fit  by  the  too  free  use 
of  files,  sand-paper,  pumice,  etc.,  and  will  insure  a  durable  plate  with 
a  permanent  imitation  of  gum-color.  Moreover,  the  artistic  taste  of 
the  operator  may  be  exercised  before  the  plate  is  molded  more  readily 
than  afterward. 

Paraffin  and  wax  compound  is  used  for  the  base  plate,  according  to 
directions  before  given,  and  the  teeth  arranged,  the  wax  carved  into 
the  shape  desired  by  means  of  carving  tools,  and  made  smooth.  The 
piece  is  then  invested  in  plaster,  the  usual  grooves  cut,  the  wax  teeth 
and  tin  foil  being  removed  with  the  upper  half  of  the  flask  in  parting. 
The  wax  is  then  removed  by  means  of  boiling  water,  as  before  de- 
scribed, the  tin  foil,  No.  60,  used  for  covering  the  parafiin  and  wax 
plate  remaining  upon  the  plaster,  and  the  investment  is  now  ready  to 
be  dried  out  preparatory  to  receiving  the  celluloid. 

Drying  the  Cast  and  Investment — To  dry  a  plaster  cast  and  invest- 
ment, and  keep  them  free  from  cracks  and  checks,  is  very  difficult  by 
the  ordinary  means,  but  with  the  New  Mode  Heater  it  can  be  done  so 
perfectly  as  to  permit  their  use  in  casting  pure  gold  or  gold  alloys. 

There  are  two  ways  of  drying  the  investment  in  the  New  Mode 
Heater:  first,  by  raising  the  temperature  to  320°,  keeping  the  hot  box 
dry;  second,  by  admitting  steam  to  the  hot  box.  The  former  method 
can  be  used  when  the  investment  is  placed  in  the  chamber  before 
getting  up  steam.  If  steam  is  up,  however,  either  method  may  be  em- 
ployed. In  using  the  dry  heat  method,  open  very  slightly  the  screw 
cap  of  the  piston  or  valve  stem,  to  permit  the  escape  of  the  steam 
generated  from  the  water  in  the  plaster,  being  careful  that  the  steam 


loyS  MECHANICS DENTAL    PROSTHESIS. 

valve  is  firmly  seated,  as  otherwise  all  the  steam  made  in  the  boiler  will 
escape.  In  using  steam  for  drying,  admit  the  live  steam  into  the 
chamber  with  the  investment  by  raising  the  valve  from  its  seat,  keep- 
ing the  screw  cap  closed.  The  steam  quickly  permeates  the  plaster, 
and  in  five  or  ten  minutes  the  temperature  of  the  plaster  is  high  enough 
to  convert  the  water  in  it  into  steam.  As  soon  as  the  plaster  is 
thoroughly  heated,  shut  off  the  steam  by  closing  the  valve,  and  raise 
the  screw  cap  very  slightly,  to  allow  that  in  the  chamber  to  escape 
slowly  through  the  small  aperture  at  the  side  of  the  screw.  In  a  few 
moments  the  cast  will  be  perfectly  dry,  the  steam  escaping  from  the 
chamber,  carrying  with  it  that  generated  from  the  moisture  in  the 
plaster.  Extreme  care  should  be  taken  that  the  steam  shall  escape 
very  slowly,  as  otherwise  the  plaster  may  be  blown  out  of  the  flask  into 
the  oven  by  the  too  rapid  expansion  of  its  vaporized  moisture.  The 
completion  of  the  drying  process  is  known  by  steam  ceasing  to  be 
given  off  at  the  screw  cap,  G.  The  drying  may  be  facilitated  by 
placing  a  small  chip  of  wood  between  the  two  parts  of  the  flask  when 
it  is  put  into  the  chamber,  thus  exposing  a  larger  surface  to  the  heat  and 
allowing  the  moisture  to  escape  more  readily. 

Molding  by  Dry  Heat. — When  the  investment  is  dried,  remove  it 
from  the  chamber  and  insert  and  carefully  adjust  the  selected  blank  ; 
replace  the  flask  in  the  oven  immediately  under  the  screws  ;  see  that 
the  two  sections  are  so  placed  that  the  guide-pins  will  enter  properly 
into  the  lugs;  open  the  screw  cap  a  turn  or  two  to  allow  the  escape  of 
the  gas  from  the  hot  box;  turn  down  the  large  screw  until  it  bears 
lightly  upon  the  top  of  the  flask,  and  close  the  machine.  In  less  than 
five  minutes  the  material  will  be  sufficiently  softened  to  permit  the 
commencement  of  the  molding.  The  screws  will  turn  readily  with  the 
thumb  and  finger  (using  the  smaller  key-wrench)  when  the  blank  is 
properly  softened.  Close  the  flask  gradually,  stopping  occasionally  if 
the  resistance  is  too  great.  Usually,  if  the  temperature  is  about  300°, 
the  flask  can  be  closed  in  ten  minutes:  but  if  a  very  thick  blank  is 
used,  the  molding  must  proceed  slowly  ;  the  small  screws  may  be  used 
to  advantage,  and  more  time,  say  thirty  minutes,  may  be  consumed. 
As  soon  as  the  flask  is  closed — unless  a  lock  flask  is  used — the  flame 
should  be  extinguished,  the  door  opened,  and  the  machine  allowed  to 
cool.  If  a  lock  flask  is  used,  it  may  be  removed  and  thoroughly  cooled 
before  opening  it,  the  oven  being  meanwhile  ready  for  another  case. 
The  cooling  may  be  accomplished  rapidly,  if  necessary,  by  placing  the 
flask  in  water.  When  perfectly  cold,  remove  the  plate  from  the  in- 
vestment ;  it  will  be  found  enveloped  in  the  tin  foil  which  had  been 
burnished  to  the  wax  plate.  Peel  off  the  foil.  The  celluloid  will 
present  a  hard,  brightly-polished  surface,  received   from  its   contact 


CELLULOID.  1079 

with  the  foil,  and  will  need  no  further  finishing  than  cutting  off  the  ex- 
cess of  material  and  smoothing  down  the  edges.  The  extra  hardness  of 
the  surface  will  thus  remain  to  preserve  the  integrity  and  color  of  the 
piece.  It  is  claimed,  also,  that  the  contact  of  the  foil  renders  the  outer 
surface,  which  is  always  the  densest  portion  of  celluloid,  much  harder. 

Imitating  Gum  Membrane. — The  plate  produced  by  the  above 
method  is  of  the  ordinary  appearance,  with  smooth,  polished  gum,  but 
a  much  more  natural,  life-like  gum  will  result  if  the  tin  foil,  after 
being  burnished  to  the  wax  plate,  is  "stippled."  This  is  done  by  "dot- 
ting "  carefully  over  its  surface  with  a  dull-pointed  instrument,  which 
should  be  held  nearly  perpendicularly  to  the  surface  to  be  operated  on, 
and  the  strokes  should  be  gentle — not  hard  enough  to  perforate  the  foil. 
When  the  foil  is  removed,  after  the  case  is  molded,  the  gums  present 
an  appearance  closely  resembling  the  natural  membrane.  The  stippling 
need  not  occupy  a  great  deal  of  time,  and  the  result  it  produces  is  a 
marked  improvement. 

Metal  Casts  and  Deep  Undercuts. — Many  dentists  who  prefer  to  use 
metal  casts  have  doubtless  found  difficulty  in  removing  the  finished 
plates  in  cases  of  deep  undercut.  The  fact  that  a  melted  metal  cools 
from  the  surface  toward  the  center  supplies  an  effectual  remedy. 
When  the  metal  is  poured  into  the  sand,  allow  it  to  chill  only  about  a 
quarter  of  an  inch  on  the  outside,  and  then  pour  the  balance  out  of 
the  mold.  This  makes  a  hollow  cast  or  shell.  Fill  up  the  cavity 
with  plaster  and  proceed  as  usual.  After  the  plate  is  molded,  remove 
the  plaster,  place  the  edges  of  the  metal  cast  in  the  jaws  of  a  vise,  and 
crush  the  shell.  This  will  free  the  piece  without  disturbing  the  teeth. 
The  plaster  in  tlie  sliell  also  affords  the  means  of  attaching  the  cast  to 
the  articulator.  A  plaster  core  in  the  form  of  a  cross  may  also  be  in- 
serted when  pouring  the  metal  die  in  the  base,  which  will  divide  the 
core  into  four  sections,  which  may  be  crushed  together  in  a  vise  and 
thus  liberate  the  celluloid  plate. 

Repairing. — If  a  portion  of  a  plate  has  been  broken  away  and  lost, 
fit  a  piece  of  celluloid  of  the  proper  shape,  leaving  it  somewhat  larger 
than  the  space  to  be  filled.  Make  sure  that  the  surfaces  to  be  united 
dst perfectly  clean  ;  even  the  perspiration  from  the  hand  may  cause  a 
dark  line.     Flask  and  mold  as  usual. 

A  crack  in  a  plate  or  the  parts  of  a  broken  plate  may  be  joined 
by  scraping  the  surfaces  clean,  or  washing  them  with  alcohol,  and 
molding  a  thin  strip  of  celluloid  into  the  seam. 

The  following  method  of  repairing  small  breaks  is  suggested  by 
Dr.  M.  H.  Cryer,  and  possesses  the  merit  of  extreme  simplicity,  and  its 
results  are  in  the  highest  degree  satisfactory  :  — 

Remove  all  portions  of  the  broken  tooth  from  the  plate,  taking  care 


lOSO  MECHANICS — DENTAL    PROSTHESIS. 

not  to  disturb  the  outlines  of  the  socket.  Select  a  tooth  of  proper 
size  and  shade  to  replace  the  broken  one.  (If  the  tooth  is  numbered, 
a  considerable  part  of  the  trouble  of  selection  may  be  saved  by  taking 
the  number  of  the  mold  from  the  reverse  impression  in  the  plate  or 
from  the  broken  pieces.)  Having  set  the  new  tooth  partly  in  its 
place,  hold  it  steadily  over  the  flame  of  an  alcohol  lamp,  carefully 
guarding  the  celluloid  from  contact  with  the  flame.  In  a  few  seconds 
the  tooth  will  begin  to  grow  warm,  and  its  heat  will  soften  the  celluloid 
sufficiently  to  allow  the  tooth  to  be  pressed  into  its  proper  position 
with  a  napkin.  This  will  cause  a  small  bulge  or  raised  spot  to  appear 
in  the  celluloid  opposite  the  lingual  portion  of  the  root  of  the  tooth. 
Invest  in  plaster,  in  the  deeper  section  of  the  flask,  covering  the  whole 
plate  and  the  teeth,  except  the  small  portion  of  the  celluloid  raised  in 
pressing  the  tooth  into  place.  Complete  the  investment,  part  the 
flask,  and  dry  the  case,  after  which  insert  a  piece  of  rather  thick 
writing  paper  or  heavy  tin  foil  over  the  raised  spot  and  place  in  the 
oven.  Heat  up  to  the  usual  temperature  for  molding  and  close  the 
flask.  When  the  case  is  cold  the  tooth  will  be  found  firmly  fixed  in 
its  position,  and  there  will  be  no  mark  to  show  that  the  plate  has  been 
repaired. 

In  case  a  small  portion  of  the  celluloid  is  chipped  away  from  the 
front  of  the  socket — enough  only  to  expose  the  end  of  the  root  when 
in  position — drop  a  little  wax  upon  the  vacant  spot  after  placing  the 
tooth  and  carve  to  the  shape  desired.  Without  removing  the  wax,  in- 
vest and  mold  as  before  described.  The  wax  will  pass  off  into  the 
plaster  and  its  place  will  be  supplied  by  the  celluloid,  of  which  there 
is  usually  enough  to  permit  the  flowing  of  the  minute  quantity  required 
without  damage. 

If  there  is  a  similar  deficiency  on  the  inside  of  the  plate,  exposing 
the  pins  of  the  tooth,  drop  wax  into  the  vacancy  and  proceed  as  be- 
fore, except  that  in  this  case  the  wax  is  to  be  removed  when  the  in- 
vestment is  made,  and  the  bit  of  writing  paper  or  tin  foil  is  to  be 
placed  just  below  the  pins,  instead  of  over  them,  so  as  to  force  the 
flowing  of  the  celluloid  to  cover  them. 

To  remove  a  tooth  from  a  celluloid  plate,  hold  the  outside  surface 
of  the  tooth  to  be  removed  in  the  flame  of  the  lamp  until  the  heat 
softens  the  celluloid  around  the  pins  slightly,  when  it  may  be  taken 
off  without  trouble,  and  it  will  come  away  clean,  without  any  of 
the  celluloid  adhering  to  the  pins.  Do  not  move  the  plate  back 
and  forth  through  the  flame,  or  other  teeth  than  the  one  desired 
may  be  loosened,  or  their  perfect  articulation  may  be  interfered  with. 
There  is  no  danger  of  cracking  the  tooth  so  long  as  the  flame  does  not 
come  in  contact  with  the  pins. 


CELLULOID. 


loSi 


Fig.  1 1 64  represents  the  first  process  in  repairing  a  celluloid  plate 
from  which  a  tooth  or  block  has  been  broken.  The  plate  being  cut 
away  sufficiently  to  allow  the  new  tooth  to  be  adjusted  by  grinding,  a 
new  piece  of  celluloid  (a)  is  fitted  to  the  space.  The  new  piece  is 
then  removed  and  its  place  filled  up  with  wax.  Fig.  1165  shows  the 
piece  invested  in  the  lower  section  of  the  flask,  the  space  filled  with 
wax  being  the  only  portion  visible,  the  entire  surfaces  of  the- plate  and 
teeth  being  covered.  The  upper  section  of  the  flask  is  then  adjusted 
and  filled  up  with  plaster.  When  the  flask  is  opened  the  wax  is  re- 
moved and  the  new  piece  of  celluloid  returned  to  its  place,  and  upon 
it  is  placed  another  small  piece  of  celluloid,  or  a  roll  of  tin  foil,  to 
produce  pressure  upon  the  new  piece  first  added,  the  edges  of  which, 
as  well  as  those  of  the  space 
into  which  it  is  fitted,  being 
moistened  with  spirits  of  cam- 
phor or  liquid  celluloid  to  bring 
about  union. 


Fig.  1 164. 


Fig.  1165. 


Liquid  celluloid  is  made  by  dissolving  small  pieces  of  celluloid  in 
spirits  of  camphor.  The  piece  is  then  placed  in  the  healer  and  sub- 
jected to  the  usual  process.  Where  the  plate  is  of  considerable  thick- 
ness, a  new  tooth  or  block  may  be  added  without  new  material  by 
cutting  away  as  little  as  possible  of  the  old  plate  on  the  lingual  surface, 
and  depending  upon  the  thickness  of  celluloid  pressing  up,  after  being 
softened  in  the  heater,  closely  to  the  new  tooth.  Loose  teeth  may  be 
tightened  in  the  same  manner,  wax  being  introduced  into  the  vacant 
space  and  removed  after  the  flasking. 

Some  object  to  the  use  of  a  solvent  in  repairing  on  account  of  the 
liability  of  the  newly-added  material  to  become  porous.  To  cleanse 
celluloid  plates  previous  to  repairing,  they  should  be  placed  in  a  solu- 
tion of  whiting  and  water,  to  which  is  added  some  liquid  ammonia, 
and  allowed  to  remain  some  time,  when  they  are  brushed  with  soap 
and  water,  and  finally  washed  in  clean  water  and  dried. 


Io82  MECHANICS— DENTAL   PROSTHESIS. 

NEW   MODE   CONTINUOUS   GUM. 

With  reference  to  the  second  objection  to  the  use  of  rubber,  it  is  to 
be  said  that  the  perfect  reproduction  of  natural  effects  and  really 
artistic  work  cannot  be  made  with  block  teeth.  To  obtain  the  proper 
expression,  each  tooth  should  be  available  for  placing  in  any  position 
desired,  instead  of  being  arbitrarily  held  in  association  with  others,  as 
in  a  block. 

The  invention  of  the  New  Mode  machine  places  in  the  hands  of 
the  profession  the  means  for  overcoming  this  objection  by  using  plain 
teeth  with  rubber  for  the  base,  and  celluloid,  which  is  well  suited  for 
the  purpose,  for  the  gum,  the  combination  forming  an  exquisite  piece 
of  work  which  the  inventor  calls  the  "  New  Mode  Continuous  Gum." 
It  is  easily  the  nearest  approach  to  porcelain  continuous  gum  that  has 
been  obtained  with  plastic  materials.  Its  general  adoption  would  do 
away  with  "bad  joints"  and  broken  blocks,  which  are  so  often  a 
source  of  serious  annoyance.  It  is  the  only  rubber  plate  upon  which 
a  tooth  may  be  replaced  without  revulcanization,  and  which  after  the 
repair  is  equal  in  strength  and  appearance  to  the  original  piece  ;  and 
the  only  one  upon  which  repairs  can  be  repeated  any  number  of  times 
without  injury  to  the  original  plate.  This  same  style  of  work  can  also 
be  done  with  gold  and  with  cast-alloy  plates. 

Directions  for  Makmg  the  New  Mode  Continuous  Gum. — Using  teeth 
made  expressly  for  continuous-gum  or  celluloid  work,  set  them  up  in 
wax  in  the  usual  manner,  leaving  the  front  or  outside  of  the  roots 
exposed.  Cut  a  thin  strip  of  the  wax,  warm  it,  and  attach  it  to  the 
upper  edge  of  the  portion  of  the  wax  plate  representing  the  gum, 
forming  a  rim  which  extends  all  around  the  outer  margin.  Finish  the 
palatine  surface  to  the  form  desired,  invest  in  the  flask  in  the  usual 
manner,  remove  the  wax,  pack  with  rubber,  and  vulcanize.  When 
removed  from  the  flask  the  case  will  present  the  appearance  shown  in 
Fig.  1 167,  the  front  or  outside  of  the  roots  being  exposed  and  the 
narrow  undercut  rim  extending  all  around,  leaving  a  space  with  retain- 
ing grooves  between  the  teeth  for  forming  a  gum  of  celluloid,  looking 
very  much  as  though  the  substance  of  the  plate  had  been  gouged  out 
for  the  purpose.  The  vulcanite  plate  is  now  completed  with  the  teeth 
firmly  attached  to  it. 

To  put  on  the  gum,  fill  up  the  groove  with  paraffin  and  wax  (this 
compound,  not  being  sticky,  does  not  adhere  to  the  instrument  and 
is  therefore  more  easily  carved  to  the  form  desired)  until  all  the  space 
inside  the  rim,  including  the  retaining  grooves  between  the  necks  of 
the  teeth,  is  occupied.  After  the  wax  has  hardened,  which  may  be 
hastened  by  placing  in  cold  water,  carve  it  into  the  desired  form  of 


NEW   MODE    CONTINUOUS    GUM. 


1083 


Fig.  1 166. 


Fig.  1169. 


1084  MECHANICS DENTAL    PROSTHESIS. 

gum.  The  wax  may  be  made  very  smooth  by  throwing  upon  it  the 
flame  of  a  spirit  lamp  with  the  aid  of  a  blowpipe,  taking  care  not  to 
destroy  the  outline  of  the  carved  gum.  Cover  the  wax  with  heavy 
tin  foil,  burnishing  it  lightly  but  smoothly  to  the  wax. 

Invest  the  piece  again  in  the  following  manner  :  Place  the  plate  in 
one  section  of  the  flask  with  the  teeth  upward,  and  raised  at  the  front 
at  a  greater  or  less  angle,  as  may  be  necessary,  so  that  when  the  in- 
vestment is  completed  the  upper  part  of  the  flask  may  be  removed 
without  dragging.  Imbed  in  plaster  to  the  rim  and  pour  plaster  over 
the  palatine  surface  covering  the  crowns,  and  taking  care  to  fill  the 
interstices  between  the  necks  of  the  teeth,  but  leaving  their  outer  sur- 
faces exposed.  After  the  investment  sets,  pour  more  plaster  around  the 
inner  edge  of  the  flask  ring,  forming  a  ridge,  leaving  a  groove  or 
space  between  it  and  the  plate.  (See  Fig.  11 69.)  Complete  the 
investment  and  remove  the  wax  from  the  groove  and  interstices  be- 
tween the  roots  of  the  teeth  by  pouring  boiling  water  over  it. 
Having  selected  a  celluloid  blank  of  proper  size,  saw  off  the  outer  rim 
(see  Fig.  1166)  ;  warm  this  rim  of  celluloid  in  boiling  water,  and  with 
the  hand  and  a  cloth  press  it  closely  about  the  teeth  and  hold  it  to  its 
place  until  stiff;  it  will  then  remain  there  until  the  two  parts  of  the 
flask  are  entered  upon  the  guide-pins.  Join  the  two  parts  of  the 
flask  together  and  place  the  investment  in  the  oven  of  the  machine, 
having  previously  heated  up  the  chamber.  When  the  temperature  of 
280°  is  reached  the  flask  may  be  closed.  As  soon  as  this  is  accom- 
plished the  case  is  ready  to  be  removed  from  the  oven  and  placed  in  a 
clamp  to  cool. 

When  perfectly  cold  remove  the  plate.  The  tin  foil  will  adhere  to 
it,  but  it  can.be  readily  removed  by  inserting  the  point  of  a  knife  under 
the  edge  and  pulling  it  off,  leaving  the  surface  of  the  celluloid  gum  as 
smooth  and  polished  as  that  of  the  foil. 

A  surface  produced  by  the  above  method  presents  a  smooth,  pol- 
ished gum,  but  if  the  tin  foil  is  "stippled,"  as  before  described,  a 
striking  resemblance  to  the  natural  membrane  will  be  produced,  the 
finished  plate  presenting  the  appearance  shown  in  Fig.  1168.  The 
adjoining  edges  of  the  celluloid  and  rubber  will  be  found  perfectly 
united,  each  preserving  its  sharp  outline. 

Dr.  D.  Genese  recommends  the  following  method  of  working  cellu- 
loid, which  will  give  a  hard,  smooth,  polished  surface  to  the  plate 
when  it  leaves  the  heater,  regulate  the  size  of  the  celluloid  blank  be- 
fore it  is  molded  to  the  surface  of  the  metal  die  or  cast  and  about  the 
teeth,  and  also  form  a  metal  cast,  which  is  easily  removed  from  the 
celluloid  plate  after  it  is  completed  : — 

Two  perfect  impressions  in  plaster  are  taken  of  the  mouth,  one  of 


NEW   MODE   CONTINUOUS    GUM.  I0S5 

which  is  used  to  secure  a  plaster  model,  upon  which  the  trial  plate  is 
formed,  of  wax  and  paraffin.  Upon  this  trial  plate  a  rim  of  wax  is 
built,  and  the  exact  bite  secured.  In  wax,  only  the  model  of  the 
piece,  desired  in  the  finished  case  is  then  formed,  which  is  attached  to 
a  metal  die,  which  has  been  obtained  by  molding  the  plaster  model  in 
sand.  The  whole  is  then  molded  in  sand,  and  a  zinc  and  lead  die  and 
counter-die  obtained,  by  means  of  which  a  tin  cap  (made  of  rolled 
tin.  No.  29  gauge)  is  swaged,  which  will  completely  envelop  the  wax 
model,  extend  over  the  gum  portion,  and  to  the  full  height  of  the 
finished  "bite."  The  edge  of  the  tin  cap,  which  is  left  rough,  is 
turned  up  at  an  angle  of  about  forty-five  degrees,  so  as  to  form  a 
support  for  it  in  the  plaster,  when  it  is  invested.  The  object  of  this 
cap  is  to  form  a  metal  mold  in  which  the  celluloid  blank  can  be 
shaped  to  the  form  and  size  desired  for  the  case  in  hand.  The  mod- 
eled wax  is  then  transferred  to  the  plaster  model,  which  is  invested 
in  the  lower  half  of  the  flask,  and  the  surface  of  the  investment  var- 
nished over  and  oiled,  to  ensure  the  required  separation.  The  tin  cap 
is  then  placed  over  the  modeled  wax  surface  and  the  upper  half  of 
the  flask  filled  with  plaster.  When  the  flask  is  separated,  the  wax  is 
removed  from  the  plaster  model,  the  tin  cap  remaining  firmly  secured 
in  the  upper  half  of  the  flask.  The  celluloid  blank  is  then  placed  in 
the  tin  cap  mold,  and  the  sections  of  the  flask  brought  together  by 
being  placed  in  a  heater.  Upon  removing  the  blank  from  the  mold, 
in  the  flask,  any  excess  of  celluloid  can  be  removed,  and  a  blank  of 
a  proper  size  and  form  secured  which  will  not  press  the  teeth  out  of 
position  in  the  subsequent  molding  of  the  plate.  It  is  necessary  to 
secure  a  duplicate  bite  to  mount  the  teeth,  which  is  done  on  a  metal 
die  or  cast,  formed  as  follows : — 

The  second  plaster  impression  is  removed  from  the  impression  cup 
and  imbedded  in  a  sand  and  plaster  investment  as  deep  as  it  is  desired 
to  have  the  cast.  A  right-angle  cross,  with  arms  about  half  an  inch 
wide  at  the  upper  surface  and  tapering  to  a  sharp  edge  (  A  ),  is  then 
made  of  plaster  mixed  with  sand  and  placed  over  the  surface  of  the 
plaster  impression  in  such  a  manner  as  to  bring  the  sharp  edge  almost, 
but  not  quite,  in  contact  with  the  impression  surface,  where  it  is 
secured  by  sealing  the  ends  of  the  arms  to  the  margin  of  the  impres- 
sion. A  metal  die  or  cast  made  in  this  manner  is  divided  into  four 
sections  by  the  cross-core,  very  nearly  to  its  surface,  and  is  more  read- 
ily removed  from  the  celluloid  plate  after  it  is  molded  than  the  hollow 
metal  cast,  as  the  removal  of  the  plaster  core  will  permit  of  the  sec- 
tions of  the  cast  being  bent  away  from  any  undercuts  which  may  exist. 
After  obtaining  the  form  of  metal  die  described,  the  teeth  are  mounted 
upon  a  trial   plate    formed   over   it  and  according  to  the  duplicate 


Io86  MECHANICS — DENTAL   PROSTHESIS. 

"  bite,"  and  the  new  wax  plate  is  modeled  into  the  form  desired  for 
the  finished  celluloid  plate.  An  impression  in  sand  of  the  whole  is 
again  obtained,  a  zinc  die  and  lead  counter-die  poured,  and  a  tin  cap 
similar  to  the  one  first  made  is  swaged.  This  tin  cap  forms  a  com- 
plete metal  casing,  and  on  flasking,  is  secured  in  the  upper  half  of  the 
flask  by  means  of  its  turned  edges.  The  case  is  then  flasked  in  the 
usual  manner,  and  on  separating  the  sections  and  removing  the  wax 
the  celluloid  blank,  which  has  been  previously  molded  into  form, 
according  to  the  manner  described  above,  will  be  found  well  adapted 
to  the  mold.  The  case  is  then  placed  in  one  of  the  combination 
heaters  and  molded  at  a  temperature  of  300°,  which  should  never  be 
exceeded  ;  and  no  pressure  should  be  applied  by  the  screws  until  this 
heat  is  obtained.  The  construction  of  partial  sets  is  more  difficult, 
but  thv.  i)rocess  is  the  same  as  for  entire  dentures,  a  cap  of  somewhat 
lighter  tin  being  used.  By  this  process  the  edge  only  of  the  plate  and 
a  slight  excess  of  material  about  the  necks  of  the  teeth  require  trim- 
ming off,  the  entire  surface  being  polished  without  any  scraping  away 
by  first  using  fine  pumice  and  glycerin,  and  finally  whiting  and  gly- 
cerin. The  plate  should  be  thoroughly  cleansed,  after  removing  it 
from  the  flask,  of  all  particles  of  plaster  that  may  adhere  to  it,  and  the 
entire  manipulation  be  conducted  with  clean  hands  and  instruments. 

A  metal  cast  somewhat  similar  to  the  one  above  described  may  be 
made  by  first  molding  in  the  usual  manner,  and  afterward  sawing  all 
around  the  alveolar  ridge  with  a  fine  saw,  leaving  only  what  will  hold 
the  parts  together.  Plaster  is  poured  into  the  spaces  made  by  the  saw, 
in  order  to  render  the  cast  solid.  When  the  set  is  finished  the  plaster 
is  removed  from  the  spaces  and  pressure  made  by  a  vise  upon  the  edges 
of  the  cast,  so  as  to  crush  them  in  and  thus  free  the  plate. 

Dr.  M.  H.  Cryer  devised  the  filing  of  notches  in  celluloid  blanks 
as  in  Fig.  11 70,  when  the  countersunk  tooth-crowns  are  to  be 
mounted  in  this  material.  The  suggestion  obviates  the  defects  found 
to  attend  the  mounting  of  these  teeth  in  the  usual  way,  for  the  con- 
fined air  in  the  cups  commonly  prevents  the  celluloid  from  entering 
far  enough  to  more  than  half  fill  them,  and  thus  the  pins  are  left  un- 
touched. As  a  consequence  the  teeth  come  off  in  the  process  of 
finishing;  or,  Fig.  11  71  shows  the  effectiveness  of  the  plan  which  pro- 
vides for  the  escape  of  the  air,  while  the  plastic  promontories  enter  the 
countersinks  and  surround  the  pins,  by  means  of  which  the  teeth  are 
firmly  secured  to  the  plate,  on  which  they  thus  have  so  strong  a  hold 
that  the  labial  necks  of  the  crowns  may,  for  conformity  to  the  adjacent 
natural  teeth,  be  quite  uncovered  by  the  celluloid  (see  Fig.  11 72),  and 
the  mounting  be  yet  a  strong  one,  as  is  evidenced  by  the  section  through 
plate   and    crown,  Fig.    1173,  which  illustrates  a  countersunk    tooth 


NEW    MODE    CONTINUOUS    GUM. 


1087 


crown.  In  this  instance  the  short  celhiloid  festoons  (see  Fig.  11 72) 
lie  close  upon  the  gum,  which  they  much  more  nearly  resemble  than 
the  dark  vulcanite  when  such  a  base  is  made. 

When  the  celluloid  blanks  are  molded  upon  plaster  surfaces,  files, 
scrapers,  and  fine  sand  or  emery  paper  are  necessary  in  the  finishing 
process,  completing  the  operation  of  polishing  with  whiting  or  pre- 
pared chalk,  applied  by  means  of  a  soft  brush  wheel.  Camphor,  ap- 
plied on  a  soft  cloth,  is  also  used  to  obtain  a  polish,  especially  between 
the  teeth  and  other  places  beyond  the  reach  of  the  brush  wheel.  Fric- 
tion with  the  brush  wheel  sufficient  to  heat  the  plate  should  be  avoided, 
on  account  of  the  danger  of  changing  the  shape  of  the  plate  and  in- 
juring the  surface.  Dark  lines  on  celluloid  plates  are  often  the  result 
of  using  blanks  too  wide  for  the  case  or  too  thin  in  the  center,  causing 


Fig.  1170. 


Fig.  1171. 


Fig.  1 172 


Fig.  1173. 


the  celluloid  to  press  toward  the  middle  of  the  plate  and  fold  upon 
itself.  Where  the  arch  of  the  mouth  is  very  deep,  the  pressure  by 
means  of  screws  should  not  be  applied  before  the  blank  is  well  softened 
by  the  heat,  otherwise  it  may  tear  apart.  Too  little  pressure,  or  too 
little  material,  may  cause  a  porous  plate;  also  overheating  in  the  dry 
heat  apparatus  ;  the  same  condition  in  steam  heating  may  result  from 
too  little  pressure  at  the  proper  time.  If  the  temperature  of  a  celluloid 
plate  is  raised  to  270°,  without  any  pressure  being  brought  to  bear  upon 
it,  the  material  becomes  puffed  up  and  is  ruined  in  texture,  and  cannot 
be  restored  by  any  subsequent  manipulation.  Celluloid  flows  verj 
sluggishly,  hence  sufficient  material  must  be  present  to  insure  a  per- 
fect plate.  The  celluloid  blank  may  be  softened  in  boiling  water  and 
formed  into  any  desired  shape,  and  an  excess  at  any  point  may  be  re- 
moved with  a  sharp  knife.     It  should  be  remembered  that  there  is  no 


lo88  MECHANICS — DENTAL    PROSTHESIS. 

union  between  celluloid  and  rubber,  hence  when  one  of  these  materials 
is  added  to  the  other,  it  can  only  be  done  by  dovetailing  or  drilling 
holes.  Good,  hard-setting  plaster  should  always  be  used  in  working 
celluloid,  and  it  should  be  well  mixed  by  adding  it  to  the  water  in 
such  a  manner  that  all  is  absorbed  that  it  will  take  up.  Care  should 
also  be  taken  not  to  mix  the  plaster  too  thin  or  to  use  very  fine  i)laster, 
as  a  coarse  grade  of  strong  plaster  will  give  better  results.  Some  are 
in  the  habit  of  adding  clean  white  sand  or  marble  dust  to  the  plaster. 
The  following  directions  are  given  in  the  use  of  the  New  Mode  Heater, 
which  will  prove  serviceable  in  the  working  of  celluloid  generally  :  — 

Always  use  good  plaster,  and  do  not  mix  too  thin ;  always  select  a 
blank  which  nearly  fits  the  cast,  with  an  excess  in  every  part ;  always 
turn  the  screws  as  soon  as  they  will  yield  to  the  thumb  and  finger,  and 
always  gently  ;  always  follow  up  the  rise  in  temperature  with  increased 
pressure ;  always  give  the  material  plenty  of  time  to  flow  between  the 
turns;  always  increase  the  pressure  toward  the  close  of  the  molding; 
always  reduce  the  temperature  of  the  piece  at  once  after  the  comple- 
tion of  the  molding,  and  keep  the  plate  under  pressure  until  it  is  stone 
cold. 

ZYLONITE. 

A  modified  form  of  celluloid  has  been  introduced  under  the  name 
o{  zylonite,  the  working  results  of  which  appear  to  show  a  great  differ- 
ence in  quality.  Zylonite,  like  celluloid,  is  composed  of  pyroxylin 
and  camphor,  but  in  different  proportions,  being,  it  is  claimed,  a 
chemical  combination,  while  celluloid  is  a  mechanical  mixture. 

Possessing  translucency,  the  effect  of  zylonite  in  the  mouth  is  very 
pleasing,  and,  so  far  as  it  has  been  tested,  promises  to  be  more  dura- 
ble than  celluloid,  without  the  tendency  to  warp  or  to  change  color 
when  ordinary  care  is  taken  in  its  manipulation,  which  is  the  same  as 
for  celluloid.  The  zylonite  blanks  are  uniform  in  color,  and  although 
this  material  requires  the  same  amount  of  pressure  to  mold,  it  flows 
with  a  more  perfect  sharpness  of  outline  than  celluloid,  and  apparently 
does  not  disintegrate. 


CHAPTER  XVI. 
PORCELAIN  TEETH. 


As  Pharmacy  was  once  a  part  of  Medical  Practice,  and  instrument- 
making  a  part  of  Surgery,  so  the  manufacture  of  porcelain  teeth  was 
at  one  time  confined  to  the  dental  laboratory.  Until  within  the  past 
forty  years  a  practical  knowledge  of  the  Dento-ceramic  art  was  con- 


PORCELAIN    TEETH.  IO89 

sidered  an  essential  part  of  dental  education.  Galen  compounded  his 
celebrated  Theriaca  for  two  Roman  emperors ;  Pare  and  Wiseman 
made  many  of  their  surgical  instruments;  and  necessity  has  compelled 
physicians  and  surgeons  in  all  ages  to  imitate  these  examples.  But 
the  medical  and  surgical  world  have  for  many  years  committed  the 
manufacture  of  drugs  and  instruments  to  those  who,  by  making  it  a 
special  art,  can  produce  far  better  results. 

The  time  has  fully  come  when  Dentistry  has  done  the  same  with 
porcelain  work,  for  two  sufficient  reasons  :  i.  Manufacturers  now  offer 
to  the  profession  porcelain  teeth  in  such  variety  of  beautiful  forms 
that  not  one  dentist  in  a  thousand  could  equal  them.  2.  Moderate 
proficiency  in  block-carving  requires  such  an  amount  of  preparatory 
training  and  of  continuous  experience,  that  the  dentist's  education  and 
practice  must  suffer  in  the  line  of  important  duties  which  cannot  thus 
be  delegated  to  others.  Hence,  nearly,  if  not  quite  all,  of  the  most 
skillful  block-carvers  engaged  in  the  practice  of  dentistry  have,  since 
the  year  1850,  one  after  another,  given  up  this  art,  which  it  cost  them 
so  much  to  acquire.  For  these  reasons,  and  also  because  the  manage- 
ment of  a  porcelain  furnace  cannot  be  taught  in  books,  we  shall  not 
attempt  in  this  chapter  to  give  a  full  and  didactic  exposition  of  the 
manner  of  making  porcelain  block  or  single  teeth.  Those  who  desire 
such  knowledge  with  a  view  to  making  it  a  specialty,  require  that 
which  no  longer  comes  within  the  scope  of  a  work  on  the  "  Principles 
and  Practice  of  Dentistry"  to  teach. 

There  is,  however,  on  the  part  of  all  students,  and  probably  of 
most  practitioners,  a  desire  to  know  the  composition  of  dental  porce- 
lain, and  to  have  some  idea  of  the  manner  in  which  a  few  earthy  ma- 
terials and  metallic  oxids  are  made  to  assume  such  beautiful  forms. 
Some  knowledge  of  the  component  parts  of  porcelain  is  essential  to  a 
correct  understanding  of  the  necessity  for  their  admixture,  as  well  as 
of  the  effects  thus  produced. 

PORCELAIN    MATERIALS. 

The  infusible  earths,  Silica  and  Alumina,  and  the  fusible  alkalies, 
Potassa  and  Soda,  form  the  bulk  of  all  porcelain.  Certain  metallic 
oxids,  in  small  quantity,  give  color,  and  some  varieties  of  pottery  are 
modified  by  small  proportions  of  Lime  and  Magnesia.  Dental  porce- 
lain is  made  from  the  purest  compounds  of  silica,  alumina,  and  potassa, 
colored  by  metallic  Gold  and  Platina,  and  by  the  oxids  of  Gold,  Ti- 
tanium, Manganese,  Cobalt,  and  Uranium. 


69 


1090  MECHANICS — DENTAL    PROSTHESIS, 

SILICA. 

Silica  (quartz,  silex,  silicic  acid)  is,  next  to  oxygen,  the  most  uni- 
versally diffused  substance  in  nature,  constituting  50  per  cent,  of  all 
rocks.  Granite,  granitic  rocks,  sandstones,  and  sand  contain  not  less 
than  three-fourths  silica  ;  mica,  schist,  clay-slate  and  clay,  not  less  than 
two-thirds;  trap-rocks  and  lava,  one-half.  Silica  is  to  the  mineral 
kingdom  what  carbon  is  to  the  vegetable — the  element  of  stability. 
In  its  purest  forms  (rock  crystal,  Brazilian  pebbles,  or  crystals  of 
quartz),  it  is  free  from  discoloration  by  iron  or  other  oxids,  it  is  ab- 
solutely infusible,  and  is  insoluble  in  water ;  this  is  the  kind  selected 
for  dental  porcelain,  but  for  other  varieties  of  porcelain  flint  is  com- 
monly used.  It  forms  silicates  with  alumina,  magnesia,  lime,  potassa, 
and  soda,  the  most  important  of  which,  in  this  connection,  are  the 
silicates  of  alumina  and  potassa.  Silica,  as  found  in  feldspar  and 
kaolin,  is  partly  pure  silica,  partly  the  silicate  of  alumina.  Now  the 
"behavior"  in  the  furnace  of  silica  and  the  silicate  of  alumina  is  dif- 
ferent ;  hence,  chemical  analysis  can  estimate  only  the  relative  purity 
of  these  substances ;  experiment  alone  can  determine  the  proportions 
of  each  necessary  for  the  development  of  any  required  property  in 
porcelain. 

FELDSPAR. 

Next  to  silica,  alumina  (oxid  of  aluminium)  is  the  most  univer- 
sally diffused  of  all  minerals;  but,  unlike  silica,  it  is  rarely  found 
uncombined.  The  gem  Sapphire  is  pure  crystallized  aluminium,  and 
is  the  next  hardest  mineral  to  the  diamond  :  a  less  pure  form  is  well 
known  in  dentistry  as  emery  or  corundum,  some  specimens  of  which 
seem,  under  the  lens,  to  be  a  collection  of  minute  crystals  of  dark- 
colored  sapphire.  For  porcelain  manufacture,  aluminium  is  never 
used  in  its  purest  state,  but  in  its  natural  combinations  with  silica,  lime, 
potassa,  and  soda.  For  dental  porcelain  only  two  of  these  are  used — 
Feldspar  (known  to  the  Chinese  as  Pe-tun-tse)  and  Kaolin.  Feldspar 
is  a  silicate  of  aluminium  and  potassa,  containing  a  little  lime  and  a 
trace  of  iron.  A  less  common  variety  of  spar  contains  soda  in  the 
place  of  potassa  ;  it  makes  a  soft  porcelain,  fusible  at  lower  heat  than 
the  potash  spar.  Lime  feldspar  is  used  in  some  kinds  of  pottery,  but 
for  dental  purposes  potash  feldspar  is  the  only  variety.  It  is  an 
abundant  mineral,  and  is  often  found  in  large  masses ;  the  purest 
varieties  alone  are  used  for  dental  porcelain.  Delaware  and  Pennsyl- 
vania spars  are  most  esteemed  by  American  manufacturers.  Its  most 
extensive  dissemination,  however,  is  as  one  of  the  components  of 
granite  and  granitic  rocks,  by  disintegration  of  the  feldspathic  con- 
stituents of  which  large  beds  of  porcelain  clay  are  formed,  as  found  in 


PORCELAIN   TEETH.  I09I 

China  and   Japan,  England,  Germany,  and  France,  and  also  in  the 

United  States. 

Kaolin. — Ka-o-lin  (the  Chinese  word  for  clay)  is  the  purest  of 
these  mixtures  of  silica  and  silicate  of  alumina,  prepared  in  Nature's 
laboratory  for  the  manufacture  of  porcelain.  Pipe  clay,  potter's  clay, 
blue  clay,  fire  clay,  and  Cornish  stone  are  similar  in  composition,  but 
only  the  purest  kaolin  is  used  for  dental  porcelain.  It  contains  nine 
parts  of  silica  and  eight  parts  aluminium  ;  whereas  spar  has  nine  parts 
silica  and  only  two  parts  aluminium;  also  spar  is  made  fusible  by  its 
silicate  of  potassa — kaolin  has  none.  Kaolin  is,  therefore,  feldspar 
deprived  of  its  soluble  silicate  of  potassa  (or  soda),  which  has  been 
washed  out  during  the  disintegration  of  the  feldspathic  rock.  It  is 
soft  and  unctuous,  and  is  highly  plastic ;  pulverized  spar  on  the 
contrary,  is  granular  or  powdery,  and  is  molded  with  difficulty. 
Kaolin,  like  silex,  is  infusible  ;  under  intense  and  continued  heat  it 
shrinks  greatly  and  becomes  extremely  hard,  but  it  is  always  porous 
and  absorbent.  Silex  lessens  the  contraction  of  kaolin,  spar  gives  it 
fusibility;  both  diminish  its  absorbent  quality,  so  objectionable  in  any 
material  that  is  to  be  worn  in  the  mouth. 

Stone  ware,  China  ware,  Wedgwood  ware,  Parian  porcelain,  and 
Dental  porcelain  vary  in  their  properties  because  of  the  different  pro- 
portions in  which  kaolin  and  feldspar  are  combined,  also  in  the  kind 
of  flux  used.  For  instance,  the  Parian  statuettes  have  kaolin  and  spar 
in  equal  proportions,  with  about  half  as  much  of  a  flux,  made  of  spar, 
quartz,  and  potash.  Dental  porcelain,  demanding  less  heat,  less 
shrinkage,  and  a  more  translucent  appearance,  has  a  very  much  greater 
proportion  of  spar.  It  has  required  a  very  extended  series  of  experi- 
ments to  combine  silica,  aluminium,  and  potassa  in  correct  proportions, 
and  to  know  just  which  of  Nature's  compounds  it  is  best  to  use  in 
order  to  harmonize  the  requisites  of  strength  and  beauty,  so  essential 
to  the  character  of  a  porcelain  tooth. 

COLORING    MATERIALS. 

The  foregoing  materials  give  a  pure  white  porcelain  of  greater  or  less 
translucency.  It  is  now  required  to  find  substances  which  will,  in  the 
strong  heat  of  the  furnace,  yield  indestructible  colors,  by  skillful  com- 
bination of  which  the  porcelain  may  imitate  the  almost  endless  varieties 
of  tint  in  the  natural  teeth  and  gum.  Of  these  there  are  three  principal 
colors  and  three  subordinate  ones. 

Titanium. — The  purest  varieties  of  the  oxid  of  titanium  are  se- 
lected ;  it  is  found  as  a  mineral  in  various  localities  throughout  the 
United  States.  The  crystals  are  reddish-brown,  and  have  a  bright, 
metallic  lustre;   they  give,  when  ground,  a  beautiful  yellow,  or  yellow- 


1092  MECHANICS — DENTAL   PROSTHESIS. 

ish-brown  color.  It  is  used  in  the  coloring  of  all  body,  and  is  the 
basis  of  color  for  the  class  of  yellowish  enamels. 

Platinum. — This  metal,  precipitated  from  its  solution  in  aqua  regia, 
then  washed  and  dried,  is  known  as  platina  sponge.  It  gives  a  gray- 
blue  color,  and  is  the  basis  of  color  for  the  class  of  grayish-blue  enamels. 

Gold. — Gold  precipitate  is  used  to  give  life  and  animation  to  the 
tooth,  producing  often  a  very  remarkable  effect.  The  oxid  of  gold, 
known  as  Purple  of  Cassius,  and  generally  considered  to  be  a  mixed 
oxid  of  gold  and  tin,  is  used  to  impart  the  well-known  red  color  of 
the  artificial  gum  ;  no  less  costly  substitute  has  ever  been  found  for  this 
purpose. 

Oxid  of  Manganese  gives  a  purplish  color,  and  is  used  occasionally 
for  some  shade  of  tooth,  but  not  of  gum.  Oxid  of  Cobalt  gives  a 
bright  blue  color.  If  wrapped  in  best  blue  paper  and  burned  in  a 
covered  crucible  it  is  called  the  ashes  of  cobalt,  and  is  thought  to  give 
a  more  desirable  tint  to  the  enamel  than  the  simple  oxid.  Oxid  of 
Uranium  is  used  in  its  mineral  form  and  gives  a  greenish-yellow  color ; 
while  a  lemon-yellow  color  may  be  given  by  the  oxid  of  silver ;  but 
this  is  a  fugitive  color  at  high  temperatures. 

These  colors,  singly  and  in  combination  with  each  other,  produce 
a  great  variety  of  colors  or  shades.  Thus,  say  forty  shades  of  body 
(olor  a.xe  made  by  using  these  materials  in  different  quantities  and  in 
different  combinations  ;  also  a  like  number  of  etiatne I  colors.  Then, 
starting  with  the  lightest  shade  of  body,  forty  different  grades  may  be 
produced  by  using  a  different  point  enamel ;  so  of  each  of  the  forty 
shades  of  the  body,  making,  if  required,  sixteen  hundred  variations 
of  shade. 

The  following  formulae  will  suffice  to  give  a  correct  idea  of  the  pro- 
portions in  which  the  preceding  materials  are  combined  to  give  the 
Body  and  Enamel  of  porcelain  teeth,  single  or  in  sections  :  — 


Feldspar, 12  oz.  Feldspar,      3  oz. 

Quartz, 2  oz.  Sponge  platina,    .    .  I   to  4  grs. 

Kaolin, 15  dwts.  Flux, 3  dwts. 

Titanium,     .        .  24  to  48  grs. 

The  Flux  here  mentioned  is  made  by  fusing  four  ounces  of  finely 
ground  quartz  with  Glass  of  Borax  and  Sal  Tartar,  each  one  ounce ;  it 
forms  a  transparent  glass.  The  following  formulae  show  the  prepara- 
tion of  Gum  Enamel :  — 

GUM  FRIT.  GUM  ENAMEL. 

Oxid  of  gold,     ....  10  grs.  Gum  frit,     ......     I  oz. 

Feldspar,      i  oz.  Feldspar, 3  oz. 

Flux, 8  dwts. 


PORCELAIN    TEETH.  i093 

The  titanium,  platina,  and  oxid  of  gold  must,  in  these  recipes,  of 
course,  be  modified  by  mixture  with  other  colors  to  produce  the  re- 
quisite varieties  of  shade. 

BODY    FOR    MOLDED    BLOCK    TEETH. 
NO.   I.  NO.  2. 

Kaolin, I  oz.  German  clay, /4  oz. 

Silica, 3  oz.  Silica,   .    .  ,    .    .    .     3    oz. 

Feldspar, 18  oz.  Feldspar, 18    oz. 

Oxid  of  titanium,     ...  65  grs.  Oxid  of  titanium,    .        .  65  grs. 

Starch,  .  10  grs.  to  each  ounce.  Starch,    .  10  grs.  to  each  ounce. 

BODY    FOR    CARVED    BLOCKS. 
NO.    I.  NO.   2. 

Kaolin, i  oz.  German  clay, }4  oz. 

Silica, 3^  oz.  Silica, 3^  oz. 

P'eldspar, I4  oz.  Feldspar,      14    oz. 

Oxid  of  titanium,    ...  40  grs.  Oxid  of  titanium,    ...  40   grs. 

BLUE   ENAMEL.  YELLOW  ENAMEL. 

Platinum  blue  frit,  ...     i  gr.  Titanium, i  gr. 

Feldspar, I  oz.  Gold  frit, 2  grs. 

Starch, 15  grs.  Starch, 15  grs. 

Feldspar,      I  oz. 

We  shall  now  briefly  describe  the  processes  by  which  the  porcelain 
teeth  and  sections  sold  to  the  profession  are  manufactured. 

PROCESS    OF   MANUFACTURE. 

The  silex  and  feldspar,  in  their  crude  state,  are  first  submitted  to 
a  red  heat,  then  suddenly  thrown  into  cold  water.  This  is  called 
"  Calcining,"  and  the  effect  is  to  render  them  more  easily  broken  and 
pulverized.  All  impurities  having  been  carefully  removed,  they  are 
crushed  between  flint  stones  ;  when  fine  enough,  they  are  put  into  a 
mill,  formed  of  burr  millstone,  with  chasers  of  the  same  material. 
They  are  ground  in  water,  then  floated  off",  and  allowed  to  settle; 
The  water  is  then  drawn  off  or  evaporated ;  the  silex  and  spar,  dried 
and  sifted,  are  then  ready  for  use.  The  kaolin,  having  been  already 
pulverized  in  Nature's  laboratory,  is  prepared  by  washing  until  per- 
fectly free  from  impurities,  and  when  dry  is  ready  for  use.  The  flux 
and  frit  are  coarsely  ground,  but  the  coloring  materials  are  reduced 
to  an  im.palpable  powder.  All  these  porcelain  materials  are  combined 
in  proper  proportions  to  form  the  body  and  the  enamel,  then  mixed 
with  water  and  worked  into  masses  resembling  putty.  When,  however, 
the  method  of  biscuiting  is  adopted  the  enamels  are  mixed  in  a  much 
thinner  state  than  the  body. 

The  unbaked  porcelain  masses  are  now  ready  for  the  molding  room. 
The  molds  in  which  single  teeth  or  sections  are  formed  are  made  of 


1094  MECHANICS — DENTAL    PROSTHESIS. 

brass  and  are  in  two  pieces — one-half  of  the  tooth  being  represented 
on  either  side.  The  precise  shapes  desired  are  carved  out  with  great 
care  ;  holes  are  drilled  to  receive  the  platina  pins  in  each  tooth;  when 
the  two  halves  are  fitted  accurately  together,  with  guiding  pins  for 
exact  closure,  the  mold  is  ready  for  use.  The  brass  matrix  must  be 
made  about  one-fifth  larger  than  the  size  desired,  to  allow  for  shrink- 
age of  the  porcelain  paste.  After  greasing  the  molds,  the  first  opera- 
tion is,  by  means  of  small  tweezers,  to  place  the  platina  pins  in  the 
holes  made  for  them  (there  are  many  sizes  of  these  pins,  differing  in 
length  and  thickness,  to  suit  the  sizes  of  the  teeth).  As  no  piece  of 
mechanism  can  be  stronger  than  its  weakest  point,  there  should  always 
be  such  a  relation  between  the  tooth  substance  and  the  pins,  as  to 
shape,  size,  and  angle  of  insertion,  that  one  will  be  as  strong  as  the 
other,  and  both  sufficient  for  all  legitimate  uses.  The  strength  of  pin, 
without  loss  of  strength  in  the  tooth,  characterizes  a  recent  and  valu- 
able improvement  made  by  the  late  Dr.  S.  S.  White,  and  known  as 
the  "  foot-shaped  pin,"  illustrated  in  Fig.  1174.  The  thickest  part 
of  this  pin  is  at  the  angle,  or  heel ;  the  point,  or  toe,  runs  upward 


^ 


Fig.  1 174. 

into  the  thick  part  of  the  tooth,  giving  additional  security  against  its 
being  drawn  out.  The  insertion  of  the  pin  at  an  upward  angle  beds 
it  in  the  strongest  portion  of  the  tooth  material  ;  thus  any  weakening 
of  the  thin  portion  of  the  tooth  is  avoided,  as  when  the  headed  pin  is 
inserted  in  a  straight  line  ;  also,  the  greatest  amount  of  material  is 
found  where  the  greatest  strain  is  brought  to  bear  upon  it.  The  force 
of  mastication  is  exerted  outward  and  toward  the  necks  of  the  teeth  ; 
thus  the  shape  and  direction  of  this  pin  are  best  calculated  directly  to 
oppose  it.  It  will  also  be  noticed  that  its  direction  and  unusual  length 
of  insertion  permit  a  close  grinding  of  the  tooth,  which  would  cause 
the  usual  short  and  horizontal  pin  very  soon  to  break  away  from  the 
porcelain.  The  double-headed  pin,  a  previous  patented  invention  of 
Dr.  White,  was  a  very  great  improvement  in  the  shape  of  tooth  pins  ; 
but  it  has  been  superseded  by  this  new  "  foot-shaped  pin." 

Fig.  1 1 75  represents  both  plain  and  sectional  gum  teeth  with  the 
lateral  or  cross-pins,  devised  by  Dr.  C.  H.  Land,  which,  it  is  claimed, 
give  greater  strength  to  the  completed  denture  than  when  teeth  with 
the  ordinary  pins  are  used.     For  continuous  gum   teeth  a  complete 


PORCELAIN    TEETH. 


1095 


arch  is  formed  by  twisting  or  soldering  the  pins  together,  thus  lessen- 
ing the  strain  upon  any  single  tooth,  and  allowing  a  much  lighter  plate 
to  be  used.  What  are  styled  "  countersunk  teeth  "  are  also  manufac- 
tured, in  which  the  pins  are  attached  to  the  teeth  in  a  depression  or 
cavity  formed  in  the  base  of  each  tooth.  (See  Dr.  Cryer's  method  of 
mounting,  in  chapter  on  Celluloid.) 

The  pins  being  properly  adjusted,  the  enamels  for  the  tooth  and  the 
gum  are  placed  in  the  molds  by  means  of  a  small  steel  spatula,  care- 
fully placing  them  in  the  exact  position  and  quantity  required ;  the 
body  is  placed  in  them  in  lumps  corresponding  to  the  size  of  the  teeth  ; 
the  top  of  the  mold  is  then  put  on  and  the  matrix  placed  under  a 
press,  which  compacts  each  separate  mass.  They  are  then  dried  by  a 
slow  heat.  When  perfectly  dry  the  top  is  removed,  and  the  teeth  will 
now  drop  out.  In  this  state  they  are  extremely  tender,  owing  to  the 
large  percentage  of  feldspar,  and  require  very  careful  handling. 

Therare  now  sent  to  the  trimmer's  room,  where  each  tooth  is  care- 


FiG.  1175. 

fully  inspected  and  all  imperfections  removed  or  filled  up ;  the  spare 
edges  left  by  the  union  of  the  two  sides  of  the  mold  are  smoothly  filed, 
and  the  arch  of  the  gum  over  each  tooth  made  rounding  and  true  with 
a  small  pointed  instrument.  They  are  then  placed  on  beds  of  coarse 
quartz  sand,  on  trays  or  slides  made  of  fire-clay,  and  are  ready  for  the 
furnace.  Formerly  there  was  another  process,  called  crucing,  or  bis- 
cuiting,  which  was  universally  practiced,  and  is  still  used  in  some 
factories  ;  it  is  also  used  in  the  making  of  blocks  carved  to  order.  It 
consists  in  submitting  the  teeth  after  molding  to  a  heat  sufficient  to 
harden  them  so  they  can  be  cut  or  filed  like  chalk,  and  what  is  called 
an  outside  enamel \%  then  applied  with  a  camel's-hair  brush;  but  it  has 
been  found  that  the  composition  of  the  tooth  is  injuriously  affected  by 
this  partial  burning,  subsequent  cooling,  enameling,  and  reburning. 
This  process  is  unavoidable  when  the  blocks  are  carved  by  hand  for 
special  cases  ;  but  whenever  they  can  be  made  in  a  matrix,  the  tooth  is 


1096  MECHANICS DENTAL    PROSTHESIS. 

better  and  stronger  when  it  is  enameled  in  the  mold  and  finished  in  a 
single  firing. 

The  furnace  is  built  substantially  on  the  principle  of  the  dentists' 
furnace  (Fig.  1096),  differing  chiefly  in  size.  The  trays  holding  the 
teeth  are  placed  in  the  muffle,  and  are  thus  protected  against  injury 
from  the  gases  of  the  fuel.  There  is  no  rule  which  can  be  given  to 
determine  the  exact  amount  of  time  the  teeth  must  remain  in  the 
furnace ;  the  practiced  eye  of  the  burner  must  determine  from  the 
appearance  of  the  teeth  when  the  firing  is  completed.  If  taken  out 
before  they  are  done  the  enamel  will  craze,  or  crack,  in  cooling  ;  if 
a  little  too  much  done,  the  surface  will  be  too  glassy  and  the  body  will 
not  be  strong.  When  cool  the  teeth  are  removed  from  the  slides, 
placed  upon  wax  cards,  and  are  then  ready  for  the  dentist. 

The  vast  variety  in  shape,  size,  color,  etc.,  of  the  teeth  thus  made 
gives  opportunity  for  the  selection  of  forms  suitable  to  nearly  every 
case  which  presents  itself  to  the  practitioner.  The  assortment  must 
of  necessity  be  very  large  and  varied  to  meet  the  wants  of  the  oper- 
ator ;  in  fact,  the  manufacturer  has  shown  a  better  appreciation  of 
the  esthetic  requirements  of  the  dental  art  than  the  practitioner. 
While  the  work  of  the  latter  too  often  exhibits  an  unmeaning  mo- 
notony, the  former  has  made  provision  for  even  the  extreme  cases 
which  are  sometimes  met  with  ;  he  has  also  given  a  beautiful  series  of 
those  various  deviations  from  a  uniform  regularity  which  are  so  com- 
mon in  natural  dentures.  In  some  mouths  these  seem  to  be  impera- 
tively demanded  to  restore  the  familiar  expression,  while  in  any  mouth 
the  use  of  some  one  or  other  of  them  would  go  far  to  disarm  that 
suspicion  of  artificiality  detection  of  which  is  mortifying  to  most 
patients. 

Porcelain  is  a  material  in  which  the  beauty  of  the  result  well  repays 
the  highest  exercise  of  Art.  It  has  been  for  centuries  a  favorite 
material  for  expressing  the  Poetry  of  Form.  The  famous  Etruscan 
vases  of  antiquity,  the  exquisite  gems  of  the  Majolica  of  the  sixteenth 
century,  the  marvelous  work  of  Bernard  Palissy,  the  prince  of  potters, 
the  beautiful  productions  of  the  Sevres  and  Dresden  manufactories, 
the  well-known  charming  designs  of  the  Wedgwood  ware,  and  the 
si  ill  more  recent  Parian  statuettes,  may  be  named  in  proof  of  the  fit- 
ness of  porcelain  to  embody  the  conceptions  of  Genius.  Dental 
porcelain  is  worthy  of  such  associations;  not  only  like  them  does  it 
delight  the  eye  and  give  evidence  of  high  esthetic  cultivation,  but  it 
adds  to  beauty  the  charm  of  usefulness.  It  is  customary  to  attribute 
the  rapid  growth  of  Dental  Art,  since  1840,  to  its  associations,  col- 
leges, journals,  and  its  didactic  literature — and  with  much  truth.  But 
to  porcelain  it  owes  its  very  existence  as  an  esthetic  art,  and  the  larger 


PORCELAIN    TEETH.  1 09 7 

part  of  its  extent  and  utility  as  a  prosthetic  art.  It  was  altogether 
impossible  for  perishable  human  teeth,  or  their  wretched  imitations  in 
ivory,  to  offer  such  tempting  fac-similes  of  nature  as  we  meet  in 
porcelain.  Bv  thus  creating  that  enormously  increased  demand  for 
dental  service  which  has  been  the  chief  cause  of  the  rapid  development 
of  its  resources,  it  has  made  the  dental  profession  its  debtor  to  a 
greater  extent  than  any  other  single  influence.  The  depot  not  only 
renders  service  by  the  superior  excellence  of  the  surgical  instruments 
and  prosthetic  materials  which  it  supplies,  but  it  directly  benefits  the 
science  and  art  of  dentistry  by  releasing  the  practitioner  from  manu- 
facturing toil,  and  giving  time  for  the  acquirement  of  increased 
knowledge  and  skill.  Thus,  if  the  time  heretofore  given  to  block- 
making  were  devoted  to  the  study  of  dental  esthetics,  patients  would 
have  the  benefit  of  an  artistic  selection  from  a  far  larger  variety  of 
porcelain  dentures  than  could  otherwise  be  possibly  made.  The  illus- 
trations of  this  chapter  can  but  imperfectly  convey  an  idea  of  the 
beauty  and  expression  of  the  originals  ;  they  will,  however,  assist  the 
student  in  his  study  of  those  principles  which  guide  in  the  selection 
and  arrangement  of  teeth ;  they  may  also  serve  to  awaken  practitioners 
to  the  extent  of  the  present  resources  of  ceramic  dentistry,  and  to  the 
importance  of  esthetic  culture  in  order  to  properly  make  full  use  of 
the  same. 

The  improvements  in  the  Dento-ceramic  Art  have  sprung  from  a 
careful  inquiry  into  the  essential  characteristics  which  artistically 
formed  porcelain  teeth  should  possess.  Among  these  are  (i)  Natural- 
ness ;  under  which  term  are  included  shape,  color,  and  a  vital  appear- 
ance, the  last  depending  upon  the  precise  amount  of  translucency,  the 
texture  of  the  surface,  and  the  nice  blending  of  the  colors  of  the  body 
and  enamel — an  appearance  which  should  be  maintained  as  well  under 
artificial  as  under  solar  light.  Many  teeth  which  will  bear  inspection 
reasonably  well  in  daylight  have  a  very  unnatural  and  artificial  ap- 
pearance when  exposed  in  the  mouth  to  a  light  under  which  the 
wearer  may  be  most  anxious  to  excite  admiration.  (2)  Shape  ;  which 
includes  a  preservation  of  the  distinctive  characteristics  of  each  tcjoth, 
securing  the  instant  recognition  of  its  position  in  the  dental  arch. 
There  must  be  some  defect  or  inaccuracy  of  form  if,  out  of  the  twenty- 
eight  teeth  of  a  set,  in  unassorted  confusion,  an  experienced  eye  cannot 
tell  the  place  of  each ;  for  every  tooth  has  its  distinctive  contour.  Not 
only  should  each  tooth  possess  the  individuality  which  belongs  to  it, 
but  it  should  also  indicate  the  character  of  its  relation  to  its  companions 
on  either  side  and  to  its  antagonist.  The  eye  trained  to  observe  nature 
should  not  be  offended  by  the  recognition  of  any  inharmony ;  should 
not  find  a  second  bicuspid  or  molar  in  place  of  a  first,  or  incisors  un- 


1098 


MECHANICS — DENTAL    PROSTHESIS. 


distinguishable  from  each  other,  or  an  upper  tooth  in  place  of  its  cor- 
responding lower  one  ;  nor  should  it  detect  in  the  midst  of  one  style 
of  denture  some  incisor  or  canine  characteristic  of  another.     Figs.  1 1 76 


Fig.  1 176. 


and  1 1 77  exhibit  very  strikingly  the  marked  peculiarities  of  each  one 
of  the  twenty-eight  teeth  of  an  artistically  designed  artificial  set ;  while 
these  and  subsequent  illustrations  demonstrate  how  possible  it  is  for 


Fig.  1177. 


modern  dentistry  to  adapt  its  work  to  the  great  varieties  of  facial  ex- 
pression.    Probably  every  reader  has  more   than   once  turned  at  the 


PORCELAIN    TEETH.  I099 

sound  of  a  familiar  voice,  to  see  a  face  strangely  resembling  thelooked- 
for  friend.  This  correspondence  between  voice  and  face,  often  so 
startling,  is  only  another  one  of  those  links  between  external  and  in- 
ternal conformation,  which  makes  the  study  of  esthetic  anatomy  essen- 
tial to  the  success  of  the  dental  mechanician. 

The  great  law  of  correspondence,  which  enabled  Cuvier  to  build 
up  the  entire  skeleton  from  a  single  bone,  makes  us  associate  the  idea 
of  intellect  with  certain  forms  of  forehead,  and  of  character  with  certain 
forms  of  mouth,  nose,  and  chin  ;  it  is  the  same  law  which  permits  us  to 
infer  from  what  remains  the  expression  of  what  is  lost.  Age,  sex,  tem- 
perament, and  complexion,  also  many  physical,  mental,  and  even  moral 
peculiarities,  are  suggested  to  the  acute  observer  by  certain  charac- 
teristics of  the  dental  organs.  The  artist  who  seeks  to  restore  harmony 
in  the  facial  expression  should  be  skilled  in  the  observance  of  these 
varied  manifestations ;  such  skill  is  demanded  alike  in  the  manufacture 
and  in  the  application  of  artificial  dentures. 

In  addition  to  these  esthetic  qualities  porcelain  teeth  should  possess 
(3)  Strength  adequate  to  the  legitimate  use  for  which  they  are  intended  ; 
this  strength  should  come  from  the  quality  of  their  composition, 
the  skillful  distribution  of  bulk  to  parts  most  requiring  it,  and  from 
the  due  form,  position,  and  proportion  of  the  pins,  rather  than  from 
any  increase  in  bulk  and  weight  beyond  that  of  the  natural  organs. 
They  should  possess,  also,  by  reason  of  their  conformation  (4)  Adap- 
tability to  the  various  irregularities  caused  by  unequal  absorption  of 
the  alveolar  ridge,  so  that  when  judiciously  selected  they  s-hall  require 
little  labor  to  adapt  and  antagonize  them.  Special  provision  should  be 
made  for  the  results  of  extreme  or  very  irregular  absorption,  or  for  the 
loss,  by  disease  or  otherwise,  of  parts  of  the  maxillary  ridge,  so  that 
in  such  cases  the  teeth  can  readily  be  made  to  articulate  and  afford 
comfort  to  the  wearer,  assisting  in  speech  and  mastication,  and  yet  not 
presenting  any  incongruous  appearance. 

There  are,  moreover,  special  modifications  demanded  by  many 
other  conditions ;  as,  for  instance,  in  cases  having  a  very  short  ar- 
ticulation, requiring  the  pins  to  be  set  in  a  recess  near  the  crowns  of 
the  teeth  and  also  in  countersunk  depressions  under  the  base  of  each 
tooth,  thus  bringing  the  greatest  resistance  where  there  is  the  greatest 
strain  in  mastication,  as  is  well  shown  in  Figs.  11 79,  1201.  In  both 
these  blocks  the  full  external  size  of  tooth  is  given,  and  its  character- 
istic form  and  the  expression  of  interdental  gum  preserved;  this  could 
not  be  done  with  the  usual  form  of  blocks,  ground  down  to  suit  such 
cases.  In  Fig.  11 78  we  have  front  blocks  for  mouths  where  a  shoulder 
.is  required  to  antagonize  with  the  lower  front  teeth  when  there  are  no 
back  teeth  remaining.     Where  early  contraction  and  protrusion  of  the 


MECHANICS — DENTAL    PROSTHESIS. 


upper  maxillary  arch  has  caused  it  to  have  a  sharply  curved  projection, 
bringing  the  closure  of  the  lower  teeth  much  behind  the  upper  ridge 


Fig.  1179. 


at  the  central  incisors,  or  where  absorption  above  has  left  a  ridge 
prominent  at  its  lower  edge  or  margin  of  the  gum,  it  becomes  neces- 
sary to  give  a  peculiar  twisted  form  to  the  front  blocks.     In  Fig.  1180 


Fig.  1180. 


the  first  two  blocks  are  for  a  pointed  arch,  accompanied  in  the  second 
by  a  crowded  denture,  so  often  seen  in  such  cases.     It  is  impossible  to 


PORCELAIN    TEETH.  ^  IIOI 

aaapt  blocks  of  ordinary  form  to  such  cases  without  destroying  their 
true  expression  at  one  or  other  of  the  joints  ;  in  fact,  much  of  both 
gum  and  tooth  is  often  sacrificed  to  get  correct  articulation.  The 
third  blocks  are  shaded  with  a  view  to  show  the  fullness  of  gum  at  the 
centrals  and  its  falling  back  over  the  canines  ;  this  is  also  shown  in  the 
sectional  views  of  the  first  and  third  blocks. 

For  cases  in  which  the  lower  jaw  closes  more  or  less  in  advance  of 
the  upper  maxillary  ridge,  a  large  gum  is  often  necessary,  as  in  Fig. 
1182;  but  such  mouths  require  a  peculiar  form  of  block  if  the  lower 
jaw  has  much  projection.  Where  such  a  prominence  of  the  gum 
exists,  from  want  of  exterior  absorption  or  the  previous  wearing  of  a 
plate,  as  to  require  the  teeth  to  be  set  directly  upon  the  ridge  there 
should  be  no  artificial  gum  between  it  and  the  lip.  When  the  molar 
block  of  lower  sets  extends  to  where  the  ramus  of  the  jaw  begins  to 
rise,  a  peculiar  plowshare  curve  of  the  base  is  required  ;  such  that, 
while  the  gum  of  the  second  bicuspid  lies  on  the  outside  of  the  ridge, 


Fig.  1181. 


the  gum  of  the  second  molar  may  lie  partly  upon  the  ridge,  so  as  to 
give  more  perfect  antagonism  with  the  upper  molars.  The  molar  and 
bicuspid  teeth  from  which  Fig.  1181  was  drawn  are  also  marked  by  a 
characteristic  curve  of  the  buccal  surfaces,  giving  not  only  a  very 
natural  appearance,  but  acting  as  a  guard  to  the  cheek  and  preventing 
its  being  caught  between  the  teeth. 

Fig.  1 182  illustrates  the  difference  of  shape  required  for  a  mouth 
where  front  absorption  permits  the  artificial  gum  to  overlap  the 
alveolus,  and  one  where  fullness  of  the  natural  gum  requires  the  block 
to  set  directly  upon  it.  In  the  latter  case,  if  the  color  of  gum  is 
judiciously  chosen  and  the  blocks  well  adapted,  the  triangles  of  arti- 
ficial gum  will  be  scarcely,  if  at  all,  distinguishable  from  the  natural ; 
we  regard  this  as  an  extremely  useful  form  of  block.  Sectional  view 
of  the  molar  in  the  upper  cut  shows  the  curve  necessary  to  bring  its 
grinding  surface  directly  under  the  ridge  ;  the  views  of  grinding  and 


II02  .  MECHANICS — DENTAL   PROSTHESIS. 

cutting  surfaces,  together  with  front  views,  show  how  each  tooth  has  a 
distinctive  character ;  as,  for  instance,  in  the  bicuspids,  so  often  chosen 
without  regard  to  the  difference  in  form  between  the  first  and  second. 
Again,  the  curve  of  the  front  block  shows  two  of  several  variations 
required  in  the  curvature  of  the  arch  ;  in  the  upper,  the  sharp  turn  at 
the  canine  gives  a  squareness  across  the  incisors ;  in  the  lower,  this  turn 
is  at  the  central  and  is  adapted   to  a  pointed  arch.     Variations  in 


Fig.  1 182. 

curvature  of  the  arch  are  also  shown  in  Figs.  11 77,  1190.  Notice  also 
the  marked  difference  in  the  character  of  the  bicuspids  and  molars  in 
upper  and  lower  cuts  and  the  totally  different  expression  of  the  front 
teeth. 

Fig.  1 183  shows  how  the  same  intermaxillary  space  maybe  filled 
with  teeth  of  a  widely  different  size  as  well  as  character.  In  the  first, 
a  very  long  tooth  and  short  gum  ;  in  the  second,  a  very  long  gum  and 


Fig.  1183. 

short  tooth.  But  length  of  teeth  is  by  no  means  the  only  difference 
here ;  relative  size  of  central  and  lateral,  direction  of  the  axis  of 
lateral  and  canine,  and  outline  of  cutting  edge  of  the  block,  are  three 
features  which  equally  mark  the  distinctness  of  these  two  styles  ;  these 
also  are  ])oints  which  demand  that  both  long  and  short  teeth  shall 
differ  among  themselves  as  widely  as  these  samples  differ  from  each 


PORCELAIN    TEETH. 


IIO-? 


other.     The  lateral  view  of  these  teeth  shows  another  marked  differ- 
ence in  form. 

Fig.  1 184  gives  the  characteristic  equality  of  lower  incisors,  or 
slightly  greater  size  of  the  lateral;  it  also  gives  some  of  the  diversities 
in  length,  width,  shape  of  cutting  edge,  and  form  at  arch  of  the  gum. 
Although  there  is  much  less  difference  in  the  shape  of  the  six  lower 
front  teeth  than  of  the  six  upper,  it  is  a  great  mistake  to  suppose  that  a 


Fig.  1 184. 

given  lower  block  will  answer  for  any  lower  case  if  only  long  enough. 
Side  views  show  also  a  difference  in  the  slant  of  the  teeth,  inward  or 
outward,  which  has  an  important  effect  in  modifying  the  expression  of 
the  lower  arch.  There  are  also  differences  in  curvature  of  the  lower 
arch  as  well  as  of  the  upper.  Fig.  11 77  shows  the  usual  upper  and 
lower  curves,  and  Figs.  1182  and  1190  show  variations  of  upper  curva- 
ture requiring  some  modifications  of  the  lower,    dependent   on   the 


Fig.  1185. 


character  of  the  articulation.  In  Fig.  1 185  are  four  other  forms  of  lower 
front  blocks,  the  value  of  which  will  be  at  once  recognized.  The  two 
right-hand  sets  differ  from  those  of  Fig.  11 84  mainly  in  the  length  and 
width  of  teeth.  The  left  lovver  set  is  well  suited  to  patients  whose 
natural  teeth,  for  many  years  before  their  loss,  w^ere  marked  by  exposure 
of  the  neck  ;  this  appearance  may  also  be  increased  (sometimes  it  may 


1104 


MECHANICS — DENTAL    PROSTHESIS. 


be  made)  by  judicious  use  of  the  corundum  wheel,  but  the  block  here 
given  is  invaluable  in  such  cases.  The  left  upper  block  is  an  admira- 
ble imitation  of  a  very  usual  arrangement  of  incisors,  resulting  from 
crowded  dentition ;  the  drawing  gives  a  very  imperfect  idea  of  the 
great  beauty  of  the  original  porcelain  block.  When  the  facial  expres- 
sion indicates  its  use,  it  will  have  great  effect  in  disarming  suspicion  of 
artificiality — a  very  desirable  quality  in  artificial  dentures. 

In  Fig.  1 1 86  we  have  very  convenient  modifications  to  suit   front 


spaces  of  two  or  four  teeth,  the  set  of  four  being  in  two  blocks.  The 
peculiarity  of  these  blocks  is  the  lateral  finish  of  the  gum  ;  instead  ot 
a  square  joint,  for  fitting  to  an  adjoining  block,  they  have  a  rounded 
edge  of  gum  color  that  can  be  adapted  to  the  curves  of  the  absorbed 
natural  gum.  There  should  also  be  blocks  of  two,  a  lateral  and  cen- 
tral, with  gum  shaped  like  the  double  central,  as  such  spaces  are  of 
frequent  occurrence.     Besides  the  four  forms  of  teeth  here  given  there 


Fig.  1 187. 


are  many  other  varieties  in  size  and  shape  of  this  very  useful  kind  of 
block. 

Figs.  1 187,  1 188,  and  1189  represent  a  fevv  of  the  great  variety  of 
forms  of  upper  incisors  and  canines  designed  to  meet  the  demands  of 
an  esthetic  discrimination.  In  Fig.  1187  we  have,  first,  a  long,  deli- 
cate lateral,  with  sloping  but  not  rounded  edge,  showing  a  decided 
space  between  it  and  the  cuspid  and  central ;  then  we  find  it  wider, 
with  cornersand  edge  rounded  and  filling  the  space.  Lastly,  for  want 
of  space,  the  laterals,  although  long  and  narrow;  overlap  the  centrals; 


PORCELAIN    TEETH. 


1105 


this  style  is  generally  accompanied  with  a  pointed  arch.  The  fourth 
block,  although  with  an  overlapping  incisor,  has  an  entirely  different 
character ;  it  is  often  found  in  a  rather  flattened  arch  and  does  not 
indicate  a  crowded  denture.  In  these  blocks  the  inclination  and 
shape  of  the  canine  as  well  as  the  shape  of  the  incisor  help  to  give  to 
each  block  a  distinctness  of  character  which  will  not  permit  the  use 
of  one  in  a  case  demanding  either  of  the  others. 

The  celare  artem  effect  of  overlapping  or  twisting  laterals,  like  that 
of  irregular  lower  incisors,  is  such  as  to  tempt  one  to  use  them  when- 
ever admissible.  In  Fig.  iiSSwe  have  some  additional  varieties  of 
this  kind  of  block.  In  all  these  six  cases  we  find  differences  in  the 
size  and  character  of  the  lateral,  in  the  extent  of  its  lapping,  and  in 
the  degree  of  twist  given  to  it.  A  careful  study  of  the  natural  teeth 
will  teach  the  dentist  what  character  of  face  is  best  suited  to  each  of 


these  different  forms,  and  thus  he  will  much  increase  the  extent  to 
which  he  may  properly  use  this  kind  of  irregularity. 

In  Fig.  1 189  the  blocks  vary  little  in  size,  yet  they  each  have  a  dis- 
tinctive character.  In  the  first  we  have  lateral  rounded  on  both  cor- 
ners and  its  axis  vertical ;  canine,  with  pointed  cusps  and  edges  quite 
rounded.  In  the  second  we  have  lateral  inclined,  with  median  corner 
pointed,  lateral  corner  quite  round ;  canine  with  blunt  cusp,  also  axis 
inclined.  In  the  third,  surface  of  the  canine  is  decidedly  furrowed, 
which,  with  the  indented  edge,  gives  it  a  marked  character  ;  the  lateral 
and  central,  unlike  the  previous  blocks,  have  square-cut  edges  with 
corners  but  slightly  rounded.  In  the  fourth,  the  lateral  is  more  nearly 
equal  to  the  central,  and  none  of  the  teeth  may  have  any  marked 
peculiarities;  this  style  of  block,  in  its  different  sizes,  suits  well  in 
many  cases,  and  is  perhaps  one  of  the  best  for  general  use  by  those 
practitioners  who  pay  no  regard,  in  their  selection  of  teeth,  to  the  in- 
dications given  by  the  physical  characteristics  of  the  face  and  head. 
70 


iio6 


MECHANICS — DENTAL    PROSTHESIS. 


The  fifth  block  is  one  of  that  class  often  met  with  in  old  age,  where, 
by  the  action  of  the  lower  teeth  or  other  causes,  the  arch  has  spread, 
widening  the  interdental  spaces.  The  interdental  gum  is  also  much 
shorter  than  in  youth,  as  is  finely  shown  in  the  original  from  which 
this  cut  is  taken. 

In  the  selection  of  porcelain  blocks  not  only  must  the  color,  size, 
and  form  of  the  teeth  be  carefully  considered,  but  reference  must 
also  be  had  to  the  curv'ature  of  the  arch.  For  although  moderate 
variations  in  curvature  can  be  fitted  by  the  same  set  of  blocks,  the 
true  expression  of  a  porcelain  denture  is  often  lost  by  the  attempt  to 
adapt  it  to  a  curve  for  which  it  was  not  designed.  In  Figs.  1177,  11 82, 
and  1 1 90  we  have  various  curves  of  the  alveolar  arch,  with  corre- 
sponding variations  in  shape  of  the  blocks.  Sometimes  the  canines 
are  made  separate  with  a  view  to  increase  the  range  of  application  of 


Fig.  1 189. 


a  given  set;  but  a  joint  on  either  side  is  very  apt  to  injure  the  effect 
of  this  important  tooth.  In  the  lower  jaw  it  is  of  less  consequence 
because  the  gum  is  less  often  exposed,  and  it  is  frequently  desirable 
to  make  the  four  incisors  in  one  block.  But  in  the  upper  jaw  it 
is  much  better  to  have  a  median  joint  and  another  behind  the 
canines. 

In  Fig.  1 190  the  reader  will  notice  that  the  centrals  of  the  first  set 
overlap  the  laterals,  an  arrangement  of  frequent  occurrence  in  pronai- 
nent  and  sharply  curved  arches.  It  will  be  observed  that  in  Fig.  1180 
the  blocks  are  so  shaped  that  the  right  or  left  central  overlaps  its 
fellow.  Thus  we  have  three  varieties  of  overlapping  upper  teeth — 
laterals  over  centrals,  centrals  over  laterals,  central  over  central — 
each  of  which  may  be  used  with  great  effect  if  applied  with  discrimi- 


PORCELAIN    TEETH. 


II07 


nation.  In  the  third  set  of  Fig.  1190,  and  in  a  few  of  the  pre- 
ceding cuts,  the  gum  over  the  cuspids  is  very  strongly  marked. 
This  is  a  very  characteristic  feature  of  some  mouths,  and  when 
correctly  used  gives  a  fine  effect ;  but  it  would  sadly  belie  the  expres- 
sion  in   a   timid   and   gentle   lady's  face.     Yet  such  incongruity  is 


Fig.  1190. 


only  one  of  hundreds  constantly  occurring,  where  every  sense  of 
esthetic  beauty  and  harmony  is  violated — teeth  of  a  Russian  in 
the  mouth  of  a  Frenchmen,  those  of  a  New  Englander  given  to  a 
South  Carolinian,  or  those  of  a  Canadian  to  a  Cuban,  the  lips  of  age 
disclosing    the   teeth   of  youth,    and  no   distinction   made   between 


cio8 


MECHANICS — DENTAL    PROSTHESIS. 


a  male  and  female  denture.  These  esthetic  blund-ers  are  not  confined 
to  the  inexperienced  tyro,  but  are  perpetrated  by  many  who  presume 
to  call  themselves  skillful  mechanicians.     When  we  consider  the  exten- 


FlG.  1191. 


sive  assortment  of  porcelain  teeth  which  ceramic  art  has  placed  at  the 
disposal  of  the  practitioner,  such  malpractice  is  without  excuse. 

These  are  only  a  few  out  of  the  great  number  of  varieties,  in  size, 
form,  and  arrangement,  of  porcelain  teeth;  they  give  to  the  dentist 


Fig.  1 192. 


Fig.  1 193. 


a  much  wider  range  of  selection  than  some  have  the  ability  or  inclina- 
tion to  avail  themselves  of.  When  to  variety  of  shape  we  add  shades 
of  color,  the  number  of  sets  that  admit  of  being  made,  distinguishable 
at  a  glance  from  each  other,  seems  almost  infinite.     A  visit  to  a  first- 


PORCELAIN    TEETH. 


1 109 


class  porcelain-tooth  manufacturer's  rooms  will  convince  any  one  that 
incongruity  or  want  of  expression  in  a  set  of  teeth  is  the  fault  of  him 
who  selects  and  applies,  rather  than  of  him  who  designs  and  makes 
dental  porcelain. 

Fig.  1 191  represents  upper  and  lower  gum  sections  of  four,  three, 
and  two  teeth,  one  of  the  upper  sections  having  partial  gums. 

Fig.  1 192  represents  an  irregular  gum  section  with  the  lateral  out  of 
line. 


Fig.  1 195. 


Fig,  1196. 

Fig.  1 193  represents  a  gum  section  with  an  extra  long  central  incisor. 

Fig.  1 194  represents  a  thin  gum  section. 

Fig.  1 1 95  represents  gum  sections  for  protruding  upper  and  lower  jaws. 

Fig.  1 196  represents  a  shouldered  gum  section. 

Fig.  1 197  represents  a  festooned  gum  section. 


mo  MECHANICS — DENTAL    PROSTHESIS. 

Fig.  1 1 98  represents  a  gum  section  for  a  V-shaped  protruding  upper 
jaw ;  the  position  of  the  lower  teeth  is  shown  by  the  dotted  lines. 

It  will  be  perceived  that  the  foregoing  illustrations*  of  the  esthetic 
principles  of  the  dento-ceraraic  art  are  taken  from  one  class  of  teeth, 
those  for  vulcanite  or  metallo-plastic  work.     We  have  done  so  because 

the  art  has  here  had  its 
fullest  recent  development 
in  consequence  of  the 
great  demand  for  this  form 
of  block.  But  dental  es- 
thetics is  quite  independ- 
ent of  the  material  of  the 
plate,  so  long  as  that 
which  is  visible  in  the 
mouth  is  porcelain ;  and 
dentures  which  show  any 
substitute  for  the  gum  other 
than  this,  however  useful 
they  may  be,  cannot  rank 
as  specimens  of  highest  art 
until  some  material  for  the 
plate  shall  be  discovered 
possessing  higher  claims  to 
beauty  than  any  yet  known. 
The  foregoing  rules  will 
apply  to  the  form  and  size  of  plate  teeth  when  these  are  set  directly 
upon  the  natural  gum  ;  but,  except  in  case  of  true  pivot  or  plate-pivot 
teeth,  it  is  impossible  to  reproduce  the  precise  natural  arching  of  the 
gnm  above  the  tooth  without  some  gum-colored  porcelain.  We  must 
often  be  content  in  such  cases  with  the  nearest  possible  approach  to 
nature.  But  when  the  plate  is  seen  on  the  outside  of  the  arch,  the 
artist's  reputation  is  dependent  upon  the  concealment  of  the  greater 
part  of  his  work  ;  even  here,  however,  the  cutting  edge  and  two-thirds 
of  the  tooth  permit  t-he  display  of  great  varieties  of  expression.     Of 


Fig.  ir 


*We  are  indebted  to  the  kindness  of  the  late  Dr.  Samuel  S.  White,  and  more  re- 
cently of  the  S.  S.  White  Dental  Manufacturing  Company,  of  Philadelphia,  for  the 
admirable  illustrations  by  the  aid  of  which  we  have  been  enabled  to  express  our 
views  upon  the  important  subject  of  Dental  Esthetics.  No  illustrations,  however, 
can  convey  a  true  idea  of  the  high  artistic  excellence  of  those  forms  the  production 
of  which  has  placed  Dr.  White  among  the  greatest  benefactors  of  Dental  Art.  We 
take  this  occasion  to  acknowledge,  also,  the  liberality  and  courtesy  with  which  our 
inquiries  for  information  on  the  manufacture  of  dental  porcelain  were  responded  to 
by  this  gentleman. 


PORCELAIN   TEETH.  II 1 1 

plain  teeth  without  gum  there  are  four  kinds,  i.  Pivot  teeth  ;  shaped 
somewhat  hke  the  crowns  of  the  upper  incisors  and  canines,  with  a 
hole  in  the  base  for  insertion  of  a  wooden  or  metallic  pivot.  2.  Plate 
teeth  ;  the  oldest  known  form  of  porcelain  teeth  having  pins  for  at- 
tachment of  a  back  by  which  to  secure  it  to  the  plate.  3.  Continuous- 
gum  teeth  ;  resembling  natural  teeth  in  having  a  root,  which  is  more 
or  less  serrated,  for  better  retention  in  the  investing  porcelain  base  ; 
they  are  sometimes  made  without  platina  pins  ;  but  they  are  better  with 
])ins,  so  that  they  may  be  securely  fastened  to  the  platina  plate.  4. 
Plain  vulcanite  (Fig.  1206);  having  a  small  neck,  by  which  they  are 
held  in  the  vulcanite  or  other  material  in  which  they  are  set.  These 
teeth  may  be  set  directly  on  the  gum  by  grinding  off  the  neck ;  they 
may  also  be  used  adjacent  to  natural  teeth  with  exposed  neck,  by  slight 
alterations  of  this  neck,  so  as  to  give  to  the  artificial  tooth  the  same 
appearance  as  the  natural  one. 

There  are  also  other  forms  of  gum  teeth  besides  those  above  repre- 
sented. Formerly,  single  gum  teeth  were  extensively  used  on  gold 
plate,  and  may  still  be  occasionally  required  when  the  supremacy  of 
that  old-fashioned  material  becomes  once  more  recognized  in  the 
laboratory.  The  great  facility  of  adapting  blocks  or  sections  in  vul- 
canite work  or  in  vulcanite  attachment  to  swaged  plates  has  led  to  the 
almost  entire  exclusion  of  this  form  of  tooth  except  for  repairing. 
A  serious  objection  to  single  gum  teeth  is  the  number  of  joints;  these 
greatly  mar  the  artistic  effect  which  it  is  the  design  of  the  artificial 
gum  to  produce,  especially  when  not  kept  perfectly  clean  or  when  the 
material  of  plastic  plates  is  allowed  to  enter  the  joints.  Figs.  11 76 
and  1 199  are  designed  to  show  the  importance  of  correct  and  accurate 
grinding  in  order  to  display  the  true  character  of  a  set  of  teeth. 
When  properly  done,  the  joint  does  not  interrupt  the  continuous  sur- 
face of  the  gum  more  than  the  lines  in  the  two  lower  sets  of  Fig.  1 199, 
nor  should  it  in  any  case  be  more  visible  than  the  heavier  lines  of  the 
first  set.  Neither  should  the  set  be  so  inaptly  chosen  as  to  require 
such  grinding  of  joints  and  base  as  to  injure  its  original  expression. 
Figs.  1 1  76  and  1199  should  also  be  carefully  studied  by  the  student 
on  account  of  the  varieties  of  form  and  relation  of  teeth  presented, 
each  of  the  four  upper  sets  here  displayed  having  a  very  distinctly 
marked  character. 

Porcelain  blocks  which  are  to  be  attached  to  a  gold  plate  by  solder- 
ing do  not  differ  in  external  appearance  from  the  forms  already  illus- 
trated ;  but  the  shape  of  inner  surface  and  the  form  of  the  pins  are 
different.  Fig.  1200  represents  such  a  set  of  upper  blocks  in  three 
sections.  If  made  in  four  sections,  the  set  should  be  divided  between 
the  centrals  and  between  the  bicuspids ;  it  may  also  be  in  five  sections, 


TII2  MECHANICS DENTAL    PROSTHESIS. 

the  four  joints  being  in  front  of  the  cuspids  and  behind  the  bicuspids  ; 
or  it  maybe  divided  into  six  sections,  as  in  Fig.  1176.  The  line 
above  the  pins  in  Fig.  1200  marks  the  division  between  the  inner 
slope  of  gum  next  the  teeth  and  the  plain  surfaces  holding  the  pins  ; 
this  surface  should  be  as  smooth  as  possible  for  the  perfect  adaptation 
of  the  gold  backing.  Blocks  may  also  be  made  in  sets  of  three  or 
five  sections,  with  the  inner  surface  finished  in  gum  enamel  to  the 
plate  ;  in  this  case  the  block  is  held  to  the  plate  by  pins  passing  into 
holes  made  in  its  base,  one  opposite  each  tooth.  The  best  material 
for  retaining  the  pins  is  undoubtedly  vulcanite,  as  described  in  the 
previous  chapter;  the  holes  should  be  rough,  for  its  better  adhesion. 

Fig.    1201    represents   the    "Countersunk  Tooth  Crowns,"  which 
allow  of  great  facility  of  adaptation  to  the  maxillary  ridge  and  (it  is 


Fig.  1 199. 


claimed)  afford  the  strongest  denture  on  a  plastic  base.  To  insur<' 
the  best  results  some  precaution  is  necessary  ii>  mcuntirjg  the'r., 
whether  on  rubber,  celluloid,  or  metal. 

For  a  vulcanite  base  the  case  should  be  flasked  as  usual,  but  each 
countersink  should  be  carefully  filled  with  small  pieces  of  rubber  ; 
otherwise  the  flat  rubber  sheet  will  cover  the  mouths  of  the  counter- 
sinks and  so  shut  in  the  air  as  to  prevent  the  rubber  from  reaching 
the  pins  and  filling  the  cavities. 

When  the  base  is  of  celluloid  the  countersinks  must  be  filled  in  like 
manner,  with  pieces  of  celluloid  moistened  with  spirits  of  camphor,  or 
preferably  with  a  solution  of  celluloid,  and  the  case  heated  to  softness 
before  closing  the  flask. 


PORCELAIN    TEEIH.  III3 

For  a  fusible  metal  base  the  hot  flask  should  be  jarred  during  the 
pouring  to  drive  the  air  out  of  the  countersink. 
Fig.  1202  represents  perforated  bicuspid  blocks. 
Fig.  1203  represents  rubber  bicuspid  blocks  with  pins. 
Porcelain,  teeth  are  now  manufactured  for  vulcanite  work  with  de- 


tachable pins  which  are  inserted  into  dovetailed  grooves  when  the 
case  is  being  packed. 

The  dental  depots  cannot  keep  on  hand  an  assortment  of  such 
blocks,  since  the  demand  is  too  limited  to  justify  the  expense  of  the 
brass  moulds.  But  in  all  our  principal  cities  there  will  be  found 
one  or  more  dental-block  carvers,  whose  experience  and  constant 
practice  enable  them  to  make  any  style  of  blocks  that  may  be  de- 


1 114 


MECHANICS DENTAL    PROSTHESIS. 


sired  for  special  cases.  We  have  elsewhere  given  our  reasons  for 
thinking  this  a  better  plan  than  for  the  dentist  himself  to  attempt 
occasional  ceramic  experiments.  Let  him  prepare  an  accurate  ar- 
ticulating model  and  adapt  a  tin-foil  plate  (to  avoid  the  risk  of  send- 
ing the  gold  one)  ;  then  select  one  or  more  teeth  to  guide  the  carver 
in  the  required  color  and  character  of  the  set.  If  any  peculiar  form 
or  deviation  from  the  normal  arrangement  is  desired,  this  should  be 
represented  in  wax  ;  then  pack  carefully  and  send  to  the  block  carver. 
This  plan  is  recommended  to  those  who  may  desire,  for  some  special 


case,  a  form  of  blocks  not  to  be  had  at  the  depots.  Necessarily  such 
blocks  are  much  more  expensive  than  those  made  by  the  quantity  in 
brass  moulds  ;  but  if  the  dentist  values  his  time,  the  blocks  would 
cost  still  more  if  made  by  himself. 

The  true  question  is,  however,  not  one  of  cost ;  if  the  depot  can 
furnish  the  form  of  blocks  which  the  case  requires,  it  is  best  to  get 
them  there,  otherwise  they  must  be  had  elsewhere  and  at  any  cost. 
Dental  tradesmen,  who  sell  their  wares  at  a  moderate  advance  on  the 


Fig.  1203. 


cost  of  production,  may  not  deem  it  prudent  to  deal  in  such  high- 
priced  materials ;  but  the  professional  dentist,  who  charges  for 
"services  rendered,"  will  never  find  it  necessary  to  hesitate  incur- 
ring any  expense  requisite  for  the  perfection  of  his  work.  The  actual 
cost  of  material  in  single  dentures  has  often  exceeded  thirty  dollars; 
yet  the  mechanician  who  exercises  a  skill  commensurate  wath  this 
cost  never  has  found,  and  never  will  find,  difficulty  in  adding  a 
just  compensation   for  his  time  and  skill.     As  a  rule,  patients  will 


SPECIAL   BLOCK    CARVING.  III5 

pay  best  for  art  when  exercised  on  expensive  material,  except  where, 
as  in  painting,  the  effect  produced  is  wholly  irrespective  of  the  cost 
of  the  means  employed.  The  true  basis  of  professional  fees  lies  in  that 
which  makes  one  man's  work  superior  to  another's ;  namely,  artistic 
skill  exercised  upon  materials,  the  quality  of  which  shall  not  detract 
from  its  just  appreciation. 

As  we  have  briefly  described  the  processes  of  manufacture  of 
porcelain  dentures  on  a  large  scale — a  work  which,  of  course,  no 
practicing  dentist  proposes  to  engage  in — it  is  proper  that  we  should 
also  give  a  brief  description  of  the  processes  by  which  blocks  are 
carved  for  special  cases,  although  we  regard  this  as  equally  out  of  the 
line  of  the  modern  dentist's  duties.  We  occasionally  find  a  genius 
whose  gift  shows  that  ceramic  art,  not  dentistry,  is  his  true  profession ; 
but  men  engaged  in  ordinary  dental  practice  must,  in  justice  to  their 
patients,  make  use  of  the  experience  of  professional  block  carvers, 
or  they  must  use  those  forms  offered  by  the  ceramic  manufacturer, 
which  are  the  results  of  the  highest  artistic  skill  which  money  can 
command. 

SPECIAL   BLOCK   CARVING. 

To  make  a  porcelain  dental  arch  in  three  sections  for  a  full  upper 
case  antagonizing  with  natural  teeth  below,  make  a  plaster  articu- 
lator, as  described  in  the  tenth  chapter,  but  having  greater  thickness 
to  permit  guiding  holes  or  grooves,  as  in  Fig.  1204.  Open  the  articu- 
lator, increasing  the  space  one-fifth  (unless  this  one-fifth  enlargement 
is  to  be  made  by  addition  of  point  enamel) ;  place  on  the  plate  a  wax 
rim,  and  trim  it  to  antagonize  with  the  lower  teeth,  giving  the  precise 
external  fullness  required  in  the  blocks.  Mark  on  wax  and  front  edge 
of  articulator  the  medial  line  and  the  lines  of  proposed  division  of 
blocks ;  that  is,  between  bicuspids  for  a  four-block  piece  and  behind 
cuspids  for  a  piece  of  three  blocks;  in  either  case  the  work  is 
carved  in  three  pieces.  It  is  also  well  to  mark,  in  fainter  lines,  the 
width  of  each  tooth  as  determined  by  the  size  of  the  lower  teeth ;  this 
will  be  some  guide  in  the  subsequent  enlargement  required  on 
account  of  shrinkage  of  the  porcelain  paste.  Next  make  a  plaster 
rim  about  half  an  inch  thick  (Fig.  1027,  on  page  921,  shows  the 
height  and  thickness),  covering  the  exterior  surface  of  model  and  wax, 
making  first  the  front  section,  extending  a  half  tooth  space  behind 
the  lines  marked  for  the  block  joints  ;  then  remove  this  and  make  the 
two  side  sections,  extending  each  a  half  tooth  space  in  front  of  these 
lines.  The  use  of  a  leaden  band  and  some  paper  pulp  will  expedite 
the  making  of  these  plaster  sections;  they  should  be  trimmed  to  the 
exact  length  required  for  the  crude  blocks.  Of  course,  neither  in 
plaster  nor  porcelain  can  the  front  and  side  sections  be  applied  to  the 


iii6 


MECHANICS — DENTAL   PROSTHESIS. 


model  or  plate  at  the  same  time,  in  consequence  of  the  one-fifth  allow- 
ance for  thickness. 

On  removing  the  wax,  each  plaster  section  is  a  matrix  to  determine 
the  external  fullness  of  the  corresponding  block,  on  which  is  to  be 
carved  the  shape  of  teeth  and  gum.  The  plate  gives  exact  form  to  the 
base  of  the  block  ;  but  when  finished  it  will  require  grinding,  because 
of  the  derangement  of  fit  caused  by  shrinkage.  The  thickness  and 
interior  form  of  the  sections  is  determined  by  the  eye,  and  will  vary 
with  the  style  of  finish  or  mode  of  attachment,  being  careful,  in  this 
direction  also,  to  make  the  one-fifth  allowance  for  shrinkage.  The 
front  block  is  first  made  and  removed,  then  each  side  block  separately; 


Fig.  1204. 


Fig.  1205. 


in  a  double  set,  both  front  blocks  are  made,  then  both  right  sections 
together  and  left  sections  together,  so  as  to  obtain  their  proper 
antagonism  ;  also,  in  double  sets,  the  separation  of  the  articulation  must 
be  sufficient  to  allow  the  one-fifth  enlargement  in  each  set. 

The  porcelain  body  is  prepared  as  already  explained  ;  it  can  be  com- 
pounded by  the  dentist  or  purchased  from  the  manufacturer.  In  mix- 
ing the  small  quantities  required  for  single  cases,  two  points  demand 
special  care — purity  of  the  water  and  absolute  exclusion  of  air  from  the 
mass.  It  must  also  be  remembered  that  irregular  contraction,  or  warp- 
ing of  blocks  in  firing,  is  often  caused  by  unequal  compression  in  pack- 


SPECIAL    BLOCK   CARVING.  III7 

ing  the  body  into  the  molds  and  by  unequal  absorption  of  its  mois- 
ture by  the  porous  plaster  rim  or  other  means  used  to  dry  it.  Again, 
it  should  be  remembered  that  in  removing  the  rim,  in  carving,  and  in 
all  other  operations  on  the  crude  paste  the  excess  of  feldspar  gives  it  a 
tenderness  very  different  from  the  tough  plasticity  of  a  kaolin  mass. 
The  putty-like  body  is  to  be  carefully  worked  into  the  well-oiled  mold, 
compressed  with  the  fingers,  trimmed  into  outline  shape,  and  then 
removed,  first  marking  upon  it  the  lines  of  the  articulator  to  guide  in 
the  carving.  The  block  may  be  partly  or  entirely  carved  while  on  the 
articulator ;  but  the  delicate  movements  of  the  very  delicately-shaped 
carving  tools  are,  in  the  opinion  of  some,  best  exercised  upon  the  free 
block. 

For  carving  no  directions  can  be  given  beyond  what  has  heretofore 
been  said  on  the  necessity  of  a  close  observance  and  exact  copying  of 
nature.  The  artist  requires  no  written  directions,  and  paper  instruc- 
tions never  yet  made  an  artist  out  of  a  bungler  ;  in  fact,  the  heaven- 
born  genius  of  art  cannot  be  created  by  teaching,  however  it  may  be 
trained  and  directed.  Many  have  wasted  years  in  porcelain  block 
carving  only  to  produce  results  surpassed  by  the  least  artistic  forms 
offered  in  the  depots ;  while,  on  the  other  hand,  some  dental  Palissy 
will  work  out  a  marvel  of  beauty  that  no  purchased  blocks  can  equal. 
But  before  one  imagines  himself  a  Bernard  Palissy  let  him  read  the  his- 
tory of  that  wonderful  struggle  of  genius,  then  ask  how  far  the  routine 
duties  of  a  dental  office  will  permit  an  exclusiveness  of  devotion  which 
ceramic  art  rigorously  exacts  as  a  condition  of  success. 

When  carved,  the  blocks  are  thoroughly  dried,  then  placed  on 
coarse  silex  upon  a  fire-clay  slab,  and  set  into  the  muffle  of  the  furnace 
(Fig.  1205).  Here  they  are  biscuited  (or  cruced),  that  is,  raised  to  a 
red  heat  sufficient  to  give  some  hardness,  but  not  to  vitrify  or  even  to 
cause  incipient  fusion.  They  are  then  slowly  cooled  and  holes  drilled 
for  the  pins,  or  else  holes  drilled  into  the  base  of  the  blocks,  as  may  be 
preferred  ;  the  pins  are  fastened  in  place  by  a  little  "  body-slip,"  care- 
fully worked  in  with  the  knife  point.  Slight  defects  of  carving  may 
now  be  corrected ;  the  enamels  are  then  applied  with  a  camel's-hair 
brush.  They  must  be  reduced  to  the  consistence  of  cream,  and  require 
much  skill  and  judgment  in  their  application,  so  that  the  point  enamel 
shall  blend  properly  with  the  body  enamel ;  also  the  gum  enamel  must 
preserve  its  distinctness  of  outline  and,  by  its  varying  thickness,  give 
those  alternations  of  shade  observable  in  the  natural  gum.  It  should 
here  be  remarked  that  some  carvers  make  no  allowance  in  the  body  for 
shrinkage  in  length  of  the  tooth,  but  compensate  by  the  addition  of 
point  enamel.  The  crowns  of  bicuspids  and  molars  are  usually 
enameled ;  also  part  of  the  inner  surface  of  the  blocks,  and  in  some 


IIl8  MECHANICS — DENTAL    PROSTHESIS. 

blocks  the  gum  enamel  extends  to  the  base.  When  platina  pins  are 
inserted,  the  part  of  the  block  to  be  covered  by  the  backing  is  not 
enameled.  It  is  scarcely  necessary  to  remark  that  a  large  assortment 
of  body,  point,  and  gum  enamels  is  required  ;  also  that  these  must,  with 
great  care,  be  kept  separate,  with  their  respective  test  pieces  attached, 
for  except  by  the  pinkish  color  of  gum  enamel  they  cannot  be  distin- 
guished when  in  form  of  powder,  paste,  or  cre?im. 

The  blocks  are  now  well  dried  and  are  ready  for  the  furnace,  Fig. 
1205.  (For  other  forms  of  furnaces  see  article  on  "  Continuous  Arti- 
ficial Gum.")  Success  thus  far  is  dependent  upon:  i.  Thorough 
mixing  of  the  body  and  its  careful  packing;  2.  Skillful  carving,  so 
as  not  only  to  give  the  required  expression,  but  also  to  know  what 
allowances  to  make  at  each  point  for  shrinkage  and  for  the  subse- 
quent application  of  the  enamels  ;  3.  Selection  of  enamels  and  their 
skillful  blending  and  shaping;  4.  The  giving  of  such  form,  in  ad- 
justment of  the  relative  length  and  thickness  of  each  block  and 
apportionment  of  material,  as  shall  prevent  warping  in  the  furnace. 
These  points,  however,  may  have  been  perfectly  attended  to  ;  yet  all 
will  have  been  done  in  vain,  unless  the  operator  has  a  thorough  prac- 
tical knowledge  of  the  management  of  the  furnace.  It  is  this  which 
makes  the  ceramic  experiments  of  the  practicing  dentist  so  often  a 
failure  ;  for  fail  he  certainly  will  unless  he  knows  the  exact  heat  at 
which  the  differing  fusibilities  of  his  body  and  various  enamels  will, 
by  their  combined  effect,  develop  the  properties  aimed  at  in  their 
combination.  Some  are  governed  in  this  by  test  pieces  ;  the  experi- 
enced workman,  guided  by  constant  practice  in  a  way  that  he  can- 
not explain,  prefers  the  indications  offered  by  looking  at  the  piece 
itself.  If  not  sufficiently  baked,  the  body  will  be  porous;  also, 
neither  this  nor  the  enamels  will  have  their  true  life-like  character. 
If  overdone,  there  is  an  offensive,  glassy,  and  transparent  condition, 
equally  fatal  to  the  natural  appearance;  also,  there  is  too  much  shrink- 
age and  greater  danger  of  warping.  Both  errors  impair  the  full 
strength  of  the  porcelain,  in  which  the  ingredients  are  so  combined 
as  to  develop  greatest  strength  at  a  certain  temperature. 

Furnace  temperature  is  measured  by  instruments  called  Pyrometers. 
The  limit  of  mercurial  registration  of  temjjerature  is  600°  Fahrenheit. 
Daniell's  pyrometer  registers  by  the  expansion  of  a  platina  rod  in  a 
plumbago  case  and  is  the  most  accurate.  Wedgwood's  pyrometer 
registers  by  the  rate  of  permanent  contraction  of  kaolin  under  intense 
heat.  A  clay  wedge  fitting  the  upper  part  of  a  tapering  groove  will, 
after  exposure  to  furnace  heat,  slip  further  into  the  groove;  supposing 
the  rate  of  contraction  uniform,  this  distance  will  be  a  measure  of  the 
heat  after  establishing  its  exact  relation  to  the  600"  point  of  Fahren- 


SPECIAL    BLOCK    CARVING.  II  I9 

heit.  But  the  contraction  of  any  two  pieces  is  not  the  same  unless 
their  composition  is  identical ;  also,  the  relation  to  the  mercurial 
scale  is  not  easy  to  determine.  Wedgwood's  zero  was  1076°  Fahren- 
heit, and  he  estimated  one  degree  of  his  pyrometer  equal  to  130°;  on 
which  basis  of  calculation  the  highest  heat  of  the  porcelain  furnace 
(130°  to  160°  Wedgwood)  would  range  from  19,000°  to  22,000°  Fah- 
renheit. Others  estimate  his  degree  at  62.5°  Fahrenheit,  reducing 
the  registration  from  9500°  to  11,000°  Fahrenheit.  Taking  the  fusion 
point  of  gold  at  2000°,  and  of  pure  iron  at  3000°,  we  thus  have  some 
idea  of  the  infusibility  of  platinum  and  the  extreme  heat  of  ceramic 
furnaces.  But  it  is  evident  that  the  correct  regulation  of  this  heat  must 
be  the  result  of  experience  rather  than  of  written  direction  ;  also,  that 
the  furnace  practice  of  different  persons  cannot  be  accurately  com- 
pared. 

The  muffle  protects  against  the  gases  of  the  fire.  Charcoal,  coke, 
or  anthracite  are  used  as  fuels,  according  to  the  location  of  the 
operator ;  the  last  is  preferable  when  it  can  be  procured,  because  it 
gives  the  steadiest  heat ;  charcoal  requires  practice  to  maintain  a 
uniform  heat  ;  coke  is  used  in  all  the  bituminous'coal  regions.  With 
either  of  these,  after  sufficient  experience,  a  furnace  may  be  kept 
regularly  at  the  required  heat  for  a  length  of  time  sufficient  to  fire  the 
porcelain  blocks.  They  must  be  thoroughly  dried  on  the  furnace- 
shelf  before  going  into  the  muffle ;  the  mouth  of  the  muffle  should  be 
well  luted,  and  the  stopper  withdrawn  only  to  examine  the  work. 
The  more  slowly  blocks  are  cooled,  the  more  perfectly  are  they  an- 
nealed, and  hence  less  liable  to  crack  from  sudden  changes  of  tem- 
perature, as  in  soldering. 

Not  to  interrupt  the  order  of  operations,  we  have  deferred  the 
description  of  a  very  ingenious  method  of  carving  devised  by  Dr. 
William  Calvert.  Instead  of  the  wax  rim  before  mentioned  Dr. 
Calvert  provided  an  assortment  of  teeth  having  all  the  varieties  of 
form  and  size  required  in  practice,  but  one-fifth  larger  than  the  given 
case.  These  are  arranged  in  a  wax  gum  and  the  plaster  mold  then 
taken.  Thus,  in  Fig.  1206,  teeth  of  the  first  size  set  in  wax  will  give, 
when  diminished  by  the  furnace,  teeth  of  the  second  size  ;  so  in  Fig. 
1184,  each  of  the  two  lower  sizes  in  wax  will  give  in  the  finished 
block  the  size  above  it.  Dr.  Calvert's  method  has  three  recommenda- 
tions :  I.  Like  continuous-gum  work,  it  limits  the  necessity  of 
esthetic  skill  (which  so  few  possess  in  high  degree)  to  the  shaping  of 
the  gum,  the  judicious  selection  of  teeth,  and  their  proper  arrange- 
ment, leaving  the  details  of  form  to  the  genius  of  the  manufacturer's 
artist.  2.  It  permits  the  application  of  enamels,  or  rather  the  addi- 
tion of  body  to  enamels,  without  the  necessity  of  crucing,  which  some 


ri20 


MECHANICS — DENTAL    PROSTHESIS. 


regard  as  injurious  to  the  tooth.  3.  By  selecting  a  variety  of  stylea 
of  model  teeth,  and  by  varying  the  relative  adjustment  of  them  in  the 
wax,  that  tendency  to  uniformity  of  style  is  obviated  which  charac- 
terizes almost  every  block-carver's  work. 

Dr.  Calvert's  process  differs  mainly  from  the  foregoing  in  the  fol- 
lowing details  :  For  a  four-block  piece  the  teeth  are  set  in  wax  shaped 
in  exact  imitation  of  the  natural  gum,  omitting  the  second  bicuspid, 
in  place  of  which  a  half-tooth  space  is  left  between  first  bicuspid  and 
molar,  the  wax  gum  being  carried  around  continuously.  The  plaster 
mold  of  the  eight  front  teeth  is  then  taken,  a  thin  septum  of  foil  being 
placed  opposite  the  mesial  line,  so  that  it  may  be  easily  broken  there 
in  the  act  of  removal,  the  plaster  coming  slightly  over  the  inside  so  as 
to  give  with  certainty  the  shape  of  the  cutting  edges.  Upon  removing 
the  front  mold,  and  before  making  the  lateral  molds,  where  as  yet  the 
wax  holds  only  two  molars,  it  is  necessary  to  detach  the  bicuspid  of  the 
front  block  and  put  it  adjacent  to  the  molar  ;  this  gives  the  arch  its  full 
complement  of  bicuspids.     This  must  be  done  very  neatly,  so  as  not 


Fig.  1206. 


to  disturb  the  continuity  of  the  wax  gum,  otherwise  the  effect  of  the 
porcelain  blocks  at  their  joints  will  be  injured.  Dr.  Calvert  prefers 
using  cuspids  for  insertion  in  the  wax  instead  of  bicuspids,  since  their 
external  expression  is  similar  and  their  form  more  convenient,  espe- 
cially in  the  change  just  described.  By  similarity  of  form  we  do  not 
mean  that  in  any  mouth  the  canines  and  bicuspids  are  alike  externally ; 
but  out  of  a  collection  of  canines,  after  choosing  the  cuspids  them- 
selves, others  may  be  selected  harmonizing  with  them  as  first  and  as 
second  bicuspids.  Besides  overlapping  the  blocks  at  the  bicuspids,  to 
compensate  shrinkage,  a  slight  extension  of  each  block  beyond  the 
last  tooth  should  be  made  to  allow  for  accurate  grinding.  If  holes  are 
made  in  the  base,  instead  of  platina  pins  in  the  back,  it  will  be  best  to 
make  a  continuous  front  block  of  six  teeth,  in  which  case  the  half- 
tooth  space  above  named  comes  behind  the  cuspid. 

Since  the  carved  wax  of  the  contained  teeth  makes  carving  of  the 
porcelain  paste  unnecessary,  the  plaster  molds  are  varnished,  oiled, 
and  treated  as  are  the  brass  molds  in.  wholesale  manufacture.    The  stiff 


ENTIRE    PORCELAIN    PLATES.  1 1  21 

paste  of  point  euamel  is  placed  witli  a  delicate  spatula  into  each  tooth 
matrix,  thickest  at  the  point  and  disappearing  at  the  neck.  The  tooth 
enamel  paste  is  then  applied,  with  thickness  reversed;  gum  enamel 
might  also  be  added  in  the  same  way,  but  it  is  usually  applied  after- 
ward with  the  brush,  as  this  permits  delicacy  and  uniformity  of  coating 
or  easier  modification  of  its  thickness.  A  layer  of  soft  body  paste  is 
now  laid  over  the  enamels,  the  mold  is  placed  on  the  articulator,  and 
the  thickness  of  the  block  is  built  out  and  shaped  in  the  usual  way, 
compressing  it  firmly,  and  removing  the  surplus  moisture  with  bibu- 
lous paper  or  the  blowpipe  flame.  The  block  is  next  carefully  re- 
m(>\ed,  and  while  resting  in  its  matrix  the  platina  pins  are  inserted  or 
holes  drilled  in  the  base,  or  dovetails  cut,  as  may  be  preferred,  and  the 
whole  inner  surface  examined  and  trimmed.  If  the  inside  of  the  block 
is  lo  be  finished  in  gum,  the  enamel  should  now  be  applied  ;  then  re- 
move the  block  from  the  matrix  and  apply  the  outside  gum  enamel 
and  trim  between  the  teeth,  where  the  thin  edges  of  the  plaster  matrix 
are  apt  to  be  defective ;  the  block  is  then  ready  to  be  dried  and  placed 
in  the  furnace,  where  it  is  fired  at  a  single  heat  without  previous  bis- 
cuiting.     The  side  blocks  are  made  in  precisely  the  same  manner. 

ENTIRE     PORCELAIN    PLATES. 

In  addition  to  what  has  already  been  said  upon  this  subject,  it  is 
only  necessary  here  to  consider  some  of  the  preceding  properties  and 
manipulations  of  the  porcelain  material  in  its  use  as  a  plate  and  without 
any  metallic  support.  Neither  in  itself,  nor  by  known  combination 
with  any  substances,  can  a  thin  porcelain  plate  be  otherwise  than  frail. 
The  fusible  porcelain  of  the  "  continuous-gum  work  "  is  supported  by 
the  platina  plate  and  the  continuously  soldered  platina  backings.  Such 
porcelain,  without  metallic  support,  would  be  very  frail.  In  endeavor- 
ing to  give  strength  by  decreasing  the  flux  and  increasing  the  refractory 
ingredients,  we  are  at  once  met  by  the  difficulty  of  shrinkage.  Thus 
we  encounter  two  horns  of  a  dilemma — a  very  fusible  porcelain  with 
less  contraction  but  great  tenderness,  a  more  refractory  porcelain  with 
greater  strength  but  the  usual  one-fifth  contraction,  which  necessarily 
destroys  the  fit  of  the  plate  if  made  over  the  unchanged  model. 

Dr.  Allen  frankly  acknowledges  the  weakness  of  his  very  beauti- 
ful porcelain  by  giving  it  a  metallic  support.  The  dentist  knows 
just  what  he  is  using  here  (see  Continuous  Gum),  and  can  exercise 
his  judgment  upon  the  suitability  of  the  work  to  any  case  in  hand. 
The  few  dentists  who  make  entire  porcelain  plates  are  more  reserved 
in  communicating  their  knowledge.  Such  unprofessional  reserve  is 
damaging  to  dentistry  as  a  science ;  it  would  injure  it  also  as  an  art 
if  entire  porcelain  dentures  had  a  strength  equal  to  their  beauty.  It 
71 


1 1  22  MECHANICS  —  DENTAL    PROSTHESIS. 

is  claimed  by  some  makers  of  these  plates  that  their  formulas  give  a 
porcelain  which  is  very  strong,  yet  has  a  very  slight  shrinkage.  But 
until  such  formulas  are  made  known  to  the  profession  and  an  oppor- 
tunity given  to  test  them,  the  general  prejudice  against  the  entire 
porcelain  base  must  continue  to  be  well  founded.  To  those  desirous 
of  experimenting  in  this  direction  we  might  suggest  the  use  of  silicate 
of  magnesia  and  lime  (asbestos)  and  coarsely  pulverized  porcelain 
fragments,  as  perhaps  lessening  the  shrinkage  of  the  mass. 

By  some  the  ordinary  dental  porcelain  paste  is  used,  making  pro- 
vision for  shrinkage  by  enlargement  of  the  model.  One  method  of 
enlargement  is  as  follows :  With  a  fine  saw  divide  the  plaster  model 
by  a  cut  through  the  median  line  and  another  on  each  side ;  separate 
these  four  sections  one-eighth  inch  and  fill  the  joints  with  plaster, 
first  saturating  them  with  water ;  then  cut  the  model  twice  at  right 
angles  to  the  first  lines  and  fill  with  plaster  as  before.  If  the  back  of 
model  is  perfectly  level  and  the  work  is  very  carefully  done  we  shall 
have  a  tolerably  accurate  enlargement  of  about  one-fifth.  Make  a 
plaster  matrix  over  this,  and  into  it  pour  a  furnace  model  composed 
of  three  or  four  parts  asbestos  or  sand  to  one  of  plaster.  On  this 
mold  and  carve  and  bake  the  plate  and  teeth  ;  else  transfer  the  plate 
to  a  pile  of  coarse  silex  so  arranged  as  to  give  it  as  much  support  as 
possible  during  the  firing. 

Teeth  and  plate  are  sometimes  carved  out  of  the  same  mass  on  the 
enlarged  model ;  or  blocks  may  be  made  as  already  described,  then 
transferred  and  united  to  a  porcelain  plate  on  this  model.  Sometimes 
the  teeth  from  the  depots  are  arranged  in  the  porcelain  paste  and 
gum  enamel  applied  around  the  teeth  and  over  the  plate.  Unlike 
continuous-gum  work,  the  teeth  are  not  attached  to  any  unyielding 
plate ;  hence  they  are  liable  to  change  position  by  the  contraction  of 
the  plate  during  firing. 

We  cannot  more  appropriately  close  this  chapter  on  dental  porce- 
lain than  by  quoting  some  remarks  of  the  great  English  ceramic 
manufacturer,  Josiah  Wedgwood,  applicable  to  the  art  which  he  did 
so  much  to  elevate.  They  have  a  significance  beyond  ceramic  art, 
and  convey,  in  this  lesson  of  the  past,  a  warning  to  those  who 
mav,  perhaps  unconsciously,  be  dishonoring  the  profession  of  their 
choice. 

"  All  works  of  taste  must  bear  a  price  in  proportion  to  the  skill, 
taste,  time,  expense,  and  risk  attending  the  invention  and  manu- 
facture. Those  things  called  dear  are,  when  justly  estimated,  the 
cheapest;  they  are  attended  with  much  less  profit  to  the  artist  than 
tho.se  which  everybody  calls  cheap.     Beautiful  forms  and  composi- 


ESOPHAGOTOMY.  .  1 1 23 

tions  are  not  made  by  chance,  nor  can  they  ever,  in  any  material, 
be  made  at  small  expense.  A  competition  for  cheapness  and  not 
for  excellence  of  workmanship  is  the  most  frequent  and  certain 
cause  of  the  rapid  decay  and  entire  destruction  of  arts  and  manu- 
factures." 

ESOPHAGOTOMY. 

As  the  accident  of  swallowing  artificial  dentures  has  occurred 
more  or  less  frequently,  and  has  in  some  cases  resulted  in  death, 
the  following  case  will  describe  the  operation  of  removal  where  all 
efforts  of  a  more  simple  nature  failed  to  give  relief:* — 

"On  Sunday,  November  14,  1886,  George  K.  (white),  aged 
thirty-two  years,  while  at  dinner  had  the  misfortune  to  partially 
swallow  his  set  of  artificial  teeth,  consisting  of  a  rather  narrow 
vulcanite  plate  for  the  upper  jaw,  to  which  were  attached  three  in- 
cisors, one  lateral  incisor  having  been  lost  from  the  plate.  The 
denture  was  arrested  in  its  passage  downward,  producing  intense 
pain  and  partially  obstructing  respiration,  while  deglutition,  even 
of  liquids,  was  rendered  impossible.  A  physician  was  summoned, 
who  detected  the  plate  in  the  upper  portion  of  the  esophagus ;  but  all 
efforts  to  remove  it  or  force  it  into  the  stomach  were  futile.  Sufficient 
opium  to  relieve  the  pain  having  been  administered,  on  the  following 
day  (Monday)  he  was  brought  by  his  physician  to  the  infirmary  of 
the  University  of  Maryland  and  placed  under  the  care  of  Dr.  L.  Mc- 
Lane  Tiffany,  professor  of  surgery.  On  the  same  afternoon,  the 
patient  having  been  etherized,  careful  attempts  to  remove  the  plate 
were  made,  but  it  was  so  firmly  impacted  in  the  upper  portion  of  the 
esophagus  that  all  effort  for  its  removal  failed.  On  Tuesday,  in  the 
presence  of  the  medical  and  dental  classes,  the  patient  was  again 
etherized  and  efforts  made  to  remove  the  plate  through  the  mouth, 
but  without  success. 

"  The  patient  lying  on  his  back,  with  his  face  turned  to  the  right,  so 
as  to  render  the  tissues  of  the  left  side  of  the  neck  tense,  Prof.  Tiffany 
made  an  incision  about  four  inches  in  length  through  the  integument 
over  the  depression  between  the  trachea  and  the  sterno-mastoid  muscle. 
The  anterior  jugular  vein  was  cut  and  ligated,  and  the  incision 
extended  from  opposite  the  upper  border  of  the  thyroid  cartilage 
nearly  as  low  as  the  sterno-clavicular  articulation.  The  platysma 
myoides  muscle  and  the  cervical  fascia  were  then  divided.  The  edges 
of  the  wound  being  held  apart  by  retractors,  the  omohyoid  muscle  was 
drawn  outward,  and  the  sterno-hyoid  and  the  sterno-thyroid  muscles 

*This  operation  was  reported  for  the  Dental  Cosmos  and  Am.  Journal  of  Dental 
Science  by  Prof.  F.  J.  S.  Gorgas. 


1 1  24  DENTAL    PROSTHESIS. 

inward.  The  carotid  sheath,  with  the  contained  vessels,  was  exposed 
and  carefully  drawn  outward,  while  the  thyroid  gland  was  separated  as 
far  as  necessary  and  drawn  inward.  The  larynx  and  trachea  were 
drawn  somewhat  forward,  and  the  finger  passed  behind,  where  the 
foreign  body  could  be  distinctly  felt  through  the  esophageal  wall. 

"  Care  being  taken  to  avoid  the  recurrent  laryngeal  nerve,  an  in- 
cision large  enough  to  admit  the  finger  was  made  into  the  esophagus, 
through  which  the  exact  position  of  the  set  of  teeth  was  ascertained. 
Forceps  were  then  introduced  and  the  plate  removed  intact.  The 
wound,  after  being  thoroughly  cleansed,  was  dressed  with  antiseptic 
gauze  and  absorbent  cotton,  no  sutures  being  employed.  On  the  fol- 
lowing Thursday  the  patient  was  walking  about  his  room,  having  a 
normal  temperature  and  pulse.  He  was  fed  by  means  of  a  stomach- 
tube  for  six  days,  after  which  he  was  able  to  swallow  liquid  food  with 
little  or  no  pain,  and  the  external  wound  had  nearly  closed." 


CHAPTER  XVII. 
DEFECTS  OF  THE  PALATINE  ORGANS. 

One  of  the  most  distressing  deformities  to  which  the  human  frame 
is  liable  is  found  in  that  defective  condition  of  the  palatine  organs 
which  is  known  to  surgeons  by  the  name  of  Cleft  Palate.  The  unfor- 
tunate sufferer  is  compelled,  in  a  great  measure,  to  be  an  alien  among 
his  fellow  creatures ;  an  object  of  compassion  to  the  considerate,  he  is 
often  made  painfully  conscious  of  notice  by  the  heartless  crowd  ;  and 
were  he  gifted  with  the  power  and  eloquence  of  a  Demosthenes  or  with 
the  garrulousness  of  a  Cleon  he  could  make  little  more  use  of  his 
endowments  than  a  mute.  Fortunately  this  painful  defect  is  no  longer 
to  be  reckoned  as  one  of  the  opprobria  medicorum  ;  for  both  surgical 
and  mechanical  means  are  now  at  hand  by  which  the  imperfection  may 
at  least  be  remedied,  and  often  cured. 

Defects  of  the  palatine  organs  maybe  divided  into  two  classes,  viz.  : 
Accidental  and  Congenital.  The  first  includes  all  loss  of  substance  in 
either  hard  or  soft  palates,  whether  occasioned  by  disease  or  otherwise. 
Such  defects  are  not  uniform  in  locality  nor  in  extent,  consisting  some- 
times of  simple  perforations  and  at  others  involving  the  destruction  of 
the  velum,  a  considerable  portion  of  the  os  palati,  the  vomer  and  turbi- 
nated bones,  and  the  loss  of  a  greater  or  less  number  of  the  teeth.  The 
second  class  includes  all  malformations,  from  the  simple  bifurcation  of 


DEFECTS    OF   THE   PALATINE   ORGANS.  1 1 25 

the  uvula  to  an  opening  through  the  vekim,  palatine,  and  maxillary 
bones,  and  a  fissure  of  the  upper  lip  ;  thus  uniting  the  nasal  passages 
with  the  oral  cavity  throughout  their  entire  extent. 

These  malformations  are  quite  similar  in  character,  but  not  uniform 
in  extent.  They  may  be  said  to  begin  with  the  uvula,  and  in  the 
uvula  and  velum  always  occupy  the  median  line  ;  but  as  the  defect  pro- 
gresses anteriorly,  it  may  deflect  to  one  side  or  the  other  of  the  vomer 
and,  following  the  nasal  passage,  divide  the  lip,  leaving  the  vomer 
articulated  with  the  palatine  bone  upon  one  side ;  while  in  other  cases 
the  deformity  seems  to  follow  the  median  line,  and  thus  involves  both 
nasal  passages,  terminating  in  a  double  fissure  of  the  lip. 

Congenital  defects  of  the  palate  are  usually  accompanied  by  more 
or  less  deformity  of  the  sides  of  the  alveolar  arch  and  of  the  teeth. 
Sometimes  the  sides  of  the  alveolar  ridge  are  forced  too  far  apart,  and 
at  other  times  they  are  too  near  each  other  ;  while  the  teeth  are  either 
too  large  or  too  small,  and  are  generally  of  a  soft  texture  with  imper- 
fectly developed  roots. 

Want  of  coaptation,  resulting  from  defective  formation  in  the  pala- 
tine plates  of  the  maxillary  and  palate  bone,  is  the  cause  of  congenital 
deficiencies  of  the  parts  in  question.  In  the  human  embryo  of  about 
the  third  week  the  development  of  the  face  is  clearly  in  progress. 
Five  tubercles  bud  out  from  the  front  of  the  cephalic  mass,  of  which 
the  middle  one  (which  is  double)  is  directed  vertically  downward,  and 
bears  the  appellation  incisive  tubercle  because  the  intermaxillary  bones, 
destined  to  hold  the  superior  incisor  teeth  exclusively,  are  developed 
in  it.  On  either  side  is  the  tubercle,  or  rudiment,  of  an  upper  maxil- 
lary bone,  which  is  separated  from  its  fellow  by  a  wide  interval, 
and  from  the  neighboring  incisive  process  by  a  fissure.  The  fourth 
and  fifth  tubercles,  also  separated  in  front,  form  by  their  subsequent 
union  in  the  median  line  the  inferior  maxillary  bone.  At  the  same 
period  the  palate  begins  to  be  formed  by  the  approach  toward  the 
median  line  of  two  horizontal  plates,  or  processes,  springing  from  the 
maxillary  process  on  either  side.  (See  Development  of  Bones  of 
Head  and  Face.) 

If  now  development  proceed  regularly  and  normally,  the  palate 
processes  of  the  superior  maxilla  meet  in  the  median  line  and  unite 
with  the  blended  intermaxillary  tubercles,  while  the  vomer  grows 
downward  to  meet  the  palate  processes  in  their  line  of  union.  The 
upper  jaw,  after  the  accomplishment  of  these  changes,  is  complete, 
and  the  formation  of  the  lip  and  primary  dental  groove  follows  in  due 
course.  But  it  sometimes  happens  that  the  superior  maxillary  and 
intermaxillary  processes  fail  to  unite  with  each  other  ;  whence  we  have 
the  malformation  known  as  harelip,  or  the  palaie  plates  are  arrested  in 


I  I  26  DENTAL    PROSTHESIS. 

iheir  growth,  and  perma.neut _^ssure  of  the  palate  is  the  result.  Con- 
sequently, the  fissure  of  single  harelip  is  never  exactly  in  the  median 
line,  but  on  the  edge  of  the  intermaxillary  bone  ;  whereas,  in  double 
harelip,  a  fissure  exists  on  each  side  of  this  bone,  in  which  the  four 
incisor  teeth  are  planted. 

Fissure  of  the  hard  palate  is  usually  a  little  lateral,  and  not  median,, 
as  it  results  from  a  deficiency  of  one  or  other 
of  the  palate  plates  of  the  upper  maxillary 
bone,  and  it  is  frequently  associated  with 
harelip  and  fissure  of  the  upper  jaw. 

The  tubercles,  or  formative  processes  of  the 
lower  jaw,  advance  and  meet  in  the  median 
line,  while  the  upper  maxillary  processes  are 
still  separate.  In  man  they  are  consolidated 
into  a  single  piece ;  but  they  remain  per- 
manently divided  in  many  of  the  lower  ani- 
mals by  a  median  suture. 
The  principal  effects  resulting  from  an  absence  of  a  portion  of  the 
palatine  organs  are,  an  impairment  of  the  functions  of  mastication, 
deglutition,  and  speech.  Distinct  utterance,  is  sometimes  wholly 
destroyed,  and  mastication  and  deglutition  are  often  so  much  embar- 
rassed as  to  be  performed  only  with  great  difificulty. 

These  effects  are  always  in  proportion  to  the  extent  of  the  separa- 
tion or  deficiency  of  the  parts.  The  simple  act  of  triturating  the 
food  may  not  be  materially  impaired  by  the  absence  of  a  portion — 
however  extensive — of  the  palatine  organs,  unless  the  natural  rela- 
tions of  the  teeth  of  the  upper  and  lower  jaws  are  changed  ;  still  the 
process  is  more  or  less  interfered  with,  as  substances  taken  into  the 
mouth  cannot  be  so  readily  managed  as  when  the  parts  are  in  their 
natural  state.  They  are  liable  to  escape  from  the  control  of  the 
tongue  and  pass  into  the  cavity  of  the  nose. 

In  cases  of  congenital  defects  of  the  palate  and  velum  it  is  difficult 
to  conceive  how  infants  manage  to  obtain  from  the  breast  of  the 
mother  or  nurse  the  food  necessary  for  their  subsistence ;  yet,  even 
when  the  anterior  part  of  the  alveolar  border  and  part  of  the  upper 
lip  are  wanting,  the  suggestions  of  natural  instinct  enable  them,  by 
a  peculiar  management  of  tongue  and  lip,  to  do  it.  The  expedient 
resorted  to  for  effecting  this  process  is  curious.  The  nipple,  instead 
of  being  seized  between  the  tongue,  upper  lip,  and  gum,  is  taken  be- 
tween its  lower  surface  and  the  under  lip  and  gum,  and  in  this  way 
it  manages  to  extract  the  nourishment  necessary  for  subsistence  and 
growth.  The  tongue  is  thus  made  to  close  the  opening  in  the  palate 
and  perform  the  office  of  an  obturator.     By  contracting  the  lip  and 


DEFECTS    OF    THE    PALATINE    ORGANS.  I  I  27 

depressing  the  tongue  the  milk  is  drawn  from  the  breast  of  the 
mother  or  nurse.  At  this  young  and  tender  age  the  child  is  not 
conscious  of  the  imperfection  of  its  palate ;  and  it  is  not  until  the 
period  arrives  when  it  should  begin  to  make  its  wants  known  bywords 
that  it  feels  the  importance  of  the  function  of  speech,  and  begins  to 
realize  the  misfortune  with  which  it  is  afflicted. 

As  the  child  arrives  at  this  period,  the  mechanism  of  sucking  is 
perfected  and  is  ultimately  applied  to  the  mastication  of  solid  ali- 
ments. The  food,  when  chewed,  is  conveyed  between  the  tongue  and 
movable  floor  (which  serves  for  a.  point  cV appiii),  and  it  is  brought 
back  between  the  teeth.  Thus  it  is  that  the  complicated  operation 
of  mastication  and  deglutition  is  performed  without  the  alimentary 
morsel  getting  into  the  nose,  or,  if  this  does  sometimes  happen,  it 
IS  the  result  of  accident.  But  in  cases  of  accidental  lesion  of  the 
palate  the  individual  has  not  the  advantage  of  this  training  of  the 
parts  during  early  infancy.  Those  who  are  afflicted  with  accidental 
ksions,  no  matter  what  may  be  their  position  and  extent,  having 
acquired  the  habit  of  eating  by  placing  the  aliment  upon,  and  not 
under,  the  tongue,  can  take  no  nourishment  without  a  part  of  it 
getting  into  the  nose.  When  to  this  inconvenience  is  added  a  change 
in  the  natural  relation  of  the  teeth  of  the  two  jaws,  mastication  is 
rendered  still  more  difficult  and  embarrassing.  When  this  is  the 
case  the  tubercles  of  the  teeth  of  one  jaw,  instead  of  being  received 
into  the  depressions  of  those  of  the  other,  strike  upon  their  pro- 
tuberances, and  cannot  be  made  to  triturate  the  food  in  as  thorough 
and  perfect  a  manner  as  is  required  for  healthy  and  easy  digestion. 
Thus  not  only  is  the  process  of  mastication  rendered  imperfect,  but  it 
is  also  more  tedious. 

The  process  of  deglutition  itself,  so  long  as  the  velum  and  uvula  are 
perfect,  is  not  materially  affected  by  a  simple  perforation  of  the  vault 
of  the  palate,  although  much  difficulty  may  be  experienced  in  convey- 
ing alimentary  and  fluid  substances  to  the  fauces  and  pharynx.  But 
when  this  curtain  is  cleft,  or  is  partially  or  wholly  wanting,  deglutition 
is  rendered  very  difficult,  for  by  the  contraction  of  the  muscles  of  the 
pharynx  part  of  the  food  is  forced  up  into  the  nose.  The  reason  of 
this  will  appear  obvious  when  we  take  into  consideration  the  form  and 
function  of  this  movable  appendage.  When  its  muscles  are  relaxed  it 
forms  a  slightly  concave  curtain  ;  but  in  the  act  of  deglutition  the 
muscles  contract,  raise  the  velum,  and  close  the  opening  from  the 
pharvnx  into  the  posterior  nares.  By  this  valvular  arrangement  ali- 
mentary substances  and  fluids  are  prevented  from  escaping  into  the 
nose.  It  matters  not,  therefore,  whether  the  imperfection  of  the  velum 
palati  be  the  result  ot  accident  or  disease  ;  its  effects  upon  deglutition 


1 1  28  DENTAL    PROSTHESIS. 

are  the  same.  In  proportion  as  the  lesion  or  deficiency  is  great  will 
this  operation  be  rendered  difficult  and  embarrassing.  There  are 
cases  where,  in  consequence  of  an  imperfection  of  the  palate,  the 
patient  can  swallow  no  fluids  without  a  part  being  returned  by  the 
nose.  To  obviate  this  inconvenience  the  head  is  thrown  sufficiently 
far  back  to  precipitate  them  into  the  esophagus.  This  is  an  expedient 
to  which  many  thus  affected  have  been  compelled  to  resort. 

Imperfection  of  speech  always  results  from  an  opening  in  the  palate  ; 
it  gives  the  voice  a  nasal  twang  and  render^  the  formation  of  some 
sounds  impossible.  The  loss  of  the  teeth,  to  a  less  extent,  is  produc- 
tive of  the  same  effect.  To  comprehend  fully  the  manner  in  which  a 
lesion  of  the  palate  may  affect  the  utterance  of  speech,  it  will  be  nec- 
essary to  understand  the  agency  which  the  several  parts  of  the  mouth 
have  in  the  formation  of  articulate  sounds.  Speech  consists  in  the 
sounds  produced  by  the  organs  of  the  glottis  modified  by  the  organs 
of  the  mouth.  The  modulation  of  the  voice,  that  is,  the  raising  or 
lowering  of  its  pitch,  is  accomplished  by  the  vocal  cords  of  the  glottis  ; 
but  the  articulation  of  the  consonants  requires  the  co- operation  of  all 
the  movable  and  fixed  parts  of  the  mouth  and  pharynx,  palate,  tongue, 
lips,  teeth,  and  palatine  arch.  Hence  if  any  of  these  be  defective  or 
wanting,  the  power  of  forming  some  of  these  sounds  is  wholly  lost,  of 
others  very  much  impaired  ;  hence,  also,  the  ability  to  sing  is  much 
less  interfered  with  than  the  power  of  distinct  speech.  The  tongue 
has  a  remarkable  power  of  adapting  itself  to  the  loss  of  teeth  and  of 
some  other  parts,  so  as  measurably  to  correct  the  effect  on  speech  :  but 
the  effect  of  the  loss  of  the  hard  or  soft  palate  upon  the  voice  cannot 
be  remedied  in  any  such  way. 

In  both  cases  (accidental  and  congenital)  the  faculty  of  distinct 
articulate  speech  is  seriously  impaired  by  defects  of  any  extent.  In 
ordinary  cases  of  congenital  deformity  in  an  adult,  deglutition  is  not 
materially  interfered  with.  The  patient,  having  never  known  any 
other  method  of  swallowing,  is  not  conscious  of  any  difficulty.  Acci- 
dental lesions,  however,  coming  generally  in  adult  life,  produce,  in 
this  respect,  very  great  inconvenience.  The  remedy  for  these  evils 
must  be  the  closing  of  the  abnormal  passage  by  some  means  which  will 
restore  to  the  deformed  organs  their  functions.  In  perforations  of  the 
hard  palate,  unless  of  extraordinary  extent,  the  method  is  very  simple. 
In  the  loss  of  the  soft  palate  by  disease  the  remedy  is  more  difficult, 
and  in  extensive  congenital  deformity  still  more  complicated  means 
must  be  resorted  to. 

STAPHYLORRHAPHY. 

The  operation  which  is  resorted  to  for  closure  of  a  cleft  in  the  soft 
palate  is  known  by  the  name  of  Staphylorrhaphy,  a  word  of  Greek 


STAPHYLORRHAPHY.  1  I  29 

derivation,  signifying  suture  of  the  uvula.  It  is  an  operation  which 
has  been  successful  in  many  instances,  although  there  are  numerous 
cases  which  will  derive  far  more  benefit  from  mechanism  than  from 
the  surgeon's  aid  or  a  surgical  velum. 

To  obtain  success  in  staphylorrhaphy,  the  first  care  must  be  to  gain 
a  practical  acquaintance  with  the  position  and  relation  of  the  muscles 
connected  with  the  palate  and  fauces ;  and  this  can  be  accomplished 
best  by  laying  open  the  pharynx  from  behind,  for  thus  the  posterior 
surface  of  the  soft  palate  is  at  once  exposed  to  view.  This  structure  is 
wholly  composed  of  muscular  tissue  covered  with  a  layer  of  mucoris 
membrane  continuous  with  that  lining  the  hard  palate. 

The  muscles  with  which  we  have  chiefly  to  do  are  :  the  palato-glossi 
and  the  palato-pharyngei,  forming  the  anterior  and  the  posterior  pil- 
lars of  the  soft  palate  respectively ;  the  levatores  palati,  the  tensores 
palati,  and  the  azygos  uvulae.  The  origin,  insertion  and  actions  of 
these  muscles  are  given  on  page  63. 

The  actions  of  these  muscles  show  what  an  important  part  they  must 
bear  in  regard  to  the  operation  of  staphylorrhaphy;  and  when  this  is 
considered  in  detail,  it  will  be  seen  why  but  little  success  was  met  with 
until  means  were  found  to  render  muscular  action  of  the  parts  im- 
possible. 

The  deficiency  of  the  palate  varies  considerably,  from  a  mere  divi- 
sion of  the  uvula  to  a  gap  which  constitutes  a  hopeless  deformity. 
When  this  abnormal  state  is  limited  to  the  soft  palate,  the  cleft  is 
always  of  a  triangular  shape,  the  apex  being  above  and  the  base  below; 
but  when  the  soft  and  hard  structures  are  involved,  it  is  of  a  more  or 
less  quadrilateral  shape. 

We  shall  here  only  consider  those  cases  which  are  congenital  in 
their  origin,  merely  alluding  to  the  distinction  between  this  class  of 
deformity  and  that  kind  which  may  be  said  to  be  acquired,  or  is  acci- 
dental. In  congenital  cleft  the  fissure  is  generally  confined  to  the 
median  line  of  the  palate,  because  the  two  halves  have  not  united  at 
that  part  at  the  usual  period.  In  acquired  or  accidental  deformity 
lesions  are  met  with  in  all  parts  of  the  palate,  to  the  right  or  left  of 
the  median  line,  and  are  usually  the  result  of  syphilitic  ulceration,  or 
have  some  traumatic  origin. 

Congenital  clefts  may  be  thus  classed  :  Firstly,  a  small,  triangular- 
shaped  fissure,  extending  through  the  uvula  and  the  posterior  portion 
of  the  velum  palati,  the  other  portion  of  the  palate  being  quite  intact 
and  sound.  Secondly,  the  whole  of  the  soft  palate  is  involved. 
Thirdly,  the  soft  palate  and  a  portion  of  the  palate  bone  is  deficient. 
Fourthly,  the  cleft  may  be  associated  with  abnormality  in  the  alveolar 
process  of  the  palate  bone,  and  even  with  harelip.     Fifthly,  openings 


II30 


DENTAL    PROSTHESIS. 


occur  in  the  hard  palate,  the  soft  palate  being  unaffected.  These  sepa- 
rations may  be  very  narrow,  not  exceeding  a  few  lines  in  width,  or  the 
gap  may  be  such  that  mouth  and  nostril  seem  but  one. 


Fig.  1208. 


Fig.  1209. 


The  fissure  posteriorly  is  always  on  the  median  line ;  anteriorly,  it 
generally  deflects  to  one  side  or  the  other  of  the  na.sal  septum,  passing 
also  to  one  side  of  the  inter-maxillary  bone.     In  some  rare  cases  both 


Fig.  1210. 


Fig.  I2II. 


nasal  passages  are  involved,  and  a  double  hareli})  is  the  consequence. 
The  effects  of  this  condition,  already  stated,  may  thus  be  briefly 
summed  up.     During  infancy  the  functions  of  suction  and  deglutition 


STAPHYLORRHAPHY. 


II3I 


are  with  difificulty  performed,  and  at  a  later  stage  mastication  and  arti- 
culation are  much  impeded.  There  is  also  imperfect  control  over  the 
muscles  of  the  palate,  both  fluids  and  solids  are  liable  to  pass  into  the 
windpipe,  and  not  unfrequently  there  is  regurgitation  through  the  nose. 
The  speech  is  guttural  and  nasal,  often  so  indistinct  as  to  render  it 
almost  entirely  unintelligible,  and  the  patient  is  only  too  anxious  to 
grasp  at  any  chance  that  may  be  held  out  as  being  likely  to  grant  some 
amelioration  of  his  condition. 

Various  methods  have  been  suggested  for  the  cure  of  this  deformity, 
such  as  pressure  on  the  yielding  bones  in  early  infancy,  the  operation 
of  staphylorrhaphy,  and  artificial  substitutes;  but  as  Dr.  Kingsley  re- 
marks, the  cases  are  very  exceptional  where  normal  articulation  is  ever 
acquired  with  a  surgical  velum — that  is  by  staphylorrhaphy. 

All  the  earlier  operations  of  staphylorrhaphy  consisted  in  paring 
away  the  edges  of  the  cleft,  and  then  bringing  them  in  contact  by 
means  of  sutures  until  union  was  ef- 
fected. The  various  stages  of  the 
operation  as  then  performed  are  suf- 
ficiently illustrated  in  the  accompany- 
ing engravings,  the  successive  steps 
being  taken  in  the  order  of  these 
drawings.  Many  modifications  of 
this  "plan  were  made  by  Warren,  Met- 
tauer,  Stevens,  Graefe,  and  others ; 
but  Fergusson  introduced  a  new  prin- 
ciple of  treatment  in  the  operation 
which  has  very  materially  added  to  its 
successful  results. 

We  have  alluded  to  the  use  of  the 
muscles  composing  the  velum  of  the 
palate  and  their  important  action  on 
it,  and  to  Fergusson  must  be  assigned 
the  credit  of  being  the  first  to  realize  practically  the  fact  that  muscular 
action  was  the  most  frequent  cause  of  failure  of  the  operation  ;  and 
he  proved  the  truth  of  his  conjecture  by  his  method  of  removing  the 
difificulty ;  namely,  the  division  of  the  muscles  of  the  palate,  thus  en- 
tirely paralyzing  their  action.  Billroth  more  recently  introduced  a 
new  procedure,  which  is  to  chisel  away  the  lower  part  of  the  pterygoid 
process  so  as  to  relieve  the  tension  produced  by  the  tensor  palati  and 
palato-pharyngeus  muscles. 

Mr.  Cartwright  proposes  the  following  method  of  treatment  to 
prepare  the  patient  for  this  operation  :  it  has  been  found  that  the 
exhibition  of  the  bromide  of  potassium  tends  to  deaden  the  sensi- 


FlG.    I2I2. 


I  132  DENTAL    PROSTHESIS. 

biiity  of  the  fauces  in  a  very  remarkable  manner,  and  thus  it  may 
become  a  most  useful  agent  preparatory  to  the  operation.  If  ex- 
hibited in  half-dram  doses,  given  thrice  daily  for  two  or  three  weeks 
prior  to  the  period  decided  upon,  but  little  irritability  of  the  parts  will 
be  found  remaining;  and  by  the  time  a  few  imaginary  operations  on 
the  parts  have  been  performed,  by  the  aid  of  such  harmless  instru- 
ments as  a  camel's-hair  brush  or  the  feather  of  a  quill,  the  patient  will 
be  found  in  a  fit  condition  to  be  operated  upon.  A  few  days  prior  to 
the  time  of  operating  more  particular  attention  must  be  paid  to  the 
condition  of  the  patient.  Primarily,  he  must  be  well  nourished,  inas- 
much as  he  will  be  forced  to  adopt  a  different  regimen  from  that  to 
which  he  has  been  accustomed  for  some  days.  His  diet  must  be  nutri- 
tious without  being  stimulating,  and  the  greatest  attention  must  be 
given  to  the  regular  action  of  the  bowels,  and,  indeed,  in  all  cases  it 
is  well  to  give  a  mild  aj^erient  before  operating. 

Sir  Wm.  Fergussons  Operation  — Mr.  Cartwright  describes  Mr. 
Fergusson's  operation  as  follows  :  He  first  divides  the  muscles  of  the 
palate  by  passing  a  curved  knife  around  between  the  velum  palati  and 
the  end  of  the  Eustachian  tube,  thus  at  once  dividing  the  levator 
palati.  In  the  second  stage  he  seizes  the  uvula,  thus  bringing  forward 
the  posterior  pillar  of  the  fauces,  which  is  snipped  across  with  round- 
pointed  scissors,  so  as  to  divide  the  fibres  of  the  palato-pharyngeus 
muscle;  should  it  be  deemed  necessary  to  do  so,  the  anterior  pillar 
may  be  divided  at  the  same  time,  so  as  to  sever  the  palato-glossus, 
though  Sir  William  lays  no  stress  upon  the  necessity  of  doing  so.  Next 
the  uvula  is  again  seized,  with  a  view  of  extending  the  palate  so  that 
the  edges  of  the  fissure  may  be  pared  away  ;  this  is  accomplished  with 
a  narrow  bistoury  from  behind  forward,  on  either  side  alternately,  the 
angle  of  union  being  left  for  subsequent  removal.  A  few  moments 
then  are  granted  to  the  patient  to  recover,  and  he  is  permitted  to 
swallow  a  few  small  pieces  of  ice,  with  the  double  view  of  refreshing 
him  and  of  staunching  the  bleeding.  When  this  has  sufficiently 
ceased,  it  is  time  to  introduce  the  sutures,  and  this  is  done  by  means 
of  a  ngevus  needle,  armed  with  a  silken  ligature  (silk-worm  gut  is  pre- 
ferable for  ligatures),  the  needle  being  introduced  about  a  quarter  of 
an  inch  from  the  edge  of  the  fissure.  Next,  the  extremity  of  the 
thread  is  pulled  out  by  means  of  forceps,  and  another  ligature  is  passed 
in  like  manner,  until  the  desired  number  of  stitches  is  attained.  The 
extremities  must  then  be  tied  loosely,  so  as  just  to  keep  the  parts  in 
apposition  and  no  more;  after  which  the  patient  is  put  to  bed,  every 
care  being  taken  to  avoid  all  motion  of  the  palate.  He  should  take 
nothing  but  nourishing  liquid  food  for  a  few  days,  and  must  be  par- 
ticularly enjoined  to  abstain  from  all  movements  involving  action  of 


STAPHYLORRHAPHY.  II33 

the  muscles  engaged  in  deglutition,  such,  as  swallowing,  coughing, 
sneezing,  and  the  like,  which  would  much  endanger  the  success  of  the 
operation.  The  next  stage  consists  in  the  removal  of  the  stitches; 
this  need  not  be  done  too  soon,  provided  they  produce  no  irritation ; 
indeed,  they  may  remain  until  union  is  perfect.  The  general  time  for 
their  removal  is  about  the  seventh  or  eighth  day,  although  Fergusson 
often  removes  them  on  the  third  or  fourth. 

Mr.  G.  Pollock  has  introduced  the  following  modifications  in  the 
performance  of  this  operation  :  Instead  of  dividing  the  muscle  with  a 
curved  knife  from  behind,  according  to  the  method  we  have  just  de- 
scribed, Mr.  Pollock  passes  a  ligature  through  the  soft  palate,  so  as  to 
contract  and  draw  it  forward,  and  he  then  pushes  a  narrow-bladed 
knife  through  it,  a  little  to  the  inner  side  of  the  hamular  process  of  the 
ptergyoid  plate  of  the  sphenoid  bone,  which  may  be  plainly  discovered 
by  passing  the  finger  along  the  roof  of  the  mouth  to  a  distance  a  little 
posterior  to  the  tuberosity  of  the  superior  maxilla.  By  raising  the 
hand,  and  so  depressing  the  point  of  the  scalpel,  he  most  effectively,  and 
in  a  very  simple  manner,  divides  the  muscle.  The  parts  having  healed, 
the  patient  must  be  impressed  with  the  necessity  of  practicing  himself 
frequently  in  elocution,  telling  him  that  his  success  in  articulation  will 
depend  upon  himself  alone.  Constant,  patient,  persevering  effort  will 
be  necessary,  and  the  end  to  be  attained  must  be  sought  by  distinctly 
articulating  every  syllable  of  every  word  which  he  may  be  called  upon 
to  utter.  It  is  a  good  exercise  to  read  a  portion  of  some  good  author 
each  day  with  a  friend,  who  will  assume  the  role  of  schoolmaster  for 
the  time  being,  permitting  no  word  to  be  indistinctly  uttered  or  slurred 
over  and  requiring  each  syllable  to  be  correctly  and  separately  pro- 
nounced. 

Fissure  of  the  hard  palate,  simple  or  connected  with  a  fissure  of  the 
soft.  Various  means  of  closure  have  been  proposed.  Dr.  Warren 
dissected  the  mucous  membrane  from  the  bone  on  either  side,  carry- 
ing his  knife  sufficiently  forward  toward  the  alveolar  border  to  form  a 
flap  broad  enough  to  meet  a  like  one  from  the  opposing  side  along  the 
median  line.  When  the  fissure  is  so  wide  as  to  prevent  the  margins 
being  brought  together,  Dr.  Mettauer,  of  Virginia,  recommended 
making  several  lateral  incisions  through  the  mucous  membrane,  with  a 
view  of  permitting  the  edges  to  be  brought  into  close  apposition.  Dr. 
Mutter,  of  Philadelphia,  who  was  very  successful  in  the  operation, 
also  had  recourse  to  the  longitudinal  incision  (as  shown  by  Fig.  12 13), 
which  was  first  proposed  by  Dieffenbach,  with  happy  results.  Dr. 
Warren's  operation  has  been  introduced  into  England  by  Mr.  Pollock, 
who,  with  his  peculiarly  constructed  instruments,  proceeds  as  follows: 
He  makes  an  incision  along  the  edge  of  the  cleft  at  the  juncture  of  the 


1134 


DENTAL   PROSTHESIS. 


nasal  and  palatal  mucous  membrane.  The  soft  covering  of  the  hard 
palate  is  carefully  dissected  or  scraped  from  the  bone  with  curved 
knives,  great  care  being  taken  that  the  mucous  membrane  and  its  sub- 
jacent fibrocellular  tissue  are  not  perforated.  When  this  has  been 
well  loosened  on  either  side,  it  will  be  found  to  hang  down  like  a  cur- 
tain from  the  vault  of  the  mouth,  the  two  parts  coming  into  apposi- 
tion along  the  median  line,  or  possibly  overlapping.  The  edges, 
being  then  smoothly  pared,  are  brought  together  by  means  of  a  few 
points  of  suture  introduced  in  the  ordinary  way  and  without  any  drag- 
ging. Where  the  hole  is  not  very  large,  Dr.  Pancoast's  operation  of 
staphyloplasty  may  be  performed,  in  which  he  raises  two  flaps  of 
mucous  membrane  from  the  bone  on  either  side,  and  then,  reflecting 
them  across  the  chasm,  their  edges  are  brought  together  by  suture  in. 


Fig.  1213. 


Fig.  1214. 


the  usual  manner,  a  plan  which  is  so  perfectly  exhibited  in  Fig.  12 14 
that  we  do  not  deem  any  further  description  necessary.  M.  Langen- 
beck  suggested  another  operation,  in  which  he  proposed  to  dissect  the 
mucous  membrane,  together  with  the  periosteum,  from  the  surface  of 
the  bone  prior  to  bringing  the  opposed  surfaces  of  the  cleft  in  apposi- 
tion ;  and  the  advantages  claimed  by  him  for  this,  which  he  considers 
to  be  a  novel  method  of  procedure,  is  that  the  chasm  is  obliterated, 
not  merely  by  soft  tissue,  but  by  bone,  which  is  formed  from  the  peri- 
osteum thus  loosened  from  contact  with  the  surface  of  the  hard  palate. 
Dr.  T.  W.  Brophy  has  recently  suggested  the  following  operation  : 
"  Vivify  the  edges  of  the  fissure  thoroughly  and  with  a  bold  hand. 
On  the  hard  palate  trim  the  opposing  surfaces  uf  the  bone  as  well ; 
the  knife  will  easily  cut  through  the  soft  bone  of  the  hard  palate  and 


STAPHYLORRHAPHY.  1 1  35 

the  alveolar  process.  The  fissure  is  then  brought  together  by  wire 
sutures  i^assing  through  a  lead  button  and  the  body  of  the  maxilla 
above  the  palatal  bone,  then  tightened  by  twisting  until  the  i)arts  are 
in  contact.  In  some  cases  the  maxillae  are  divided  horizontally  be- 
neath the  malar  process.  If  the  resistance  is  such  that  the  edges  do 
not  readily  approximate,  the  malar  process  is  divided  on  either  side  by 
the  aid  of  a  heavy  scalpel." 

There  are  many  cases  of  abnormality  in  the  os  palati  which  can 
only  be  relieved  by  mechanical  appliances,  and  this  relief  can  be  af- 
forded in  a  most  satisfactory  manner,  no  more  inconvenience  being 
felt  by  the  patient  than  he  would  experience  in  wearing  an  artificial 
denture,  with  which  the  false  palate  could  be  connected,  were  it 
necessary  to  do  so.  Artificial  aid  has  been  several  times  alluded  to  in 
reference  to  the  operation  of  staphylorrhapy ;  but  it  is  now  a  well 
established  fact,  that  in  the  large  majority  of  cases  a  scientifically 
constructed  artificial  velum  will  prove  satisfactory.  The  main  and  only 
object  is  to  give  to  the  afilicted  the  power  of  articulate  speech,  and 
this,  as  Dr.  Kingsley  remarks,  can  only  be  produced  normally  by  vol- 
untarily opening  and  closing  the  passage  from  the  larynx  to  the  nose. 
If  this  cannot  be  accomplished,  because  of  the  inability  of  the  palate 
to  act,  speech  will  be  defective.  Undoubtedly,  the  operations  which 
have  been  described  are  often,  as  far  as  mere  union  is  concerned,  most 
satisfactory  in  their  results  ;  but  there  are  other  considerations  besides 
these.  Naturally  the  chief  desire  of  the  patient  is  to  take  a  footing 
in  society  on  equal  terms  with  other  men ;  and  there  are  no  means 
which  will  enable  him  to  do  so,  unless  they  can  restore  to  him  his  lost 
or  impaired  power  of  speech — that  divine  gift  which  places  man  so 
immeasurably  above  the  brute  creation.  This  has  been  almost  lost  in 
many  cases  of  cleft  palate  ;  and  it  is  the  great  object  of  treatment  to 
put  the  sufferer  in  a  way  of  uttering  his  thoughts  in  plainly-spoken 
words  like  those  around  him  ;  whatever  means  are  best  calculated  to 
bestow  this  inestimable  benefit  are  those  which  the  conscientious  sur- 
geon ought  to  select. 

There  are  certain  cases  where  the  opening  is  not  large,  and  as 
there  is  little  tension  of  the  parts  the  opposite  sides  come  together 
in  close  proximity;  staphylorrhaphy  may  here  be  performed  with 
good  results,  for  it  must  be  recollected  that  it  is  always  a  desidera- 
tum to  avoid  the  presence  of  foreign  substance  as  a  substitute  for 
natural  tissues,  if  these  are  equally  effective.  Allusion  has  been 
made  to  the  liability  to  injury  of  the  parts  by  a  division  of  the 
muscles.  Where  an  artificial  palate  is  used  the  muscles  are  unim- 
paired ;  and  it  is  claimed  that  persons  who  when  without  the  instru- 
ment  could    not    be   understood,  spoke   fluently  and    distinctly    the 


1136  DENTAL    PROSTHESIS. 

moment  they  introduced  it  into  their  mouths.  So  far  as  the  dis- 
comforts of  wearing  such  an  apparatus  are  concerned,  after  a  short 
time  the  wearers  become  entirely  unconscious  that  they  are  wearing 
anything  artificial. 

OBTURATORS    AND    ARTIFICIAL    PALATES. 

We  have  classified  palatine  defects  as  accidental  and  congenital; 
we  shall  also  classify  the  appliances  used  for  their  remedy.  The 
term  obturator  will  be  used  for  all  instruments  intended  to  stop  or 
cover  all  those  openings  in  the  hard  or  soft  palate  which  have  a  well 
defined  border  or  outline.  The  term  artificial  velum  is  applied  to  a 
mechanical  contrivance  which  consists  of  an  elastic,  movable  valve 
which  is  under  the  control  of  adjacent  or  surrounding  muscles  and 
capable  of  closing  or  opening  the  posterior  nares  at  will,  and  which 
is  applicable  to  cases  of  congenital  cleft-palate,  and  also  in  certain 
cases,  when  the  soft  palate  has  been  destroyed  by  ulceration. 

Any  unnatural  opening  between  the  oral  and  nasal  cavities  which 
will  permit  the  free  passage  of  the  breath  will  impair  articulation. 
Any  appliance  which  will  close  such  passage  and  can  be  worn  without 
inconvenience  will  restore  articulation.*  Obturators  were  formerly 
made  of  metallic  plate,  gold  or  silver  being  most  commonly  em- 
ployed, and  many  very  ingenious  pieces  of  mechanism  were  the  result 
of  such  efforts ;  but  latterly  vulcanized  rubber  has  almost  entirely 
superseded  the  use  of  metals.  Vulcanite  has  been  found  preferable  to 
metals,  being  much  lighter  and  much  more  easily  formed  and  adapted, 
particularly  when  of  peculiar  shape.  In  regard  to  the  age  of  the 
patient  which  is  most  suitable  for  the  application  of  an  artificial 
velum,  Dr.  Kingsley  remarks  that  for  some  thirty  years  past  he  has 
been  applying  such  contrivances  repeatedly  for  children  under  ten 
years  of  age. 

Bourdet  was  the  first  who  proposed  to  employ  simply  a  metallic  plate 
fitted  to  the  vault  of  the  palate  and  large  enough  to  cover  the  opening, 
with  two  lateral  prolongations,  one  on  each  side,  extending  to  the 
teeth,  to  which  they  are  fastened  by  means  of  ligatures.  This  was  also 
found  to  be  objectionable,  as  the  ligatures  were  productive  of  constant 
irritation  to  the  gums;  moreover,  they  did  not  hold  the  plate  in  place 
with  sufficient  stability,  and  its  use  was  soon  abandoned.  But  these 
objections  were  both  obviated  by  an  improvement  made  by  M.  Dela- 


*  The  student  will  bear  in  mind  that  no  cognizance  is  here  taken  of  openings 
similar  to  those  described  in  cases  of  congenital  fissure,  where  the  surgeon  has 
united  the  soft  palate,  and  left  an  opening  through  the  hard  palate  to  be  covered  by 
an  obturator. 


OBTURATORS    AND    ARTIFICIAL    PALATES. 


II37 


barre,  which  consisted  in  the  employment  of  clasps,  instead  of  liga- 
tures, attached  to  lateral  branches  of  the  plate.  To  prevent  these  from 
slipping  too  high  up  on  the  teeth  he  attaches  to  each  a  kind  of  spur, 
which  was  so  bent  as  to  come  down  over  the  grinding  surface  of  the 
tooth  to  which  it  is  applied.  The  last-named  author  also  made 
another  modification,  which  consisted  in  the  application  of  a  drum  to 
the  upper  surface  of  the  plate  (Fig.  12 15).  The  object  of  this  was  to 
prevent  the  accumulation  of  mucous  fluids  from  the  nose  in  the  cul-de- 
sac,  formed  by  simply  closing  the  opening  below;  also  to  prevent 
fluids,  in  swallowing,  from  passing  up  between  the  obturator  and  the 
soft  parts  through  the  opening  into  the  nose.  The  drum  evidently 
offers  the  same  impediment  to  nature's  efforts  in  closing  the  opening 
as  the  obturator  before  mentioned ;  on  this  score,  therefore,  it  is 
equally  objectionable. 

When  the  opening  in  the  palate  is  small,  and  has  710  connection  with 
the  velum,  it  is  unnecessary  to  raise  the  upper  surface  of  the  plate  by 


Fig.  1215. 


attaching  a  drum  or  air  chamber  to  it.  If  it  be  accurately  fitted  to 
the  vault  of  the  palate,  it  will  effectually  prevent  fluids,  in  deglutition, 
from  passing  up  in  the  nasal  cavities,  or  the  escape  of  any  portion  of 
the  voice  through  the  opening;  also  by  frequently  removing  the  plate 
the  accumulation  of  the  secretions  in  the  cul-de-sac  will  be  prevented. 
A  simple  plate,  like  the  one  represented  in  Fig.  12 16,  will  be  all  that 
is  required  to  remedy  the  defect ;  and  this,  in  fact,  will  probably  be 
found  the  best  form  in  all  cases,  whether  the  openings  be  large  or 
small. 

Fig.  1217  represents  an  obturator  without  teeth  and  without  clasps 
for  a  perforation  of  the  hard  palate,  being  sustained  in  situ  by  imping- 
ing upon  the  natural  teeth  with  which  it  comes  in  contact.  Accu- 
racy of  adaptation  and  delicacy  in  form  are  all  that  is  essential  in  such 
cases,  and  the  restoration  of  the  speech  will  follow  immediately. 

A  clumsy  contrivance  will  interfere  with  articulation  almost  as  much 
72 


ii-,8 


DENTAL    PROSTHESIS. 


as  it  is  improved  by  stopping  the  opening;  therefore,  if  the  obturator 
could  be  confined  entirely  to  the  opening,  like  a  cork  in  a  bottle,  it 
would  be  more  desirable.  As  this  cannot  be,  resort  must  be  had  to 
clasping  the  contiguous  teeth,  if  there  are  any ;  if  there  are  none,  the 
obturator  must  extend  over  the  whole  jaw  and  receive  its  support  in 
the  same  manner  as  would  a  set  of  artificial  teeth.  In  fact,  this  is 
precisely  what  it  becomes  in  such  a  case — an  upper  set  of  teeth  bridg- 
ing over  and  filling  up  an  opening  in  the  palate,  thus  combining  an 
obturator,  with  a  denture.  Fig.  1218  represents  a  more  complicated 
obturator,  adapted  to  an  opening  in  the  soft  palate.  The  necessity 
for  a  variation  in  the  plan  will  be  found  in  the  anatomical  fact  of  the 
constant  muscular  action  of  the  soft  palate,  which  would  not  permit, 
without  irritation,  the  presence  of  an  immovable  fixture.  This  is  con- 
trived, therefore,  with  a  joint,  which  will  permit  the  part  attached  to 
the  teeth  to  remain  stationary,  while  the  obturator  proper  is  carried  up 
or  down  as  moved  by  the  muscles.     The  joint.  A,  should  occupy  the 


Fig.  1217. 


position  of  the  junction  of  the  hard  and  soft  palates.  The  joint  and 
principal  part  of  the  appliance  is  made  of  gold,  the  obturator  of  vul- 
canite. The  projection,  B,  lies  like  a  flange  upon  the  superior  surface 
of  the  palate  and  sustains  it;  otherwise  the  mobility  of  the  joint 
would  allow  it  to  drop  out  of  the  opening.  This  flange  is  better  seen 
in  the  side  view,  marked  C.  It  is  readily  placed  in  position  by  entering 
the  obturator  first,  and  carrying  the  clasps  to  the  teeth  subsequently. 

Figs.  1 21 7  and  12 18  will  illustrate  the  essential  principles  involved 
in  all  obturators.  The  ingenuity  of  the  dentist  will  often  be  taxed  in 
their  application,  as  the  cases  requiring  such  appliances  all  vary  in  form 
and  magnitude.  The  steps  to  be  taken  in  the  formation  of  an  obtu- 
rator are  not  unlike  those  used  in  making  a  base  for  artificial  teeth. 
It  is  essential  that  an  accurate  model  be  obtained  of  the  opening,  the 
adjacent  palatal  surface,  and  the  teeth,  if  any  remain  in  the  jaw. 
For  this  purpose  an  impression  taken  in  plaster  is  the  only  kind  to  be 
relied  upon.     Care  must  be  used  that  a  surplus  of  plaster  is  not  forced 


ARTIFICIAL    PALATES.  1 1 39 

through  the  opening,  thus  preventing  the  withdrawal  of  the  impression 
by  an  accumulated  and  hardened  mass  larger  than  the  opening  through 
which  it  passed.  To  avoid  this,  beginners  or  timid  operators  had  better 
take  an  impression  in  the  usual  manner  with  wax.  If  this  is  forced 
through,  it  can  be  easily  removed  without  injury  to  the  patient.  From 
this  wax  impression  make  a  plaster  model,  and  upon  this  plaster  model 
form  an  impression  cup  of  sheet  gutta-percha,  using  a  stick,  a  piece  of 
wire,  strip  of  metal,  or  any  other  convenient  thing  for  a  handle. 
This  extemporized  impression  cup  must  not  impinge  upon  the  borders 
of  the  opening,  neither  should  it  enter  to  any  extent.  With  a  uniform 
film  of  soft  plaster,  of  from  one-sixteenth  to  one-eighth  of  an  inch  in 
thickness,  laid  over  this  cup  a  correct  impression  can  be  taken  without 
any  surplus  to  give  anxiety.  Upon  a  correct  plaster  model  taken  from 
such  an  impression  the  obturator  should  be  molded  out  of  gutta-percha 
or  any  other  plastic  substance,  the  subsequent  steps  being  in  principle 
the  same  as  in  making  any  other  piece  of  vulcanite.  It  is  desirable 
that  it  should  enter  the  perforation  and  restore,  as  far  as  possible,  the 
lost  portion  of  the  palate;  but  it  must  not  intrude  into,  or  in  any 
way  obstruct,  the  nasal  passage.  The  entire  freedom  of  the  nasal  pas- 
sage is  essential  to  the  purity  of  articulation.  That  portion  of  the 
obturator  which  occupies  the  oral  cavity  should  be  made  as  delicate  as 
possible,  consistent  with  its  strength  and  durability. 

ARTIFICIAL    PALATES. 

Before  proceeding  to  a  description  of  artificial  palates,  a  brief  refer- 
ence to  the  anatomical  relations  and  functions  of  the  velum palati  \\\\\ 
be  necessary.  The  palate  exercises  quite  as  important  an  office  in  the 
articulation  of  the  voice  as  does  the  tongue  or  lips.  Being  a  muscular 
and  movable  partition  to  separate  the  nasal  and  oral  cavities,  one  edge 
is  attached  to  the  border  of  the  hard  palate,  while  the  other  vibrates 
between  the  pharynx  and  the  tongue.  The  voice,  therefore,  as  it  issues 
from  the  larynx,  is  directed  by  the  palate  entirely  into  the  mouth  or 
through  the  nose,  or  permitted  to  pass  both  ways. 

A  very  slight  deviation  in  this  organ  from  its  natural  form  will  make 
the  voice  give  a  different  sound  ;  so  the  presence  of  anything  that  clogs 
the  natural  passages,  either  oral  or  nasal,  modifies  the  vocal  vibrations. 
Place  any  obstruction  in  the  nasal  passages,  paralyze  the  soft  palate, 
or  let  it  be  deficient  in  size,  and  the  power  of  distinct  articulation 
is  wanting.  Evidence  of  this  statement  is  very  frequently  found 
after  the  surgeon  has  successfully  performed  the  operation  of  sta- 
phylorrhaphy in  case  of  congenital  fissure.  In  such  instances  (with 
rare  exceptions)  the  newly-formed  palate  is  so  deficient  in  length  and 
so  tense  as  to  be  deprived  of  its  function.     It  cannot  be  raised  so  as 


II40 


DENTAL    PROSTHESIS. 


Fig.  1219. 


to  meet  the  pharynx  and  shut  off  the  nasal  passage,  but  hangs  like  an 
immovable  septum  to  divide  the  column  of  sound. 
|.    Fig.  1 219  represents  a  defective  palate  belonging  to  the  first  class, 
the  uvula  and  a  portion  of  the  contiguous  soft  palate  being  destroyed 

by  disease.  In  such  a  case  an  ob- 
turator would  be  useless ;  the  con- 
stant activity  of  the  surrounding 
parts  would  not  tolerate  it.  The 
material  used  for  a  substitute  must 
be  soft,  flexible,  and  elastic  ;  and 
the  elastic  vulcanite  is  admirably 
adapted  to  this  purpose. 

By  observing  the  cut  (Fig. 
1 219),  it  will  be  seen  that  a  por- 
tion of  the  soft  palate  along  the 
median  line  remains,  and  conse- 
quently there  will  be  consider- 
ble  muscular  movement  which 
must  be  provided  for  and  which 
may  be  taken  advantage  of.  It  is 
desirable  to  make  this  movement 
available  in  using  an  artificial  palate,  as  thereby  more  delicate  sounds 
are  produced  than  otherwise. 

This  case  presented  some  extraordinary  difficulties  in  the  fact  that 
all  the  teeth  of  the  upper  jaw  had  been  extracted  ;  and  it  was  neces- 
sary, therefore,  to  adapt  a  plate  which  should  not  only  sustain  the 
teeth  for  mastication,  but  bear  the  additional  res])onsibility  of  sup- 
porting the  artificial  palate.  In  the  choice  of  material  best  adapted  as 
a  base  for  the  teeth  in  such  instances,  it  is  preferable  to  adopt  that 
which  will  prove  the  most  durable.  There  are  too  many  interests 
involved  to  risk  the  adoption  of  anything  but  the  best.  In  the  case 
under  description  the  patient  desired  duplicates,  and  two  sets  of  teeth 
were  made,  one  on  gold  and  the  other  on  platina,  with  continuous 
gum.  The  plates  were  made  like  other  sets  of  teeth,  with  the  excep- 
tion of  a  gro(>ve  located  on  the  median  line  at  the  posterior  edge  to 
receive  the  attachment  for  the  palate  (marked  C  in  Fig.  1220). 

Fig.  1220  will  indicate  the  set  of  teeth  with  palate  attached.  The 
wings,  marked  A  and  B,  are  made  of  soft  rubber ;  the  frame  to  sup- 
port them  is  made  of  gold,  with  a  joint  to  provide  for  the  perpendicu- 
lar motion  of  the  natural  palate,  as  in  the  case  of  the  obturator  repre- 
sented in  Fig.  1 2 18.  When  the  artificial  palate  is  in  use,  the  joint 
and  frame  immediately  contiguous  lie  close  to  the  roof  of  the  mouth ; 
the  rubber  wing,  letter  A,  bridges  across  the  opening  on  the  inferior 


ARTIFICIAL    PALATES. 


II4I 


surface  of  side  next  the  tongue ;  the  wing,  letter  B,  bridges  across  the 
opening  on  the  superior  or  nasal  surface,  and  is  also  prolonged  back- 
ward until  it  nearly  touches  the  muscles  of  the  pharynx  when  they  are 
in  repose. 

Both  these  wings  reach  beyond  the  boundary  of  the  opening  and 
rest  on  the  surface  of  the  soft  palate  for  a  distance  of  from  one-eighth 
to  one-quarter  of  an  inch,  thus  embracing  the  entire  free  edge  of  the 


Fig.  1220. 


soft  palate.  This  last  provision  enables  the  natural  palate  to  carry  the 
artificial  palate  up  or  down,  as  articulation  may  require. 

When  the  organs  of  speech  are  in  repose  there  is  an  opening  behind 
the  palate  sufficient  for  respiration  through  the  nares.  When  these 
organs  are  in  action,  a  slight  elevation  of  the  palate  or  a  contraction 
of  the  pharynx  will  entirely  close  the  nasal  passage  and  direct  all  the 
voice  through  the  mouth.  The  palate  thus  becomes  a  valve  to  open  oi 
close  the  nares,  and  to  be  tolerated 
must  be  made  with  thin,  delicate  edges 
which  will  yield  upon  pressure.  An 
instrument  thus  made  will  restore,  as 
far  as  possible  by  mechanism,  the  func- 
tions of  the  natural  organ. 

Fig.  1 221  represents  the  artificial 
palate  separated  into  its  constituent 
parts.  The  frame  is  bent  at  the  joint 
in  the  engraving  to  show  a  stop  marked 
D,  which  prevents  the  appliance  from 
dropping  out  of  position.     Letter   C 

shows  the  tongue,  which  enters  the  groove  in  the  plate  of  teeth  and 
connects  them.  Letters  A  and  B  are  the  rubber  flaps,  which  are 
secured  to  the  frame  by  the  hooks,  as  seen  in  the  engraving.  The 
process  for  making  rubber  wings  will  be  found  described  on  page  1 155. 

Fig.  1222  shows  a  more  extensive  palatine  defect  of  the  first  class. 


Fig.  1221. 


II42 


DENTAL    PROSTHESIS. 


In  this  case  the  entire  soft  palate  is  gone,  together  with  a  small  portion 
of  the  hard  palate  at  the  median  line.  Although  this  defect  is  greater 
in  extent,  the  means  for  its  remedy  are  more  simple.  The  muscles  of 
the  palate  are  entirely  gone,  and,  consequently,  no  perpendicular 
movement  need  be  provided  for.  The  appliance  in  this  case  will  re- 
semble an  elastic  obturator  more  than  the  valve-like  palate  of  the  pre- 
ceding one.  The  principle  here  adopted  is  substantially  that  recom- 
mended by  Mr.  Sercombe,  of  London,  some  years  since,  and  consists 
of  a  plate  with  a  set  of  teeth  in  the  usual  form,  and  attached  to  its 
posterior  edge  an  apron  of  soft  rubber,  which  shall  bridge  the  opening 
on  its  inferior  surface,  extending  nearly  to  the  pharynx.  Fig.  1223 
represents   the    set   of    teeth    with   the    palate    attached.      In    Mr. 


Sercombe's  appliance  this  apron  was  made  of  the  common  sheet 
rubber  in  the  market,  prepared  for  other  uses,  and  is  objectionable  for 
two  reasons:  ist.  A  want  of  purity  in  the  materials  of  which  it  is 
compounded,  in  many  instances  substances  being  used  in  its  manu- 
facture which  would  prove  deleterious  to  the  health  of  the  patient ; 
and,  2,  its  uniformity  of  thickness.  It  is  far  preferable,  therefore,  to 
make  a  mold  from  which  to  form  a  palate  of  pure  and  harmless 
materials,  one  which  shall  be  of  sufficient  thickness  in  the  central 
part  and  at  its  anterior  edge  to  give  stability,  and  yet  shall  have  a  thin 
and  delicate  boundary  wherever  it  comes  in  contact  with  movable 
tissue.  Such  a  palate  may  be  made  in  a  mold  by  substantially  the 
same  process  as  hereafter  described.     (See  page  1155.)     It  maybe 


ARTIFICIAL    PALATES.  1 1  43 

secured  to  the  plate  by  a  variety  of  simple  means.  One,  which  will 
give  as  little  trouble  to  the  patient  as  any  other,  is  to  make  a  series  of 
small  holes  along  the  edge  of  the  plate  and  stitch  it  on  with  silk,  or 
fine  platina,  gold,  or  silver  wire  may  be  used.  It  is  desirable  in  this 
case  to  have  the  plate  and  palate  present  a  uniform  surface  on  the 
lingual  side.  In  fitting  the  plate,  therefore,  it  may  be  raised  along 
the  posterior  edge  from  the  sixteenth  to  the  tenth  of  an  inch,  accord- 
ing to  the  thickness  of  the  palate  desired.  The  rubber  will  thus  be 
placed  on  the  palatine  surface  of  the  plate  and  present  uniformity  on 
the  lingual  surface. 

A  little  thought  will  show  that  in  this  case  the  patient  must  edu- 
cate the  muscles  of  the  pharynx  alone  to  do  the  work  of  shutting  off  the 
nares,  which,  in  the  former  case,  was  performed  by  them  in  conjunc- 
tion with  the  muscles  of  the  palate.  Perfection  of  articulation  will, 
therefore,  depend  upon  the  success  of  the  patient  in  this  new  use  of 
these  muscles. 

In  cases  of  accidental  lesions  of  the  palate,  such  as  are  under  con- 
sideration, this  education  of  the  muscles  to  a  new  work  will  not  be 
diffictilt.  The  patient  at  some  former  time  has  had  the  power  of  dis- 
tinct articulation  ;  his  ear  has  recognized  in  his  own  voice  the  contrast 
between  his  present  and  former  condition  ;  the  ear  will  therefore  direct 
and  criticize  the  practice  until  the  result  is  attained. 

In  the  case  illustrated  by  Fig.  1222,  the  defect  had  existed  for 
twenty-eight  years,  the  patient,  at  the  time  of  the  introduction  of 
the  artificial  palate,  being  nearly  fifty  years  of  age.  The  effect  upon 
the  speech  was  instantaneous.  Articulation  was  immediately  almost 
as  distinct  as  in  youth;  and  this  remarkable  distinctness  can  only  be 
accounted  for  upon  the  assumption  that  the  pharyngeal  muscles  had 
undergone  a  thorough  training  in  the  vain  effort  to  articulate  without 
any  palate.* 

These  two  cases,  chosen  to  illustrate  the  application  of  artificial 
palates  in  accidental  lesion,  have  required,  as  will  have  been  per- 
ceived, entire  upper  sets  of  artificial  teeth  in  connection  with  the 
palates.  This  selection  was  purposely  made  because  the  difficulties 
to  be  overcome  are  much  greater.  In  cases  where  there  are  natural 
teeth  remaining  in  the  upper  jaw,  the  palate  and  its  connection  with 
a  plate  would  be  substantially  the  same,  and  the  plate  might  easily 
be  secured  to  the  teeth  by  clasps,  in  the  same  manner  as  a  partial 
denture. 

Artificial  Palates  for  Congenital  Fissure. — Congenital  fissure  of  the 


*  An  account  of  this  case  appeared  in  the  Argus,  of  Bainbridge,  Georgia,  August 
1st,  1868,  written  by  the  patient  himself,  who  was  the  editor  of  that  paper. 


1 1 44  DENTAL   PROSTHESIS. 

palate  presents  far  greater  difficulties  to  be  overcome  than  cases  of 
accidental  lesion.  The  opening  is  commonly  more  extensive,  the 
appliance  more  complicated,  and  the  result  more  problematical. 
Nevertheless,  appliances  have  been  made  in  a  large  number  of  cases 
which  have  enabled  the  wearers  to  articulate  with  entire  distinctness, 
so  much  so  as  not  in  the  least  to  betray  the  defect. 

The  first  efforts  made  in  this  direction  resembled  obturators.  They 
were  simply  plugs  to  close  the  posterior  nares,  and  the  results  were  far 
from  satisfactory.  It  was  not  until  it  was  recognized  that  the  two 
classes  of  cases,  accidental  and  congenital,  were  entirely  distinct,  that 
much  progress  was  made. 

Nearly  every  case  of  accidental  lesion  can  be  treated  by  an  obtu- 
rator with  considerable  success ;  but  very  rarely  will  an  obturator  be 
of  any  benefit  in  congenital  fissure,  even  if  the  congenital  and  acci- 
dental cases  present  substantially  the  same  form  of  opening.  For  this 
reason  much  embarrassment  has  been  thrown  around  these  appliances 
within  a  few  years  past.  The  character  of  the  different  classes  has  been 
confounded,  and  an  mstrument  adjnirably  adapted  to  one  class  has  had 
claimed  for  it  an  equal  application  to  the  other  class.  Let  it  be  under- 
stood, therefore,  as  a  rule  to  which  there  will  be  but  few  exceptions, 
that  congenital  fissure  of  the  soft  palate  requires  for  its  successful  refnedy 
a  soft,  elastic,  and  movable  appliance ;  and  that,  with  the  most  skill- 
fully made  instrument,  iwcal  articulatio7i  must  be  learned  Wke  any  other 
accomplishment.  Various  inventions  have  been  made  for  this  purpose 
within  the  last  twenty-five  years,  from  the  most  complicated  one  of 
Mr.  Stearns,  described  in  a  former  edition  of  this  work,  to  the  ex- 
tremely simple  one  of  bridging  the  gap  with  a  single  flap  of  rubber. 
The  Stearns  instrument,  with  all  its  complexity,  embodied  the  only 
true  principle,  viz.,  rendering  available  the  muscles  of  the  ?iatural 
palate  to  control  the  movements  of  the  artificial  palate. 

The  essential  requisites  of  an  artificial  palate  are  (i)  to  replace,  as 
far  as  possible,  the  natural  form  of  the  defective  organs  (2)  with  such 
material  as  shall  restore  their  functions.  Muscular  power  certainly 
cannot  be  given  to  a  piece  of  mechanism,  but  the  material  and  form 
may  be  such  that  it  will  yield  to,  and  be  under  the  control  of,  the 
muscles  surrounding  it,  and  thus  measurably  bestow  upon  it  the  func- 
tion of  the  organ  which  it  represents. 

Fig.  1224  represents  a  model  of  a  fissured  palate,  complicated  with 
harelip  on  the  left  of  the  median  line.  There  is  a  division  also  of  the 
maxilla  and  alveolar  process;  the  sides,  being  covered  with  mucous 
membrane,  lie  in  contact  with  each  other,  but  they  are  not  united. 
If  it  is  desired,  a  very  simple  surgical  operation  can  be  performed 
which  will  unite  both  soft  and  hard  tissues  at  this  point  of  division. 


ARTIFICIAL    PALATES.  1 1  45 

The  left  lateral  incisor  and  left  canine  tooth  are  not  developed.  Fig. 
1225  represents  the  artificial  velum  as  viewed  upon  its  superior  surface, 
together  with  the  attachment  of  a  plate  containing  a  clasp  and  two 
artificial  teeth  to  fill  the  vacancy. 

The  lettered  portion  of  this  appliance  is  made  of  elastic  vulcanized 
rubber ;  its  attachment  to  the  teeth,  of  hard  vulcanized  rubber,  to 


Fig.  1224. 

which  the  velum  is  connected  by  a  stout  gold  pin,  firmly  imbedded 
at  one  end  in  the  hard  rubber  plate.  The  other  end  has  a  head,  marked 
C,  which,  being  considerably  larger  than  the  pin  and  than  the  corre- 
sponding hole  in  the  velum,  it  is  forced  through — the  elasticity  of  the 
velum  permitting — and  the  two  are  securely  connected.     The  process 


Fig.  1225. 

B  laps  over  the  superior  surface  of  the  maxilla  (the  floor  of  the  nares) 
and  effectually  prevents  all  inclination  to  droop.  The  wings,  A,  A, 
reach  across  the  pharynx,  at  the  base  of  the  chamber  of  the  pharynx, 
behind  the  remnant  of  the  natural  velum.  The  wings,  D,  D,  rest  upon 
the  opposite  or  anterior  surface  of  the  soft  palate. 


1 1 46 


DENTAL    PROSTHESIS. 


Fig.  1226  represents  a  model  the  same  as  Fig.  1224,  with  the  appli- 
ance, Fig.  1225,  in  situ ;  the  wing,  D,  D,  in  Fig.  1225,  and  the 
posterior  end  of  the  artificial  velum,  A,  alone  being  visible  in  this 
figure. 

The  reader  will  bear  in  mind  that  the  essential  characteristics  of 
this  appliance  are  a  soft,  elastic  substance  filling  the  gap  in  the  soft 
palate,  with  a  flap  behind  as  well  as  before,  which  enables  it  to  follow 
all  movements  of  the  muscles  with  which  it  comes  in  contact,  and  thus 
perform,  to  a  very  considerable  degree,  the  function  of  the  fully  de- 
veloped natural  organ. 

It  is  this  characteristic  alone  which  made  the  Stearns  palate  a  suc- 
cess, and  to  produce  which  result  Stearns  invented  the  complicated 
and,  for  most  cases  impracticable,  machinery  as  shown  in  Figs.  1233 


Fig.  1226. 


and  1234.  It  was  to  produce  the  same  effect  by  a  simple  appliance 
that  the  writer  labored  unremittingly  for  more  than  ten  years,  the  ajjpli- 
ance  of  to-day  being  no  modification  in  any  sense  of  the  Stearns 
instrument,  nor  of  that  of  any  other  author,  but  an  individual  and 
separate  invention,  so  very  simple  that  we  can  conceive  of  no  different 
way  by  which  perfection  of  result  can  be  so  nearly  attained.  A  hun- 
dred instruments  of  like  character  now  being  successfully  worn  attest 
the  writer's  confidence  in  it.  Simplicity  has  gone  but  one  step  further, 
and  that  has  been  to  leave  off  entirely  the  posterior  flap  marked  A,  A 
in  Fig.  1225.  This  has  been  done  in  England,  France,  and  Germany, 
and  occasionally  in  our  own  country,  and  a  parade  made  of  the  fact, 
as  an  improvement  on  the  inventions  of  the  writer  ;  but  the  experience 
of  the  past  shows  that  in  all  these  cases  the  makers  have  failed  to  com- 


ARTIFICIAL    PALATES. 


II47 


prehend  the  requirements  of  the  case,  and  have,  in  attempting  to  im- 
prove the  instrument,  dispensed  with  one  of  its  essential  characteristics. 

A  later  invention,  and  one  which  the  author  believes  to  be  of  almost 
universal  application,  is  represented  in  Fig.  1227.  To  appreciate  the 
importance  of  this  invention  it  must  be  borne  in  mind  that  heretofore 
an  instrument  peculiar  in  form  has  been  required  for  every  separate 
case.  Each  appliance,  being  made  in  a  mold  of  special  adapta- 
tion, has  therefore  entailed  upon  the  operator  a  large  amount  of 
labor. 

With  this  later  invention  it  is  believed  that  with  a  few  molds,  pro- 
ducing a  limited  variety  of  palates  adapted  to  the  leading  features  in 
such  cases,  nearly  every  case  of  congenital  cleft  can  be  provided  for 
upon  the  same  principle  as  other  forms  of  surgical  appliance  are  made 
for  general  use.     It  was  only  after  years  of  experience  and  the  obser- 


FiG.  1227. 


vation  of  many  cases  that  the  characteristics  which  were  common  to  all 
could  be  determined. 

Those  common  features  are  :  (a)  The  fissure  through  the  soft  palate 
is  always  in  the  median  line ;  (^)  the  variations,  if  any,  from  the 
median  line  are  anterior  to  the  soft  palate  in  the  palatine  and  maxil- 
lary bones;  (c)  thickness  of  the  border  of  the  fissure  in  the  remnant 
of  the  soft  palate  is  generally  uniform  ;  (d)  the  sides  correspond  very 
nearly  with  each  other  in  length,  breadth,  thickness,  and  contour; 
(<?)  the  chief  variation  in  nearly  all  clefts  of  the  soft  palate  is  in  their 
size  or  breadth,  and  this  is  true  without  any  reference  as  to  whether 
the  fissure  extends  forward  into  the  hard  palate  or  not.  Figs.  1224 
and  1227  represent  two  cases  of  remarkable  general  likeness,  although 


1 1 48  DENTAL    PROSTHESIS. 

they  differ  twenty  years  in  age  and  more  than  five  years  in  the  period 
of  time  at  which  they  were  treated. 

The  palate  placed  in  situ  in  Fig.  1227  shows  an  instrument  which, 
with  variations  in  size,  is  of  almost  universal  application.  It  is  nearly 
identical  with  the  palate.  Figs.  1225  and  1226,  were  that  one  cut 
across  the  middle.  Like  the  other,  it  is  made  of  soft  rubber,  and, 
moreover,  it  will  need  an  additional  fixture  to  fill  the  gap  in  the  hard 
palate  and  also  keep  the  artificial  velum  from  being  swallowed.  In 
Fig.  1225  there  is  a  projection  marked  B,  which  is  made  of  soft  rubber 
and  is  a  part  of  the  velum.  This  projection,  as  has  already  been 
noticed,  is  intended  to  assist  in  supporting  the  velum  in  position.  This 
is  not  always  necessary  or  desirable  ;  there  are  cases  where  the  velum 
is  quite  as  well  sustained  without  this  projection,  and  where,  if  it  were 
applied,  it  would  certainly  injure  the  tone  of  the  voice  by  clogging  the 
nasal  passage.  In  the  case  of  Fig.  1227,  if  support  were  desired  by 
lapping  on  the  floor  of  the  nares,  toward  the  apex  of  the  fissure,  it 
would  form  a  portion  of  the  hard  palate  or  obturator  instead  of  being 
part  of  the  velum  or  soft  palate  as  heretofore. 

OBTURATORS   AND    PALATES    COMBINED. 

We  shall  proceed  now  to  consider  another  class  of  cases,  the  proper 
treatment  of  which  has  been  followed  by  the  most  encouraging  results. 

For  fifty  years  the  operation  of  staphylorraphy  has  been  a  favorite 
one  with  surgeons,  yet  the  number  of  cases  in  which  there  has  been 
only  a  partial  union  are  largely  in  the  majority.  In  many  instances 
all  that  has  been  accomplished  is  simply  the  tying  together  of  a 
small  portion  of  the  soft  palate  across  the  back  part  of  the  fissure, 
leaving  an  opening  of  greater  or  less  size  through  the  hard  palate, 
anterior  to  the  newly  formed  septum.  This  opening  has  generally 
been  plugged  with  an  obturator,  but  vocal  articulation  has  been  little, 
if  at  all,  improved.  To  meet  this  emergency  a  new  form  of  artificial 
velum  was  invented.  Fig.  1228  will  illustrate  such  a  case  with  the 
obturator  and  artificial  palate  in  situ. 

The  patient  was  a  man  fifty  years  of  age.  The  operation  of 
staphylorraphy  had  been  performed  twenty  years  previously ;  an 
obturator  of  silver,  and  afterward  one  of  vulcanite,  has  been  worn 
constantly  ever  since.  Nevertheless,  the  articulation  was  not  bene- 
fited, the  reason  being  the  same  as  in  every  other  case  of  sta- 
phylorraphic  operation,  the  new  fleshy  palate,  marked  A,  not  being 
long  enough  to  close  by  any  muscular  effort  the  passage  to  the 
nares.  There  was,  however,  some  remaining  muscular  action,  to 
utilize  which  power  was  the  desired  object  to  be  attained.  Letter  B, 
shows  the  obturator,  the  letter  C,  the  velum.   In  this  instance  the  obtu- 


OBTQRAIORS    AND    PALATES    COMBINED. 


1 149 


rator  is  made  of  soft  rubber,  the  same  as  the  velum,  and  when  in  use  the 
velum  is  but  an  extension  of  the  natural  palate,  as  seen  in  Fig.  1228. 

Fig.  1229  shows  the  appliance  when  not  in  use.  The  plate,  D, 
secures  the  obturator  to  the  teeth,  as  in  other  cases  of  artificial 
palates.  In  order  to  introduce  the  piece,  the  broad  flap,  C,  should  be 
first  passed  through  the  opening  in  the  roof  and  pushed  back;  the 


Fig.  1228. 

whole  fixture  will  readily  fall  into  correct  position.  In  the  case  of 
this  patient,  the  improvement  in  vocal  articulation  was  immediate  and 
very  decided. 

Fig.  1230  illustrates  another  case  of  a  similar  character,  but  with 
incidental  circumstances  much  more  interesting.  The  patient  was 
a  lady,  sixty-two  years  of 
age,  for  whom  staphylor- 
raphy  was  performed  in 
1845,  by  a  distinguished 
surgeon,  and  the  result  was 
a  remarkable  success,  so  far 
as  the  union  of  the  parts 
was  concerned.  The  union 
was  perfect  throughout  the 
entire  length  of  the  fissure, 
including  the  uvula ;  but 
although  the  patient  had  ap- 
plied   herself    diligently    to 

the  improvement  of  her  speech,  she  was  unsatisfied  with  her  progress. 
The  fault  ueing  the  same  as  in  all  other  cases — too  short  a  palate — 


Fig.  1229. 


^5° 


DENTAL    PROSTHESIS. 


the  remedy  must  be  the  same.  But  here  arose  another  difficulty. 
There  was  no  opening  through  the  roof  of  the  mouth,  as  in  case  of 
Fig.  1227,  and  there  was  no  method  of  securing  the  desired  palate 
extension  to  the  inferior  surface  of  the  natural  palate.  To  convey 
to  the  artificial  velum  the  action  of  the  levatores  palati  was  essential 
to  success.  After  consultation  with  a  skillful  and  distinguished 
surgeon  of  this  city  (Dr.  George  A.  Peters,  New  York),  it  was 
decided  to  undo,  in  a  measure,  the  operation  of  twenty-five  years 
before,  and  an  opening  was  made  through  the  soft  palate  on  the 
median  line  immediately  behind  the  hard  palate,  as  shown  in  Fig. 
1230.  The  opening  was  a  simple  straight  incision,  which  was  subse- 
quently enlarged  by  wearing  a  tent  for  a  short  time.     There  was  no 


Fig.  1230. 


pain;  but  little  bleeding;  and  in  a  few  days  it  was  entirely  healed. 
What  complicated  the  case  still  further  was  the  loss  of  all  the  teeth  in 
the  upper  jaw,  and  an  entire  upper  denture  had  been  worn  for  years. 
The  artificial  palate  was  attached  to  such  a  denture,  and,  instead  of 
proving  detrimental  to  the  denture,  it  was  an  advantage,  serving, 
when  in  place,  to  keep  the  back  edge  of  the  plate  from  the  possibility 
of  dropping.  The  marked  improvement  in  articulation  and  the 
gratification  of  the  patient  were  a  sufficient  justification  for  the  partial 
undoing  of  such  an  admirable  surgical  operation. 

The  later  experience  of  the  writer  favors  the  idea  of  a  partial  sta- 
phylorraphic  operation,  with  a  view  of  making  a  narrow  bridge  across 
the  posterior  part  of  the  fissure.     Even   the  tying  of  the  bifurcated 


OBTURATORS   AND    PALATES    COMBINED.  I151 

iivula  together  would  be  of  far  more  service  to  the  patient  than  a 
union  throughout  the  length  of  the  cleft.  Such  a  slight  bridge  of  the 
gap  is  more  easily  and  certainly  obtained  than  when  greater  attempts 
are  made  ;  as  the  surgical  operation  can  be  supplemented  by  an  arti- 
ficial velum  of  a  very  simple  character,  the  patient  thus  derives  the 
highest  benefit  which  surgical  skill  can  at  this  day  give. 

Method  of  Making  an  Artificial  Palate. — The  success  of  these  ap- 
pliances depends  very  much  upon  the  perfect  accuracy  of  the  model., 
since  it  is  upon  this  that  the  parts  are  molded.  It  is  essential  that 
the  entire  border  of  the  fissure,  from  the  apex  to  the  uvula,  should  be 
perfectly  represented  in  the  model,  as  these  parts  are  when  in  repose. 
It  is  also  necessary  that  the  model  show  definitely  the  form  of  the  cav- 
ity above,  and  on  either  side  of,  the  opening  through  the  hard  palate, 
since  that  part  of  the  cavity  is  hidden  from  the  eye.  It  is  desirable, 
although  it  is  not  essential,  that  the  posterior  surface  of  the  remnant 
of  the  soft  palate  be  shown  ;  but  it  is  especially  important  that  the 
anterior  or  under  surface  be  represented  with  relaxed  muscles,  and  in 
perfect  repose.  The  impression  for  such  a  model  must  be  taken  in 
plaster  ;  it  is  the  only  material  now  in  use  adapted  to  the  purpose. 
An  ordinary  britannia  impression  cup  may  be  used,  selecting  one  cor- 
responding in  size  and  form  to  the  general  contour  of  the  jaw.  This 
cup  will  be  found  too  short  at  the  posterior  edge  to  receive  the  soft 
palate,  but  it  may  be  extended  by  the  addition  of  a  piece  of  sheet 
gutta-percha,  which  must  be  molded  into  such  form  as  not  to  impinge 
upon  the  soft  palate,  but  which  will  reach  under  and  beyond  the  uvula, 
and  thus  protect  the  throat  from  any  droppings  of  plaster.  Before 
using  the  plaster,  the  posterior  edge  of  the  gutta-percha  extension  may 
be  softened  by  heat  and  introduced  into  the  mouth.  Contact  with 
the  soft  palate  will  cause  it  to  yield,  so  that  there  is  no  danger  of  its 
forcing  away  the  soft  tissues  when  the  plaster  is  used.  The  first  effort 
will  be  to  get  only  the  lingual  surface,  taking  precaution  not  to  use  too 
much  plaster.  After  trial,  if  the  impression  show  definitely  the  entire 
border  of  the  fissure,  and  the  soft  palate  has  not  been  pushed  up  by 
the  spasmodic  action  of  the  levator  muscles,  it  is  all  that  is  thus  far 
desired.  If,  however,  the  soft  parts  have  been  disturbed  (which,  on 
close  comparison,  a  little  experience  will  decide),  it  is  better  to  take 
a  model  from  the  impression  ;  and  from  this  model  extemporize  an 
impression  cup,  as  described  on  page  1139.  This  temporary  cup  will 
have  the  advantage  of  the  former,  inasmuch  as  it  requires  but  a  thin 
film  of  plaster  to  accomplish  the  result,  thus  lessening  the  danger  of 
disturbing  the  soft  tissues.  After  the  removal,  if  it  is  seen  that  any 
surplus  has  projected  through  the  fissure  and  spread  out  over  the  floor 
of  the  nares,  it  should  be  trimmed  off. 


II52 


DENTAL    PROSTHESIS. 


In  most  cases  such  an  impression  will  be  all  that  is  required.  Such 
an  impression  can  be  taken,  with  a  little  experience,  quite  as  readily 
as  a  correct  impression  for  a  set  of  teeth.  The  all-important  point  is 
to  have  the  border  of  the  fissure  closely  defined,  with  the  soft  parts 
hanging  in  their  j-elaxed  condition.  It  is  not  essential  to  one  of  ex- 
perience that  the  pharynx  behind  the  uvula  should  be  taken  in  the 
impression.  When  the  model  is  obtained  from  the  impression,  a 
representation  of  the  pharynx  can  be  made,  with  sufficient  accuracy 
for  practical  purposes,  by  carving.  It  is  only  when  the  floor  of  the 
nares  is  used  for  the  support  of  the  palate  that  it  becomes  necessary  to 
obtain  a  more  complicated  impression,  one  which  shall  represent  not 
only  a  portion  of  the  buccal  cavity,  but  all  the  superjacent  nasal  cavity. 
When  this  is  required,  the  next  step  will  be  to  obtain,  in  conjunction 
with  this  impression  of  the  under  surface  (which  we  call  the  palatal 
impression),  an  impression  of  the  upper  or  nasal  surface  of  the  hard 
palate.  This  can  be  done  by  filling  the  cavity  above  the  roof  of  the 
mouth  with  soft  plaster  down  to  the  border  of  the  fissure,  and  while 
yet  very  soft,  immediately  carrying  the  palatal  impression  against  it 
and  retaining  it  in  that  position  until  the  plaster  is  hard,  which  can 
be  easily  ascertained  by  the  remains  in  the  vessel  from  which  it  was 
taken.  Taking  the  precaution  to  paint  the  surface  of  the  palatal 
impression  with  a  solution  of  soap,  to  prevent  the  two  masses  from 
adhering  when  brought  in  contact,  there  will  be  no  difficulty  in 
removing  it  from  the  mouth,  leaving  the  mass  Avhich  forms  the  nasal 
portion  i?t  situ.  With  a  suitable  pair  of  tweezers  this  mass  is  easily 
carried  backward  and  withdrawn  from  the  mouth;  the  irregular  sur- 
face of  contact  indicates  its  relation  to  its  fellow  when  brought 
together. 

Fig.  1 231  will  show  such  an  impression.  The  portion  marked  A, 
B,  C  will  readily  be  distinguished  as  that  which  entered   the  nasal 

cavity.  The  line  of  separation 
from  the  palatal  impression  is 
plainly  indicated  in  the  engraving. 
The  groove  marked  D  shows  clearly 
the  impression  made  by  the  delicate 
uvula  in  the  soft  plaster.  The 
nasal  portion  is  relatively  large, 
showing  an  unusually  large  nasal 
cavity.  The  vomer  lies  between 
the  projections  marked  A,  A,  these 
projections  entering  the  nasal  pas. 
sages.  The  surfaces  marked  B,  B,  come  in  contact  with  the  middle 
turbinated  bones  ;  the  surface  marked  C,  in  contact  with  the  inferior 


Fig.  1231. 


OBTURATORS    AND    PALATES    COMBINED.  II53 

turbinated  bone.     In   many  instances  these  turbinated  bones  are  so 
large  as  to  nearly  to  fill  the  nasal  passages. 

The  method  of  obtaining  a  model  of  the  mouth  from  this  impression 
does  not  require  any  particular  description.  The  process  is  similar  to 
the  making  of  a  cast  into  any  other  mouth  impression.  The  model 
represented  in  Fig.  1230  shows  a  convenient  form  for  such  a  case. 

When  the  nasal  portion  of  the  impression  does  not  indicate  the 
superior  surface  of  the  soft  palate,  the  part  may  be  represented  in  the 
model  by  carving.  It  is  not  essential  to  the  success  of  the  artificial 
palate  that  the  posterior  surface  of  the  soft  palate  should  be  repre- 
sented with  the  same  accuracy  that  is  required  on  the  inferior  surface 
or  on  both  surfaces  of  the  hard  palate.  By  the  aid  of  a  small  mirror 
and  a  blunt  probe  the  thickness  of  the  velum  and  the  depth  behind 
the  fissure  can  be  ascertained  ;  approximate  accuracy  is  sufficient,  since 
the  portion  of  the  artificial  palate  coming  in  contact  with  it  is  so  elastic 
that  it  easily  adapts  itself  to  a  slight  inequality,  rendering  absolute 
accuracy  less  important. 

The  next  step  will  be  the  formation  of  a  model  or  pattern  of  the 
palate.  Sheet  gutta-percha  is  preferable  foi  this  purpose,  although 
wax  or  some  other  plastic  substance  might  answer.  The  form  which 
should  be  given  is  better  indicated  by  the  drawing,  Figs.  1225  and 
1237,  than  it  could  be  by  written  description.  The  Stearns  instrument, 
of  which  a  cut  is  here  given  (Figs.  1233  and  1234),  was  made  to  em- 
brace the  edges  of  the  fissure  and  was  slit  up  through  the  middle,  so 
that  when  the  edges  of  the  fissure  approached  each  other,  as  they 
always  do  in  swallowing,  the  two  halves  of  the  instrument  would  slide 
by  each  other  ;  a  third  flap  or  tongue  was  made  and  supported  by  a 
gold  spring,  to  cover  and  keep  closed  this  central  slit. 

Fig.  1232  shows  Dr.  Kingsley's  original  artificial  velum,  conceived 
to  meet  the  requirement  for  a  more 
simple  contrivance  than  the  compli- 
cated Stearns  instrument.  It  is  said 
that  Dr.  Stearn  before  his  death 
abandoned  his  complex  apparatus,  and 
was  wearing  one  made  upon  the  same 
plan  as  Dr.  Kingsley's. 

Steam's  complicated  provision   for 
the    contraction  of  the  fissure   is  en- 
tirely superseded    in    Figs.    1225  and 
1237  by  making  the  instrument  some- 
what in  the  form  of  two  leaves,  one  to  lie  on  the  inferior  and  the  other 
upon  the  superior  surface  of  the  palate,  and  joined  together  along  the 
median  line.     When   the  fissure  contracts,  the  halves  of  the  divided 
73 


II54 


DENTAL   PROSTHESIS. 


uvula  slide  toward  each  other  between  these  two  leaves.  The  posterior 
portion,  marked  A,  in  Fig.  1225,  is  made  very  thin  and  delicate  on  all 
its  edges,  as  it  occupies  the  chamber  of  the  pharynx,  and  is  subject  to 
constant  muscular  movement.  The  sides  are  rolled  slightly  upward, 
while  the  posterior  end  is  curved  downward.  The  inferior  portion, 
marked  D,  D,  should  reach  only  to  the  base  of  the  uvula,  and  bridge 
directly  across  the  chasm  at  this  point  (Fig.  1226);  and  no  effort  to 
imitate  the  uvula  should  be  made.  The  extreme  posterior  end  should 
not  reach  the  posterior  wall  of  the  pharynx  by  a  quarter  of  an  inch 
when  all  the  muscles  are  relaxed  (although  subsequent  use  must  deter- 
mine whether  to  increase  or  diminish  this  space),  thus  leaving  abundant 
room  for  respiration  and   for  the  passage  of  nasal  sounds.     In  cases 


Fig.  1233. 


Fig.  1234. 


where  it  is  desirable  to  make  the  instrument,  as  far  as  possible,  inde- 
pendent of  the  teeth  for  its  support,  the  anterior  part  which  occupies 
the  apex  of  the  fissure  in  the  hard  palate  may  lap  over  upon  the  floor 
of  one  or  both  nares.  Such  a  projection  is  seen  in  Fig  1225,  marked 
B,  and  a  like  process  is  seen  in  Fig.  1237,  but  not  lettered.  Were  it 
not  for  this  process  in  the  first  case,  the  palate  would  drop  from  the 
fissure  into  the  mouth,  the  single  clasp  at  the  extreme  anterior  edge 
not  being  sufficient  to  keep  the  whole  appliance  in  place  throughout 
its  entire  length.  Caution  must  be  exercised  that  this  projection 
entering  the  nares  be  not  too  large,  or  it  will  obstruct  the  passage,  and 
give  a  disagreeable  nasal  tone  to  the  voice. 


OBTURATORS    AND    PALATES    COMBINED. 


^^55 


All  the  peculiarities  described  must  be  provided  for  in  the  gutta- 
percha model,  which  after  having  been  carefully  formed  upon  the  cast, 
may  be  tried  in  the  mouth,  to  ascertain  its  length  or  necessary  varia- 
tions. When  its  ultimate  form  has  been  determined,  provision  must 
be  made  to  duplicate  it  in  soft  rubber.  A  familiar  illustration  of  the 
process  here  to  be  adopted  is  found  in  the  parallel  process  employed 
when  a  set  of  teeth  is  made  on  the  vulcanite  base.  A  model  form  is 
made  of  wax  and  gutta-percha,  bearing  the  teeth,  and  in  all  its  promi- 
nent characteristics  has  the  shape  desired  in  the  completed  denture, 
the  rubber  duplicate  being  vulcanized  in  a  plaster  mold.  In  like 
manner  the  rubber  duplicate  of  the  palate,  as  before  described,  may  be 
made  in  a  plaster  mold. 

If  plaster  is  used  for  the  molds,  it  must  be  worked  so  that  the  surface 
shall  be  free  from  air  bubbles,  or  the  rubber  palate  will  be  covered  with 


Fig.  1235. 


excrescences  that  cannot  readily  be  removed.  By  covering  the  surface 
of  the  mold  with  collodion  or  liquid  silex,  it  will  be  much  improved. 
But,  ordinarily,  plaster  molds  will  be  found  too  troublesome  for  general 
use.  They  may  be  put  to  a  most  excellent  use,  however,  by  using  one 
to  make  a  duplicate  of  the  gutta-percha  in  hard  rubber.  This  is  not 
necessary  with  those  who  have  had  much  experience,  but  with  begin- 
ners it  will  be  difficult  to  work  up  the  gutta-percha  as  nicely  as  may  be 
desired  ;  a  duplicate  in  vulcanite  will  enable  the  operator  to  make  a 
more  artistic  model  of  the  palate,  and  one  which  can  be  handled  with 
greater  freedom. 

As  in  the  course  of  a  lifetime  a  considerable  number  of  elastic 
palates  will  be  required,  the  mold  which  produces  them  should  be 
made  of  some  durable  material.  The  type  metal  of  commerce  is  ad- 
mirably adapted  to  this  use.     A  very  complete  mold  is  one  made  of 


II56 


DENTAL    PROSTHESIS. 


four  pieces  which  will  produce  a  palate  in  one  continuous  piece.  Such 
a  mold  requires  very  nice  mechanical  skill  in  fitting  all  the  parts  accu- 
rately, and  unless  the  operator  has  had  experience  in  such  a  direction 
it  is  better  to  simplify  the  matter.     Fig.   1235  shows  a  mold  in  four 

pieces.  The  blocks,  C,  C,  are 
accurately  adapted  to  the  body 
of  the  mold  marked  A,  and  are 
prevented  from  coming  into 
inaccurate  contact  with  each 
other  by  the  flanges,  D,  D, 
which  overlap  and  rest  upon 
the  sides  of  the  main  piece.  B, 
shows  the  top  of  the  mold,  and 
the  groove,  E,  provides  for  the 
surplus  rubber  in  packing. 
Such  a  mold  makes  as  perfect  an 
appliance  as  can  be  produced. 
The  palate  is  one  homogeneous 
and  inseparable  piece.  The  cut  will  sufficiently  indicate  the  form  of  the 
several  parts.  Each  of  these  pieces  is  first  made  in  plaster,  having  ex- 
actly the  form  desired  in  the  type  metal.  They  are  then  molded  in 
sand,  and  the  type  metal  cast  as  in  making  an  ordinary  die  for  swaging. 
When  in  use  a  clamp  similar  to  Fig.  1236  is  placed  around  the  mold 
to  keep  the  several  parts  firm  in  their  position. 

Fig.    1237  shows   the  palate   complete  with  its  attachment  to  the 
teeth.     The  palate  is  secured  to  the  plate  by  a  pin   of  gold  passing 


Fig.  1236. 


Fig.  1237. 


Fig.  1238. 


tnrough  a  hole  of  the  same  size  in  the  palate,  the  head  on  the  pin 
being  larger  than  the  hole  through  which  it  is  forced. 

By  making  the  palate  in  two  pieces  to  be  joined  after  vulcanizing, 
as  shown  in  Fig.  1238,  the  mold  may  be  made  in  only  two  pieces  and 
with  very  little  trouble.  When  in  use  the  two  pieces,  as  here  repre- 
sented,  are   bound    together   at  the   forward   part   by   the  gold    pin 


OBTURATORS    AND    PALATES    COMBINED. 


II57 


before  referred  10,  and  a  few  stitches  of  silk  secure  it  at  the  posterior 
part. 

The  instrument  then  becomes  identical  with  that  shown  in  Fig. 
1237. 

Fig.  1239  shows  the  mold  or  flask  in  which  it  is  vulcanized.  These 
flasks  were  made  expressly  for  this  purpose ;  but  they  are  not  so  unlike 
the  flasks  in  common  use  in  dentists'  laboratories  that  the  latter  will 
not  answer.     The  common  flask  is  simply  unnecessarily  thick  or  deep. 

The  mold  is  readily  produced  in  the  following  manner:  Imbed  the 
two  pieces  of  the  palate  in  the  plaster  in  one-half  of  the  flask;  when 
the  plaster  is  set  and  trimmed  into  form,  duplicate  it  in  type-metal  by 
removing  the  palate,  varnishing  the  surface,  molding  in  sand,  and 
casting.  In  making  the  sand  mold,  take  a  ring  of  sheet  iron  of  the 
same  diameter  as  the  flask  and  three  or  four  inches  high  ;  slip  it  over 


Fig.  1239. 

the  flask  and  pack  full  of  sand.  Separate  them,  remove  the  plaster, 
return  the  flask  to  the  sand  mold,  and  fill  with  the  melted  metal 
through  a  hole  made  in  the  side  or  bottom  of  the  flask.  Having  thus 
made  one-half,  substantially  the  same  process  will  produce  the  counter- 
part. 

Fig.  1240  shows  the  mold  which  produces  the  palate  illustrated  by 
Fig.  1227.  It  is  the  most  simple  and  at  the  same  time  the  most  com- 
plete of  any  mold  yet  invented.  The  mold  is  made  in  three  pieces, 
and  is  inclosed  in  a  flask  exactly  the  same  as  Fig.  1239,  but  with  this 
improvement :  the  latter  mold  yields  a  piece  formed  of  two  separate 
parts  of  rubber,  which  must  be  afterward  joined  by  stitching  or  other- 
wise ;  while  the  former  (Fig.  1240)  produces  an  appliance  in  one  piece, 
and  as  perfectly  finished  as  by  the  more  complicated  mold  of  four 
pieces,  shown  in  Fig.  1235.     Letter  A,  represents  the  base  of  the  mold; 


11=^8 


DENTAL    PROSTHESIS. 


B,  the  middle  section,  which  is  placed  on  the  top  of  A ;  and  the  third 
section,  or  top,  C,  completes  it. 

The  mechanical  process  by  which  this  mold  is  made  is  substantially 
the  same  as  given  for  making  those  before  described.  The  packing 
of  the  mold  with  rubber  should  be  done  in  the  same  manner  as  when 
hard  rubber  is  used  for  a  dental  base,  with  which  process  it  is  assumed 
that  the  reader  is  familiar.     By  washing  the  surface  of  the  mold  with 


a  thick  solution  of  soap  previous  to  packing,  the  palate  will  be  more 
easily  removed  after  vulcanizing.  The  rubber  used  for  this  purpose 
must  be  a  more  elastic  compound  than  that  for  a  dental  base-plate. 
The  composition  used  for  the  elastic  fabrics  of  commerce  will  answer, 
if  made  of  selected  materials.  There  is  also  on  sale  at  the  dental 
depots  a  soft,  elastic  compound  admirably  adapted  to  the  purpose, 
with  accompanying  instructions  for  vulcanizing  ;  the  best  results  being 


VOCAL    TRAINING    OF    CLEFT-PALATE    PATIENTS.  1 1 59 

obtained  by  heating  up  to  230°,  and  gradually  increasing  during  four 
or  five  hours  to  270°. 

The  following  article  on  the  treatment  and  education  of  Cleft- 
Palate  Patients  by  Dr.  Norman  W.  Kingsley  is  both  interesting  and 
instructive  :* — 

"  The  only  necessity  for  interference,  in  congenital  cleft-palate 
cases,  is  to  remedy  the  defective  speech. 

"  From  time  to  time  it  has  been  asserted  that  the  difficulties  which 
the  patient  met  with  in  deglutition  would  justify  a  surgical  operation, 
but  this  is  a  mistake.  Long  before  the  child  has  reached  maturity  he 
has  learned  to  accommodate  himself  to  his  unfortunate  condition,  and 
has  acquired  the  habit  of  swallowing  so  well  that  it  does  not  cause  him 
embarrassment. 

"There  is  no  other  evil  attending  cleft  palate  except  the  difficulty  of 
articulate  speech,  and  this  does  not  lie  in  the  fact  that  one  cannot 
articulate,  but  only  that  his  articulation  is  necessarily  different  from 
that  of  people  who  have  normal  organs  of  speech. 

"  The  fault  is  not  defective  vocal  organs,  because  the  vocal  organs  are 
always  as  well  formed,  and  in  themselves  as  capable  of  perfect  speech, 
as  those  of  the  rest  of  mankind.  The  difficulty  arises  from  the  inabil- 
ity of  the  patient  to  manipulate  his  voice  in  the  production  of  the 
consonants,  which  form  so  large  a  part  of  spoken  language.  With  the 
exception  of  intonation,  the  vowel  sounds  of  articulate  language  are 
comparatively  pure  in  these  cases. 

"The  effect,  however,  of  an  inability  to  articulate  many  consonants 
renders  the  speech  in  some  instances  quite  unintelligible,  and  in  all 
cases  very  disagreeable.  But  if  all  people  were  born  with  cleft  palates, 
there  would  be  no  defective  speech.  The  speech  of  mankind  would 
then  be  made  without  the  introduction  of  certain  consonants,  which 
now  form  a  distinguishing  part  of  all  languages.  Thus  we  see  that 
articulate  speech  is  not  a  normal  function,  but  an  acquirement  of  man 
as  he  evolved  from  an  original  speechless  condition. 

"For  treatment  of  congenital  cleft  palate  both  surgery  and  mechan- 
ism have  been  resorted  to.  Surgery  was  naturally  first  suggested.  As 
operators  became  more  and  more  skilled  in  their  art,  it  was  but  reason- 
able to  suppose  that  a  complete  surgical  union  of  the  split  palate 
would  cure  the  obvious  evil.  Staphylorrhaphy  first  became  famous 
about  the  year  1820,  through  the  skill  of  an  American  surgeon,  Dr. 
Warren,  of  Boston.  For  many  years  thereafter  the  operation  was  re- 
garded as  one  requiring  unusual  skill,  and  it  became  a  favorite  with 
ambitious  surgeons  desirous  of  distinction. 

*  Dental  Cos/nos,  February,  1894. 


ii6o 


DENTAL    PROSTHESIS. 


"But  surgery,  after  a  full  trial  under  the  advantages  of  the  most 
skilled  artists  for  more  than  half  a  century,  has  disappointed  expecta- 
tions. 

"The  cases  are  very  exceptional  where  normal  articulation  is  ever 
accjuired  with  a  surgical  velum.  To  understand  the  reason  involves 
a  knowledge  of  the  mechanism  of  speech ;  a  knowledge  of  the  posi- 
tions which  normal  organs  assume  in  the  formation  of  consonant 
sounds.  The  palate  plays  an  important  part  in  this  function.  It  serves 
to  close  the  passage  to  the  nasal  cavity  and  to  the  buccal  cavity,  and 
also  to  split  the  voice  as  it  issues  from  the  larynx.    Each  of  these  oper- 


FiG.  1241. 


ations  changes  the  voice,  thus  producing  different  sounds,  which  form 
an  essential  part  of  all  languages. 

"  The  surgical  palate  is  incapable  of  all  these  actions.  In  many 
instances  it  is  so  tense  and  so  short  that  it  appears  to  be  more  of  an 
interference  than  a  benefit.  Besides,  surgery  is  limited  in  its  applica- 
tion. No  prudent  surgeon  would  attempt  to  operate  without  what  he 
regarded  as  an  abundance  of  tissue,  with  which  to  bridge  over  the  gap. 
Thus  are  excluded  a  large  number  of  cases  involving  extensive  fissures 
of  the  hard  palate,  for  which  surgery  can  find  no  remed}'. 

"  Mechanism,  with  all  its  objections,  has  produced  the  best  results. 
Appliances  are  made  sometimes  flexible,  or  elastic,  and  sometimes 
rigid,  or  non-elastic.     Flexible   instruments  have  been  made  which 


VOCAL    TRAINING    OF    CLEFT-PALATE    PATIENTS. 


I  i6i 


perform  measurably  the  physical  functions,  and  quite  fully  the  physi- 
ological functions,  of  the  natural  velum.  Rigid  appliances  (obtura- 
tors), while  not  performing  the  physical  functions,  nevertheless,  in 
many  instances,  perform  the  physiological  functions  of  articulation 
equally  well.     Any  one  who  has  had  long  experience  in  making  such 


Fig.  1242. 

instruments,,  and  noting  the  effects  of  both  sorts  of  apparatus,  will 
have  seen  abundant  evidence  that  neither  kind  of  instrument  is  the  best 
in  all  cases.  Each  has  its  advantages,  and  there  are  objections  to  the 
universal  application  of  either. 

"  I  make  a  distinction   in   name  between   the  two  kinds  of  appli- 


FiG.  1243. 


ances.  Flexible  instruments  are  "artificial  vela;"  non-elastic  in- 
struments are  "obturators."  Figs.  1241  and  1242  show  the  former, 
Figs.  1243  ^'^^^  1244  the  latter. 

"In  the  hands  of  a  skillful  artist  of  long  experience,  the  flexible 


I  1 62  DENTAL    PROSTHESIS. 

instrument  is  undoubtedly  the  best  with  which  to  acquire  articulation, 
and  were  it  not  for  the  perishable  nature  of  the  material  of  which  it 
is  made,  there  is  no  case  in  which  it  should  not  be  preferred.  It 
imitates  the  form  and  action  of  the  natural  velum  quite  as  well  as 
artificial  teeth  imitate  the  shape  of  natural  teeth  and  perform  the 
function  of  mastication,  and  with  it  one  can  learn  to  articulate  more 
readily  than  with  an  obturator. 

'' Obturators  are  simply  plugs  filling  up  to  a  greater  or  less  extent 
the  upper  pharynx  or  the  posterior  nares.  When  properly  adapted 
they  are  especially  valuable  to  supplement  the  use  of  an  artificial 
velum,  and  in  many  cases  their  use  v/ould  be  justified  as  a  primary 
instrument. 

"  No  rule  can  be  given,  or  description  made,  which  will  indicate  to 
the  inexperienced  which  sort  of  apparatus  is  likely  to  confer  the  most 
help  in  any  case.  No  study  of  a  model  of  the  parts  involved  will  be 
of  much  advantage.  It  is  only  the  experienced  eye,  watching  the 
action  of  the  muscular  tissues  in  the  remainder  of  the  palate  and  of 
the  superior  pharynx,  which  will  guide  to  a  determination. 

"Nor  is  it  at  all  possible, 
by  observation  of  such  action, 
to  form  any  opinion  of  the 
effect  upon  the  speech.  That 
can  be  known  only  by  hear- 
ing. With  a  personal  expe- 
rience of  more  than  thirty 
years,  and  an  observation  of 
Fig.  i244_  more  than  a  thousand  cases,  I 

have  failed  to  discover  all  the 
causes  which  are  in  force  in  producing  mal-articulation.  It  is  easy  to 
discern  physical  causes,  but  the  esoteric  physiological  causes  are  so 
remote  that  to  me  they  still  continue  to  be  a  mystery. 

"  I  have  seen  horrible  deformities  in  the  absence  of  the  velum,  the 
hard  palate,  and  all  the  anterior  part  of  the  alveolar  arch,  including 
also  the  upper  lip,  where  the  speech  was  absolutely  unintelligible. 
Fig.  1245  represents  the  model  of  such  a  case.  Here  the  inexperienced 
would  readily  find  a  cause  for  the  mal-articulation.  But  I  have  seen 
very  small  clefts,  fissures  of  the  velum  only,  nasal  passages  normal, 
neither  vomer,  turbinated,  nor  palatal  bones  abnormal,  and  no  hare- 
lip, where  the  speech  was  as  defective  as  in  the  former  case.  Fig. 
1246  represents  one  of  the  latter  class. 

"I  have  also  seen  an  extensive  fissure,  involving  hard  and  soft 
palates,  a  portion  of  the  alveolar  process,  and  a  harelip,  where  but 
that  the  lip  directed  attention  to  the  possibility  of  a  palatal  cleft,  such 


VOCAL    TRAINING    OF    CLEFT-PALATE    PATIENTS. 


#63 


a  deformity  would  not  have  been  suspected  from  the  syjeech,  except  by 
the  most  critical  ear.     For  ordinary  purposes  of  life,  and  to  the  aver- 


FiG.  1245. 


Fig.  1246. 

age  listener,  the  speech  was  good.     The  only  admixture  was  an  occa- 


ii64J 


DENTAL    PROSTHESIS. 


sional  guttural  sound,  which  does  not  belong  to  pure  English.      Fig. 
1 247  is  the  model  of  that  case. 

'■  Where  a  cleft  palate  does  not  reach  the  alveolar  border,  there  is 
no  apparent  anatomical  reason  why  the  sound  of  "  s  "  should  almost 
invariably  be  absent ;  but  it  is  a  fact  ;  and  there  is  every  anatomical 
reason  apparently  in  all  clefts  for  the  inability  to  form  the  sounds  of 
"k  "  and  "  g  ;  "  yet  I  have  heard  these  sounds  made  with  great  dis- 
tinctness, without  an  instrument,  and  without  special  training.  Such 
cases,  however,  are  very  rare.  The  possession  of  an  apjjaratus,  of 
whatever  nature,  however  cunningly  conceived  and  skillfully  adjusted 
to  the  needs  of  the  patient,  will  not  transform  him  immediately  into  a 


Fig.  1247. 

perfectly  speaking  person,  any  more  than  would   the  possession  of  a 
violin  transform  the  possessor  into  a  master  of  that  instrument. 

"  Articulate  speech  is  an  acquired  function,  and,  being  an  acquire- 
ment, involves  application  and  practice.  An  acquirement  which  so 
pre-eminently  involves  mental  application  must  depend  for  its  success 
largely  upon  the  mental  attitude  of  the  applicant,  and  demands  natural 
aptitude,  as  well  as  desire,  determination,  and  perseverance.  It  is  an 
imposition  upon  the  credulity  of  this  deformed  class  of  people,  under- 
going constant  mortification  from  their  defect  and  terribly  anxious  for 
relief,  to  hold  out  the  encouragement  that  they  will  certainly  obtain 
relief  by  simply  wearing  an  instrument.  It  is  quite  possible,  and  even 
probable,  that  if  an  instrument  could  be  applied  in  infancy,  the  same 
faculty  which  enables  the  child  to  learn,  without  special  instruction, 


VOCAL  TRAINING  OF  CLEFT  PALATE  PATIENTS.        -1 65 

to  speak  with  normal  organs,  would  lead  him  to  the  same  result  with 
an  artificial  organ  ;  but  the  people  with  whom  we  have  to  deal  rarely 
come  into  our  hands  until  early  infancy  has  passed,  and  bad  habits  of 
speech  have  become  almost  fixed.  The  muscles  involved  in  the  me- 
chanism of  speech  have  acquired  improper  actions  in  their  efforts  to 
make  up  for  their  deficiency,  and  so  it  follows  that  the  majority  of 
people,  upon  the  introduction  of  an  artificial  palate,  are  handicapped 
by  the  bad  habits  of  speech  which  must  be  unlearned  or  overcome. 

"After  a  somewhat  lengthy  experience,  lam  convinced  that  not 
more  than  one  person  in  ten  wearing  an  artificial  palate  (and  I  use 
the  term  now  indiscriminately  for  both  classes  of  instruments),  having 
passed  the  age  of  childhood  before  its  introduction,  will  of  his  own 
volition  attain  such  perfection  of  articulation  and  enunciation  that. he 
does  not  betray  his  defect ;  while  I  also  know  that  there  are  innu- 
merable instances  of  persons  who  have  reached  mature  age  before  they 
began  their  work  of  correction,  who,  under  proper  instruction  and 
with  perseverance,  have  attained  absolute  perfection. 

"The  imperative  need  of  instruction  was  recognized  by  me  in  the 
earlier  part  of  my  practice,  and  from  time  to  time  I  referred  patients 
to  teachers  of  elocution  for  help.  The  result  was  not  always  satisfac- 
tory. Most  of  such  teachers  placed  more  importance  upon  elocution 
than  upon  articulation,  and  although  some  of  the  pupils  made  won- 
derful progress  in  articulation,  I  was  not  altogether  satisfied  with  the 
methods  of  instruction. 

"  For  the  last  ten  years  or  more  there  has  been  associated  with  me 
in  my  practice  a  lady  who  possesses,  besides  other  accomplishments  of 
education,  a  vocal  and  elocutionary  training.  She  conceived  the  idea 
of  formulating  a  system  of  teaching  articulation  to  cleft-palate  people 
which  might  be  denominated  *a  system  of  vocal  gymnastics,'  based 
upon  the  methods  used  in  teaching  elocution  and  in  teaching  deaf 
mutes  to  articulate.  Her  system  is  not  one  of  fixed  and  rigid  rules. 
It  is  not  one  that  could  be  taught  in  books,  but  it  is  one  of  general 
principles,  varied  in  its  application  to  the  idiosyncrasies  of  each  case. 

"  As  the  result  of  having  such  an  able  coadjutor,  of  late  years  I  have 
insisted  that  it  would  be  almost  useless  for  me  to  make  an  apparatus 
for  any  patient  unless  my  work  could  be  supplemented  by  proper  in- 
struction ;  and,  furthermore,  I  have  carried  this  denial  to  the  extent 
of  refusing  to  make  an  apparatus  for  any  one  whose  apparent  mental 
condition  showed  an  incapacity  for  study  and  improvement. 

"  The  results  under  such  tuition  as  indicated  have  sometimes  been 
rapid  and  marvelous. 

"  A  lady,  about  twenty-five  years  of  age,  from  a  distant  State,  applied 
to  me.     She  carried  in  her  appearance  evidence  of  intellect  and  good 


1 1 66  DENTAL    PROSTHESIS. 

breeding,  but  there  was  a  certain  hopelessness  in  her  countenance, 
bordering  on  despair.  Her  case  was  not  unlike  many  others,  and, 
fortunately  for  her,  there  was  no  harelip  to  disfigure  a  rather  hand- 
some face.  Her  speech  was  the  speech  of  the  average  cleft-palate  pa- 
tient, but  she  was  very  averse  to  talking,  and  brought  a  companion  to 
speak  for  her.  The  arrangements  were  made  for  me  to  do  my  work, 
and  for  her  to  go  under  tuition. 

"Before  I  had  made  much  progress,  her  morbid  condition  impressed 
me  so  much  that  I  spoke  to  her  of  it.  I  told  her  that  to  me  it  be- 
trayed unmistakable  evidence  that  she  had  no  hope  that  she  would  re- 
ceive benefit.  She  then  told  me  that  she  had  little  or  no  faith  in  the 
result;  that  an  effort  had  been  made  two  or  three  times  before,  both 
by  surgery  and  by  mechanism,  but  all  had  failed  ;  that  she  was  of  an  ex- 
ceedingly sensitive  nature,  and  had  avoided  all  society  ;  that  she  had 
neglected  her  education  because  of  her  deformity ;  and  that  she  had 
come  to  me  as  a  final  resort,  with  the  determination  that  if  this  failed 
she  would  never  return  to  her  family,  but  would  find  some  way  to  end 
all  her  troubles. 

"I  told  her  that  it  was  almost  useless  for  me  to  go  on,  unless  she 
made  an  effort  to  throw  off  that  condition  and  assume  one  of  expec- 
tation of  relief;  that  I  could  promise  her,  with  absolute  certainty, 
great  benefit,  if  my  directions  were  faithfully  carried  out. 

"Suffice  it  to  say  that  while  at  first  she  seemed  incapable  under 
tuition  of  comprehending  what  she  was  taught  and  directed  to  do, 
because  her  faculties  had  been  dormant  through  neglected  education, 
nevertheless  she  shortly  began  to  rouse  herself,  and  made  progress. 

"  I  lost  sight  of  her  for  three  months,  during  a  summer's  vacation, 
and  on  my  return  was  astounded  at  the  change.  She  was  speaking 
exceedingly  well,  her  face  was  brilliant  with  joy  and  gratitude,  and 
she  fully  realized  that  there  was  something  in  life  for  her;  that  life 
was  worth  living. 

"  It  has  been  generally  supposed  that  a  child  with  a  congenital  cleft 
must  wait  until  the  jaw  and  alveolar  arch  were  pretty  fully  developed, 
or  until  about  the  twelfth  year  of  age,  before  it  was  prudent  to  apply 
an  artificial  palate.  I  favored  that  idea  myself  many  years  ago,  partly 
because  I  wished  to  avoid  the  annoyance  to  which  the  child  might  be 
submitted,  and  partly  to  save  the  expense  of  a  second  apparatus  when 
the  child  should  become  older, 

"  My  first  use  of  such  an  appliance  for  a  child  was  in  January,  1865. 
It  was  for  a  boy  eight  years  of  age,  who  was  nervous  and  irritable,  and 
the  results  discouraged  me. 

"  But  the  experience  of  many  cases  since  has  convinced  me  that  my 
hesitation  was  a  mistake.     The  advantages  gained  by  an  early  inter- 


VOCAL    TRAINING    OF    CLEFT-PALATE    PATIENTS.  1167 

ference  far  outweigh  any  financial  considerations,  and  I  find  that 
children  become  accustomed  to  the  presence  of  such  a  foreign  body 
quite  as  readily  as  adults. 

"The  benefit  to  be  gained  by  preventing  improper  efforts  at  articu- 
lation from  becoming  fixed  habits,  as  well  as  the  greater  ease  with 
which  habits  already  formed  can  be  broken  up,  must  be  manifest  to 
every  one.  Children  adopt  involuntarily  the  tone  of  voice,  accent, 
and  peculiarities  of  utterance  of  those  with  whom  they  are  a.ssociated, 
and  I  am  satisfied  that  perfect  results  are  attained  more  rapidly  and 
with  less  effort  by  supplying  an  artificial  velum  early  in  life. 

"A  little  girl  seven  years  of  age  was  brought  to  me.  She  had  a 
harelip,  which  had  been  closed  by  a  very  fair  operation,  but  leaving 
one  nostril  much  more  open  than  the  other.  I  recommended  a  sup- 
plementary operation  for  reducing  the  size  of  that  nostril,  because  I 
have  found  that  an  excessively  open  nostril,  in  such  cases,  makes 
articulation  more  difficult,  besides  altering  the  tone  of  the  voice. 

"  For  this  child  I  made  an  artificial  velum,  and  she  was  put  under 
training.  This  training  was  an  hour's  lesson  three  times  a  week,  the 
practice  to  be  kept  up  under  the  care  of  her  governess.  The  tuition 
continued  for  three  months,  after  which  the  child  was,  by  the  removal 
of  the  parents,  taken  beyond  the  reach  of  her  teacher.  Within  a 
year  she  was  speaking  quite  as  clearly  as  the  children  of  her  age,  and 
the  nasal  resonance  peculiar  to  such  cases  had  entirely  disappeared. 
During  the  following  year,  before  she  was  nine  years  of  age,  her 
parents  were  spending  the  summer  at  a  noted  fashionable  resort,  and 
the  child  was  placed  in  a  select  private  school.  She  had  learned  to 
keep  the  fact  secret  that  she  was  wearing  an  artificial  palate,  and  her 
speech  in  nowise  betrayed  her.  After  a  time  her  school-teacher 
came  to  her  mother,  and  inquired  if  the  child  had  ever  had  any 
special  attention  given  to  her  enunciation,  because,  said  she,  "she 
speaks  so  much  more  clearly  and  precisely  than  other  children,  that  I 
thought  she  must  have  had  some  special  training." 

"  Another  instance  of  a  peculiarly  interesting  nature  is  that  of  a  child 
six  years  of  age.     The  model  of  this  case  is  shown  in  Fig.  1248. 

"  I  hesitated  very  much  about  undertaking  this  case,  because  of  the 
difficulty  of  finding  anything  to  which  I  could  secure  an  artificial 
palate.  The  crowns  of  all  the  deciduous  teeth  in  her  mouth,  except 
one,  had  decayed  off  level  with  the  gums,  and  the  first  permanent 
molars  had  not  erupted.  But  the  mother  of  the  child  was  persistent, 
and  I  made  an  artificial  velum,  clasping  the  fairly  whole  crown  of  a 
temporary  molar  on  one  side,  and  putting  a  gold  crown  on  the  re- 
mainder of  its  mate  on  the  other  side  of  the  jaw,  to  which  the  second 
clasp  was  fitted.  This  child  was  for  three  months  mider  the  care  of 
my  teacher  of  articulation.     She  was  formally  given  a  short  lesson 


:ioS 


DENTAL    PROSTHESIS. 


twice  a  day,  and  informally  kept  up  a  more  or  less  continuous  practice. 
She  had  never  learned  to  read,  not  even  knowing  the  letters  of  the 
alphabet.  At  the  end  of  three  months  she  could  read  simple  lessons 
with  ease,  and  her  articulation  was  as  faultless  as  that  of  the  best  chil- 
dren of  her  age.  Previous  to  the  beginning  of  this  child's  training 
her  imperfect  speech  was  recorded  by  a  phonograph.* 

"The  next  case,  shown  in  Fig.  1246,  is  one  of  especial  interest. 
The  fissure  is  very  small, — one  of  the  smallest  that  I  have  ever  at- 
tempted to  treat.  It  would  probably  have  encouraged  the  average 
surgeon  to  undertake  an  operation  if  he  overlooked  the  fact  which  I 
have  frequently  pointed  out, — viz,  that  even  with  the  gap  in  the  velum 
perfectly  closed  there  would  still  he  a  gap  between  it  and  the  pharyngeal 
wall,  which  could  not  be  bridged  across  except  by  an  appliance  ;  and. 


Fig.  1249. 

fuf  thermore ,  if  the  split  in  the  velum  were  surgically  closed,  it  would 
prevent  the  introduction  of  a  suitable  apparatus . 

"  In  this  case,  notwithstanding  the  smallness  of  the  fissure,  the 
speech  was  about  as  bad  as  bad  could  be. 

"  This  was  a  lad  about  ten  years  old,  and  to  publicly  prove  his  mal- 
articulation  I  took  him  before  one  of  the  medical  societies  in  New 
York,  and  submitted  him  to  the  following  test :  I  gave  to  each  person 
in  the  audience  a  piece  of  paper,  upon  which  were  thirty-four  blank 
spaces  numbered  from  one  to  thirty-four  (consecutively.  I  held  in  my 
hand  a  i)rinted  slip,  on  which  were  thirty-four  words. 

"  I  asked  the  lad  to  pronounce  loudly,  and  with  as  much  distinctness 
as  possible  for  him,  the  word  against  each  number  as  I  y^ointed  to  it. 


*  At  the  time  of  this  writing,  one  year  after  the    introduction  of  the  instrument,  I 
have  seen  the  child,  and  her  speech  is  without  defect. — N.  W.  K. 


VOCAL    TRAINING    OF    CLEFT-PALATE    PATIENTS. 


1 1  69 


Fig.  1249. 


As  he  did  so  I  lequested  the  audience  to  write  on  the  slips  against  the 
same  number  their  interpretation  of  what  they  heard.  The  advantage 
of  this  test  lay  in  the  fact  that  the 
auditors  had  no  clue  to  the  coming 
words,  and  therefore  were  guided 
solely  by  their  hearing.  The  lad 
was  repeatedly  asked  to  repeat  the 
words,  and  in  the  end  the  slips 
written  by  the  audience  were  com- 
pared with  the  printed  slip  held  by 
me.  Many  of  the  records  showed  that  not  a  single  word  had  reached 
the  writer  correctly,  and  in  no  instance  had  more  than  five  of  the 
whole  list  been  fully  understood. 

"  The  instrument  which  I  made  for  this  lad  is  illustrated  by  Fig. 
1249,  and  its  position  when  in  the  mouth  is  seen  in  Fig.  1250.  By  an 
observation  of  Fig.  1246  it  will  be  seen  that  the  apex  of  the  cleft  is 
only  about  half-way  from  the  uvula  to  the  junction  of  the  hard  and 
soft  palates. 


Fig.  1250. 


"To  accommodate  considerable  vertical  movement  in  the  unrup- 
tured portion  of  the  natural  velum,  the  instrument  is  hinged  at  the 
posterior  border  of  the  palatal  bone,  so  that  ample  provision  is  made 
for  the  vertical  movement  of  the  artificial  velum.  The  hinge  is  sup- 
plied with  a  stop  to  prevent  the  velum  from  dropping  below  the  fissure, 
but  it  can  be  carried  upward  with  ease." 
74 


INDEX. 


Single  references  will  be  found  under  leading  word  of  title ;  many  subjects  are 
referred  to  under  each  word  of  title,  and  sometimes  under  its  synonym.  Principal 
subjects  are  alphabetically  arranged  ;  but  details  and  subdivisions  are  usually  given 
in  the  order  of  description  in  the  text,  so  as  to  present  a  full  synopsis  of  the  subjects 
indexed. 


Abnormal  development  and  arrangement 
of  teeth,  103 

Abrasion  of  teeth,  317 

Abscess,  alveolar,  217 ;  causes,  220;  med- 
ical treatment,  221  ;  surgical  treat- 
ment, 257 

Absorption,  of  roots  of  deciduous  teeth, 
175  ;  of  alveolar  walls  around  teeth, 
303  ;  time  required  after  extraction 
of  teeth,  677 

Acids,  effects  on  teeth,  Westcott's  and 
Miller's  experiments,  328,  329  ;  use 
in  refining  gold,  809;  for  pickling 
gold  plate,  870,  977  ;  after  solder- 
ing, 940 

Actual  cautery  for  destroying  pulp,  259. 

Adhesion,  of  gum  to  cheek,  209 ;  of 
contact,  965 ;  of  vacuum  cavity, 
969 

Adjustment  of  porcelain  teeth,  to  gold 
plate,  90S;  to  aluminium  plate, 
1002  ;  to  vulcanite  plate,  1021 

Alkalies,  action  on  teeth,  326  ;  for  cleans- 
ing gold  plate,  942  ;  in  composition 
of  dental  porcelain,  1091  ;  continu- 
ous gum,  985. 

Alloying  gold,  818 

Alloys,  for  gold  plate,  822 ;  formulas, 
822 ;  for  dies,  859  ;  properties  and 
formulas,  859;  of  tin  for  plates, 
989 ;   stannic,  991. 

Aluminium,  history  and  properties,  looi  ; 
refining,  lOOi  ;  swaged  plates  and 
solder,  1002  ;  durability  in  mouth, 
976,  1002. 

Alumino-plastic  process,  1003  ;  swaged 
aluminium  plates,  1003 

Alveolar  abscess,  217  ;  periodontitis, 
210 

Alveolar  processes,  anatomy,  36  ;  necro- 
sis and  exfoliation,  300  ;  absorption, 
around  teeth,  303  ;  after  extraction, 
677  ;   hypertrophy  of  walls,  306 


Alveolar  pyorrhea,  226 

Amalgam,  for  filling  teeth  ;  instruments 
for  using,  452 

Analysis  of  cementum,  149  ;  of  dentine, 
144  ;  of  enamel,  141 

Anatomical  relations  of  the  mouth,  92 

Anatomy  and  physiology  of  the  mouth 
and  face,  25 

Anesthesia,  general, 595  ;  ether  and  chlo- 
roform, 595 ;  hydrate  of  chloral 
bichlorid  of  methylene,  601 ;  nitrous 
oxid  and  apparatus,  596 ;  bromid 
of  ethyl,  600 

Anesthesia,  local;  congelation,  602; 
hypodermic  injection,  602  ;  electro- 
magnetism,  602  ;  spray  apparatus, 
604  ;  hydrochlorate  of  cocain,  606  ; 
obtunders,  606 

Angle's  systems,  396,  620 

Annealing,  gold  plate,  870 

Antagonism  of  artificial  teeth,  873; 
natural  teeth,  102 

Antimony,  effect  on  tin,  989;  as  alloy 
for  metallic  dies,  859 

Antrum  Highmorianum,  34  ;  diseases  of 
and  treatment,  635 

Aphthous  stomatitis,  186 

Aqua  regia  process  for  refining  gold,  809 

Arkansas,  Hindostan,  and  Scotch  stones, 

435 
Arsenious   acid,  action   on  nerve    pulp, 

261 
Arteries  of  mouth  and  face,  67  ;   internal 

carotid,  67  ;     external    carotid    and 

branches,  68 
Articulation,  Bonwill's  system,  891 
Articulation,    of     natural     teeth     (gom- 

phosis),     I02;     of    artificial    teeth, 

873 
Articulations,  65 

Articulators,  metallic,  879;  plaster,  876 
Artificial  palates  or  vela,  II36,  1 139 
Artificial  teeth,  1088 


II72 


INDEX. 


Asbestos,  over  exposed  pulp,  547  ;  use 
in  soldering,  927  ;  continuous-gum, 
982 

Atmospheric  pressure ;  history  of  appli- 
cation to  plates  ;  illustration  of  prin- 
'  ciple  ;  adhesion  of  contact ;  vacuum 

cavity,  962-969 

Atrophy  of  dental  pulp,  245 

Automatic  mallets,  501 

Babbitt  metal  for  dies,  859 

Backing  porcelain  teeth  ;  preparation  for  ; 
different  forms  and  processes  for  gold 
plate,  926  ;  teeth  for  vulcanite  plates, 
III3 

Basement  membrane,  88 

Bichlorid  of  methylene  for  anesthesia, 
601 

Bings's  method  of  crowns,  739 

Bismuth,  use  as  alloy  for  metallic  dies,  861 

Bite  plates,  880 

Bleaching  necrosed  teeth,  308 

Block  teeth,  porcelain,  IO99  ;  manufac- 
ture of,  1093  ;  special  block  carving. 

Blood-vessels  of  mouth  and  face,  67 

Blowpipe,  mouth,  method  of  using  ;  al- 
coholic or  self-acting,  mechanical, 
nitrous-oxid  gas,  930-938 

Body,  porcelain,  formulas  of  composi- 
tion, 1088 

Bone,  composition  and  development,  26  ; 
maxillary,  superior,  33 ;  inferior, 
37  ;  palate,  40 

Bones,  of  head  and  face,  development 
of,  28 

Bonwill's  engine  mallet,  502  ;  articulator, 
89 1 

Bonwill's  method  of  articulating  teeth, 
891 

Bonwill's  method  of  correcting  irregu- 
larity, 415 

Borax,  use  in  melting  gold,  81 1  ;  in  sold- 
ering, 928  ;  in  composition  of  con- 
tinuous gum,  979 

Bridge- work,  739-809 

Bridge- work,  methods,  739-809 

Britannia  impression  trays,  831 

Broaches  for  nerve  filling,  55 1 

Bromid  of  ethyl,  600 

Brush  wheels  for  polishing,  942 

Buccal  glands,  85 

Building  up  whole  or  part  of  crown  of 
tooth,  534 

Bur  drills,  for  excavating  teeth,  469 

Burnishers,  for  fillings,  506 ;  for  plate 
work,  943 

Burs  for  finishing  fillings,  505 

Calcareous  conditions  in  pulp,  248 
Calcic  deposits  on  the  teeth,  285 
Calcification  of  teeth,  175 


Calcined  plaster,  842  ;  silex  and  feldspar, 
1090 

Calculus,  salivary,  285  ;  dark  green  de- 
posit, 298;  chemical  composition, 
289,  290 ;  origin,  289  ;  effects  on 
teeth,  gums,  and  alveoli,  292 ;  re- 
moval, 293 

Calculus,  sanguinary,  or  serumal,  297 

Calipers,  907 

Canaliculi  of  bone,  form  and  function, 
28 ;   cementum,  149 

Cancrum  oris,  189 

Capping  exposed  pulps,  545 

Carat  valuation  of  gold,  formulas  and 
tables,  820 

Carbolized  potash,  266 

Carborundum  wheels,  9II 

Caries  of  the  teeth,  321  ;  causes,  326  ; 
prevention,  ^;^2  !  treatment,  427  ; 
of  the  maxillary  bones,  650 

Carriers  for  files,  431,  433,  505  ;  tape,  505 

Carving  block  teeth,  1088 

Cassius,  purple  of,  1092 

Catarrhal  stomatitis,  180 

Cavities  in  teeth  (see  Filling),  509  ;  va- 
cuum, 969 

Cells,  of  dentinal  pulp,  I39;  of  enamel, 
141  ;   dentine,  143  ;   cementum,  149 

Celluloid,  preparation  and  composition, 
manipulation  ;  heaters  and  appara- 
tus, for  steam,  for  oil  or  glycerin, 
for  moist  air,  drying  cast  and  invest- 
ment ;  imitating  gum  membrane- 
stippling,  metal  casts  and  deep 
undercuts,  liquid  celluloid,  repair- 
ing, new  mode  continuous-gum, 
finishing,  cause  of  imperfections, 
zylonite,  1066-108S 

Cementation  process  for  refining  gold, 
809 

Cementum,  characteristics  of,  149 

Cementum,  origin,  development,  132 

Cementum,  structure,  150 

Ceramic  art,  dental,  1088  ;  materials  and 
processes,  1088 

Ceramo-plastic  work,  988 

Characteristics  of  the  teeth,  159 

Charcoal,  ingot  mold,  822  ;  for  solder- 
ing, 938 

Chase's  metallic  roof  plate,  1061 

Cheoplastic  metal,  history,  990 

Chisels  for  enamel,  429 

Chloral -hydrate,  601 

Chlorid  of  gold,  Sio ;  of  zinc,  263 

Chloroform  for  sensitive  dentine,  264; 
use  in  extraction,  595 

Clamps  for  rubber-dam,  481-483 ;  for 
swaging,  868  ;   for  soldering,  967 

Clasp  plates,  shape  of,  955 

Clasps  :  value  and  conditions  of  use, 
946.  947 ;  teeth  suitable  for,  953 ; 
shaping  and  adjusting,  949 


INDEX. 


II73 


Classification  of  teeth,  93  ;  anatomical, 
95;  pathological,  103;  structural, 
140 

Cleft  palate,  accidental  and  congenital, 
1 1 24 

Cleft  palate  patients,  treatment  of,  1 159 

Cobalt,  oxid  of,  coloring  material  for 
porcelain,  1092 

Cocain,  606 

Cohesive  gold  foil,  450,  494 

Coke,  as  fuel,  1119 

Collars  or  bands,  747 

Coloring  materials   for  porcelain,  109 1 

Combination  of  vulcanite  with  metal  for 
dental  plates,  1057 

Condensing  instruments  used  in  filling 
teeth,  487 

Condit's  combination  of  bridge-  and 
plate-work,  787 

Congelation  as  an  anesthetic,  602 

Congenital  defects  of  soft  palate,  1 1 24 

Consolidating  gold  in  tilling  teeth,  500 

Continuous-gum  work,  history,  proper- 
ties, composition,  swaging  and  back- 
ing, applying  gum  and  baking,  977- 
986 

Contour  fillings,  534 

Copper,  as  alloy  :  for  gold,  8l8  ;  for  zinc 
and  tin,  863-864 

Corallite,  1014 

Corium,  88 

Corundum  points,  434;   wheels,  912 

Counter  dies,  fusible  and  type  metal, 
lead,  tin,  zinc,  partial,  863 

Creosote,  use  in  pulp  operations,  231 

Crown  and  bridge  work,  679,  716 

Crown-facings  and  cusps  of  gold  for 
crown-  and  bridge-work,  731 

Crown  of  tooth  :  artificial,  679;  build- 
ing up  with  cohesive  or  sponge  gold, 

534 

Crucibles,  preparation  of,  816 

Crusta  petrosa,  149 

Crystals,  or  sponge  gold,  451  ;  instru- 
ments and  manner  of  using,  455 

Cylinder  filling,  491 

Cystic  diseases,  278 


Decalcification  of  teeth,  175 
Deep-seated  caries,  treatment  of,  448 
Defects  of  the  palatine  organs,  1124 
Deformity  from  excessive  development  of 

lower  jaw,  390 
Dental,  caries,  321  ;  treatment  of,  427  ; 

porcelain,  1088;  prosthesis,  657 
Dental  engine,  469 
Dental  follicle,  121 
Dental  pulp,  137  ;   diseases  of,  231 
Denies  sapientije,  99  ;  time  of  eruption, 

174;   irregularity  of,  174 


Dentigerous  cysts,  278 

Dentinal  fibrilhe  and  tubuli,  143 

Dentine,  143 ;  characteristics  of,  144 ; 
origin  and  development,  126 

Dentifrices,  formukie,  334 

Dentition,  163,  172,  177 

Dento-electric  cautery,  266 

Denuding  or  erosion  of  the  teeth,  313 

Detachable  bridge- work,  755 

Devitalization  of  pulp,  257 

Dies  and  counter-dies,  854 ;  fusible 
metal,  S64 ;  dipping  process,  855; 
sand  molding,  856 ;  metals  and 
alloys  suitable  for,  859 

Differences  between  temporary  and  per- 
manent teeth,  loi 

Dilaceration,  1 14 

Discs  for  cutting   teeth   structures,  etc., 

435 

Diseases  of  dental  pulp,  231  ;  of  denti- 
tion, 166;  of  mucous  membrane, 
180;  of  gums,  197;  of  peridental 
membrane,  210 

Dislocation  of  lower  jaw,  612 

Downie  system  of  crown  work  and  fur- 
nace, 797,  802,  815 

Drills  for  excavating  teeth,  469  ;  for  lab- 
oratory use,  919 

Drying  cavities  in  teeth,  477 

Ducts,  salivary,  8 1 


Electric  mouth  lamp,  464 

Electro-magnetic  mallet,  502 

Electro-magnetism  as  an  anesthetic,  603 

Electro-metallic  plate,  1013 

Elephant  ivory  for  dentures,  664 

Elevators,  etc.,  for  extracting  roots,  585 

Emery  wheels,  912  ;   cloth,  907 

Enamel :  origin  and  development,  1 20, 
140  ;  characteristics,  140 

Enamel  chisels,  429 

Enamel  organ,  121,  125 

Engine  mallets  and  pluggers,  502 

Epithelial  process  or  cord,  1 20 

Epithelium,  88 

Epulis,  269 

Erosion  of  the  teeth,  313 

Eruption,  of  deciduous  teeth,  164 ;  of 
permanent  teeth,  174 

Esophagotomy,  11 23 

Esthetics  in  selection  and  arrangement 
of  teeth,  908 ;  rules  and  illustra- 
tions, 910 

Ether  as  an  anesthetic,  605 

Ethmoid  bone,  49 

Evans's  system  of  crown-work,  792 

Excavators,  467,  468 

Excising  forceps,  679 

Exfoliation  of  alveolar  ridge,  300 

Exostosis,  hypercementosis  of  teeth,  3II 


II74 


INDEX. 


Explorers,  466 

Exposed  pulps,  231,  545  ;  destruction  of, 
257;  extirpation,  257;  tilling  over 
and  treatment  of,  545 

Extraction  of  teeth,  564  ;  temporary 
teeth,  591;  roots,  584;  teeth  and 
roots  for  artificial  work,  675  ;  instru- 
ments of — key,  568  ;  forceps  (see 
Forceps),   568;  indications  for,  565 


Face  of  an  embryo,  29 
Facial  nerve,  78 
Facings  of  porcelain,  544>  7^^ 
Fascia,  54 

Fatty  degeneration  of  pulp,  246 
Fauces,  65 

F'eldspar,   1090 ;    composition  of  contin- 
uous gum,  979;  porcelain,  1092 
Fibers,  muscular,  54 
J'ifth  pair  of  nerves,  72 
File  carriers,  431,  433 
Files,  separating,  428;    V-shaped,  431; 
for  finishing  filling,  502  ;   vulcanite, 
1044 
Filling  teeth,  509  ;  materials,  449 
formation  of  cavity,  473 
drying  cavities,  480 
introducing  gold,  489 
condensation  with  mallet,  500  ;   finish- 
ing, 502  ;  non  conductors  over  sen- 
sitive pulp,  508 
filling  over  exposed  or  sensitive  pulp, 

545 
filling  pulp  chamber  and  root  canal, 
551  ;  destruction  of  pulp  by  cautery, 
by  arsenic,  and  by  extirpation,  257  ; 
instruments  for  preparing  and  filling 
pulp-canals,  557-559 
filling  special  cavities,  509  ;  in  superior 
incisors  and  cuspids,  509 ;  superior 
bicuspids  and  molars,  518  ;  inferior 
incisors  and  cuspids,  529;  inferior 
bicuspids  and  molars,  531  ;  contour 
filling,  534 

Fineness  of  gold,  of  gold  plates  and 
solder,  formulae  and  tables  for  calcu- 
lation, 822-829 

Finishing,  surface  of  fillings,  502  ;  gold 
work,  940  ;   vulcanite  work,  1043 

Fissure  of  Glaserius,  40  ;  spheno-maxil- 
lary,  pterygo-maxillary,  ;^^  ■  of  hard 
palate,  1 1 33 

Flask,  molding,  Bailey's,  857  ;  Hawes', 
858;  Watt's,  991  ;  Reese's,  loil  ; 
Hayford's,  1012;  vulcanite,  1032; 
Kingsley's,  for  palate,  II57  ;  alu- 
minium, 1004 

Flask  press,  1072 

Fluids  of  the  mouth,  83,  84 

Flux  for  melting  and  soldering  gold,  819; 


continuous-gum,     980;      porcelain, 

1092 ;   bridge-work,  786 
Foil,  gold  (see  Filling), 440,  494;  tin,  452 
Foil,  spatula,  488 
Follicle,  dental,  121 
Follicular  sac  or  wall,  130 
Foramen,     anterior    mental,     38;     infra- 
orbital,   33  ;    posterior   dental,    39  ; 

posterior  palatine,  44 
Forceps,    extracting,    568;     manner    of 

using,  580 
Form  and  outline  of  base  plates,  955 
Forming  the  cavity,  473 
Fountain  drip  point  and  mouth  protector, 

437  ;   spittoon,  478 
Fracture  of  the  jaws,  615,  620;  of  the 

teeth,  319 
Frsenum  linguae,  87 
Freezing  mixture,  602 
Frontal  bone,  41 
Fuel  and  furnaces  for  melting  gold,  815, 

860  ;   for  porcelain,  S02  ;   zinc,  lead, 

860 
Fungous  growth  of  pulp,  247 
Fused  teeth,  107 
Fusibility  of  gold  solder,    828;  of  tin, 

lead,  etc.,  861 
Fusible  metal  for  dies,  861  ;   alloys,  859 


Ganglion,  Gasserian,  72  ;  Meckel's,  75  ; 
submaxillary,  76 

Gangrene  of  the  mouth,  189  ;  of  pulp, 
246 

Gas  regulator,  1029 

Gauge  and  draw-plates,  826 

Gauge-plate,  826 

Geminous  or  fused  teeth,  108 

Genial  tubercles,  38 

Gingivitis,  197 

Glands,  salivary  ;  parotid,  81  ;  submax- 
illary, 83  ;   sublingual,  87  ;  mucous, 

85    ■ 

Gold  alloy  cast  base,  1008 

Gold,  for  filling  teeth  ;  foil,  440,  494  ; 
cohesive,  450 ;  crystal  or  sponge, 
45 1  ;  for  base  plates,  822  ;  necessity 
and  effect  of  alloys,  818  ;  refining, 
809 

Gorgas's  impromptu  interdental  splints, 
618 

Green  stain  on  teeth,  298 

Grinding  porcelain  teeth,  91 1 

Gum  lancets,  580 

Gum  teeth,  single,  blocks,  or  sections, 
1088 

Gums,  anatomy,  90  ;  general  pathology, 
197;  inflammation,  198;  hypertro- 
phy, 203;  mercurial  inflammation, 
193,  205  ;  ulceration,  207  ;  adhesion 
to  cheek,  209  ;   tumors  of,  268 


INDEX. 


II75 


Gutta-percha,  over  sensitive  pulps,  547  ; 
for  filling  teeth,  457 ;  for  impres- 
sions, value  of,  839  ;  for  impression 
trays,  837 ;  for  articulating  rims, 
876  ;  for  a  base,  1014 

Hammers  for  swaging,  868 

Hand-lathes,  913 

Hand-pieces  for  dental  engine,  471 

Hard  rubber  (see  Vulcanite),  1014 

Harris's,  C.  A.,  dentifrice,  334;  mouth- 
wash, 201 

Hayford's  alloy  and  press,  1012 

Heavy  gold- foil,  497 

Hemorrhage  after  extraction,  592 

Herbst  method  of  tilling  teeth,  492  ;  ob- 
tundent, 607 

Hills  stopping  and  instruments  for  using, 

457 
Hippopotamus  ivory,  664 
Hook  for  extracting  roots,  585 
Hot-air  syringe,  484 
How's  soldering  flux,  786 
Human  teeth  attached  to  artificial  plate, 

663 
Hydrate  of  chloral,  601 
Hydrochlorate  of  cocain,  606 
Hydrostatic  blowpipes,  935 
Hypercementosis,  31 1 
Hyperemia  of  pulp,  232 
Hypersensitive  dentine,  263 
Hypertrophy    of     cementum,     311  ;    of 

gums,  203  ;  of  walls  of  alveoli,  306 
Hypodermic  syringe,  601 

Immediate  root  filling,  561 

Implantation  of  teeth,  610 

Impression  cups,  or  trays,  830 ;  mate- 
rials, properties,  and  classification, 
837 ;  wax  and  compounds,  838 ; 
gutta-percha,  837  ;  plaster,  841 ; 
modeling  composition,  840;  com- 
parative value,  844 

Impressions  :  methods  of  taking,  842 
preparation  for  model,  849;  remo 
val  from  model,  851  ;  for  vulcanite 
1018  ;  for  obturator,  II38  ;  for  arti 
ficial  palate,  1 146 

India-rubber,  for  regulating  teeth,  354 
for  separating  teeth,  439  ;   sulphur- 
ated, 1014 

Inferior  maxilla,  37  ;  dislocation  and 
fracture  of,  612  ;   protrusion  of,  394 

Inferior  turbinated  bones,  51 

Inflammation  of  gums,  198;  dental  pulp, 
235  ;  maxillary  sinus,  640 

Ingot,  method  of  pouring,  and  molds ; 
iron,  soapstone,  charcoal,  822 

Injuries  of  teeth  from  mechanical  vio- 
lence, 319 

Inlays,  porcelain,  709 


Instruments  for  forming  cavities  in  teeth, 
466;  introducing  gold,  484  ;  finish- 
ing fillings,  4S9  ;  nerve-operations, 
551  ;  manner  of  using,  for  extraction 
of  teeth,  580  ;   roots,  584 

Instruments,  sets  of,  545 

Interdental  splints,  618 

Interglobular  spaces  of  dentine,  I49 

Inter  or  pre-maxillary  bones,  32 

Intertubular  substance  of  dentine,  148 

Introducing  gold,  509 

Investment,  of  plaster  preparatory  to 
backing  teeth,  asbestos  (or  sand)  and 
plaster,  preparatory  to  soldering,  927 

Irregular  arrangement  of  artificial  teeth, 
919 

Irregularity  of  natural  teeth,  in  form 
103  ;  in  arrangement,  339,  345  ; 
treatment  and  apparatus  for,  350 

Irritation  of  dental  pulp,  232 


Jacket  crown,  804 
Jarvis's  separators,  44I 
Jaws,  tumors  of,  268 
Jointing  blocks,  91 1 


Kaolin,    1091  ;  use    in   continuous-gum, 

979  ;   in  dental  porcelain,  1091 
Key  of  Garengeot,  568 
Knapp's  blowpipe,  936 


Lachrymal  bones,  51 

Ladles,  860 

Lamps,  soldering,  930 

Lancing  the  gums,  169 

Land's  system  of  facing,  805  ;  cross-pin 
teeth,  1095  ;   enamel  sections,  806 

Lathes  for  grinding  teeth,  etc. ,  hand 
and  foot,  913,  914 

Lead  for  filling  cavities  in  teeth,  452; 
for  counter-dies,  863 ;  alloys  of, 
865  ;  effects  of  antimony,  866  ;  for 
swaging-hammer,  868 

Liability  of  teeth  to  decay,  323 

Ligament,  external  lateral,  spheno- 
maxillary, stylo-maxillary,  65 

Local  anesthetics,  602 

Loop  matrices,  523 

Low's  system,  760 

Lower  jaw,  excess  of  teeth  in,  protru- 
sion, 394;  dislocation,  612;  frac- 
ture, 615,  620 


Magnet,  for  refining  gold  filings,  815 
Magnetism,   electro-,   as    an    anesthetic, 

603 
Malar  bones,  50  ;   process,  50 
Malformed  teeth,  103 


1 1 76 


INDEX. 


Malleability  of  gold,  450,  870 

Mallet,    force    in  condensation  of  gold, 

500  ;  hand  and  automatic,  500,  501  ; 

engine  pluggers,  502 
Mandrel  system  of  bridge-work,  745 
Mandrels,  746 
Manganese,  oxid  of,  coloring  material  of 

porcelain,  1092 
Manufacture  of  porcelain  teeth,  1088 
Materials  :    for    filling    teeth,    449  ;     for 

impressions,  837  ;  for  swaged  plates, 

866  ;  for  plastic  or  molded  plates, 

1014  ;   for  dental  porcelain,  1092 
Matrices  for  filling  teeth,  524 
Matrix  of  bone,  25 
Maxilla,  superior,  ^;^  ;   inferior,  37 
Mechanical  abrasion  of  teeth,  317 
Mechanics,  or   mechanism   of  dentistry, 

classification,  655 
Meckel's  cartilage,  31 
Melotte's  system,  767 
Membrana  eboris,  130,  143 
Membrana  preformativa,  89,  129 
Mercurial  stomatitis,  193  ;  inflammation 

of  gums,  193 
Metal  crown  caps,  729 
Metallic  enamel,  sections  and    coatings, 

806 
Metallic  impression  trays,  britannia,  830  ; 

swaged  copper,  830  ;  dies  and  coun- 
ter dies,  854 
Metallic  roof-plate,  1061 
Metallo-plastic  work,   989 ;   cheoplastic, 

990 ;     stanno-plastic,    989 ;     alumi- 

no-plastic,  looi 
Metals  for  filling  teeth,  440  ;   for  swaged 

plates,  822  ;   for  plastic  plates,  989  ; 

for  dies  and  counter-dies,  854 
Metal  tape,  507 
Method   of  directing   second   dentition, 

339 
Methylene,  bichlorid  of,  6oi 
Miller's  experiments  on  effects  of  acids, 

329 
Modeling  compound  or  composition,  840 
Model,  plaster.  847  ;   different  forms  of, 
for  swaging,  848;   vulcanite,  I019; 
sectional,  Westcott's,  851  ;  Bean's, 
850  ;   articulating,  876 
Molar  glands,  85 

Molded  plates  of  plastic  materials,  986 
Molding-flasks,  857  ;  sand,  spatula,  857  ; 

ladles,  860 
Mouth,  anatomy  and  physiology  of,  25  ; 
bones,  28  ;  muscles,  53  ;   blood-ves- 
sels,  67  ;  nerves,    72  ;    glands,  81 
mucous  membrane,  87  ;  tumors,  268 
mirrors,    462 ;    fluids    of,    83,    84 
relations  of,  25  ;  washes,  201  ;  treat- 
ment   of,   preparatory   to    artificial 
work,    675  ;    impressions    of,    842 ; 
cups  or  trays,  830 


Mouth-lamp,  electric,  464 
Mouth- wash  (C.  A.  Harris),  201 
Mucous  membrane  of   mouth,  87  ;    dis- 
eases, 180;   glands,  85;    deposit  on 
teeth,  298 
Muscles  of  the  mouth  and  face,  53  ;  clas- 
sification of,  54 


Nasal  bones,  50 

Nasmyth's  membrane,  I42 

Necrosis  of  alveolar  walls,  300 ;  of  the 
teeth,  307 

Nerve  exposed,  filling  over,  and  instru- 
ments for,  557  ;  destruction  and  re- 
moval of,  257  ;  inflammation  of,  235  ; 
broaches,  551 

Nerves  of  the  mouth  and  face :  fifth 
pair  (trigemini),  72;  ophthalmic 
branches,  superior  maxillary  branch- 
es, 73-77  ;  inferior  maxillary  branch- 
es, 77  ;  facial  nerve  (portio  dura  of 
the  seventh  pair)   and   branches,  78 

Nitrate  of  potash,  for  refining  gold,  809 

Nitric-acid  process,  809 

Nitro-muriatic  acid  process,  809 

Nitrous  oxid  gas  and  a]>paratus,  for  an- 
esthesia, 596;  in  blowpipe,  936 

Nitrous  oxid  liquefied,  598 

Nodular  teeth,  no 

Non-cohesive  gold,  440,  489 

Non-conductors  in  filling,  508 


Obturators,  1136;  Kingsley's  for  soft 
palate,  1 140;  combined  with  arti- 
ficial palate,  1148 

Occipital  bone,  44 

Odontalgia,  235,  250 

Odontatropia,  1 16 

Odontitis,  235,  250 

Odontomes,  III 

Operations  in  organic  prosthesis,  655  ;  in 
structural  prosthesis,  321 

Oral  fluid,  composition  of,  84 

Organic  defects  of  structure  of  teeth,  1 15 

Organic  prosthesis,  or  replacement  of 
dental  organs,  655 

Origin  and  development  of  teeth,  118; 
of  salivary  calculus,  285  ;  of  the 
permanent  teeth,  132 

Orthodontia,  339 

Os,  artificial,  459 

Osseous  union  of  teeth,  107 

Ossification  of  dental  pulp,  249 

Osteology,  26 

Osteo-dentine,  150 

Osteo-sarcoma,  268 

Outline  form  of   full   and   partial    plates, 

.  955 
Oxidation  of   eighteen   carat   gold,  809 ; 
of  tin  alloy,  989 


INDEX. 


II77 


Oxid  of  cobalt,  igti  ;    gold  manganese, 

titanium,  and  uranium,  I091 
Oxychlorid  of  zinc,  459 
Oxyphosphate  of  zinc,  459 


Packing  vulcanite,  1036 

Palate,  hard,  40;  soft,  41 ;  muscles  of,  41 

Palates,  arlihcial,  1 1 36-1 169 

Palatine  organs,  defects  of:  accidental; 
treatment  by  obturators  and  arti- 
ficial palates ;  by  staphylorraphy, 
1 1 24 

Palladium  for  base  plates,  981 

Papillae,  of  tongue,  circumvallate,  fungi- 
form, 86;  dental,  126 

Paraffine  with  wax,  for  impressions,  838 

Parietal  bones,  43 

Parotid  gland,  81 

Partial  counter  dies,  862,  868  ;  clasps  or 
stays,  954 ;  dies,  862 ;  swaging, 
866  ;  outline  forms,  955 

Pellets,  494 

Pericementitis,  210 

Peridental  membrane,  9 1 

Periodontitis,  210 

Periosteum,  alveolo-dental,  91 

Periostitis,  alveolar,  210 

Permanent  teeth,  94  ;  extraction  of,  564  ; 
separation  of,  438-448 

Phosphor-necrosis,  301 

Physiognomy,  importance  of  esthetic 
study  of,  1097 

Physiological  relations  of  the  mouth,  92 

Pickling  gold  plate,  to  remove  borax, 
940  ;  lead  and  other  swaging  metals, 
940  ;  surface  alloy,  977 

Pivot  teeth  (and  crown )  :  value  and  con- 
ditions of  use,  excision  of  crown  for, 
treatment  of  pulp,  selection  of  crown, 
methods,  679-739 

Plaster,  calcined  :  for  impressions,  841  ; 
manner  of  using,  842  ;  comparative 
value,  844 ;  for  models,  847  ;  for 
temporary  investing  band,  after 
grinding  teeth,  925  ;  for  soldering 
batter,  926 

Plaster  impressions  for  articulating,  903 

Plastic  work,  986  ;  ceramo-plastic,  988  ; 
rheoplastic,  990;  stanno-plastic, 
989  ;  alumino-plastic,  1003  ;  vul- 
cano-plastic,  1013 

Plate,  swaged  for  dental  base,  swaging, 
854-866;  adjusting  teeth  to,  908; 
articulating,  soldering   teeth  to,  928 

Platinum,  as  alloy  of  gold,  976;  precipi- 
tation of,  811  ;  backings  for  gold- 
plate,  926 ;  for  ordinary  swaged 
plate,  923 ;  for  continuous-gum 
work,  979 ;  sponge  for  coloring 
porcelain,  1092  ;  pins  for  teeth,  how 
inserted,  1094 


Plugging  pliers,  48S ;  instruments  for 
sponge  gold,  498  ;  for  nerve  cavities, 

551 

Polishing  fillings,  504-508 

Polypus  of  antrum  and  jaw,  272 

Porcelain  bridge- work,  803 

Porcelain  crowns,  684 

Porcelain  facings,  inlaying  of,  709 

Po>-"elain  facings  or  veneers,  544-786 

Porcelain  impression  trays,  836  ;  forms 
for  filling  cavities,  709;  plates,  1121  ; 
materials,  1052  ;  coloring  materials, 
1091 

Porcelain  teeth,  kinds  of,  aesthetic  rules 
for  selection  of,  variety  and  beauty 
of,  requirements  of,  illustrations  of 
different  styles  of,  adjustment  to 
metal  plates,  manufacture  of,  in 
blocks  carved  for  special  cases,  1088- 
1 121  ;  inlays,  709 

Portio  dura  of  the  seventh  pair  (facial 
nerve),  78 

Potassium,  bromid  of,  to  deaden  sensi- 
bility of  fauces  and  mucous  mem- 
brane of  the  mouth,  II31 

Prepai-ation,  of  nerve  cavity  and  root  for 
filling,  551  ;  of  mouth  for  artificial 
work,  675  ;  of  root  for  artificial 
crown,  679 

Prevention  of  caries,  333 

Primary  curvatures  of  dentine,  145 

Prismatic  cells  of  enamel,  122 

Process  :  alveolar,  36  ;  malar,  35  ;  nasal^ 
35  ;  palate,  36  ;  mental,  38  ;  coro- 
noid,  38;  condyloid,  39;  orbital,  41, 

50 

Prosthesis,  dental,  655 

Protection  against  explosion  of  vulcan- 
izers,  1030 ;  against  saliva,  477 

Protrusion  of  lower  jaw,  394 

Ptyaline,  83 

Pulp,  dental,  137  ;  diseases  of,  231 ;  irri- 
tation, 232 ;  inflammation,  235  ; 
suppuration  of,  244 ;  spontaneous 
disorganization  of,  246 ;  degenera- 
tion of  structure,  245  ;  fungous 
growth,  247;  ossification,  248,  249; 
treatment  of,  545  ;  exposed,  231  ; 
devitalization  and  removal  of,  257  ; 
action  of  arsenic  on,  261  ;  chlorid 
of  zinc,  263 

Pulp  enamel,  121  ;  cavity,  filling,  551 

Pulpitis,  235 

Pumice  for  dentifrice,  379  ;  for  support 
in  soldering,  928  ;  for  stanno-plastic 
model.  1079;  fo''  finishing  vulcanite 
plates,  1043 

Punch  forceps,  922  ;  for  extracting  roots, 
585  ;  rubber  dam,  479 

Purple  of  Cassius,  1092 

Purulent  engorgement  of  maxillary  si- 
nus, 635 


1178 


INDEX. 


Pyorrhea,  alveolar,  226 
Pyrometer,  m8 


Rapid  breathing  as  a  pain  obtunder,  607 

Recipes  for  dentifrice,  334  ;  mouth  wash, 

201  ;  alloying  gold  plate,  822  ;  gold 

solder,    828  ;  continuous-gum,  977  ; 

porcelain  body  and    enamel,  1092  ; 

flux,  gum    frit,    and    gum    enamel, 

1093 

Reese's  gold  alloy  cast  base,  1008 

Kefming  gold  by  various  processes,  809, 

812 
Relations  of  the  teeth  to  each  other,  loi 
Removable  bridge-work,  755,  777 
Repairing    continuous-gum    work,   985 ; 
stannic  alloys,  looo;  vulcanite,  1049; 
celluloid,  1079 
Replacement  of  teeth  (organic  prosthe- 
sis), 655  ;  order  of  operations,  655 
Replantation,     transplantation,  and    im- 
plantation of  teeth,  608 
Retaining  screws  for  fillings,  541 
Retention  of,  artificial  work,  667,  944; 
on   natural  roots,  667  ;   clasps,  946  ; 
spiral    springs,     671,    962;     atmos- 
pheric   pressure,  672;    adhesion  of 
contact,  965  ;    vacuum  cavity,  672, 
969 
Robinson's  remedy,  266 
Rolling  mills,  824 
Root,  orris,  for  dentifrice,  334 
Roots  of  teeth,  filling   canals   of,    551  ; 
extraction  of,  584;   necessity  of  re- 
moval for  artificial  work,  675  ;  prep- 
aration for  pivot  tooth,  679 
Rubber  dam,  Barnum's,  477  ;   punches, 
479  ;  clamps,  480 ;   India,  1014 


Saliva,  composition,  function,  83  ;  pumps 

for  removal  of,  477 
Salivary  calculus,  285  ;  glands  and  saliva, 

81 
Sand   molding,    857  ;    with    plaster    for 

soldering  batter,  927 
Sanguinary  or  serumal  calculus,  297 
Scalers  for  removing  tartar,  294 
Scorbutus,  195 
Screws    for  forceps,  587  ;    for  retaining 

fillings,  541  ;   for  roots,  585 
Secondary  dentine,  150 
Second    dentition,    1 72;   teeth    of,     94; 

method  of  directing,  339 
Selection  of  artificial  teeth,  908 
Self-acting  blowpipes,  933,  936 
Sensitive  dentine,  263 
Separating  files,  428 


Separation  of  teeth,  permanent,  438,  483 

Separators,  483 

Shears,  plate,  866 

Shrinkage  of  metallic  dies,  854 

Silica  in  porcelain,  1090 

Silver,  as  alloy  of  gold,  8i8  ;  as  base- 
plate, 975  ;   solder,  976 

Sixth-year  molars,  345 

Soapstone  ingot  mold,  822 

Socket  handles,  468 

Soft  palate  (see  Palate),  41 

Solder,  gold,  828,  829;   silver,  829,  976 

Soldering  :  conditions  of  success,  928  ; 
process,  929  ;  lamps  for,  930 ;  blow- 
pipes for,  931;  pan,  938;  carbon 
cylinders  for,  934,  939 

Spar  (feldspar)  in  porcelain,  1090 

Sphenoid  bone,  47 

Spiral  springs,  S26,  944 

Spontaneous  disorganization  of  pulp,  246 

Spray  apparatus  for  anesthesia,  604 

Spring  plates,  1063 

Springing  of  plates  in  soldering,  939 

Stannic  (tin)  alloys  for  metallic  dies, 
1079  ;  for  base  plates,  989 

Staphyloplasty,  1128 

Staphylorrhaphy  ;  history  ;  earlier  forms 
of  operation  ;  Fergusson's  first  oper- 
ation ;  his  later  method ;  Cart- 
wright's  preparation  of  patient ; 
combination  with  Kingsley's  arti- 
ficial palate  ;  Brophy  ;  comparison 
of,  with  mechanism,  1 1 28 

Starr's  measuring  glass,  1037 

Steam  pressure,  1030 

Stellate  cells,  122 

Steno,  duct  of,  81 

Sterilizing  instruments,  592 

Stomatitis,  180  ;  simple  or  catarrhal,  182  ; 
ulcerous,  184;  aphthous,  186  ;  thrush, 
187  ;  gangrene  of  the  mouth,  189; 
mercurial,  193  ;  scorbutus  scurvy, 
195  ;   syphilitic,  193 

Stomatoscopes,  463 

Stratum  intermedium,  124 

Student's  instruments,  545 

Styptics,  594 

Sublingual  glands,  84 

Submaxillary  glands,  8^ 

Submucous  areolar  tissue,  88 

Substitutes  for  teeth  :  human  teeth,  662  ; 
teeth  of  cattle,  ivory,  663,  664 ; 
porcelain,  665 

Substitution,  or  replacement  of  teeth 
(organic  prosthesis),  655  ;  classifi- 
cation  of  operations,  655 

Sulphur,  combination  of,  with  gutta- 
percha, 1014;  with  India-rubber, 
1014  ;  action  on  vulcanite,  1021 

Sulphuric  acid,  process  for  refining  gold, 
809  ;   for  pickling  gold  plate,  940 

Superficial  caries,  removal  of,  427 


INDEX. 


II79 


Superior  maxilla,  33 

Supernumerary  teeth,  109 

Supplemental  teeth,  1 10 

Suppuration    of  antrum,    643  ;    of  pulp, 

Swaged  work,  operations  of  classified, 
655  ;  metals  used  for,  858 

Swaging  process,  866 

Syphilitic  teeth:  effects  of  syphilis,  112  ; 
ulceration  of  the  mouth,  193 

Syringe,  hot  air,  484  ;   hypodermic,  602 

Syringes,  abscess,  221,  472 


Tables  :  for  ascertaining  fineness  of  gold, 
820;  for  alloying  gold,  821  ;  of  fusi- 
ble alloys,  864 ;  of  fusibility  and 
specific  gravity,  862  ;  of  steam  pres- 
sure and  temperature,  1030  ;  of  time 
and  temperature  in  vulcanizing,  1041 

Tape  arbor,  507  ;   metal,  506 

Tartar  (see  Calculus),  285 

Teeth :  anatomical  classification  and 
description,  93,  95  ;  origin  and 
formation,  1 18;  structure  of,  140 
diseases  of,  231  ;  caries,  321  ;  filling 
(structural  prosthesis),  509  ;  extrac- 
tion, 564  ;  irregularity,  339 
as  indicated  by  the  temperament,  660 
replacement  of  loss  of  (organic  pros- 
thesis), 655  ;  substitutes  for,  661  ; 
methods  of  replacing,  655  ;  articula- 
tion or  antagonism  of,  anatomical, 
65  ;  prosthetic,  873  ;  clasping,  955  ; 
grinding  and  adjusting  to  plate,  91 1  ; 
manufacture  of  porcelain,  I088 ; 
various  forms  and  esthetic  study  of, 
1099 

Temperaments,  classification  of,  155 

Temporal  bones,  45 

Temporary :  teeth,  94  ;  extraction  of, 
591  ;  investing  rims  of  plaster,  after 
grinding  teeth,  927 

Temporo-maxillary  articulation,  65 

Third  dentition,  177 

Thrush,    187 

Time  after  extraction,  for  insertion  of 
artificial  teeth,  677 

Tin  and  its  alloys  ;  for  swaging,  863  ; 
for  base  plates,    989 

Tin-foil:  for  filling  teeth,  452:  for  in 
vesting  impressions,  847  ;  for  pat- 
terns of  plate,  866  ;  for  temporary 
articulating  plates,  and  for  tempo- 
rary use  in  grinding  teeth,  1020 

Titanium,  oxid  of,  for  coloring  porce- 
lain, 1091 

Tongue,  86 

Tonsils,  65 

Toothache  (Odontalgia),  235,  250 


Tooth  structures,  140 
Transplantation  of  teeth,  608 
Trephines  for  opening  antrum,  648 
Trial  of  teeth  before  soldering,  925 
Tumors    of  the   mouth    and  jaws,  268 ; 

cystic,  278 
Type-metal,  for  metallic  dies,  859 


Ulceration  of  the  gums,  205 
Ulcerous  stomatitis,  184 
Ulitis,  198 
United  teeth,  107 

Uranium,    oxid   of,  for   coloring   porce- 
lain, 1092 
Use   of  anesthetic  agents   in  extraction, 

595 
Uvula,  41 


Vacuum  cavity  :  history,  form  and  posi- 
tion, 969 

Varnishes    for   plaster   impressions    and 
models,  843 

Veins  of  the  mouth  and  face,  67 

Vela,  artificial,  1 136 

Voltaic  narcotism,  604 

Vomer,  52 

Vulcanite,  composition  and  varieties  of, 
effect  of  the  vermilion  in,  impres- 
sions, models,  articulation,  grinding 
and  arranging  teetli,  making  matrix 
plate,  packing  and  preparing  flasks, 
time  of  vulcanizing,  removal  from 
flask  and  finishing,  repairs  of,  1014- 
1066 
teeth,  suitable  tor,  102 1  ;  partial  sets 
and  gold  clasps  for,  1057  ;  attaching 
teeth  to  metal  plates  by,  1057 
merits  and  demerits  of,  1042 

Vulcanizers,  1026 ;  flasks  for,  1032 
regulation  of  temperature  by  steam 
gauge,  1028  ;  by  thermometer,  1027; 
steam  high-pressure  tables,  1030 ; 
strength  of  vulcanizers,  1031  ;  time 
of  vulcanizing,  1041 

Vulcano-plastic  work,  1013 


Ward's  electro-metallic  dentures,  1013 

Warping  of  plates,  939 

Warty  teeth,  1 1 1 

Watts'  alloy,  990 ;    process    of  refining 

gold,  813 
Wax  :  for  impressions,  838  ;  comparative 

value,  844 
Wedge-cutter,  443 
Wedges  for  separating  teeth,  442 


ii8o 


INDEX. 


Westcott's    experiments    on    acids  and 

alkalies,  328 
Weston's  fusible  metal,  990 
Wharton's  duct,  83 
Wheels  for  polishing,  941 ;  for  grinding, 

911,  912 
Wood  polishing  points,  436 
Wood's  metal  for  filling  and  base,  990 
Wounded  pulps,  treatment  of,  243 


Younger' s  operation,  610 


Zinc :  preparations  for  filling  teeth,  459  ; 

for   dies,    854 ;    oxy-chlorid,    459 ; 

oxyphosphate,  460;  white  oxid  of> 

for  polishing,  1045 
Zylonite,  1088 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 

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This  book  is  fiUt.Vk*^  M^t  date  stamped  below. 


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